CN108974235B - Bicycle rear sprocket assembly - Google Patents

Abstract

The bicycle rear sprocket assembly includes at least one sprocket having a total number of teeth equal to or greater than 15. At least one sprocket includes at least ten internal spline teeth configured to engage a bicycle hub assembly.

Description

Bicycle rear sprocket assembly

Cross Reference to Related Applications

The present application is a continuation-in-part application of U.S. patent application No. 15/608,924 filed on 30/5/2017. The contents of this application are incorporated herein by reference in their entirety.

Technical Field

The present invention relates to a bicycle rear sprocket assembly.

Background

Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One bicycle component that has been extensively redesigned is the drive train.

Disclosure of Invention

In accordance with a first aspect of the present invention, a bicycle rear sprocket assembly includes at least one sprocket having a total number of teeth equal to or greater than 15. The at least one sprocket includes at least ten internal spline teeth configured to engage a bicycle hub assembly.

With the bicycle rear sprocket assembly according to the first aspect, the at least ten internal spline teeth reduce the rotational force applied to each of the at least ten internal spline teeth as compared to a sprocket that includes nine or less internal spline teeth. This improves the durability of the at least one sprocket and/or improves the freedom of material selection of the at least one sprocket without reducing the durability of the at least one sprocket.

According to a second aspect of the present invention, the bicycle rear sprocket assembly according to the first aspect is configured such that the total number of the at least ten internal spline teeth is equal to or greater than 20.

With the bicycle rear sprocket assembly according to the second aspect, the at least twenty internal spline teeth reduce the rotational force applied to each of the at least twenty internal spline teeth as compared to a sprocket that includes nine or less internal spline teeth. This improves the durability of the at least one sprocket and/or improves the freedom of material selection of the at least one sprocket without reducing the durability of the at least one sprocket.

According to a third aspect of the present invention, the bicycle rear sprocket assembly according to the second aspect is configured such that the total number of the at least ten internal spline teeth is equal to or greater than 25.

With the bicycle rear sprocket assembly according to the third aspect, the at least twenty-five internal spline teeth further reduce the rotational force applied to each of the at least twenty-five internal spline teeth as compared to a sprocket that includes nine or less internal spline teeth. This further improves the durability of the at least one sprocket and/or further improves the freedom of material selection of the at least one sprocket without reducing the durability of the at least one sprocket.

According to a fourth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the first to third aspects is configured such that the at least ten internal spline teeth have a first internal tooth pitch angle and a second internal tooth pitch angle that is different from the first internal tooth pitch angle.

With the bicycle rear sprocket assembly according to the fourth aspect, the difference between the first and second inner pitch angles assists the user in properly mounting the bicycle rear sprocket assembly to the bicycle hub assembly, particularly with respect to the circumferential position of each sprocket of the bicycle rear sprocket assembly.

According to a fifth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the first to fourth aspects is configured such that the at least one sprocket includes at least ten sprockets.

With the bicycle rear sprocket assembly according to the fifth aspect, at least ten sprockets enable a wide range of bicycle rear sprockets.

According to a sixth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the first to fourth aspects is configured such that the at least one sprocket includes at least eleven sprockets.

With the bicycle rear sprocket assembly according to the sixth aspect, at least eleven sprockets enable a wider range of bicycle rear sprockets.

According to a seventh aspect of the present invention, the bicycle rear sprocket assembly according to any one of the first to fourth aspects is configured such that the at least one sprocket includes at least twelve sprockets.

With the bicycle rear sprocket assembly according to the seventh aspect, at least twelve sprockets enable a wider range of bicycle rear sprockets.

According to an eighth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the first to seventh aspects is configured such that the at least one sprocket includes a plurality of sprockets and at least one internally splined tooth configured to engage a bicycle hub assembly. The plurality of sprockets includes a largest sprocket having a crest diameter. The at least one internal spline tooth has an internal spline base diameter. The ratio of the bottom diameter of the internal spline to the top diameter of the tooth is in the range of 0.1 to 0.2.

With the bicycle rear sprocket assembly according to the eighth aspect, the ratio enables the bicycle rear sprocket assembly to have a wide range and improves the durability of at least one sprocket.

