JP7232296B2 - bicycle rear hub assembly - Google Patents

Description

The present invention relates to a bicycle rear hub assembly.

Bicycling is an increasingly popular form of recreation as well as a means of transportation. Riding a bicycle is also popular as a competitive sport for both professionals and amateurs. Whether for recreational, travel or athletic use, the bicycle industry is constantly improving various bicycle components. One widely redesigned bicycle component is the hub assembly (see, for example, U.S. Pat.

U.S. Pat. No. 8,820,852

An object of the technique disclosed in the present application is to improve the durability of the sprocket support and/or to increase the degree of freedom in selecting the material for the sprocket support without reducing the durability of the sprocket support. be.

According to a first aspect of the present invention, a bicycle rear hub assembly includes a hub axle, a hub body and a sprocket support. The hub body is attached to the hub axle so as to be rotatable about the central axis of rotation of the bicycle rear hub assembly. A sprocket support is rotatably mounted on the hub axle about a central axis of rotation. The sprocket support includes at least ten external spline teeth configured to engage a bicycle rear sprocket assembly. Each of the at least ten externally splined teeth has an externally splined drive surface contactable with the bicycle rear sprocket assembly to receive rotational driving force from the bicycle rear sprocket assembly during pedaling and an externally splined non-drive surface. and have At least one of the at least ten outer spline teeth has a rotation center axis from a rotation center axis to a circumferential center point of a radially outermost peripheral edge of at least one of the at least ten outer spline teeth. It is circumferentially symmetrical with respect to a radially extending reference line of .

A bicycle rear hub assembly according to the first aspect wherein at least 10 outer spline teeth provide rotation acting on each of the at least 10 outer spline teeth as compared to a sprocket support including no more than 9 outer spline teeth. force is reduced. This improves the durability of the sprocket support and/or provides greater flexibility in choosing the material for the sprocket support without reducing the durability of the sprocket support. In addition, the symmetrical shape increases manufacturability of the sprocket support.

According to the second aspect of the present invention, in the bicycle rear hub assembly according to the first aspect, the total number of at least ten outer spline teeth is in the range of 22-24.

In the bicycle rear hub assembly according to the first aspect, the total number of outer spline teeth of at least ten improves the durability of the sprocket support while increasing the manufacturability of the bicycle rear hub assembly.

According to a third aspect of the present invention, in the bicycle rear hub assembly according to the first aspect, the total number of at least ten outer spline teeth is 28 or more.

A bicycle rear hub assembly according to the third aspect can improve the durability of the sprocket support and/or the freedom to choose the material of the sprocket support without reducing the durability of the sprocket support. degree can be increased.

According to a fourth aspect of the present invention, in the bicycle rear hub assembly according to the first to third aspects, at least one of the plurality of outer spline drive surfaces includes an outer spline drive surface and a and a first radial line extending from the center axis of rotation to the radially outermost edge of the outer spline drive surface. The first outer spline face angle is less than or equal to 6 degrees.

In the bicycle rear hub assembly according to the fourth aspect, the strength of the outer spline drive surface can be increased.

According to a fifth aspect of the present invention, in the bicycle rear hub assembly according to the fourth aspect, at least one of the plurality of outer splined non-driving surfaces comprises an outer splined non-driving surface and rotation of the rear bicycle hub assembly. and a second radial line extending from the central axis to the radially outermost edge of the outer splined non-drive surface. The second outer spline face angle is 6 degrees or less.

In the bicycle rear hub assembly according to the fifth aspect, since the outer spline driving surface and the outer spline non-driving surface are symmetrical, the productivity of the bicycle rear sprocket assembly can be improved.

According to a sixth aspect of the present invention, in the bicycle rear hub assembly according to any one of the first to fifth aspects, the axial length of at least one spline tooth among the at least ten outer spline teeth is , 27 mm or less.

In the bicycle rear hub assembly according to the sixth aspect, the weight of the sprocket support can be reduced.

The technology disclosed in the present application can improve the durability of the sprocket support and/or increase the degree of freedom in selecting the material for the sprocket support without reducing the durability of the sprocket support. can.

1 is a schematic diagram of a bicycle drivetrain according to an embodiment; FIG. 2 is an exploded perspective view of the bicycle drivetrain shown in FIG. 1; FIG. FIG. 3 is a cross-sectional view of the bicycle drivetrain taken along line III-III of FIG. 2; 3 is a perspective view of a rear bicycle hub assembly of the bicycle drivetrain shown in FIG. 2 with locking members of the rear bicycle sprocket assembly; FIG. 2 is a side view of the bicycle rear sprocket assembly of the bicycle drivetrain shown in FIG. 1; FIG. 5 is an enlarged cross-sectional view of the bicycle drivetrain shown in FIG. 4; FIG. FIG. 6 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. 5; FIG. 6 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. 5; FIG. 6 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. 5; Fig. 6 is a side view of the first sprocket of the bicycle rear sprocket assembly shown in Fig. 5; FIG. 6 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. 5; FIG. 6 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. 5; FIG. 6 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. 5; FIG. 6 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. 5; FIG. 6 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. 5; FIG. 6 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. 5; FIG. 6 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. 5; FIG. 6 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. 5; Fig. 6 is an exploded perspective view of the bicycle rear sprocket assembly shown in Fig. 5; 5 is a perspective view of the sprocket support of the bicycle rear hub assembly shown in FIG. 4; FIG. 5 is another perspective view of the sprocket support of the bicycle rear hub assembly shown in FIG. 4; FIG. 5 is a rear view of the sprocket support of the bicycle rear hub assembly shown in FIG. 4; FIG. 5 is a side view of the sprocket support of the bicycle rear hub assembly shown in FIG. 4; FIG. FIG. 11 is a side view of a sprocket support of a bicycle rear hub assembly according to a modification; 24 is an enlarged cross-sectional view of the sprocket support shown in FIG. 23; FIG. FIG. 24 is a cross-sectional view of the sprocket support shown in FIG. 23; Fig. 5 is a perspective view of the bicycle rear hub assembly shown in Fig. 4; FIG. 5 is a side view of the bicycle rear hub assembly shown in FIG. 4; Fig. 5 is a rear view of the bicycle rear hub assembly shown in Fig. 4; 5 is an exploded perspective view of a sprocket support and a plurality of spacers of the bicycle rear hub assembly shown in FIG. 4; FIG. FIG. 5 is an enlarged exploded sectional view of the bicycle drivetrain shown in FIG. 4; 9 is another side view of the sprocket shown in FIG. 8; FIG. FIG. 10 is a side view of the sprocket shown in FIG. 9; The side view of the sprocket shown in FIG. 9 which concerns on a modification. FIG. 30 is an enlarged sectional view of the sprocket shown in FIG. 29; 30 is another cross-sectional view of the sprocket shown in FIG. 29; FIG. 3 is another cross-sectional view of the bicycle drivetrain shown in FIG. 2; FIG. 9 is an exploded perspective view of the sprocket shown in FIGS. 7 and 8; FIG. 9 is another exploded perspective view of the sprocket shown in FIGS. 7 and 8; FIG. 5 is an exploded perspective view of a portion of the bicycle rear hub assembly shown in FIG. 4; FIG. 41 is an exploded perspective view of a portion of the bicycle rear hub assembly shown in FIG. 40; FIG. 41 is an exploded perspective view of a portion of the bicycle rear hub assembly shown in FIG. 40; FIG. 41 is an exploded perspective view of a portion of the bicycle rear hub assembly shown in FIG. 40; FIG. 41 is a partial cross-sectional view of the bicycle rear hub assembly shown in FIG. 40; FIG. FIG. 45 is a cross-sectional view of the bicycle rear hub assembly taken along line XLV-XLV in FIG. 44; 41 is a perspective view of the spacer of the bicycle rear hub assembly shown in FIG. 40; FIG. 41 is another perspective view of the spacer of the bicycle rear hub assembly shown in FIG. 40; FIG. Fig. 41 is a schematic diagram showing the operation (pedaling) of the first ratchet member and sprocket support of the bicycle rear hub assembly shown in Fig. 40; Figure 41 is a schematic diagram illustrating the motion (inertia) of the first ratchet member and sprocket support of the bicycle rear hub assembly shown in Figure 40; FIG. 5 is an enlarged cross-sectional view of a sprocket support according to a modification; FIG. 4 is an enlarged cross-sectional view of a sprocket according to a modification; FIG. 11 is a side view of a sprocket support of a bicycle rear hub assembly according to a modification; FIG. 53 is an enlarged cross-sectional view of the sprocket support shown in FIG. 52; FIG. 4 is an exploded perspective view of a sprocket of a bicycle rear sprocket assembly according to a modification; Another exploded perspective view of the sprocket of the bicycle rear sprocket assembly according to the modification. The side view of the sprocket of the bicycle rear sprocket assembly according to the modified example. The side view of the sprocket of the bicycle rear sprocket assembly according to the modified example. The side view of the sprocket of the bicycle rear sprocket assembly according to the modified example. 58 is a side view of the sprocket shown in FIG. 57; FIG. 58 is an enlarged sectional view of the sprocket shown in FIG. 57; FIG. FIG. 5 is a partial side view of a sprocket support member of a bicycle rear sprocket assembly according to a modification; Sectional drawing of the drivetrain for bicycles which concerns on a modification.

Embodiments are described herein with reference to the accompanying drawings. In the various drawings, like reference numbers indicate corresponding or identical elements.

As shown in FIG. 1 , an exemplary bicycle drivetrain 10 includes a rear bicycle hub assembly 12 and a rear bicycle sprocket assembly 14 . The bicycle rear hub assembly 12 is fixed to the bicycle frame BF. A bicycle rear sprocket assembly 14 is attached to the bicycle rear hub assembly 12 . A bicycle brake rotor 16 is attached to the bicycle rear hub assembly 12 .

Bicycle drivetrain 10 further includes crank assembly 18 and bicycle chain 20 . Crank assembly 18 includes crankshaft 22 , right crank arm 24 , left crank arm 26 and front sprocket 27 . A right crank arm 24 and a left crank arm 26 are fixed to the crankshaft 22 . Front sprocket 27 is fixed to at least one of crankshaft 22 and right crank arm 24 . Bicycle chain 20 engages front sprocket 27 and rear bicycle sprocket assembly 14 to transfer pedaling force from front sprocket 27 to rear bicycle sprocket assembly 14 . Crank assembly 18 includes front sprocket 27 as a single sprocket in the illustrated embodiment. However, the crank assembly 18 may include multiple front sprockets. The bicycle rear sprocket assembly 14 is a rear sprocket assembly. However, the structure of the bicycle rear sprocket assembly 14 is applicable to the front sprocket.

As used herein, the following directional terms "front", "rear", "forward", "backward", "left", "right", "lateral", "upward" and "downward" As well as any other similar directional terms refer to those directions determined on a user (eg, rider) basis by the bicycle saddle (not shown) facing the handlebars (not shown). Accordingly, these terms as utilized to describe the bicycle drivetrain 10, the bicycle rear hub assembly 12, or the bicycle rear sprocket assembly 14, as used in the upright riding position in the horizontal plane, are: Interpreted for a bicycle with a bicycle drivetrain 10 , a rear bicycle hub assembly 12 , or a rear bicycle sprocket assembly 14 .

As shown in FIG. 2, the bicycle rear hub assembly 12 and the bicycle rear sprocket assembly 14 have a central axis of rotation A1. The bicycle rear sprocket assembly 14 is rotatably supported by the bicycle rear hub assembly 12 with respect to the bicycle frame BF around the rotation center axis A1 (Fig. 1). The bicycle rear sprocket assembly 14 is configured to engage the bicycle chain 20 to transmit a driving rotational force F1 between the bicycle chain 20 and the bicycle rear sprocket assembly 14 during pedaling. . The bicycle rear sprocket assembly 14 rotates about the rotation center axis A1 in the drive rotation direction D11 during pedaling. A drive rotation direction D11 is defined along the circumferential direction D1 of the bicycle rear hub assembly 12 or the bicycle rear sprocket assembly 14 . The reverse rotation direction D12 is opposite to the drive rotation direction D11 and is defined along the circumferential direction D1.

As shown in FIG. 2 , the bicycle rear hub assembly 12 includes a sprocket support 28 . The bicycle rear sprocket assembly 14 is configured to be attached to the sprocket support 28 of the bicycle rear hub assembly 12 . The bicycle rear sprocket assembly 14 is attached to the sprocket support 28 so as to transmit the driving rotational force F1 between the sprocket support 28 and the bicycle rear sprocket assembly 14 . The bicycle rear hub assembly 12 has a hub axle 30 . The sprocket support 28 is rotatably mounted on the hub axle 30 about the central axis of rotation A1. The bicycle rear sprocket assembly 14 further includes a locking member 32 . The locking member 32 is fixed to the sprocket support 28 so as to retain the bicycle rear sprocket assembly 14 against the sprocket support 28 in an axial direction D2 relative to the rotation center axis A1.

As shown in FIG. 3, the bicycle rear hub assembly 12 is fixed to the bicycle frame BF by a wheel fixing mechanism WS. Hub axle 30 includes an axle through hole 30A. A fixing rod WS1 of the wheel fixing mechanism WS extends through an axle through hole 30A of the hub axle 30. As shown in FIG. Hub axle 30 includes a first axle end 30B and a second axle end 30C. A hub axle 30 extends between a first axle end 30B and a second axle end 30C along a center axis of rotation A1. The first axle end 30B is provided in the first recess BF11 of the first frame BF1 of the bicycle frame BF. The second axle end 30C is provided in the second recess BF21 of the second frame BF2 of the bicycle frame BF. The hub axle 30 is held between the first frame BF1 and the second frame BF2 by a wheel fixing mechanism WS. The wheel securing mechanism WS includes structures known in the bicycle field. Therefore, for the sake of brevity, detailed description is omitted here.

In this embodiment, the axle through-hole 30A has a minimum inner diameter BD1 of 13 mm or more. A minimum inner diameter BD1 of the axle through-hole 30A is preferably 14 mm or more. A minimum inner diameter BD1 of the axle through-hole 30A is preferably 21 mm or less. In this embodiment, the minimum inner diameter BD1 of the axle through-hole 30A is 15 mm. However, the minimum inner diameter BD1 is not limited to this embodiment and the above range.

Hub axle 30 has a maximum outer diameter BD2 of 17 mm or more. The maximum outer diameter BD2 of the hub axle 30 is preferably 20 mm or more. The maximum outer diameter BD2 of the hub axle 30 is preferably 23 mm or less. In this embodiment, the maximum outer diameter BD2 of the hub axle 30 is 21 mm. However, the maximum outer diameter BD2 of the hub axle 30 is not limited to this embodiment and the above range. Hub axle 30 has a minimum outer diameter BD3 of 15 mm or more. The minimum outer diameter BD3 is preferably 17 mm or more. The minimum outer diameter BD3 is preferably 19 mm or less. In this embodiment, the minimum outer diameter BD3 of the hub axle 30 is 17.6 mm. However, the minimum outer diameter BD3 is not limited to this embodiment and the above range.

Hub axle 30 includes an axle tube 30X, a first axle portion 30Y, and a second axle portion 30Z. The axle tube 30X has a cylindrical shape and extends along the rotation center axis A1. The first axle part 30Y is fixed to the first end of the axle tube 30X. The second axle part 30Z is fixed to the second end of the axle tube 30X. At least one of the first axle portion 30Y and the second axle portion 30Z may be provided integrally with the axle tube 30X.

As shown in FIGS. 3 and 4 , the bicycle rear hub assembly 12 further includes a brake rotor support 34 . The brake rotor support 34 is rotatably attached to the hub axle 30 about the center axis A1. Brake rotor support 34 is coupled to bicycle brake rotor 16 ( FIG. 1 ) to transmit braking torque from bicycle brake rotor 16 to brake rotor support 34 .