According to a ninth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the first to eighth aspects is configured such that the at least one sprocket includes a first sprocket and a second sprocket. The first sprocket has a first total number of teeth. The second sprocket has a second total tooth number less than the first total tooth number. The first sprocket includes at least one first shift facilitation area to facilitate a first shift operation of a bicycle chain from the second sprocket to the first sprocket, and at least one second shift facilitation area to facilitate a second shift operation of the bicycle chain from the first sprocket to the second sprocket.

With the bicycle rear sprocket assembly according to the ninth aspect, the at least one first shift facilitation zone and the at least one second shift facilitation zone make the first and second shifting operations smoother.

According to a tenth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the first to ninth aspects further comprises a locking member configured to prevent the at least one sprocket mounted on the bicycle hub assembly from moving axially relative to a rotational center axis of the bicycle rear sprocket assembly. The locking member includes a tubular body portion and a protruding portion. The tubular body portion has a central axis. The protruding portion extends radially outward from the tubular body portion relative to a central axis of the tubular body portion. The tubular body portion has an externally threaded portion configured to engage an internally threaded portion of the bicycle hub assembly. The projection is configured to abut against the at least one sprocket.

With the bicycle rear sprocket assembly according to the tenth aspect, the bicycle rear sprocket assembly may be attached to the bicycle hub assembly to prevent the at least one sprocket from moving axially relative to the bicycle hub assembly.

According to an eleventh aspect of the present invention, the bicycle rear sprocket assembly according to the tenth aspect is configured such that the tubular body portion has a first outer diameter equal to or less than 26 mm.

With the bicycle rear sprocket assembly according to the eleventh aspect, the first outer diameter enables the bicycle rear sprocket assembly to have a wide range and prevents the at least one sprocket from moving axially relative to the bicycle hub assembly.

According to a twelfth aspect of the present invention, the bicycle rear sprocket assembly according to the eleventh aspect is configured such that the first outer diameter is equal to or greater than 25 mm.

With the bicycle rear sprocket assembly according to the twelfth aspect, the first outer diameter ensures the strength of the locking member and enables the bicycle rear sprocket assembly to have a wide range.

According to a thirteenth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the tenth to twelfth aspects is configured such that the protruding part has a second outer diameter equal to or less than 32 mm.

With the bicycle rear sprocket assembly according to the thirteenth aspect, the second outer diameter enables the bicycle rear sprocket assembly to have a wide range and prevents the at least one sprocket from moving axially relative to the bicycle hub assembly.

According to a fourteenth aspect of the present invention, the bicycle rear sprocket assembly according to the thirteenth aspect is configured such that the second outside diameter is equal to or greater than 30 mm.

With the bicycle rear sprocket assembly according to the fourteenth aspect, the second outer diameter ensures the strength of the locking member and enables the bicycle rear sprocket assembly to have a wide range.

According to a fifteenth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the tenth to fourteenth aspects is configured such that the locking member has a tool engaging portion.

With the bicycle rear sprocket assembly according to the fifteenth aspect, it is possible to easily attach and detach the locking member to and from the bicycle hub assembly.

According to a sixteenth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the first to fifteenth aspects further comprises a sprocket support. The at least one sprocket includes a plurality of sprockets attached to the sprocket support.

With the bicycle rear sprocket assembly according to the sixteenth aspect, the weight of the bicycle rear sprocket assembly can be reduced.

According to a seventeenth aspect of the present invention, the bicycle rear sprocket assembly according to the sixteenth aspect is configured such that the plurality of sprockets are attached to the sprocket support by an adhesive.

With the bicycle rear sprocket assembly according to the seventeenth aspect, metal fasteners can be reduced or eliminated. This effectively reduces the weight of the bicycle rear sprocket assembly.

According to an eighteenth aspect of the present invention, the bicycle rear sprocket assembly according to the sixteenth or seventeenth aspect is configured such that the sprocket support is made of a non-metallic material that includes a resin material.

With the bicycle rear sprocket assembly according to the eighteenth aspect, the non-metallic material more effectively reduces the weight of the bicycle rear sprocket assembly.