As shown in FIG. 4 , the bicycle rear hub assembly 12 includes a hub body 36 . The hub body 36 is attached to the hub axle 30 so as to be rotatable about the rotation center axis A1 of the bicycle rear hub assembly 12 . In this embodiment, sprocket support 28 is a separate member from hub body 36 . Brake rotor support 34 is provided integrally with hub body 36 as one unitary member. However, the sprocket support 28 may be provided integrally with the hub body 36 . The brake rotor support 34 may be a separate member from the hub body 36 . For example, the hub body 36 is made of a metal material containing aluminum.

As shown in FIG. 5, the bicycle rear sprocket assembly 14 comprises a plurality of bicycle sprockets. The plurality of bicycle sprockets has a first sprocket and a second sprocket. In this embodiment, the multiple bicycle sprockets have multiple first sprockets SP1 and SP2 provided as first sprockets. Also, the plurality of bicycle sprockets has a plurality of second sprockets SP3 and SP4 provided as second sprockets. Multiple bicycle sprockets have additional sprockets. In this embodiment, the multiple bicycle sprockets have multiple additional sprockets SP5-SP12. However, the total number of first sprockets is not limited to this embodiment. The total number of second sprockets is not limited to this embodiment. The total number of additional sprockets is not limited to this embodiment. Further, although in this embodiment the first sprocket SP1 is a separate sprocket from the first sprocket SP2, the first sprockets SP1 and SP2 may be integrally formed as one single member. Similarly, although in this embodiment the second sprocket SP3 is a separate sprocket from the second sprocket SP4, the second sprockets SP3 and SP4 may be integrally formed as one unitary member.

For example, the total number of bicycle sprockets is ten or more. The total number of bicycle sprockets may be eleven or more. The total number of bicycle sprockets may be twelve or more. In this embodiment, the total number of bicycle sprockets is twelve. However, the total number of bicycle sprockets is not limited to this embodiment. For example, the total number of bicycle sprockets may be thirteen, fourteen, fifteen or more.

In this embodiment, first sprocket SP1 is the smallest sprocket in bicycle rear sprocket assembly 14 . Additional sprocket SP12 is the largest sprocket in bicycle rear sprocket assembly 14 . The first sprocket SP2 corresponds to the top gear in the bicycle rear sprocket assembly 14 . The additional sprocket SP12 corresponds to the low gear in the bicycle rear sprocket assembly 14 .

As shown in FIG. 5, the first sprocket SP1 has a pitch diameter PCD1. The first sprocket SP2 has a pitch diameter PCD2. The second sprocket SP3 has a pitch diameter PCD3. The second sprocket SP4 has a pitch diameter PCD4. Additional sprocket SP5 has a pitch diameter PCD5. Additional sprocket SP6 has a pitch diameter PCD6. Additional sprocket SP7 has a pitch diameter PCD7. Additional sprocket SP8 has a pitch diameter PCD8. Additional sprocket SP9 has a pitch diameter PCD9. The additional sprocket SP10 has a pitch diameter PCD10. The additional sprocket SP11 has a pitch diameter PCD11. The additional sprocket SP12 has a pitch diameter PCD12.

The first sprocket SP1 has a pitch circle PC1 with a pitch diameter PCD1. The first sprocket SP2 has a pitch circle PC2 with a pitch diameter PCD2. The second sprocket SP3 has a pitch circle PC3 with a pitch diameter PCD3. The second sprocket SP4 has a pitch circle PC4 with a pitch diameter PCD4. The additional sprocket SP5 has a pitch circle PC5 with a pitch diameter PCD5. Additional sprocket SP6 has a pitch circle PC6 with a pitch diameter PCD6. The additional sprocket SP7 has a pitch circle PC7 with a pitch diameter PCD7. Additional sprocket SP8 has a pitch circle PC8 with a pitch diameter PCD8. The additional sprocket SP9 has a pitch circle PC9 with a pitch diameter PCD9. The additional sprocket SP10 has a pitch circle PC10 with a pitch diameter PCD10. The additional sprocket SP11 has a pitch circle PC11 with a pitch circle diameter PCD11. The additional sprocket SP12 has a pitch circle PC12 with a pitch diameter PCD12.

The pitch circle PC1 of the first sprocket SP1 is defined by the central axis of the pin of the bicycle chain 20 (FIG. 2) engaged with the first sprocket SP1. Pitch circles PC2 to PC12 are defined in the same manner as pitch circle PC1. Therefore, for the sake of brevity, detailed description is omitted here.

In this embodiment, the pitch diameter PCD1 is smaller than the pitch diameter PCD2. The pitch diameter PCD2 is smaller than the pitch diameter PCD3. The pitch diameter PCD3 is smaller than the pitch diameter PCD4. The pitch circle diameter PCD4 is smaller than the pitch circle diameter PCD5. The pitch diameter PCD5 is smaller than the pitch diameter PCD6. The pitch diameter PCD6 is smaller than the pitch diameter PCD7. The pitch circle diameter PCD7 is smaller than the pitch circle diameter PCD8. The pitch circle diameter PCD8 is smaller than the pitch circle diameter PCD9. The pitch diameter PCD9 is smaller than the pitch diameter PCD10. The pitch circle diameter PCD10 is smaller than the pitch circle diameter PCD11. The pitch circle diameter PCD11 is smaller than the pitch circle diameter PCD12.

The pitch diameter PCD1 is the minimum pitch diameter of the bicycle rear sprocket assembly 14 . The pitch diameter PCD12 is the maximum pitch diameter of the bicycle rear sprocket assembly 14 . The first sprocket SP1 corresponds to the top gear in the bicycle rear sprocket assembly 14 . The additional sprocket SP12 corresponds to the low gear in the bicycle rear sprocket assembly 14 . However, the first sprocket SP1 may correspond to other gears in the bicycle rear sprocket assembly 14 . Additional sprocket SP12 may correspond to other gears in bicycle rear sprocket assembly 14 .

As shown in FIG. 6, the first sprocket SP2 is the first sprocket without any other sprockets between the first sprockets SP1 and SP2 in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14. As shown in FIG. Adjacent to sprocket SP1. The second sprocket SP3 is adjacent to the first sprocket SP2 without having another sprocket between the first sprocket SP2 and the second sprocket SP3 in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14. are doing. The second sprocket SP4 is adjacent to the second sprocket SP3 without having another sprocket between the second sprocket SP3 and the second sprocket SP4 in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14. are doing. The first sprockets SP1 and SP2, the second sprocket SP3, the second sprocket SP4, and the additional sprockets SP5-SP12 are arranged side by side in the axial direction D2 in this order.

As shown in FIG. 7, the first sprocket SP1 includes a sprocket body SP1A and a plurality of sprocket teeth SP1B. A plurality of sprocket teeth SP1B extend radially outward from the sprocket body SP1A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. As shown in FIG. The total number of teeth of the first sprocket SP1 (the total number of at least one sprocket tooth SP1B) is 10 or less. In this embodiment, the total number of at least one sprocket tooth SP1B of the first sprocket SP1 is ten. However, the total number of sprocket teeth SP1B of the first sprocket SP1 is not limited to the present embodiment and the above range.

As shown in FIG. 8, the first sprocket SP2 includes a sprocket body SP2A and a plurality of sprocket teeth SP2B. A plurality of sprocket teeth SP2B extend radially outward from the sprocket body SP2A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. As shown in FIG. In this embodiment, the total number of at least one sprocket tooth SP2B is twelve. However, the total number of sprocket teeth SP2B of the first sprocket SP2 is not limited to this embodiment.

The first sprocket SP2 includes at least one first shift facilitating area SP2F1 for facilitating a first shift operation in which the bicycle chain 20 shifts from the first sprocket SP2 to the first sprocket SP1. The first sprocket SP2 includes at least one second shift facilitating area SP2F2 for facilitating a second shift operation in which the bicycle chain 20 shifts from the first sprocket SP1 to the first sprocket SP2. In this embodiment, the first sprocket SP2 includes a plurality of first shift acceleration areas SP2F1 for promoting the first shift operation. The first sprocket SP2 includes a plurality of second gear shift promotion areas SP2F2 for promoting the second gear shift operation. However, the total number of first shift acceleration areas SP2F1 is not limited to the present embodiment. The total number of second shift acceleration areas SP2F2 is not limited to that of the present embodiment. As used herein, the term "shift-enhancing region" is intentionally designed to facilitate shifting action of a bicycle chain from one sprocket to another axially adjacent sprocket within that region. intended for areas covered by

In this embodiment, the first sprocket SP2 includes a plurality of first gear shift facilitating recesses SP2R1 for facilitating the first gear shifting operation. The first sprocket SP2 includes a plurality of second shift facilitating recesses SP2R2 for facilitating the second shift operation. The first shift facilitating recess SP2R1 is provided in the first shift facilitating region SP2F1. However, the first shift facilitating region SP2F1 may include other structures instead of or in addition to the first shift facilitating recess SP2R1. The second shift facilitating region SP2F2 may include other structures instead of or in addition to the second shift facilitating recess SP2R2.

As shown in FIG. 9, the second sprocket SP3 includes a sprocket body SP3A and a plurality of sprocket teeth SP3B. A plurality of sprocket teeth SP3B extend radially outward from the sprocket body SP3A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. As shown in FIG. In this embodiment, the total number of at least one sprocket tooth SP3B is fourteen. However, the total number of sprocket teeth SP3B of the second sprocket SP3 is not limited to this embodiment.

The second sprocket SP3 includes at least one first shift facilitating area SP3F1 for facilitating the first shift operation of the bicycle chain 20 from the second sprocket SP3 to the first sprocket SP2 (FIG. 6). The second sprocket SP3 includes at least one second shift facilitating region SP3F2 for facilitating a second shifting operation of the bicycle chain 20 from the first sprocket SP2 (FIG. 6) to the second sprocket SP3. In this embodiment, the second sprocket SP3 includes a plurality of first gear shift promotion areas SP3F1 for promoting the first gear shift operation. The second sprocket SP3 includes a plurality of second gear shift promotion areas SP3F2 for promoting the second gear shift operation. However, the total number of first shift acceleration areas SP3F1 is not limited to that of the present embodiment. The total number of second shift acceleration areas SP3F2 is not limited to that of the present embodiment.

In this embodiment, the second sprocket SP3 includes a plurality of first gear shift facilitating recesses SP3R1 for facilitating the first gear shifting operation. The second sprocket SP3 includes a plurality of second shift facilitating recesses SP3R2 for facilitating the second shift operation. The first shift facilitating recess SP3R1 is provided in the first shift facilitating region SP3F1. However, the first shift facilitating region SP3F1 may include other structures instead of or in addition to the first shift facilitating recess SP3R1. The second shift facilitating region SP3F2 may include other structures instead of or in addition to the second shift facilitating recess SP3R2.

As shown in FIG. 10, the second sprocket SP4 includes a sprocket body SP4A and a plurality of sprocket teeth SP4B. A plurality of sprocket teeth SP4B extend radially outward from the sprocket body SP4A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14 . In this embodiment, the total number of at least one sprocket tooth SP4B is sixteen. However, the total number of sprocket teeth SP4B of the second sprocket SP4 is not limited to this embodiment.

The second sprocket SP4 includes at least one first shift facilitating region SP4F1 for facilitating the first shift operation of the bicycle chain 20 from the second sprocket SP4 to the second sprocket SP3. The second sprocket SP4 includes at least one second shift facilitating region SP4F2 for facilitating the second shift operation of the bicycle chain 20 from the second sprocket SP3 to the second sprocket SP4. In this embodiment, the second sprocket SP4 includes a plurality of first shift acceleration areas SP4F1 for promoting the first shift operation. The second sprocket SP4 includes a plurality of second gear shift promotion areas SP4F2 for promoting the second gear shift operation. However, the total number of first shift acceleration areas SP4F1 is not limited to the present embodiment. The total number of second shift acceleration areas SP4F2 is not limited to that of the present embodiment.

In this embodiment, the second sprocket SP4 includes a plurality of first gear shift facilitating recesses SP4R1 for facilitating the first gear shift operation. The second sprocket SP4 includes a plurality of second shift facilitating recesses SP4R2 for facilitating the second shift operation. The first shift facilitating recess SP4R1 is provided in the first shift facilitating region SP4F1. However, the first shift facilitating region SP4F1 may include other structures instead of or in addition to the first shift facilitating recess SP4R1. The second shift facilitating region SP4F2 may include other structures instead of or in addition to the second shift facilitating recess SP4R2.

As shown in FIG. 11, additional sprocket SP5 includes a sprocket body SP5A and a plurality of sprocket teeth SP5B. A plurality of sprocket teeth SP5B extend radially outward from the sprocket body SP5A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14 . In this embodiment, the total number of at least one sprocket tooth SP5B is eighteen. However, the total number of sprocket teeth SP5B of the additional sprocket SP5 is not limited to this embodiment.

The additional sprocket SP5 includes at least one first shift facilitating area SP5F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP5 to the adjacent small sprocket SP4. Additional sprocket SP5 includes at least one second shift facilitating region SP5F2 for facilitating a second shift operation in which bicycle chain 20 shifts from adjacent small sprocket SP4 to additional sprocket SP5. The adjacent small sprocket SP4 is adjacent to the additional sprocket SP5 without having another sprocket between the additional sprocket SP5 and the adjacent small sprocket SP4 in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14 . In this embodiment, the additional sprocket SP5 includes a plurality of first gear shift promotion areas SP5F1 for promoting the first gear shift operation. The additional sprocket SP5 includes a plurality of second gear shift promotion areas SP5F2 for promoting the second gear shift operation. However, the total number of first shift acceleration areas SP5F1 is not limited to that of the present embodiment. The total number of second shift acceleration areas SP5F2 is not limited to that of the present embodiment.

In this embodiment, the additional sprocket SP5 includes a plurality of first gear shift facilitating recesses SP5R1 for facilitating the first gear shifting operation. The additional sprocket SP5 includes a plurality of second shift facilitating recesses SP5R2 for facilitating the second shift operation. The first shift facilitating concave portion SP5R1 is provided in the first shift facilitating region SP5F1. The second shift facilitating recess SP5R2 is provided in the second shift facilitating region SP5F2. However, the first shift facilitating region SP5F1 may include other structures instead of or in addition to the first shift facilitating recess SP5R1. The second shift facilitating region SP5F2 may include other structures instead of or in addition to the second shift facilitating recess SP5R2.

As shown in FIG. 12, additional sprocket SP6 includes a sprocket body SP6A and a plurality of sprocket teeth SP6B. A plurality of sprocket teeth SP6B extend radially outward from the sprocket body SP6A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. As shown in FIG. In this embodiment, the total number of at least one sprocket tooth SP6B is twenty-one. However, the total number of sprocket teeth SP6B of the additional sprocket SP6 is not limited to this embodiment.

The additional sprocket SP6 includes at least one first shift facilitating area SP6F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP6 to the adjacent small sprocket SP5. Additional sprocket SP6 includes at least one second shift facilitating region SP6F2 for facilitating a second shift operation in which bicycle chain 20 shifts from adjacent small sprocket SP5 to additional sprocket SP6. The adjacent small sprocket SP5 is adjacent to the additional sprocket SP6 without having another sprocket between the additional sprocket SP6 and the adjacent small sprocket SP5 in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14. there is In this embodiment, the additional sprocket SP6 includes a plurality of first gear shift promotion areas SP6F1 for promoting the first gear shift operation. The additional sprocket SP6 includes a plurality of second gear shift promotion areas SP6F2 for promoting the second gear shift operation. However, the total number of first shift acceleration areas SP6F1 is not limited to the present embodiment. The total number of second shift acceleration areas SP6F2 is not limited to that of the present embodiment.

In this embodiment, the additional sprocket SP6 includes a plurality of first gearshift facilitating recesses SP6R1 for facilitating the first gearshift operation. The additional sprocket SP6 includes a plurality of second shift facilitating recesses SP6R2 for facilitating the second shift operation. The first shift facilitating recess SP6R1 is provided in the first shift facilitating region SP6F1. The second shift facilitating recess SP6R2 is provided in the second shift facilitating region SP6F2. However, the first shift facilitating region SP6F1 may include other structures instead of or in addition to the first shift facilitating recess SP6R1. The second shift facilitating region SP6F2 may include other structures instead of or in addition to the second shift facilitating recess SP6R2.

As shown in FIG. 13, additional sprocket SP7 includes a sprocket body SP7A and a plurality of sprocket teeth SP7B. A plurality of sprocket teeth SP7B extend radially outward from the sprocket body SP7A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14 . In this embodiment, the total number of at least one sprocket tooth SP7B is twenty-four. However, the total number of sprocket teeth SP7B of the additional sprocket SP7 is not limited to this embodiment.

The additional sprocket SP7 includes at least one first shift facilitating region SP7F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP7 to the adjacent small sprocket SP6. Additional sprocket SP7 includes at least one second shift facilitating region SP7F2 for facilitating a second shift operation in which bicycle chain 20 shifts from adjacent small sprocket SP6 to additional sprocket SP7. The adjacent small sprocket SP6 is adjacent to the additional sprocket SP7 without having another sprocket between the additional sprocket SP7 and the adjacent small sprocket SP6 in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14. there is In this embodiment, the additional sprocket SP7 includes a plurality of first gear shift promotion areas SP7F1 for promoting the first gear shift operation. The additional sprocket SP7 includes a plurality of second gear shift promotion areas SP7F2 for promoting the second gear shift operation. However, the total number of first shift acceleration areas SP7F1 is not limited to that of the present embodiment. The total number of second shift acceleration areas SP7F2 is not limited to that of the present embodiment.

In this embodiment, the additional sprocket SP7 includes a plurality of first gear shift facilitating recesses SP7R1 for facilitating the first gear shifting operation. The additional sprocket SP7 includes a plurality of second shift facilitating recesses SP7R2 for facilitating the second shift operation. The first shift facilitating recess SP7R1 is provided in the first shift facilitating region SP7F1. The second shift facilitating concave portion SP7R2 is provided in the second shift facilitating region SP7F2. However, the first shift facilitating region SP7F1 may include other structures instead of or in addition to the first shift facilitating recess SP7R1. The second shift facilitating region SP7F2 may include other structures instead of or in addition to the second shift facilitating concave portion SP7R2.

As shown in FIG. 14, additional sprocket SP8 includes a sprocket body SP8A and a plurality of sprocket teeth SP8B. A plurality of sprocket teeth SP8B extend radially outward from the sprocket body SP8A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14 . In this embodiment, the total number of at least one sprocket tooth SP8B is twenty-eight. However, the total number of sprocket teeth SP8B of the additional sprocket SP8 is not limited to this embodiment.

The additional sprocket SP8 includes at least one first shift facilitating area SP8F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP8 to the adjacent small sprocket SP7. Additional sprocket SP8 includes at least one second shift facilitating region SP8F2 for facilitating a second shift operation in which bicycle chain 20 shifts from adjacent small sprocket SP7 to additional sprocket SP8. The adjacent small sprocket SP7 is adjacent to the additional sprocket SP8 without having another sprocket between the additional sprocket SP8 and the adjacent small sprocket SP7 in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14. there is In this embodiment, the additional sprocket SP8 includes a plurality of first gear shift promotion areas SP8F1 for promoting the first gear shift operation. The additional sprocket SP8 includes a plurality of second gear shift promotion areas SP8F2 for promoting the second gear shift operation. However, the total number of first shift acceleration areas SP8F1 is not limited to that of the present embodiment. The total number of second shift acceleration areas SP8F2 is not limited to that of the present embodiment.

In this embodiment, the additional sprocket SP8 includes a plurality of first gear shift facilitating recesses SP8R1 for facilitating the first gear shifting operation. The additional sprocket SP8 includes a plurality of second shift facilitating recesses SP8R2 for facilitating the second shift operation. The first shift facilitating concave portion SP8R1 is provided in the first shift facilitating region SP8F1. The second gear shift facilitating recess SP8R2 is provided in the second gear shift facilitating area SP8F2. However, the first shift facilitating region SP8F1 may include other structures instead of or in addition to the first shift facilitating recess SP8R1. The second shift facilitating region SP8F2 may include other structures instead of or in addition to the second shift facilitating recess SP8R2.

As shown in FIG. 15, additional sprocket SP9 includes a sprocket body SP9A and a plurality of sprocket teeth SP9B. A plurality of sprocket teeth SP9B extend radially outward from the sprocket body SP9A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14 . In this embodiment, the total number of at least one sprocket tooth SP9B is 33. However, the total number of sprocket teeth SP9B of the additional sprocket SP9 is not limited to this embodiment.

The additional sprocket SP9 includes at least one first shift facilitating area SP9F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP9 to the adjacent small sprocket SP8. Additional sprocket SP9 includes at least one second shift facilitating region SP9F2 for facilitating a second shift operation in which bicycle chain 20 shifts from adjacent small sprocket SP8 to additional sprocket SP9. The adjacent small sprocket SP8 is adjacent to the additional sprocket SP9 without having another sprocket between the additional sprocket SP9 and the adjacent small sprocket SP8 in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14. there is In this embodiment, the additional sprocket SP9 includes a plurality of first gear shift promotion areas SP9F1 for promoting the first gear shift operation. The additional sprocket SP9 includes a plurality of second gear shift promotion areas SP9F2 for promoting the second gear shift operation. However, the total number of first shift acceleration areas SP9F1 is not limited to that of the present embodiment. The total number of second shift acceleration areas SP9F2 is not limited to that of the present embodiment.

In this embodiment, the additional sprocket SP9 includes a plurality of first gearshift facilitating recesses SP9R1 for facilitating the first gearshift operation. Additional sprocket SP9 includes a plurality of second shift facilitating recesses SP9R2 for facilitating second shift operation. The first shift facilitating recess SP9R1 is provided in the first shift facilitating region SP9F1. The second shift facilitating concave portion SP9R2 is provided in the second shift facilitating region SP9F2. However, the first shift facilitating region SP9F1 may include other structures instead of or in addition to the first shift facilitating recess SP9R1. The second shift facilitating region SP9F2 may include other structures instead of or in addition to the second shift facilitating recess SP9R2.

As shown in FIG. 16, the additional sprocket SP10 includes a sprocket body SP10A and a plurality of sprocket teeth SP10B. A plurality of sprocket teeth SP10B extend radially outward from the sprocket body SP10A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. As shown in FIG. In this embodiment, the total number of at least one sprocket tooth SP10B is thirty-nine. However, the total number of sprocket tooth portions SP10B of the additional sprocket SP10 is not limited to this embodiment.

The additional sprocket SP10 includes at least one first shift facilitating region SP10F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP10 to the adjacent small sprocket SP9. The additional sprocket SP10 includes at least one second shift facilitating area SP10F2 for facilitating a second shift operation of the bicycle chain 20 from the adjacent small sprocket SP9 to the additional sprocket SP10. The adjacent small sprocket SP9 is adjacent to the additional sprocket SP10 without having another sprocket between the additional sprocket SP10 and the adjacent small sprocket SP9 in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14. there is In this embodiment, the additional sprocket SP10 includes a plurality of first shift acceleration areas SP10F1 for promoting the first shift operation. The additional sprocket SP10 includes a second gear shift promotion area SP10F2 for promoting the second gear shift operation. However, the total number of first shift acceleration areas SP10F1 is not limited to that of the present embodiment. The total number of second shift acceleration areas SP10F2 is not limited to that of the present embodiment.

In this embodiment, the additional sprocket SP10 includes a plurality of first gear shift facilitating recesses SP10R1 for facilitating the first gear shifting operation. The additional sprocket SP10 includes a plurality of second shift facilitating recesses SP10R2 for facilitating the second shift operation. The first shift facilitating recess SP10R1 is provided in the first shift facilitating region SP10F1. The second shift facilitating recess SP10R2 is provided in the second shift facilitating region SP10F2. However, the first shift facilitating region SP10F1 may include other structures instead of or in addition to the first shift facilitating recess SP10R1. The second shift facilitating region SP10F2 may include other structures in place of or in addition to the second shift facilitating concave portion SP10R2.

As shown in FIG. 17, the additional sprocket SP11 includes a sprocket body SP11A and a plurality of sprocket teeth SP11B. A plurality of sprocket teeth SP11B extend radially outward from the sprocket body SP11A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. As shown in FIG. In this embodiment, the total number of at least one sprocket tooth SP11B is 45. However, the total number of sprocket tooth portions SP11B of the additional sprocket SP11 is not limited to this embodiment.

The additional sprocket SP11 includes at least one first shift facilitating area SP11F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP11 to the adjacent small sprocket SP10. The additional sprocket SP11 includes at least one second shift facilitating area SP11F2 for facilitating a second shift operation in which the bicycle chain 20 shifts from the adjacent small sprocket SP10 to the additional sprocket SP11. The adjacent small sprocket SP10 is adjacent to the additional sprocket SP11 without having another sprocket between the additional sprocket SP11 and the adjacent small sprocket SP10 in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14. there is In this embodiment, the additional sprocket SP11 includes a plurality of first shift acceleration areas SP11F1 for promoting the first shift operation. The additional sprocket SP11 includes a plurality of second gear shift promotion areas SP11F2 for promoting the second gear shift operation. However, the total number of first shift acceleration areas SP11F1 is not limited to that of the present embodiment. The total number of second shift acceleration areas SP11F2 is not limited to that of the present embodiment.

In this embodiment, the additional sprocket SP11 includes a plurality of first gear shift facilitating recesses SP11R1 for facilitating the first gear shifting operation. The additional sprocket SP11 includes a plurality of second shift facilitating recesses SP11R2 for facilitating the second shift operation. The first shift facilitating recess SP11R1 is provided in the first shift facilitating region SP11F1. The second shift facilitating recess SP11R2 is provided in the second shift facilitating region SP11F2. However, the first shift facilitating region SP11F1 may include other structures instead of or in addition to the first shift facilitating recess SP11R1. The second shift facilitating region SP11F2 may include other structures instead of or in addition to the second shift facilitating recess SP11R2.

As shown in FIG. 18, additional sprocket SP12 includes a sprocket body SP12A and a plurality of sprocket teeth SP12B. A plurality of sprocket teeth SP12B extend radially outward from the sprocket body SP12A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14 . The total number of teeth of the additional sprocket SP12 is 46 or more. The total number of teeth of the additional sprocket SP12 may be 50 or more. In this embodiment, the total number of teeth of the additional sprocket SP12 is 51. However, the total number of at least one sprocket tooth SP12B of the additional sprocket SP12 is not limited to this embodiment and the above range.

The additional sprocket SP12 includes at least one first shift facilitating region SP12F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP12 to the adjacent small sprocket SP11. Additional sprocket SP12 includes at least one second shift facilitating region SP12F2 for facilitating a second shift operation in which bicycle chain 20 shifts from adjacent small sprocket SP11 to additional sprocket SP12 to SP12. The adjacent small sprocket SP11 is adjacent to the additional sprocket SP12 without having another sprocket between the additional sprocket SP12 and the adjacent small sprocket SP11 in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14. there is In this embodiment, the additional sprocket SP12 includes a plurality of first shift acceleration areas SP12F1 for promoting the first shift operation. The additional sprocket SP12 includes a second gear shift promotion area SP12F2 for promoting the second gear shift operation. However, the total number of first shift acceleration areas SP12F1 is not limited to the present embodiment. The total number of second shift acceleration areas SP12F2 is not limited to that of the present embodiment.

In this embodiment, the additional sprocket SP12 includes a plurality of first gear shift facilitating recesses SP12R1 for facilitating the first gear shifting operation. The additional sprocket SP12 includes a plurality of second shift facilitating recesses SP12R2 for facilitating the second shift operation. The first shift facilitating recess SP12R1 is provided in the first shift facilitating region SP12F1. The second shift facilitating recess SP12R2 is provided in the second shift facilitating region SP12F2. However, the first shift facilitating region SP12F1 may include other structures instead of or in addition to the first shift facilitating recess SP12R1. The second shift facilitating region SP12F2 may include other structures instead of or in addition to the second shift facilitating recess SP12R2.

As shown in FIG. 19, the sprockets SP1-SP12 are separate members. However, at least one of the sprockets SP1-SP12 may be at least partially integrated with the other sprockets among the sprockets SP1-SP12. All of the sprockets SP1-SP12 may be integrally formed with each other as one single unit. In such cases, at least one of the sprockets SP3-SP12 may include at least ten internal spline teeth.

The bicycle rear sprocket assembly 14 further includes a sprocket support member 37, a plurality of spacers 38, a first ring 39A and a second ring 39B. The first ring 39A is provided between the second sprocket SP3 and the second sprocket SP4 in the axial direction D2. The second ring 39B is provided between the second sprocket SP4 and the additional sprocket SP5 in the axial direction D2. Additional sprockets are configured to be attached to the sprocket support member 37 . In this embodiment, the additional sprockets SP5-SP12 are configured to be attached to the sprocket support member 37. FIG.

As shown in FIG. 6, for example, additional sprockets are attached to sprocket support member 37 by adhesive 37A. In this embodiment, additional sprockets SP5-SP12 are attached to sprocket support member 37 by adhesive 37A. Therefore, the weight of the bicycle rear sprocket assembly 14 can be reduced by reducing or eliminating metal fasteners. However, at least one of the additional sprockets SP5-SP12 may be attached to the sprocket support member 37 by other structures (including metal fasteners) than the adhesive 37A. At least one of the additional sprockets SP5-SP12 may engage sprocket support 28 without sprocket support member 37. FIG. The sprocket support member 37 can be omitted from the bicycle rear sprocket assembly 14 . Furthermore, at least one of the second sprockets SP3 and SP4 may be attached to the sprocket support member 37.

As shown in FIG. 4, the lock member 32 includes a tubular portion 32A, a male thread portion 32B, and radial protrusions 32C. The tubular portion 32A includes a first axial end 32D and a second axial end 32E. The second axial end 32E is arranged on the opposite side of the first axial end 32D in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. As shown in FIG. As shown in FIG. 6, the first axial end 32D is positioned closer to the rear bicycle hub assembly 12 than the second axial end 32E with the rear bicycle sprocket assembly 14 mounted to the rear bicycle hub assembly 12. As shown in FIG. 12 at a position close to the axial center plane CPL. The axial center plane CPL is perpendicular to the rotation center axis A1. As shown in FIG. 3, the axial center plane CPL is defined to bisect the axial length of the rear bicycle hub assembly 12 in the axial direction D2.

As shown in FIG. 6, the male threaded portion 32B is connected to the female threaded portion 28A of the sprocket support 28 of the bicycle rear hub assembly 12 when the bicycle rear sprocket assembly 14 is mounted on the bicycle rear hub assembly 12. As shown in FIG. It is provided at the first axial end 32D for engagement. The radial projection 32C is configured to limit axial movement of the first sprocket SP2 relative to the sprocket support 28 of the rear bicycle hub assembly 12 with the rear bicycle sprocket assembly 14 mounted to the rear bicycle hub assembly 12. extends radially outward from the second axial end 32E with respect to the rotation center axis A1.

First sprocket SP1 includes a first inner side surface SP1G and a first outer side surface SP1H. The first outer side surface SP1H is arranged on the side opposite to the first inner side surface SP1G in the axial direction D2. The radial projection 32C is configured to contact the first sprocket SP1 at the first outer side surface SP1H. The first sprockets SP1 and SP2 are arranged axially between the radial projection 32C and the second sprocket SP3. The first sprockets SP1 and SP2, the second sprocket SP3, the second sprocket SP4, and the first ring 39A are held between the radial projection 32C and the sprocket support member 37 in the axial direction D2.