According to a nineteenth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the first to eighteenth aspects further includes a rear hub abutment surface configured to abut against the bicycle hub assembly in an axial direction with respect to a rotational center axis of the bicycle rear sprocket assembly in a state in which the bicycle rear sprocket assembly is mounted to the bicycle hub assembly. The at least one sprocket comprises a plurality of sprockets including a largest sprocket. The largest sprocket has an axially inner surface and an axially outer surface disposed on opposite sides of the axially inner surface in the axial direction. The axially outer surface is closer to the rear hub abutment surface in the axial direction than the axially inner surface. An axial distance defined between the axially inner surface and the rear hub abutment surface in the axial direction is equal to or greater than 7 mm.

With the bicycle rear sprocket assembly according to the nineteenth aspect, the axial distance enables the bicycle rear sprocket to have a wide range.

According to a twentieth aspect of the present invention, the bicycle rear sprocket assembly according to the nineteenth aspect is configured such that the axial distance is equal to or greater than 10 mm.

With the bicycle rear sprocket assembly according to the twentieth aspect, the axial distance further enables a wider range of the bicycle rear sprocket.

According to a twenty-first aspect of the present invention, a bicycle rear sprocket assembly includes at least one sprocket having a total number of teeth equal to or greater than 15. The at least one sprocket includes at least one internally splined tooth configured to engage a bicycle hub assembly. The at least one internal spline tooth has an internal spline base diameter equal to or less than 30 mm.

With the bicycle rear sprocket assembly according to the twenty-first aspect, a bicycle rear sprocket having a total number of teeth equal to or less than 10 can be manufactured. Thus, the shift range of the bicycle rear sprocket assembly on the high gear side can be widened. The twenty-first aspect may be combined with any one of the first to twentieth aspects.

According to a twenty-second aspect of the present invention, the bicycle rear sprocket assembly according to the twenty-first aspect is configured such that the inner spline bottom diameter is equal to or greater than 25 mm.

With the bicycle rear sprocket assembly according to the twenty-second aspect, it is possible to ensure the strength of at least one sprocket and widen the shift range of the bicycle rear sprocket assembly on the high gear side.

According to a twenty-third aspect of the present invention, the bicycle rear sprocket assembly according to the twenty-first aspect is configured such that the inner spline bottom diameter is equal to or greater than 29 mm.

With the bicycle rear sprocket assembly according to the twenty-third aspect, it is possible to further ensure the strength of at least one sprocket and widen the shift range of the bicycle rear sprocket assembly on the high gear side.

According to a twenty-fourth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the twenty-first to twenty-third aspects is configured such that the at least one internal spline tooth has an internal spline crest diameter equal to or less than 28 mm.

With the bicycle rear sprocket assembly according to the twenty-fourth aspect, the inner spline crest diameter can increase a radial length of the drive surface of the at least one inner spline tooth. This improves the strength of the at least one sprocket.

According to a twenty-fifth aspect of the present invention, the bicycle rear sprocket assembly according to the twenty-fourth aspect is configured such that the inner spline top diameter is equal to or greater than 25 mm.

With the bicycle rear sprocket assembly according to the twenty-fifth aspect, it is possible to secure the strength of at least one sprocket and widen the range of gears of the bicycle rear sprocket assembly on the high gear side.

According to a twenty-sixth aspect of the present invention, the bicycle rear sprocket assembly according to the twenty-fourth or twenty-fifth aspect is configured such that the inner spline top diameter is equal to or greater than 27 mm.

With the bicycle rear sprocket assembly according to the twenty-sixth aspect, it is possible to determine to secure the strength of at least one sprocket and to widen the shift range of the bicycle rear sprocket assembly on the high gear side.

According to a twenty-seventh aspect of the present invention, the bicycle rear sprocket assembly according to any one of the twenty-first to twenty-sixth aspects is configured such that the at least one internal spline tooth includes a plurality of internal spline teeth including a plurality of internal spline drive surfaces to receive driving rotational force from the bicycle hub assembly during pedaling. The plurality of inner spline drive surfaces each include a radially outermost edge, a radially innermost edge, and a radial length defined from the radially outermost edge to the radially innermost edge. The sum of the radial lengths is equal to or greater than 7 mm.

With the bicycle rear sprocket assembly according to the twenty-seventh aspect, the radial length of the plurality of internally splined drive surfaces can be increased. This improves the strength of the at least one sprocket.