As shown in FIG. 4, the locking member 32 has a tool engaging portion 32F. The tool engaging portion 32F is provided on the inner peripheral surface 32A1 of the cylindrical portion 32A so as to be engaged with a fixture (not shown). In this embodiment, the tool engaging portion 32F has a plurality of engagements to engage the fastener when the locking member 32 is threaded onto the sprocket support 28 by the external threads 32B and the internal threads 28A. Includes groove 32G.

As shown in Figures 20 and 21, the sprocket support 28 includes at least one external spline tooth 40 configured to engage the bicycle rear sprocket assembly 14 (Figure 6). The sprocket support 28 includes at least ten external spline teeth 40 configured to engage the bicycle rear sprocket assembly 14 (FIG. 6). That is, the at least one outer spline tooth 40 includes multiple outer spline teeth 40 .

The sprocket support 28 includes a base support 41 having a tubular shape. The base support portion 41 extends along the rotation center axis A1. Outer spline teeth 40 extend radially outwardly from base support 41 . Sprocket support 28 includes a large diameter portion 42 , a flange 44 and a plurality of outer helical spline teeth 46 . Large diameter portion 42 and flange 44 extend radially outward from base support portion 41 . The large diameter portion 42 is provided between the plurality of outer spline teeth 40 and the flange 44 in the axial direction D2. The large diameter portion 42 and the flange are provided between the plurality of outer spline teeth 40 and the plurality of outer helical spline teeth 46 in the axial direction D2. As shown in FIG. 6, the bicycle rear sprocket assembly 14 is held between the large diameter portion 42 and the radial protrusion 32C of the lock member 32 in the axial direction D2. Large diameter portion 42 may have an internal cavity so that a drive mechanism, such as a one-way clutch mechanism, can be accommodated within the internal cavity. The large diameter portion 42 can be omitted from the bicycle rear hub assembly 12 if desired.

As shown in FIG. 22, at least one of the at least ten outer spline teeth 40 has a spline tooth axial length SL1. Each of the plurality of outer spline teeth 40 has a spline tooth axial length SL1. The spline tooth axial length SL1 is 27 mm or less. The spline tooth axial length SL1 is 22 mm or more. In this embodiment, the spline tooth axial length SL1 is 24.9 mm. However, the spline tooth axial length SL1 is not limited to the present embodiment and the above range.

As shown in FIG. 23, the total number of at least ten external spline teeth 40 is twenty or more. The total number of at least ten external spline teeth 40 is preferably twenty-five or more. The total number of at least ten external spline teeth 40 is preferably twenty-eight or more. The total number of external spline teeth 40 is preferably 72 or less. In this embodiment, the total number of external spline teeth 40 is twenty-nine. However, the total number of outer spline teeth 40 is not limited to this embodiment and the above range.

At least ten outer spline teeth 40 have a first outer pitch angle PA11 and a second outer pitch angle PA12. At least two outer spline teeth out of the at least ten outer spline teeth 40 are arranged at a first outer pitch angle PA11 in the circumferential direction about the rotation center axis A1. In other words, at least two of the plurality of outer spline teeth 40 are arranged at the first outer pitch angle PA11 in the circumferential direction with respect to the rotation center axis A1 of the bicycle rear hub assembly 12 . At least two outer spline teeth out of the at least ten outer spline teeth 40 are arranged at a second outer pitch angle PA12 in the circumferential direction about the rotation center axis A1 of the bicycle rear hub assembly 12 . In other words, at least two of the plurality of outer spline teeth 40 are arranged at the second outer pitch angle PA12 in the circumferential direction about the rotation center axis A1 of the bicycle rear hub assembly 12 . In this embodiment, the second outer pitch angle PA12 is different than the first outer pitch angle PA11. However, the second outer pitch angle PA12 may be substantially the same as the first outer pitch angle PA11.

In this embodiment, the plurality of outer spline teeth 40 are arranged at a first outer pitch angle PA11 in the circumferential direction D1. Two outer spline teeth of the plurality of outer spline teeth 40 are arranged at a second outer pitch angle PA12 in the circumferential direction D1. However, at least two of the plurality of outer spline teeth 40 may be arranged at other outer pitch angles in the circumferential direction D1.

The first outer pitch angle PA11 is in the range of 5 degrees to 36 degrees. The first outer pitch angle PA11 is preferably in the range of 10 degrees to 20 degrees. The first outer pitch angle PA11 is preferably 15 degrees or less. In this embodiment, the first outer pitch angle PA11 is 12 degrees. However, the first outer pitch angle PA11 is not limited to this embodiment and the above range.

The second outer pitch angle PA12 is in the range of 5 degrees to 36 degrees. In this embodiment, the second outer pitch angle PA12 is 24 degrees. However, the second outer pitch angle PA12 is not limited to this embodiment and the above range.

At least one of the plurality of outer spline teeth 40 may have a first spline shape different from other second spline shapes of the plurality of outer spline teeth 40 . At least one of the at least ten external spline teeth 40 may have a first spline size that is different than other second spline sizes of the at least ten external spline teeth 40 . At least one of the plurality of outer spline teeth 40 has a contour different from other contours of the plurality of outer spline teeth 40 when viewed along the rotation center axis A1. In this embodiment, the outer spline tooth 40X has a first spline shape different from the other second spline shapes of the plurality of outer spline teeth 40 . The outer spline teeth 40X have a first spline size that is different from the other second spline sizes of the plurality of outer spline teeth 40 . However, as shown in FIG. 24, at least ten outer spline teeth 40 may have the same spline shape as each other. At least ten outer spline teeth 40 may have the same spline size as each other. At least ten outer spline teeth 40 may have the same profile as each other.

As shown in FIG. 25, each of the at least ten external spline teeth 40 has an external spline drive surface 48 and an external spline non-drive surface 50 . The plurality of externally splined teeth 40 includes a plurality of externally splined drive surfaces 48 for receiving rotational driving force F1 from the bicycle rear sprocket assembly 14 (FIG. 6) during pedaling. The plurality of externally splined teeth 40 includes a plurality of externally splined non-driving surfaces 50 . The externally splined drive surface 48 is contactable with the rear bicycle sprocket assembly 14 for receiving rotational driving force F1 from the rear bicycle sprocket assembly 14 (FIG. 6) during pedaling. The outer spline drive surface 48 faces the reverse rotation direction D12. The outer splined drive surface 48 faces the inner splined drive surface 66 of the rear bicycle sprocket assembly 14 when the rear bicycle sprocket assembly 14 is mounted on the rear bicycle hub assembly 12 . The outer spline non-drive surface 50 is provided opposite the outer spline drive surface 48 in the circumferential direction D1. The externally splined non-drive surface 50 faces in the driving rotational direction D11 so as not to receive the driving rotational force F1 from the bicycle rear sprocket assembly 14 during pedaling. The outer splined non-drive surface 50 faces the inner splined non-drive surface 68 of the rear bicycle sprocket assembly 14 when the rear bicycle sprocket assembly 14 is mounted on the rear bicycle hub assembly 12 .

Each of the at least ten outer spline teeth 40 has a maximum circumferential width MW1. Each of the plurality of outer spline teeth 40 has a maximum circumferential width MW1. A maximum circumferential width MW1 is defined as the maximum width to receive the thrust force F2 acting on the outer spline tooth 40 . A maximum circumferential width MW1 is defined as a linear distance based on the outer splined drive surface 48 .

Each of the plurality of outer spline drive surfaces 48 includes a radially outermost peripheral edge 48A and a radially innermost peripheral edge 48B. Outer splined drive surface 48 extends from radially outermost peripheral edge 48A to radially innermost peripheral edge 48B. A first reference circle RC11 is defined on the radially innermost peripheral edge 48B and centered on the rotation center axis A1. A first reference circle RC11 intersects the outer spline non-drive surface 50 and has a reference point 50R. Circumferential maximum width MW1 extends linearly from radial innermost edge 48B to reference point 50R in circumferential direction D1.

Each of the plurality of outer splined non-driving surfaces 50 includes a radially outermost peripheral edge 50A and a radially innermost peripheral edge 50B. Outer splined non-drive surface 50 extends from radially outermost peripheral edge 50A to radially innermost peripheral edge 50B. In this embodiment, the reference point 50R coincides with the radially innermost peripheral edge 50B. However, the reference point 50R may be offset from the radially innermost peripheral edge 50B.

The total circumferential maximum width MW1 is 55 mm or more. The total circumferential maximum width MW1 is preferably 60 mm or more. The total circumferential maximum width MW1 is preferably 70 mm or less. In this embodiment, the total circumferential maximum width MW1 is 60.1 mm. However, the total circumferential maximum width MW1 is not limited to the present embodiment and the above range.

As shown in FIG. 26, at least one outer spline tooth 40 has an outer spline ridge diameter DM11 of 34 mm or less. The outer spline crest diameter DM11 is 33 mm or less. The outer spline ridge diameter DM11 is 29 mm or more. In this embodiment, the outer spline thread diameter DM11 is 32.6 mm. However, the outer spline thread diameter DM11 is not limited to the present embodiment and the above range.

At least one outer spline tooth 40 has an outer spline root diameter DM12. At least one outer spline tooth 40 has an outer spline root circle RC12 with an outer spline root diameter DM12. However, the outer spline root circle RC12 may have other diameters different from the outer spline root diameter DM12. The outer spline root diameter DM12 is 32 mm or less. The outer spline root diameter DM12 is 31 mm or less. The outer spline root diameter DM12 is 28 mm or more. In this embodiment, the outer spline root diameter DM12 is 30.2 mm. However, the outer spline root diameter DM12 is not limited to the present embodiment and the above range.

The large diameter portion 42 has an outer diameter DM13 that is larger than the outer spline crest diameter DM11. The outer diameter DM13 is in the range of 32mm to 40mm. In this embodiment, the outer diameter DM13 is 35 mm. However, the outer diameter DM13 is not limited to this embodiment.

As shown in FIG. 25, each of the plurality of outer spline drive surfaces 48 includes a radial length RL11 defined from the radially outermost peripheral edge 48A to the radially innermost peripheral edge 48B. The total radial length RL11 of the plurality of outer spline drive surfaces 48 is 7 mm or more. The total radial length RL11 is 10 mm or more. The total radial length RL11 is 15 mm or more. The total radial length is 36 mm or less. In this embodiment, the total radial length RL11 is 16.6 mm. However, the total radial length RL11 is not limited to this embodiment.

The plurality of outer spline teeth 40 have an additional radial length RL12. Each additional radial length RL12 is defined from the outer spline root circle RC12 to the radially outermost edge 40A of the plurality of outer spline teeth 40 . The sum of the additional radial lengths RL12 is 20 mm or more. In this embodiment, the total additional radial length RL12 is 31.2 mm. However, the total additional radial length RL12 is not limited to this embodiment.

At least one of the at least ten outer spline teeth 40 is circumferentially symmetrical about the reference line CL1. The reference line CL1 extends from the rotation center axis A1 of at least one radially outermost peripheral end portion 40A of the at least ten outer spline teeth 40 in the radial direction with respect to the rotation center axis A1 to the circumferential center point CP1. However, at least one of the plurality of outer spline teeth 40 may have an asymmetric shape with respect to the reference line CL1. At least one of the at least ten external spline teeth 40 includes an external spline drive surface 48 and an external spline non-drive surface 50 .

At least one surface of the plurality of outer spline drive surfaces 48 has a first outer spline surface angle AG11. A first outer spline face angle AG11 is defined between the outer spline drive face 48 and the first radial line L11. The first radial line L11 extends from the rotation center axis A1 of the bicycle rear hub assembly 12 to the radially outermost edge 48A of the outer spline drive surface 48. As shown in FIG. A first outer pitch angle PA11 or a second outer pitch angle PA12 is defined between adjacent first radial lines L11 (see, eg, FIG. 23).

At least one of the outer spline non-drive faces 50 has a second outer spline face angle AG12. A second outer spline surface angle AG12 is defined between the outer spline non-driving surface 50 and the second radial line L12. The second radial line L12 extends from the rotation center axis A1 of the bicycle rear hub assembly 12 to the radially outermost edge 50A of the outer spline non-driving surface 50. As shown in FIG.

In this embodiment, the second outer spline face angle AG12 is equal to the first outer spline face angle AG11. However, the first outer spline face angle AG11 may be different than the second outer spline face angle AG12.

The first outer spline surface angle AG11 is 6 degrees or less. The first outer spline surface angle AG11 is 0 degrees or more. The second outer spline face angle AG12 is 6 degrees or less. The second outer spline surface angle AG12 is 0 degrees or more. In this embodiment, the first outer spline surface angle AG11 is 5 degrees. The second outer spline surface angle AG12 is 5 degrees. However, the first outer spline surface angle AG11 and the second outer spline surface angle AG12 are not limited to the present embodiment and the ranges described above.

27 and 28, brake rotor support 34 includes at least one additional external spline tooth 52 configured to engage bicycle brake rotor 16 (FIG. 1). In this embodiment, brake rotor support 34 includes an additional base support 54 and a plurality of additional external spline teeth 52 . The additional base support portion 54 has a cylindrical shape and extends from the hub body 36 along the rotation center axis A1. Additional outer spline teeth 52 extend radially outwardly from additional base support 54 . The total number of additional external spline teeth 52 is fifty-two. However, the total number of additional outer spline teeth 52 is not limited to this embodiment.

As shown in FIG. 28, at least one additional outer spline tooth 52 has an additional outer spline thread diameter DM14. As shown in FIG. 29, the additional outer spline ridge diameter DM14 is larger than the outer spline ridge diameter DM11. Additional outer spline thread diameter DM14 is substantially equal to outer diameter DM13 of large diameter portion 42 . However, the additional outer spline ridge diameter DM14 may be less than or equal to the outer spline ridge diameter DM11. The additional outer spline thread diameter DM14 may be different from the outer diameter DM13 of the large diameter portion 42 .

As shown in FIG. 29, the hub body 36 includes a first spoke attachment portion 36A and a second spoke attachment portion 36B. A plurality of first spokes SK1 are connected to the first spoke attachment portions 36A. A plurality of second spokes SK2 are coupled to the second spoke attachment portions 36B. In this embodiment, the first spoke attachment portion 36A includes a plurality of first attachment holes 36A1. The first spoke SK1 extends through the first attachment hole 36A1. The second spoke attachment portion 36B includes a plurality of second attachment holes 36B1. The second spoke SK2 extends through the second mounting hole 36B1. As used herein, the term "spoke attachment portion" means that the spoke attachment openings are in the flange such that the spoke attachment portions extend radially outwardly with respect to the center axis of rotation of the rear bicycle hub assembly as shown in FIG. and a configuration in which the spoke attachment portions are openings formed directly on the radially outer peripheral surface of the hub body.

The second spoke attachment portions 36B are separated from the first spoke attachment portions 36A in the axial direction D2. The first spoke attachment portions 36A are provided between the sprocket support 28 and the second spoke attachment portions 36B in the axial direction D2. The second spoke attachment portion 36B is provided between the first spoke attachment portion 36A and the brake rotor support 34 in the axial direction D2.

The first spoke attachment portion 36A has a first axial outermost portion 36C. The second spoke attachment portion 36B has a second axial outermost portion 36D. The first axially outermost portion 36C includes a surface facing the first frame BF1 in the axial direction D2 when the bicycle rear hub assembly 12 is mounted on the bicycle frame BF. The second axially outermost portion 36D includes a surface facing the second frame BF2 in the axial direction D2 when the bicycle rear hub assembly 12 is mounted on the bicycle frame BF.

Hub body 36 includes a first axial length AL1. The first axial length AL1 is the distance between the first axial outermost portion 36C of the first spoke attachment portion 36A and the second axial length AL1 of the second spoke attachment portion 36B in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14. It is defined between the biaxially outermost portion 36D. The first axial length AL1 may be 55 mm or more. The first axial length AL1 may be 60 mm or more. The first axial length AL1 may be 65 mm or more. In this embodiment, the first axial length AL1 may be 67 mm. However, the first axial length AL1 is not limited to the present embodiment and the above range. Examples of first axial length AL1 include 55.7 mm, 62.3 mm, and 67 mm.