According to a twenty-eighth aspect of the present invention, the bicycle rear sprocket assembly according to the twenty-seventh aspect is configured such that a sum of radial lengths is equal to or greater than 10 mm.

With the bicycle rear sprocket assembly according to the twenty-eighth aspect, the radial length of the plurality of internally splined drive surfaces can be further increased. This improves the strength of the at least one sprocket.

According to a twenty-ninth aspect of the present invention, the bicycle rear sprocket assembly according to the twenty-seventh aspect is configured such that the sum of the radial lengths is equal to or greater than 15 mm.

With the bicycle rear sprocket assembly according to the twenty-ninth aspect, the radial length of the plurality of externally splined driving surfaces can be further increased. This further improves the strength of the at least one sprocket.

According to a thirtieth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the twenty-first to twenty-ninth aspects is configured such that the at least one sprocket includes at least ten sprockets.

With the bicycle rear sprocket assembly according to the thirtieth aspect, at least ten sprockets enable the bicycle rear sprocket assembly to have a wide range.

According to a thirty-first aspect of the present invention, the bicycle rear sprocket assembly according to any one of the twenty-first to twenty-ninth aspects is configured such that the at least one sprocket includes at least eleven sprockets.

With the bicycle rear sprocket assembly according to the thirty-first aspect, at least eleven sprockets enable a wide range of bicycle rear sprocket assemblies.

According to a thirty-second aspect of the present invention, the bicycle rear sprocket assembly according to any one of the twenty-first to twenty-ninth aspects is configured such that the at least one sprocket includes at least twelve sprockets.

With the bicycle rear sprocket assembly according to the thirty-second aspect, at least twelve sprockets enable a wide range of bicycle rear sprocket assemblies.

According to a thirty-third aspect of the present invention, the bicycle rear sprocket assembly according to any one of the twenty-first to thirty-second aspects is configured such that the at least one sprocket includes a plurality of sprockets. The plurality of sprockets includes a largest sprocket having a crest diameter. The ratio of the bottom diameter of the internal spline to the top diameter of the tooth is in the range of 0.1 to 0.2.

With the bicycle rear sprocket assembly according to the thirteenth aspect, the ratio enables the bicycle rear sprocket assembly to have a wide range and improves durability of at least one sprocket.

According to a thirty-fourth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the twenty-first to thirty-third aspects is configured such that the at least one sprocket includes a first sprocket and a second sprocket. The first sprocket has a first total number of teeth. The second sprocket has a second total tooth number less than the first total tooth number. The first sprocket includes at least one first shift facilitation area to facilitate a first shift operation of a bicycle chain from the second sprocket to the first sprocket; and at least one second shift facilitation area to facilitate a second shift operation of the bicycle chain from the first sprocket to the second sprocket.

With the bicycle rear sprocket assembly according to the thirty-fourth aspect, the at least one first shift facilitation zone and the at least one second shift facilitation zone make the first and second shifting operations smoother.

According to a thirty-fifth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the twenty-first to thirty-fourth aspects further comprises a locking member configured to prevent axial movement of the at least one sprocket mounted on the bicycle hub assembly relative to a rotational center axis of the bicycle rear sprocket assembly. The locking member includes a tubular body portion and a protruding portion. The tubular body portion has a central axis. The protruding portion extends radially outward from the tubular body portion relative to a central axis of the tubular body portion. The tubular body portion has an externally threaded portion configured to engage an internally threaded portion of the bicycle hub assembly. The protruding portion is configured to abut against the at least one sprocket.

With the bicycle rear sprocket assembly according to the thirty-fifth aspect, the bicycle rear sprocket assembly may be attached to a bicycle hub assembly to prevent axial movement of the at least one sprocket relative to the bicycle hub assembly.

According to a thirty-sixth aspect of the present invention, the bicycle rear sprocket assembly according to the thirty-fifth aspect is configured such that the tubular body portion has a first outer diameter equal to or less than 26 mm.

With the bicycle rear sprocket assembly according to the thirty-sixth aspect, the first outer diameter enables the bicycle rear sprocket assembly to have a wide range and prevents axial movement of the at least one sprocket relative to the bicycle hub assembly.