As shown in FIG. 29, hub axle 30 includes a first axial frame contact surface 30B1 and a second axial frame contact surface 30C1. The first axial frame contact surface 30B1 is formed on the bicycle frame BF in the axial direction D2 about the rotation center axis A1 of the bicycle rear sprocket assembly 14 when the bicycle rear hub assembly 12 is attached to the bicycle frame BF. It is configured to contact the first portion BF12. The second axial frame contact surface 30C1 is configured to contact the second portion BF22 of the bicycle frame BF in the axial direction D2 when the bicycle rear hub assembly 12 is mounted on the bicycle frame BF. The first axial frame contact surface 30B1 is located closer to the sprocket support 28 than the second axial frame contact surface 30C1 in the axial direction D2. The sprocket support 28 is provided between the first axial frame contact surface 30B1 and the second axial frame contact surface 30C1 in the axial direction D2.

Hub axle 30 includes a second axial length AL2 defined between first axial frame contact surface 30B1 and second axial frame contact surface 30C1 in axial direction D2. The second axial length AL2 may be 140 mm or more. The second axial length AL2 may be 145 mm or more. The second axial length AL2 may be 147 mm or more. The second axial length AL2 may be 148 mm. However, the second axial length AL2 is not limited to the present embodiment and the above range. Examples of the second axial length AL2 include 142 mm, 148 mm, and 157 mm.

A ratio of the first axial length AL1 to the second axial length AL2 may be 0.3 or more. A ratio of the first axial length AL1 to the second axial length AL2 may be 0.4 or more. A ratio of the first axial length AL1 to the second axial length AL2 may be 0.5 or less. For example, the ratio of the first axial length AL1 (67 mm) to the second axial length AL2 (148 mm) is approximately 0.45. However, the ratio of the first axial length AL1 to the second axial length AL2 is not limited to this embodiment and the above range. Examples of ratios of the first axial length AL1 to the second axial length AL2 are about 0.42 (AL1 is 62.3 mm and AL2 is 148 mm) or about 0.39 (AL1 is 55 mm). .7 mm and AL2 is 142 mm).

As shown in FIG. 6, the sprocket support 28 has a first axial end 28B, a second axial end 28C, and a sprocket axial contact surface 28D. The second axial end 28C is arranged on the opposite side of the first axial end 28B in the axial direction D2. The axial center plane CPL bisects the second axial length AL2 in the axial direction D2. The sprocket axial contact surface 28D is located closer to the axial center plane CPL of the bicycle rear hub assembly 12 than the first axial end 28B in the axial direction D2. The second axial end portion 28C is located closer to the axial center plane CPL of the bicycle rear hub assembly 12 than the sprocket axial contact surface 28D in the axial direction D2. The sprocket axial contact surface 28D is provided on the large diameter portion 42 in this embodiment, whereas the sprocket axial contact surface 28D is provided on other portions of the bicycle rear hub assembly 12 as desired. may be provided. The sprocket axial contact surface 28D contacts the bicycle rear sprocket assembly 14 when the bicycle rear sprocket assembly 14 is mounted on the sprocket support 28. As shown in FIG. The sprocket axial contact surface 28D faces the first axial end 28B in the axial direction D2.

As shown in FIG. 6, a sprocket arrangement axial length AL3 is defined between the first axial frame contact surface 30B1 of the sprocket support 28 and the sprocket axial contact surface 28D in the axial direction D2. In this embodiment, the sprocket arrangement axial length AL3 is in the range of 35 mm to 45 mm. For example, the sprocket arrangement axial length AL3 is 39.64 mm. The sprocket arrangement axial length AL3 can be extended up to 44.25 mm, for example, by omitting the large diameter portion 42 . However, the sprocket arrangement axial length AL3 is not limited to the present embodiment and the above range.

The large diameter portion 42 has an axial end portion 42A farthest from the first axial frame contact surface 30B1 in the axial direction D2. An additional axial length AL4 is defined from the first axial frame contact surface 30B1 to the axial end 42A in the axial direction D2. The additional axial length AL4 is in the range of 38mm to 47mm. The additional axial length AL4 may be in the range 44mm-45mm. Also, the additional axial length AL4 may be in the range of 40 mm to 41 mm. In this embodiment, the additional axial length AL4 is 44.25 mm. However, the additional axial length AL4 is not limited to this embodiment and the above range.

A large-diameter axial length AL5 of the large-diameter portion 42 is within a range of 3 mm to 6 mm. In this embodiment, the large diameter axial length AL5 is 4.61 mm. However, the large-diameter axial length AL5 is not limited to the present embodiment and the above range.

The ratio of the first axial length AL1 to the sprocket arrangement axial length AL3 is within the range of 1.2 to 1.7. For example, the ratio of the first axial length AL1 to the sprocket axial length AL3 is given when the first axial length AL1 is 55.7 mm and the sprocket axial length AL3 is 39.64 mm. is 1.4. However, the ratio of the first axial length AL1 to the sprocket arrangement axial length AL3 is not limited to this embodiment and the above range. For example, the ratio of the first axial length AL1 to the sprocket axial length AL3 is given when the first axial length AL1 is 62.3 mm and the sprocket axial length AL3 is 39.64 mm. can be 1.57, or the ratio of the first axial length AL1 to the sprocket arrangement axial length AL3 is such that the first axial length AL1 is 67 mm and the sprocket arrangement axial length AL3 is If it is 39.64 mm, it may be 1.69.

As shown in FIG. 30, sprocket support member 37 includes hub engaging portion 60 and a plurality of support arms 62 . A plurality of support arms 62 extend radially outwardly from hub engaging portion 60 . The support arm 62 includes first through eighth mounting portions 62A through 62H. The plurality of spacers 38 includes a plurality of first spacers 38A, a plurality of second spacers 38B, a plurality of third spacers 38C, a plurality of fourth spacers 38D, a plurality of fifth spacers 38E, and a plurality of sixth spacers 38E. It includes a spacer 38F and a plurality of seventh spacers 38G.

As shown in FIG. 6, the first spacer 38A is provided between the additional sprockets SP5 and SP6. A second spacer 38B is provided between the additional sprockets SP6 and SP7. A third spacer 38C is provided between the additional sprockets SP7 and SP8. A fourth spacer 38D is provided between the additional sprockets SP8 and SP9. A fifth spacer 38E is provided between the additional sprockets SP9 and SP10. A sixth spacer 38F is provided between the additional sprockets SP10 and SP11. A seventh spacer 38G is provided between the additional sprockets SP11 and SP12.

Additional sprocket SP6 and first spacer 38A are attached to first attachment portion 62A by adhesive 37A. Additional sprocket SP7 and second spacer 38B are attached to second attachment portion 62B by adhesive 37A. Additional sprocket SP8 and third spacer 38C are attached to third attachment portion 62C by adhesive 37A. Additional sprocket SP9 and fourth spacer 38D are attached to fourth attachment portion 62D by adhesive 37A. Additional sprocket SP10 and fifth spacer 38E are attached to fifth attachment portion 62E by adhesive 37A. Additional sprocket SP11 and sixth spacer 38F are attached to sixth attachment portion 62F by adhesive 37A. Additional sprocket SP12 and seventh spacer 38G are attached to seventh attachment portion 62G by adhesive 37A. Additional sprocket SP5 and second ring 39B are attached to eighth attachment portion 62H by adhesive 37A. The hub engaging portion 60, the sprockets SP1 to SP4, the first ring 39A and the second ring 39B are held between the large diameter portion 42 and the radial projection 32C of the locking member 32 in the axial direction D2.

In this embodiment, each of the sprockets SP1-SP12 is made of a metal material such as aluminum, iron, or titanium. The sprocket support member 37 is made of a nonmetallic material including a resin material. Each of the first to seventh spacers 38A to 38G, the first ring 39A, and the second ring 39B is made of nonmetallic material such as resin material. However, at least one of the sprockets SP1-SP12 may be constructed at least partially from a non-metallic material. At least one of sprocket support member 37, first through seventh spacers 38A-38G, first ring 39A, and second ring 39B is at least partially constructed from a metallic material such as aluminum, iron, or titanium. may be

As shown in FIG. 7, the first sprocket SP1 includes a first opening SP1K. The first opening SP1K has a first minimum diameter MD1. As shown in FIG. 31, the tubular portion 32A of the locking member 32 extends through the first opening SP1K of the first sprocket SP1 when the bicycle rear sprocket assembly 14 is mounted on the sprocket support 28. As shown in FIG. The first opening SP1K of the first sprocket SP1 is such that when the bicycle rear sprocket assembly 14 is mounted on the sprocket support 28, the first axial end 32D of the tubular portion 32A of the locking member 32 is positioned to the first sprocket SP1. is configured to pass through the first opening SP1K of the A first axial end 28B of the sprocket support 28 is spaced from the first opening SP1K of the first sprocket SP1 without extending through the first opening SP1K. The first minimum diameter MD1 is smaller than the minimum outer diameter MD28 of the sprocket support 28 of the bicycle rear hub assembly 12. As shown in FIG. In this embodiment, the minimum outer diameter MD28 is equal to the outer spline root diameter DM12 of the plurality of outer spline teeth 40 of the sprocket support 28 (Fig. 26).

As shown in FIG. 31, the tubular portion 32A has a first outer diameter ED1 of 27 mm or less. The first outer diameter ED1 is 26 mm or more. The radial projection 32C has a second outer diameter ED2 of 32 mm or less. The second outer diameter ED2 is 30 mm or more. In this embodiment, the first outer diameter ED1 is 26.2 mm. The second outer diameter ED2 is 30.8 mm. However, at least one of the first outer diameter ED1 and the second outer diameter ED2 is not limited to this embodiment and the above range.

The radial projection 32C has an axial width ED3 defined in the axial direction D2. For example, the axial width ED3 of the radial protrusion 32C is 2 mm. However, the axial width ED3 is not limited to this embodiment.

The locking member 32 has an axial length ED4 defined from the radial projection 32C to the first axial end 32D in the axial direction D2. The axial length ED4 of the locking member 32 is 10 mm. However, the axial length ED4 is not limited to this embodiment.

As shown in FIG. 8, the first sprocket SP2 includes a first opening SP2K. That is, each of the multiple first sprockets SP1 and SP2 includes a first opening SP2K. First opening SP2K has a first minimum diameter MD2. As shown in FIG. 31, the tubular portion 32A of the locking member 32 extends through the first opening SP2K of the first sprocket SP2 when the bicycle rear sprocket assembly 14 is mounted on the sprocket support 28. As shown in FIG. A first axial end 28B of the sprocket support 28 is spaced from the first opening SP2K of the first sprocket SP2 without extending through the first opening SP2K. The first minimum diameter MD2 is less than the minimum outer diameter MD28 of the sprocket support 28 of the bicycle rear hub assembly 12. As shown in FIG.

As shown in FIG. 9, the second sprocket SP3 includes a second opening SP3K. The second opening SP3K has a second minimum diameter MD3. As shown in FIG. 31, the tubular portion 32A of the lock member 32 and the sprocket support 28 are arranged to engage the second opening SP3K of the second sprocket SP3 with the bicycle rear sprocket assembly 14 attached to the sprocket support 28. As shown in FIG. extend through. A first axial end 28B of the sprocket support 28 is provided between the second opening SP3K and the first opening SP1K in the axial direction D2. A first axial end 28B of the sprocket support 28 is provided between the second opening SP3K and the first opening SP2K in the axial direction D2. The second minimum diameter MD3 is greater than or equal to the minimum outer diameter MD28 of the sprocket support 28 of the bicycle rear hub assembly 12. As shown in FIG.

As shown in FIG. 10, the second sprocket SP4 includes a second opening SP4K. That is, each of the plurality of second sprockets SP3 and SP4 includes a second opening SP4K. The second aperture SP4K has a second minimum diameter MD4. The sprocket support 28 extends through the second opening SP4K of the second sprocket SP4 with the bicycle rear sprocket assembly 14 mounted on the sprocket support 28, as shown in FIG. A first axial end 28B of the sprocket support 28 is provided between the second opening SP4K and the first opening SP1K in the axial direction D2. Second minimum diameter MD4 is greater than or equal to minimum outer diameter MD28 of sprocket support 28 of bicycle rear hub assembly 12 .

As shown in FIG. 32 , first sprocket SP2 includes at least ten internal spline teeth 63 configured to engage sprocket support 28 of bicycle rear hub assembly 12 . At least ten inner spline teeth 63 are provided in the first opening SP2K. At least ten internal spline teeth 63 are provided as a first torque transmission structure of the first sprocket SP2, as described below.

The total number of at least ten inner spline teeth 63 of the first sprocket SP2 is twenty or more. The total number of at least ten inner spline teeth 63 of the first sprocket SP2 is 28 or more. The total number of internal spline teeth 63 is 72 or less. In this embodiment, the total number of inner spline teeth 63 is twenty-nine. However, the total number of inner spline teeth 63 is not limited to this embodiment and the above range.

As shown in FIG. 9 , second sprocket SP3 includes at least ten internal spline teeth 64 configured to engage sprocket support 28 of bicycle rear hub assembly 12 . In this embodiment, the at least ten inner spline teeth 64 of the second sprocket SP3 define a second minimum diameter MD3 as the inner spline ridge diameter of the at least ten inner spline teeth 64.

The total number of at least ten inner spline teeth 64 of the second sprocket SP3 is twenty or more. The total number of at least ten inner spline teeth 64 of the second sprocket SP3 is 28 or more. The total number of internal spline teeth 64 is 72 or less. In this embodiment, the total number of internal spline teeth 64 is twenty-nine. However, the total number of inner spline teeth 64 is not limited to this embodiment and the above ranges.

As shown in FIG. 10 , second sprocket SP4 includes at least ten internal spline teeth 65 configured to engage sprocket support 28 of bicycle rear hub assembly 12 . That is, each of the plurality of second sprockets SP3 and SP4 includes at least ten internal spline teeth configured to engage the sprocket support 28 of the bicycle rear hub assembly 12. As shown in FIG. In this embodiment, the at least ten inner spline teeth 65 of the second sprocket SP4 define a second minimum diameter MD4 as the inner spline ridge diameter of the at least ten inner spline teeth 65.

The total number of at least ten inner spline teeth 65 of the second sprocket SP4 is twenty or more. The total number of at least ten inner spline teeth 65 of the second sprocket SP4 is 28 or more. The total number of internal spline teeth 65 is 72 or less. In this embodiment, the total number of internal spline teeth 65 is twenty-nine. However, the total number of inner spline teeth 65 is not limited to this embodiment and the above range.

As shown in FIG. 33, at least ten inner spline teeth 64 of second sprocket SP3 have a first inner pitch angle PA21 and a second inner pitch angle PA22. At least two inner spline teeth out of the at least ten inner spline teeth 64 of the second sprocket SP3 are arranged at a first inner pitch angle PA21 in the circumferential direction about the rotation center axis A1 of the bicycle rear sprocket assembly 14. be done. At least two of the at least ten inner spline teeth 64 are adjacent to each other in the circumferential direction D1 with no other spline tooth therebetween. In other words, at least two of the plurality of inner spline teeth 64 are arranged at the first inner pitch angle PA21 in the circumferential direction about the rotation center axis A1 of the bicycle rear sprocket assembly 14 . At least the other two inner spline teeth of the at least ten inner spline teeth 64 of the second sprocket SP3 are arranged at a second inner pitch angle PA22 in the circumferential direction about the rotation center axis A1. At least two other inner spline teeth of the at least ten inner spline teeth 64 of the second sprocket SP3 are adjacent to each other in the circumferential direction D1 with no other spline tooth therebetween. In other words, at least two of the plurality of inner spline teeth 64 of the second sprocket SP3 are arranged at the second inner pitch angle PA22 in the circumferential direction about the rotation center axis A1. In this embodiment, the second inner pitch angle PA22 is different from the first inner pitch angle PA21. However, the second inner pitch angle PA22 may be substantially the same as the first inner pitch angle PA21.

In this embodiment, the plurality of inner spline teeth 64 are circumferentially arranged at a first inner pitch angle PA21 in the circumferential direction D1. Two inner spline teeth of the plurality of inner spline teeth 64 are arranged at a second inner pitch angle PA22 in the circumferential direction D1. However, at least two inner spline teeth among the plurality of inner spline teeth 64 may be arranged at other inner pitch angles in the circumferential direction D1.

The first inner pitch angle PA21 is in the range of 5 degrees to 36 degrees. The first inner pitch angle PA21 is in the range of 10 degrees to 20 degrees. The first inner pitch angle PA21 is 15 degrees or less. In this embodiment, for example, the first inner pitch angle PA21 is 12 degrees. However, the first inner pitch angle PA21 is not limited to this embodiment and the above range.

The second inner pitch angle PA22 is in the range of 5 degrees to 36 degrees. In this embodiment, the second inner pitch angle PA22 is 24 degrees. However, the second inner pitch angle PA22 is not limited to this embodiment and the above range.

At least one of the at least ten inner spline teeth 64 of the second sprocket SP3 has a first spline shape that is different from the other second spline shapes of the at least ten inner spline teeth 64 . At least one of the at least ten inner spline teeth 64 of the second sprocket SP3 has a first spline size that is different than the other second spline sizes of the at least ten inner spline teeth 64 . At least one of the at least ten internal spline teeth 64 has a cross-sectional shape that is different from other cross-sectional shapes of the at least ten internal spline teeth 64 . However, as shown in FIG. 34, the inner spline teeth 64 may have the same shape as each other. At least ten inner spline teeth 64 may have the same size as each other. At least ten inner spline teeth 64 may have the same cross-sectional shape as each other.

At least one of the at least ten internal spline teeth 64 includes an internal spline drive surface 66, as shown in FIG. At least one of the at least ten inner spline teeth 64 includes an inner spline non-drive surface 68 . The at least ten inner spline teeth 64 include a plurality of inner spline drive surfaces 66 for receiving rotational driving force F1 from the rear bicycle hub assembly 12 (FIG. 6) during pedaling. At least ten inner spline teeth 64 include a plurality of inner spline non-driving surfaces 68 . The inner splined drive surface 66 is contactable with the sprocket support 28 to transmit drive rotational force F1 from the sprocket SP1 to the sprocket support 28 during pedaling. The inner spline drive surface 66 faces the drive rotation direction D11. The inner splined drive surface 66 faces the outer splined drive surface 48 of the rear bicycle hub assembly 12 when the rear bicycle sprocket assembly 14 is mounted on the rear bicycle hub assembly 12 . The inner spline non-drive surface 68 is provided opposite the inner spline drive surface 66 in the circumferential direction D1. The inner splined non-drive surface 68 is oriented in the counter-rotational direction D12 so as not to transmit the driving torque F1 from the sprocket SP1 to the sprocket support 28 during pedaling. The inner splined non-drive surface 68 faces the outer splined non-drive surface 50 of the rear bicycle hub assembly 12 when the rear bicycle sprocket assembly 14 is mounted on the rear bicycle hub assembly 12 .

Each of the at least ten inner spline teeth 64 has a maximum circumferential width MW2. Each of the plurality of inner spline teeth 64 has a maximum circumferential width MW2. A maximum circumferential width MW2 is defined as the maximum width to receive the thrust force F3 applied to the inner spline teeth 64 . A maximum circumferential width MW2 is defined as a linear distance based on the inner splined drive surface 66. As shown in FIG.

Each of the plurality of inner spline drive surfaces 66 includes a radially outermost peripheral edge 66A and a radially innermost peripheral edge 66B. A second reference circle RC21 is defined on the radial outermost edge 66A and centered on the rotation center axis A1. A second reference circle RC21 intersects the inner splined non-drive surface 68 and has a reference point 68R. Circumferential maximum width MW2 extends straight from radial innermost edge 66B to reference point 68R in circumferential direction D1.

The inner splined non-drive surface 68 includes a radially outermost peripheral edge 68A and a radially innermost peripheral edge 68B. The inner splined non-drive surface 68 extends from the radially outermost peripheral edge 68A to the radially innermost peripheral edge 68B. The reference point 68R is provided between the radially outermost peripheral edge 68A and the radially innermost peripheral edge 68B.

The total circumferential maximum width MW2 is 40 mm or more. The total circumferential maximum width MW2 may be 45 mm or more. The total circumferential maximum width MW2 may be 50 mm or more. In this embodiment, the total circumferential maximum width MW2 is 50.8 mm. However, the total circumferential maximum width MW2 is not limited to this embodiment.

As shown in FIG. 36, at least ten inner spline teeth 64 of the second sprocket SP3 have an inner spline root diameter DM21. At least one inner spline tooth 64 of sprocket SP3 has an inner spline root circle RC22 with an inner spline root diameter DM21. The inner spline root diameter DM21 is 34 mm or less. The inner spline root diameter DM21 of the second sprocket SP3 is 33 mm or less. The inner spline root diameter DM21 of the second sprocket SP3 is 29 mm or more. In this embodiment, the inner spline root diameter DM21 of the second sprocket SP3 is 32.8 mm. However, the inner spline root diameter DM21 of the second sprocket SP3 is not limited to this embodiment and the above range.

At least ten inner spline teeth 64 of the second sprocket SP3 have an inner spline thread diameter DM22 that is less than or equal to 32 mm. The inner spline crest diameter DM22 is 31 mm or less. The inner spline crest diameter DM22 is 28 mm or more. In this embodiment, the inner spline thread diameter DM22 is 30.4 mm. However, the inner spline thread diameter DM22 is not limited to the present embodiment and the above range.

As shown in FIG. 18, additional sprocket SP12 has a maximum tip diameter TD12. A maximum tip diameter TD12 is the maximum outer diameter defined by a plurality of sprocket teeth SP12B. The ratio of the inner spline root diameter DM21 (Fig. 36) to the maximum tooth tip diameter TD12 is in the range of 0.15-0.18. In this embodiment, the ratio of the inner spline root diameter TD12 to the maximum tooth tip diameter TD21 is 0.15. However, the ratio of the inner spline root diameter DM21 to the maximum tooth tip diameter TD12 is not limited to this embodiment and the above range.

As shown in FIG. 35, the plurality of inner splined drive surfaces 66 includes a radially outermost peripheral edge 66A and a radially innermost peripheral edge 66B. Each of the plurality of inner spline drive surfaces 66 includes a radial length RL21 defined from the radially outermost peripheral edge 66A to the radially innermost peripheral edge 66B. The total radial length RL21 of the plurality of inner spline drive surfaces 66 is 7 mm or more. The total radial length RL21 is 10 mm or more. The total radial length RL21 is 15 mm or more. The total radial length RL21 is 36 mm or less. In this embodiment, the total radial length RL21 is 16.6 mm. However, the total radial length RL21 is not limited to the present embodiment and the above range.

The plurality of inner spline teeth 64 have an additional radial length RL22. Each additional radial length RL22 is defined from the inner spline root circle RC22 of the plurality of inner spline teeth 64 to the radially innermost peripheral edge 64A. The total additional radial length RL22 is 12 mm or more. In this embodiment, the total additional radial length RL22 is 34.8 mm. However, the total additional radial length RL22 is not limited to this embodiment and the above range.

At least one of the at least ten inner spline teeth 64 of second sprocket SP3 is circumferentially symmetrical with respect to reference line CL2. The reference line CL2 extends from the rotation center axis A1 to the circumferential center point CP2 of at least one radially innermost peripheral end portion 64A of the at least ten inner spline teeth 64 in the radial direction with respect to the rotation center axis A1. extends to However, at least one of the plurality of inner spline teeth 64 may have an asymmetric shape with respect to the reference line CL2. At least one of the inner spline teeth 64 has an inner spline drive surface 66 and an inner spline non-drive surface 68 .

The inner spline drive surface 66 has a first inner spline surface angle AG21. A first inner spline surface angle AG21 is defined between the inner spline drive surface 66 and the first radial line L21. The first radial line L21 extends from the rotation center axis A1 of the bicycle rear sprocket assembly 14 to the radially outermost peripheral edge 66A of the inner spline drive surface 66. As shown in FIG. A first inner pitch angle PA21 or a second inner pitch angle PA22 is defined between adjacent first radial lines L21 (see, eg, FIG. 33).

The inner spline non-drive surface 68 has a second inner spline surface angle AG22. A second inner spline surface angle AG22 is defined between the inner spline non-drive surface 68 and the second radial line L22. The second radial line L22 extends from the rotation center axis A1 of the bicycle rear sprocket assembly 14 to the radially outermost edge 68A of the inner spline non-driving surface 68. As shown in FIG.

In this embodiment, the second inner spline surface angle AG22 is equal to the first inner spline surface angle AG21. However, the first inner spline face angle AG21 may be different from the second inner spline face angle AG22.

The first inner spline face angle AG21 is in the range of 0 degrees to 6 degrees. The second inner spline face angle AG22 is in the range of 0 degrees to 6 degrees. In this embodiment, the first inner spline surface angle AG21 is 5 degrees. The second inner spline surface angle AG22 is 5 degrees. However, the first inner spline surface angle AG21 and the second inner spline surface angle AG22 are not limited to the present embodiment and the ranges described above.

As shown in FIG. 37, the plurality of inner spline teeth 64 mesh with the plurality of outer spline teeth 40 to transmit the driving rotational force F1 from the second sprocket SP3 to the sprocket support 28. As shown in FIG. The inner splined drive surface 66 is contactable with the outer splined drive surface 48 to transmit the driving rotational force F1 from the second sprocket SP3 to the sprocket support 28. The inner splined non-drive surface 68 is spaced apart from the outer splined non-drive surface 50 with the inner splined drive surface 66 in contact with the outer splined drive surface 48 .

The plurality of inner spline teeth 63 of the first sprocket SP2 and the plurality of inner spline teeth 65 of the second sprocket SP4 have substantially the same mechanism as the plurality of inner spline teeth 64 of the second sprocket SP3. Therefore, for the sake of brevity, detailed description is omitted here.

As shown in FIG. 2 , sprocket support member 37 includes at least ten internal spline teeth 76 configured to engage sprocket support 28 of bicycle rear hub assembly 12 . The plurality of inner spline teeth 76 have substantially the same mechanism as the plurality of inner spline teeth 64 . Therefore, for the sake of brevity, detailed description is omitted here.

As shown in FIG. 38, first sprocket SP1 includes a first torque transmission structure SP1T provided on first inner side surface SP1H to directly or indirectly transmit pedaling torque to sprocket support 28. As shown in FIG. In this embodiment, the first torque transmission structure SP1T includes a plurality of first torque transmission teeth SP1T1 to indirectly transmit pedaling torque to the sprocket support 28 . The first torque transmission structure SP1T includes at least ten first torque transmission teeth SP1T1. Preferably, the total number of at least ten first torque transmission teeth SP1T1 is 20 or more. More preferably, the total number of at least ten first torque transmission teeth SP1T1 is 28 or more. In this embodiment, the total number of at least ten first torque transmission teeth SP1T1 is twenty-nine. However, the total number of at least ten first torque transmission teeth SP1T1 is not limited to this embodiment and the above range.

As shown in Figures 38 and 39, the first sprocket SP2 includes a first inner side surface SP2H and a first outer side surface SP2G. The first outer side surface SP2G is arranged on the opposite side of the first inner side surface SP2H in the axial direction D2 relative to the rotation center axis A1 of the bicycle rear sprocket assembly 14 . The first sprocket SP2 includes a first torque transmission structure SP2M provided on the first inner side surface SP2H to directly or indirectly transmit the pedaling torque to the sprocket support 28 . In this embodiment, the inner spline tooth 63 of the first sprocket SP2 can also be referred to as the first torque transmission tooth 63. First torque transmission structure SP2M includes a plurality of first torque transmission teeth 63 to directly transmit pedaling torque to sprocket support 28 . The first torque transmission structure SP2M includes at least ten first torque transmission teeth 63 . Preferably, the total number of at least ten first torque transmission teeth 63 is twenty or more. More preferably, the total number of at least ten first torque transmission teeth 63 is 28 or more. In this embodiment, the total number of at least ten first torque transmission teeth 63 is twenty-nine. However, the total number of at least ten first torque transmission teeth 63 is not limited to the above embodiment and range. First torque transmission tooth 63 may also be referred to as internal spline tooth 63 .

As shown in FIG. 39, first sprocket SP2 includes a second torque transmission structure SP2T to receive pedaling torque from first sprocket SP1. The second torque transmission structure SP2T is provided on the first outer side surface SP2G. In this embodiment, the second torque transmission structure SP2T includes a plurality of second torque transmission teeth SP2T1. Preferably, the total number of second torque transmission teeth SP2T1 is 20 or more. More preferably, the total number of second torque transmission teeth SP2T1 is 28 or more. In this embodiment, the total number of second torque transmission teeth SP2T1 is twenty-nine. However, the total number of second torque transmission teeth SP2T1 is not limited to this embodiment and the above range. The first torque transmission structure SP1T is engaged with the second torque transmission structure SP2T. The plurality of first torque transmission teeth SP1T1 mesh with the plurality of second torque transmission teeth SP2T1 so as to transmit the driving torque F1.

As shown in FIGS. 23 and 24, the sprocket support 28 includes a hub indicator 28I provided at the axial end of the base support 41. As shown in FIGS. The hub display portion 28I is provided in the region of the second outer pitch angle PA12 when viewed along the rotation center axis A1. In this embodiment, the hub indicator 28I includes dots. However, hub indicator 28I may include other shapes such as triangles and lines. Additionally, hub display 28I may be a separate member that is attached to sprocket support 28 by a bonding mechanism, such as an adhesive. The position of the hub display portion 28I is not limited to this embodiment.

As shown in FIG. 7, the first sprocket SP1 includes a sprocket indicator SP1I provided at the axial end of the sprocket body SP1A. In this embodiment, the sprocket indicator SP1I includes dots. However, the sprocket indicator SP1I may include other shapes such as triangles and lines. Further, sprocket indicator SP1I may be a separate member attached to sprocket SP1 by a coupling mechanism, such as an adhesive. The position of the sprocket display part SP1I is not limited to this embodiment. The sprocket display portion SP1I may be provided on any one of the other sprockets SP2 to SP12. The sprocket indicator SP1I may also be provided on the sprocket support member 37 .

As shown in FIG. 6 , the bicycle rear hub assembly 12 further includes a freewheel mechanism 78 . Sprocket support 28 is operatively connected to hub body 36 by a freewheel mechanism 78 . The freewheel mechanism 78 is configured to couple the sprocket support 28 to the hub body 36 to rotate the sprocket support 28 with the hub body 36 in the drive rotation direction D11 (FIG. 5) during pedaling. The freewheel mechanism 78 is configured to allow the sprocket support 28 to rotate relative to the hub body 36 in the reverse rotational direction D12 (FIG. 5) during coasting. Therefore, the freewheel mechanism 78 may be rephrased as a one-way clutch mechanism 78. The freewheel mechanism 78 will be detailed later.

Bicycle rear hub assembly 12 includes a first bearing 79A and a second bearing 79B. A first bearing 79A and a second bearing 79B are provided between the sprocket support 28 and the hub axle 30 so as to rotatably support the sprocket support 28 with respect to the hub axle 30 about the rotation center axis A1.

In this embodiment, each of sprocket support 28, brake rotor support 34, and hub body 36 are constructed from a metallic material such as aluminum, iron, or titanium. However, at least one of sprocket support 28, brake rotor support 34, and hub body 36 may be constructed from non-metallic materials.

As shown in FIG. 40, freewheel mechanism 78 includes first ratchet member 80 and second ratchet member 82 . First ratchet member 80 is configured to engage one of hub body 36 and sprocket support 28 in a torque transmitting manner. Second ratchet member 82 is configured to engage the other of hub body 36 and sprocket support 28 in a torque transmitting manner. In this embodiment, the first ratchet member 80 engages the sprocket support 28 in a torque transmitting manner. The second ratchet member 82 engages the hub body 36 on the torque transmitting side. However, first ratchet member 80 may be configured to engage hub body 36 in a torque transmitting manner. The second ratchet member 82 may be configured to engage the sprocket support 28 in a torque transmitting manner.

The first ratchet member 80 is attached to the sprocket support 28 so as to rotate together with the sprocket support 28 relative to the hub body 36 about the rotation center axis A1. The second ratchet member 82 is attached to the hub body 36 so as to rotate together with the hub body 36 with respect to the sprocket support 28 about the rotation center axis A1. Each of the first ratchet member 80 and the second ratchet member 82 has an annular shape.

At least one of the first ratchet member 80 and the second ratchet member 82 is movable relative to the hub axle 30 in an axial direction D2 about the rotation center axis A1. In this embodiment, each of the first ratchet member 80 and the second ratchet member 82 is movable relative to the hub axle 30 in the axial direction D2. The second ratchet member 82 is movable with respect to the hub body 36 in the axial direction D2. The first ratchet member 80 is movable relative to the sprocket support 28 in the axial direction D2.

The hub body 36 includes a freewheel housing 36H having an annular shape. The freewheel housing 36H extends in the axial direction D2. The first ratchet member 80 and the second ratchet member 82 are provided in the freewheel housing 36H in an assembled state.

As shown in FIG. 41, first ratchet member 80 includes at least one first ratchet tooth 80A. In this embodiment, the at least one first ratchet tooth 80A includes a plurality of first ratchet teeth 80A. The plurality of first ratchet teeth 80A are arranged in the circumferential direction D1 to provide a serration.

As shown in FIG. 42, second ratchet member 82 includes at least one second ratchet tooth 82A configured to engage at least one first ratchet tooth 80A in a torque transmitting manner. At least one second ratchet tooth 82A engages at least one first ratchet tooth 80A to transmit rotational force F1 from sprocket support 28 to hub body 36 (Fig. 40). In this embodiment, the at least one second ratchet tooth 82A includes a plurality of second ratchet teeth 82A configured to engage the plurality of first ratchet teeth 80A in a torque transmitting manner. A plurality of second ratchet teeth 82A are arranged in the circumferential direction D1 to provide serrations. The plurality of second ratchet teeth 82A are engageable with the plurality of first ratchet teeth 80A. The first ratchet member 80 and the second ratchet member 82 rotate together with the plurality of second ratchet teeth 82A engaging the plurality of first ratchet teeth 80A.

As shown in Figures 41 and 42, the sprocket support 28 has an outer peripheral surface 28P with first helical splines 28H. The first ratchet member 80 is configured to engage the sprocket support 28 in a torque transmitting manner and includes a second helical spline 80H that meshes with the first helical spline 28H. The first ratchet member 80 moves in the axial direction D2 relative to the sprocket support 28 via a second helical spline 80H that meshes with the first helical spline 28H during actuation by a first thrust force applied from the sprocket support 28. possible to be installed. In this embodiment, first helical spline 28H includes a plurality of outer helical spline teeth 46 . The second helical spline 80H includes multiple inner helical spline teeth 80H1 that mesh with the multiple outer helical spline teeth 46 .

As shown in FIG. 43, the hub body 36 includes an inner peripheral surface 36S and at least one first tooth 36T. At least one first tooth 36T is provided on the inner peripheral surface 36S. In this embodiment, the freewheel housing 36H includes an inner peripheral surface 36S. The hub body 36 includes a plurality of first teeth 36T. A plurality of first teeth 36T are provided on the inner peripheral surface 36S and extend radially inward from the inner peripheral surface 36S with respect to the rotation center axis A1. The plurality of first teeth 36T are arranged in the circumferential direction D1 to define a plurality of recesses 36R between two adjacent teeth of the plurality of first teeth 36T.

The second ratchet member 82 engages with the hub body 36 in a torque transmitting manner so as to transmit the rotational force F1 from the first ratchet member 80 to the hub body 36 via the hub body engaging portion 82E. Includes junction 82E. One of hub body engaging portion 82E and hub body 36 includes at least one radially extending protrusion. The other of hub body engaging portion 82E and hub body 36 includes at least one recess that is engaged with at least one projection. In this embodiment, the hub body engaging portion 82E includes at least one radially extending protrusion 82T. Hub body 36 includes at least one recess 36R engaged with at least one projection 82T. In this embodiment, the hub body engaging portion 82E includes a plurality of protrusions 82T. The plurality of protrusions 82T are engaged with the plurality of recesses 36R.

As shown in FIG. 42, the outer peripheral surface 28P of the sprocket support 28 has a guide portion 28G configured to guide the first ratchet member 80 toward the hub body 36 during coasting. The guide portion 28G is arranged to define an obtuse angle AG28 (FIG. 48) with the first helical spline 28H. Sprocket support 28 includes a plurality of guide portions 28G. Guide portion 28G is configured to guide first ratchet member 80 toward hub body 36 during coasting or freewheeling. Guide portion 28G extends toward hub body 36 to release meshing engagement with at least one first ratchet tooth 80A (FIG. 41) and at least one second ratchet tooth 82A during coasting. guides the ratchet member 80; The guide portion 28G is configured to move the first ratchet member 80 away from the second ratchet member 82 in the axial direction D2. The guide portion 28G extends at least in the circumferential direction D1 with respect to the sprocket support 28. As shown in FIG. The guide portion 28G extends from one tooth of the plurality of outer helical spline teeth 46 at least in the circumferential direction D1. Although the guide portion 28G is provided integrally with the outer helical spline teeth 46 as one single member in this embodiment, the guide portion 28G may be a separate member from the plurality of outer helical spline teeth 46. First ratchet member 80 and second ratchet member 82 are offset from each other during coasting due to guide portion 28G, particularly when guide portion 28G is arranged to define an obtuse angle AG28 with respect to first helical spline 28H. Disengages smoothly. This also reduces noise during coasting because the at least one first ratchet tooth 80A and the at least one second ratchet tooth 82A are smoothly separated during coasting.

As shown in FIG. 40, the bicycle rear hub assembly 12 further comprises a biasing member 84. As shown in FIG. A biasing member 84 is disposed between the hub body 36 and the first ratchet member 80 to bias the first ratchet member 80 in the axial direction D2 toward the second ratchet member 82 . In this embodiment, for example, biasing member 84 is a compression spring.

As shown in FIG. 44, biasing member 84 is compressed between hub body 36 and first ratchet member 80 in axial direction D2. The biasing member 84 maintains the engaged state in which the first ratchet member 80 and the second ratchet member 82 are engaged with each other via the plurality of first ratchet teeth 80A and the plurality of second ratchet teeth 82A. 2 biasing the first ratchet member 80 toward the ratchet member 82;

Preferably, biasing member 84 is engaged with hub body 36 for rotation therewith. The biasing member 84 is attached to the hub body 36 so as to rotate together with the hub body 36 about the rotation center axis A1 (FIG. 40). Biasing member 84 includes a coiled body 84A and a connecting end 84B. The hub body 36 includes a connection hole 36F. The connecting end portion 84B is provided in the connecting hole 36F so that the biasing member 84 rotates together with the hub body 36 around the rotation center axis A1 (FIG. 40).

As shown in FIG. 44, the outer peripheral surface 28P of the sprocket support 28 supports the first ratchet member 80 and the second ratchet member 82. As shown in FIG. The first ratchet member 80 includes an axial surface 80S facing in the axial direction D2. At least one first ratchet tooth 80A is disposed on the axial surface 80S of the first ratchet member 80. As shown in FIG. In this embodiment, the plurality of first ratchet teeth 80A are arranged on the axial surface 80S of the first ratchet member 80. As shown in FIG. The axial surface 80S is substantially perpendicular to the axial direction D2. However, the axial surface 80S may be non-perpendicular to the axial direction D2.

The second ratchet member 82 includes an axial surface 82S facing in the axial direction D2. At least one second ratchet tooth 82A is disposed on the axial surface 82S of the second ratchet member 82. As shown in FIG. The axial surface 82S of the second ratchet member 82 faces the axial surface 80S of the first ratchet member 80. As shown in FIG. In this embodiment, the plurality of second ratchet teeth 82A are arranged on the axial surface 82S of the second ratchet member 82 . The axial surface 82S is substantially perpendicular to the axial direction D2. However, the axial surface 82S may be non-perpendicular to the axial direction D2.

As shown in FIG. 40, the bicycle rear hub assembly 12 includes a spacer 86, a support member 88, a slide member 90, an additional biasing member 92, and a receiving member 94. As shown in FIG. However, at least one of spacer 86 , support member 88 , slide member 90 , additional biasing member 92 and receiving member 94 may be omitted from bicycle rear hub assembly 12 .

As shown in FIGS. 44 and 45, the spacer 86 is at least partially between the at least one first tooth 36T and the at least one protrusion 82T in the circumferential direction D1 defined about the rotation center axis A1. be provided. In this embodiment, the spacers 86 are partially provided between the multiple first teeth 36T and the multiple projections 82T in the circumferential direction D1. However, the spacers 86 may be provided entirely between the multiple first teeth 36T and the multiple projections 82T in the circumferential direction D1.

As shown in FIGS. 45-47, spacer 86 includes at least one intermediate portion 86A provided between at least one first tooth 36T and at least one projection 82T. At least one intermediate portion 86A is provided between at least one first tooth 36T and at least one projection 82T in the circumferential direction D1. In this embodiment, the spacer 86 includes a plurality of intermediate portions 86A respectively provided between the plurality of first teeth 36T and the plurality of projections 82T in the circumferential direction D1. Although spacer 86 includes multiple intermediate portions 86A in this embodiment, spacer 86 may include one intermediate portion 86A.

As shown in FIGS. 46 and 47, spacer 86 includes connecting portion 86B. A plurality of intermediate portions 86A extend from the connecting portion 86B in an axial direction D2 parallel to the rotation center axis A1. The spacer 86 includes a connecting portion 86B in this embodiment, but the connecting portion 86B may be omitted from the spacer 86. FIG.

Spacer 86 comprises a non-metallic material. In this embodiment, the non-metallic material includes a resin material. Examples of resin materials include synthetic resins. The non-metallic material may contain a material other than the resin material instead of or in addition to the resin material. Although intermediate section 86A and connecting section 86B are provided integrally with each other as one unitary member in this embodiment, at least one of intermediate sections 86A may be a separate part from connecting section 86B. .

As shown in FIGS. 44 and 45, the plurality of intermediate portions 86A are provided between the inner peripheral surface 36S of the hub body 36 and the outer peripheral surface 82P of the second ratchet member 82 in the radial direction.

As shown in FIG. 44, the support member 88 is provided between the hub body 36 and the second ratchet member 82 in the axial direction D2. A support member 88 is attached to the second ratchet member 82 . The support member 88 is provided radially outside the first ratchet member 80 . A support member 88 is contactable with the first ratchet member 80 . Support member 88 preferably comprises a non-metallic material. The support member 88 constructed of non-metallic material reduces noise during operation of the bicycle rear hub assembly 12 . In this embodiment, the non-metallic material includes a resin material. The non-metallic material may contain a material other than the resin material instead of or in addition to the resin material.

The sliding member 90 is provided between the sprocket support 28 and the second ratchet member 82 in an axial direction D2 parallel to the rotation center axis A1. The second ratchet member 82 is provided between the first ratchet member 80 and the sliding member 90 in the axial direction D2. Sliding member 90 preferably comprises a non-metallic material. The sliding member 90 constructed of non-metallic material reduces noise during operation of the bicycle rear hub assembly 12 . In this embodiment, the non-metallic material includes a resin material. The non-metallic material may contain a material other than the resin material instead of or in addition to the resin material.

Sprocket support 28 includes a contact portion 28E for contacting second ratchet member 82 to limit axial movement of second ratchet member 82 away from hub body 36 . The contact portion 28E can indirectly contact the second ratchet member 82 via the sliding member 90 in this embodiment. Alternatively, the contact portion 28E may contact the second ratchet member 82 directly. The first ratchet member 80 is arranged on the side opposite to the contact portion 28E of the sprocket support 28 in the axial direction D2 with respect to the second ratchet member 82 . The sliding member 90 is provided between the contact portion 28E of the sprocket support 28 and the second ratchet member 82 in the axial direction D2.

44, an additional biasing member 92 is provided between the hub body 36 and the second ratchet member 82 in the axial direction D2 to bias the second ratchet member 82 toward the sprocket support 28. be done. In this embodiment, the additional biasing member 92 biases the second ratchet member 82 in the axial direction D2 via the support member 88 . The additional biasing member 92 is provided radially outside the biasing member 84 . The additional biasing member 92 is provided radially outside the plurality of second ratchet teeth 82A in this embodiment.

The receiving member 94 includes a non-metallic material. Constructed from a non-metallic material, the receiving member 94 prevents excessive twisting of the biasing member 84 during operation of the rear bicycle hub assembly 12 . In this embodiment, the non-metallic material includes a resin material. The non-metallic material may contain a material other than the resin material instead of or in addition to the resin material. The receiving member 94 includes an axial receiving surface 96 and a radial receiving surface 98 . The axial receiving surface 96 is provided between the first ratchet member 80 and the biasing member 84 in the axial direction D2. The radial receiving surface 98 extends from the axial receiving surface 96 in the axial direction D2. The radial receiving surface 98 is provided radially inward of the biasing member 84 . Axial bearing surface 96 and radial bearing surface 98 are provided integrally with each other as one unitary member. However, the axial receiving surface 96 may be a separate member from the radial receiving surface 98 .

As shown in FIG. 44, the bicycle rear hub assembly 12 includes a seal structure 100. As shown in FIG. A seal structure 100 is provided between the sprocket support 28 and the hub body 36 . Hub body 36 includes an interior space 102 . Each of sprocket support 28 , biasing member 84 , first ratchet member 80 , and second ratchet member 82 are disposed at least partially within interior space 102 of hub body 36 . The internal space 102 is sealed by the sealing structure 100 . Although no lubricant is provided within the interior space 102 in this embodiment, the bicycle rear hub assembly 12 may have lubricant provided within the interior space 102 . Compared to the case where the bicycle rear hub assembly 12 has a lubricant provided within the interior space 102, if no lubricant is provided, the gaps between the members disposed within the interior space 102 are reduced. can.

The operation of the bicycle rear hub assembly 12 is described in detail below with reference to FIGS. 44, 48 and 49. FIG.

As shown in FIG. 44, the axial direction D2 includes a first axial direction D21 and a second axial direction D22 opposite to the first axial direction D21. A biasing force F5 is applied from the biasing member 84 to the receiving member 94 in the first axial direction D21. The biasing force F5 of the biasing member 84 biases the receiving member 94, the first ratchet member 80, the second ratchet member 82, and the sliding member 90 toward the sprocket support 28 in the first axial direction D21. This results in engagement of the plurality of first ratchet teeth 80A with the plurality of second ratchet teeth 82A.

Furthermore, as shown in FIG. 48, when the pedaling torque T1 is input to the sprocket support 28 in the drive rotation direction D11, the plurality of inner helical spline teeth 80H1 rotate relative to the sprocket support 28 in the first axial direction D21. are guided by a plurality of outer helical spline teeth 46. This provides a strong engagement of the plurality of first ratchet teeth 80A with the plurality of second ratchet teeth 82A. In this state, the pedaling torque T1 is transmitted from the sprocket support 28 to the hub body 36 (FIG. 44) via the first ratchet member 80 and the second ratchet member 82 (FIG. 44).

As shown in FIG. 48, the first ratchet member 80 is engaged from the second ratchet member 82 by the rotational friction force F6 generated between the biasing member 84 (FIG. 44) and the first ratchet member 80 during coasting. It contacts the guide portion 28G so as to release the mating. As shown in FIG. 49, the inertia torque T2 acts on the hub body 36 in the drive rotation direction D11 during coasting. Inertia torque T2 is transmitted from hub body 36 (FIG. 44) to first ratchet member 80 via second ratchet member 82 (FIG. 44). At this time, the inner helical spline teeth 80H1 are guided by the outer helical spline teeth 46 with respect to the sprocket support 28 in the second axial direction D22. This causes the first ratchet member 80 to move relative to the sprocket support 28 in the second axial direction D22 against the biasing force F5. Therefore, the first ratchet member 80 moves away from the second ratchet member 82 in the second axial direction D22, and the engagement between the plurality of first ratchet teeth 80A and the plurality of second ratchet teeth 82A is weakened. Become. This allows the second ratchet member 82 to rotate relative to the first ratchet member 80 in the drive rotation direction D11, and the inertia torque T2 is applied to the hub body 36 via the first ratchet member 80 and the second ratchet member 82. to the sprocket support 28. At this time, the multiple first ratchet teeth 80A slide with the multiple second ratchet teeth 82A in the circumferential direction D1.

Modification As shown in FIG. 50, in the above embodiment and other modifications, the outer spline tooth 40 has a groove 40G provided between the outer spline driving surface 48 and the outer spline non-driving surface 50 in the circumferential direction D1. may contain. The groove 40G reduces the weight of the bicycle rear hub assembly 12. As shown in FIG.

As shown in FIG. 51, in the above embodiment and other variations, the inner spline tooth 64 includes a groove 64G provided between the inner spline driving surface 66 and the inner spline non-driving surface 68 in the circumferential direction D1. You can The grooves 64G reduce the weight of the bicycle rear sprocket assembly 14.

In this application, in the above embodiments, at least 10 internal spline teeth are provided directly on the second opening of each of the second sprockets SP3 and SP4, but at least 10 internal spline teeth are provided directly on the second opening of the second sprockets SP3 and SP4. It may be provided indirectly in the two openings. For example, instead of providing at least ten internal spline teeth directly on the second opening of the second sprocket SP3 and/or the second sprocket SP4, at least one of the second sprockets SP3 and SP4 has at least ten internal spline teeth. It may be attached to a sprocket support member having teeth. Alternatively, instead of providing the at least ten internal spline teeth directly in the second opening of the second sprocket, the at least one second sprocket includes, as one single member, at least one internal spline tooth including at least ten internal spline teeth. It may be integrally formed with the additional sprocket. Since such a second sprocket indirectly includes at least ten internal spline teeth via a sprocket support member and/or an additional sprocket, it also serves as a sprocket support for a bicycle rear hub assembly. It is meant to include at least ten internal spline teeth configured to engage.

Although the bicycle rear sprocket assembly 14 includes two first sprockets SP1 and SP2 in the above embodiment, the bicycle rear sprocket assembly 14 includes only one first sprocket or more than two first sprockets. May include sprockets.

Although the bicycle rear sprocket assembly 14 includes two second sprockets SP3 and SP4 in the above embodiment, the bicycle rear sprocket assembly 14 may include only one second sprocket or two second sprockets. may include more second sprockets.

As shown in FIG. 52, the total number of at least ten external spline teeth 40 on the sprocket support 28 may be in the range of twenty-two to twenty-four. For example, the total number of at least ten external spline teeth 40 may be twenty-three. The first outer pitch angle PA11 may be in the range of 13 degrees to 17 degrees. For example, the first outer pitch angle PA11 may be 15 degrees. The second outer pitch angle PA12 may be in the range of 28 degrees to 32 degrees. For example, the second outer pitch angle PA12 may be 30 degrees. The first outer pitch angle PA11 is half the second outer pitch angle PA12. However, the first outer pitch angle PA11 may differ from half the second outer pitch angle PA12. The total number of at least ten external spline teeth 40 is not limited to the above variations and ranges. The first outer pitch angle PA11 is not limited to the above modifications and range. The second outer pitch angle PA12 is not limited to the above modifications and range.

As shown in FIG. 53, in the sprocket support 28, the total radial length RL11 of the plurality of outer spline drive surfaces 48 may be within the range of 11 mm to 14 mm. The total radial length RL11 of the plurality of outer spline drive surfaces 48 may be 12.5 mm. The total additional radial length RL12 may be in the range of 26 mm to 30 mm. For example, the total additional radial length RL12 may be 28.2 mm. However, the total additional radial length RL12 is not limited to the above variations and ranges.

As shown in FIG. 54, in the first torque transmission structure SP1T of the first sprocket SP1, the total number of at least ten first torque transmission teeth SP1T1 may be in the range of 22-24. For example, the total number of at least ten first torque transmission teeth SP1T1 may be twenty-three. However, the total number of at least ten first torque transmission teeth SP1T1 is not limited to the above modifications and ranges.

As shown in FIG. 55, in the second torque transmission structure SP2T of the first sprocket SP2, the total number of at least ten second torque transmission teeth SP2T1 may be in the range of 22-24. For example, the total number of at least ten second torque transmission teeth SP2T1 may be twenty-three. However, the total number of at least ten second torque transmission teeth SP2T1 is not limited to the above variations and ranges.

As shown in FIG. 56, in the first sprocket SP2, the total number of at least ten internal spline teeth 63 of the first sprocket SP2 may be in the range of 22-24. For example, the total number of at least ten internal spline teeth 63 of the first sprocket SP2 may be twenty-three. However, the total number of at least ten internal spline teeth 63 is not limited to the above variations and ranges.

As shown in FIG. 57, in the second sprocket SP3, the total number of at least ten internal spline teeth 64 of the second sprocket SP3 may be in the range of twenty-two to twenty-four. For example, the total number of at least ten internal spline teeth 64 of the second sprocket SP3 may be twenty-three. However, the total number of at least ten inner spline teeth 64 is not limited to the above variations and ranges.

As shown in FIG. 58, in the second sprocket SP4, the total number of at least ten internal spline teeth 65 of the second sprocket SP4 may be in the range of 22-24. For example, the total number of at least ten internal spline teeth 65 of the second sprocket SP4 may be twenty-three. However, the total number of at least ten internal spline teeth 65 is not limited to the above variations and ranges.

As shown in FIG. 59, for at least ten inner spline teeth 64 of the second sprocket SP3, the first inner pitch angle PA21 may be in the range of 13 degrees to 17 degrees. For example, the first inner pitch angle PA21 may be 15 degrees. The second inner pitch angle PA22 may be in the range of 28 degrees to 32 degrees. For example, the second inner pitch angle PA22 may be 30 degrees. The first inner pitch angle PA21 may be half the second inner pitch angle PA22. However, the first inner pitch angle PA21 may differ from half the second inner pitch angle PA22. The first inner pitch angle PA21 is not limited to the above modifications and range. The second inner pitch angle PA22 is not limited to the above modification and range.

As shown in FIG. 60, in the plurality of inner spline teeth 64 of the second sprocket SP3, the total radial length RL21 of the plurality of inner spline drive surfaces 66 may be within the range of 11 mm to 14 mm. For example, the total number of radial lengths RL21 of the multiple inner spline drive surfaces 66 may be 12.5 mm. However, the total radial length RL21 is not limited to the above modifications and range. The total additional radial length RL22 may be in the range of 26mm to 29mm. For example, the total additional radial length RL22 is 27.6 mm. However, the total additional radial length RL22 is not limited to this embodiment and the above range. The inner spline teeth 63 of the first sprocket SP2 and the inner spline teeth 65 of the second sprocket SP4 have the same mechanism as the inner spline teeth 64 of the second sprocket SP3.

As shown in FIG. 61, the inner spline teeth 76 of the sprocket support member 37 may have the same features as those of the inner spline teeth 64 of the second sprocket SP3 shown in FIGS. The total number of at least ten internal spline teeth 76 of sprocket support member 37 may be in the range of twenty-two to twenty-four. For example, the total number of at least ten internal spline teeth 76 of sprocket support member 37 may be twenty-three. However, the total number of at least ten inner spline teeth 76 is not limited to the above variations and ranges. The multiple internal spline teeth 64 arrangement shown in FIG. 60 is applicable to the multiple internal spline teeth 76 of the sprocket support member 37 .

As shown in FIG. 62, the bicycle rear sprocket assembly 14 may include an additional sprocket SP13. The additional sprocket SP13 is connected to the additional sprocket SP12 by a plurality of connecting members SP13R. Additional sprocket SP13 includes a sprocket body SP13A and at least one sprocket tooth SP13B. The sprocket body SP13A of the additional sprocket SP13 is connected to the sprocket body SP12A of the additional sprocket SP12 by a plurality of connecting members SP13R. At least one sprocket tooth SP13B extends radially outward from sprocket SP13A. The total number of at least one sprocket tooth SP13B is greater than the total number of at least one sprocket tooth SP12B. Preferably, the total number of teeth of at least one sprocket tooth SP13B is 46 or more. More preferably, the total number of teeth of at least one sprocket tooth SP13B is 50 or more. For example, the total number of teeth of at least one sprocket tooth SP13B is 54.

The tooth profiles of the sprocket teeth SP1B-SP13B of the sprockets SP1-SP13 may have conventional tooth profiles and/or narrow-wide tooth profiles. Specifically, as narrow/wide tooth profiles, sprocket teeth SP1B-SP13B of sprockets SP1-SP13 also include at least one first tooth each having a first axial maximum chain engagement width and a first axial and at least one second tooth each having a second axial maximum chain engagement width that is less than the maximum chain engagement width. The first axial maximum chain engagement width and the second axial maximum chain engagement width are measured along the axial direction D2. The first axial maximum chain engagement width is greater than the axial inner link space defined by the pair of inner link plates of the bicycle chain 20 and is axially defined by the pair of outer link plates of the bicycle chain 20 . Smaller than the outer link space. The pair of outer link plates face each other in the axial direction D2 when the bicycle chain 20 engages one of the sprockets SP1-SP13. The second maximum axial chain engagement width is smaller than the axial inner link space defined by the pair of inner link plates of the bicycle chain 20 . Accordingly, the at least one first tooth is configured to engage a pair of outer link plates facing each other in the axial direction D2 when the bicycle chain 20 engages one of the sprockets SP1-SP13. , the at least one second tooth is configured to engage a pair of inner link plates facing each other in the axial direction D2. Preferably, the at least one first tooth and the at least one second tooth are alternately arranged on the circumference of at least one of the sprockets SP1-SP13. Preferably, the sprocket teeth SP1B-SP13B of the sprockets SP1-SP13 each have a plurality of first teeth each having the aforementioned first axial maximum chain engagement width and the aforementioned second axial maximum chain engagement width respectively. and a plurality of second teeth. Preferably, the plurality of first teeth and the plurality of second teeth are alternately arranged on the outer circumference of at least one of the sprockets SP1-SP13. Preferably, the sprocket teeth of the largest sprocket may have such a narrow-wide tooth profile. Therefore, sprocket tooth SP12B of sprocket SP12 in FIG. 6 or sprocket tooth SP13B of sprocket SP13 in FIG. It preferably includes at least one of at least one second tooth having a width.

As used herein, "comprising" and its derivatives are open-ended terms describing the presence of elements and do not exclude the presence of other elements not listed. This also applies to the words "having", "including" and their derivatives.

The terms "member", "part", "element", "body" and "structure" can have multiple meanings such as single part and multiple parts.

Ordinal numbers such as "first" and "second" are merely terms to identify configurations and have no other meaning (eg, a particular order, etc.). For example, the presence of a "first element" does not imply the existence of a "second element", nor does the presence of a "second element" imply the existence of a "first element". does not imply that

As used herein, the term "a pair of" includes both a pair of elements having the same shape and structure as well as a pair of elements having different shapes and structures.

Terms such as "substantially," "about," and "approximately" expressing degree can mean a reasonable amount of deviation such that the final result does not change significantly. All numerical values set forth in this application may be interpreted to include words such as "substantially," "about," and "approximately."

Obviously, many variations and modifications of the present invention are possible in view of the above disclosure. Accordingly, the present invention may be practiced otherwise than as specifically disclosed herein without departing from the spirit of the invention.

10 Bicycle drive train 12 Bicycle rear hub assembly 14 Bicycle rear sprocket assembly 16 Bicycle brake rotor 18 Crank assembly 20 Bicycle chain 22 Crankshaft 24 Right crank arm 26 Left crank arm , 27 front sprocket, 28 sprocket support, 30 hub axle, 32 lock member, 34 brake rotor support, 36 hub body, 37 sprocket support member, 38 spacer, 40 outer spline teeth, 64 inner spline teeth, A1 rotation center axis

Claims (7)

a hub axle;
a hub body mounted on the hub axle to be rotatable about the central axis of rotation of the bicycle rear hub assembly;
a sprocket support rotatably mounted on the hub axle about the central axis of rotation;
the sprocket support includes at least ten external spline teeth configured to engage a bicycle rear sprocket assembly;
each of said at least ten outer spline teeth having an outer spline drive surface contactable with said rear bicycle sprocket assembly to receive rotational driving force from said rear bicycle sprocket assembly during pedaling; a non-driving surface;
At least one of the at least ten outer spline teeth is a radially outermost peripheral end portion of at least one of the at least ten outer spline teeth from the rotation center axis in a radial direction with respect to the rotation center axis. is circumferentially symmetrical about a reference line extending to the circumferential center point of
the outer spline drive surface includes a radial length defined from a radially outermost periphery to a radially innermost periphery;
the sum of the radial lengths of the outer spline drive surfaces of the at least 10 outer spline teeth is equal to or greater than 7 mm;
the at least 10 outer spline teeth have an outer spline ridge diameter of 34 mm or less;
the at least 10 outer spline teeth have an outer spline root diameter of 28 mm or more;
Bicycle rear hub assembly. a hub axle;
a hub body mounted on the hub axle to be rotatable about the central axis of rotation of the bicycle rear hub assembly;
a sprocket support rotatably mounted on the hub axle about the central axis of rotation;
the sprocket support includes at least ten external spline teeth configured to engage a bicycle rear sprocket assembly;
each of said at least ten outer spline teeth having an outer spline drive surface contactable with said rear bicycle sprocket assembly to receive rotational driving force from said rear bicycle sprocket assembly during pedaling; a non-driving surface;
At least one of the at least ten outer spline teeth is a radially outermost peripheral end portion of at least one of the at least ten outer spline teeth from the rotation center axis in a radial direction with respect to the rotation center axis. is circumferentially symmetrical about a reference line extending to the circumferential center point of
the outer spline drive surface includes a radial length defined from a radially outermost periphery to a radially innermost periphery;
the sum of the radial lengths of the outer spline drive surfaces of the at least ten outer spline teeth is no less than 7 mm and no more than 36 mm;
the at least 10 outer spline teeth have an outer spline ridge diameter of 34 mm or less;
Bicycle rear hub assembly. the total number of said at least 10 external spline teeth is in the range of 22-24;
The bicycle rear hub assembly according to claim 1 or 2 . the total number of said at least 10 external spline teeth is 28 or more;
A bicycle rear hub assembly according to any one of claims 1 to 3 . The outer spline drive surface is located between the outer spline drive surface and a first radial line extending from the center axis of rotation of the bicycle rear hub assembly to a radially outermost edge of the outer spline drive surface. having a first outer spline face angle defined;
The first outer spline face angle is 6 degrees or less,
A bicycle rear hub assembly according to any one of claims 1 to 4 . The outer spline non-driving surface includes: the outer spline non-driving surface; and a second radial line extending from the rotation center axis of the bicycle rear hub assembly to a radially outermost edge of the outer spline non-driving surface; with a second outer spline face angle defined between
The second outer spline face angle is 6 degrees or less,
The bicycle rear hub assembly according to claim 5 . The axial length of at least one spline tooth among the at least ten outer spline teeth is 27 mm or less.
A bicycle rear hub assembly according to any one of claims 1-6 .

Images