According to a thirty-seventh aspect of the present invention, the bicycle rear sprocket assembly according to the thirty-sixth aspect is configured such that the first outer diameter is equal to or greater than 25 mm.

With the bicycle rear sprocket assembly according to the thirty-seventh aspect, the first outer diameter ensures the strength of the locking member and enables the bicycle rear sprocket assembly to have a wide range.

According to a thirty-eighth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the thirty-fifth to thirty-seventh aspects is configured such that the projecting portion has a second outer diameter equal to or less than 32 mm.

With the bicycle rear sprocket assembly according to the thirty-eighth aspect, the second outer diameter enables the bicycle rear sprocket assembly to have a wide range and prevents axial movement of the at least one sprocket relative to the bicycle hub assembly.

According to a thirty-ninth aspect of the present invention, the bicycle rear sprocket assembly according to the thirty-eighth aspect is configured such that the second outer diameter is equal to or greater than 30 mm.

With the bicycle rear sprocket assembly according to the thirty-ninth aspect, the second outer diameter ensures the strength of the locking member and enables the bicycle rear sprocket assembly to have a wide range.

According to a fortieth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the thirty-fifth aspect to the thirty-ninth aspect is configured such that the locking member has a tool engaging portion.

With the bicycle rear sprocket assembly according to the fortieth aspect, it is possible to easily attach and detach the locking member to and from the bicycle hub assembly.

According to a forty-first aspect of the present invention, the bicycle rear sprocket assembly according to any one of the twenty-first to fortieth aspects further comprises a sprocket support. The at least one sprocket includes a plurality of sprockets attached to the sprocket support.

With the bicycle rear sprocket assembly according to the fourteenth aspect, the weight of the bicycle rear sprocket assembly can be reduced.

According to a forty-second aspect of the present invention, the bicycle rear sprocket assembly according to the forty-first aspect is configured such that the plurality of sprockets are attached to the sprocket support by an adhesive.

With the bicycle rear sprocket assembly according to the forty-second aspect, metal fasteners can be reduced or eliminated. This effectively reduces the weight of the bicycle rear sprocket assembly.

According to a fourteenth aspect of the present invention, the bicycle rear sprocket assembly according to the forty-first or forty-second aspect is configured such that the sprocket support is made of a non-metallic material that includes a resin material.

With the bicycle rear sprocket assembly according to the fourteenth aspect, the non-metallic material more effectively reduces the weight of the bicycle rear sprocket assembly.

According to a fourteenth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the twenty-first to the forty-third aspects further includes a rear hub abutment surface configured to abut against the bicycle hub assembly in an axial direction with respect to a rotational center axis of the bicycle rear sprocket assembly in a state in which the bicycle rear sprocket assembly is mounted to the bicycle hub assembly. The at least one sprocket comprises a plurality of sprockets including a largest sprocket. The largest sprocket has an axially inner surface and an axially outer surface disposed on opposite sides of the axially inner surface in the axial direction. The axially outer surface is closer to the rear hub abutment surface in the axial direction than the axially inner surface. An axial distance defined between the axially inner surface and the rear hub abutment surface in the axial direction is equal to or greater than 7 mm.

With the bicycle rear sprocket assembly according to the fourteenth aspect, the axial distance enables the bicycle rear sprocket to have a wide range.

According to a forty-fifth aspect of the present invention, the bicycle rear sprocket assembly according to the forty-fourth aspect is configured such that the axial distance is equal to or greater than 10 mm.

With the bicycle rear sprocket assembly according to the forty-fifth aspect, the axial distance further enables a wider range of the bicycle rear sprocket.

In accordance with a forty-sixth aspect of the present invention, a bicycle rear sprocket assembly includes a plurality of sprockets, a rear hub abutment surface and an axial distance. The plurality of sprockets includes a largest sprocket. The largest sprocket has an axially inner surface and an axially outer surface disposed on opposite sides of the axially inner surface in an axial direction with respect to a rotational center axis of the bicycle rear sprocket assembly. The rear hub abutment surface is configured to abut against the bicycle hub assembly in the axial direction with the bicycle rear sprocket assembly mounted to the bicycle hub assembly, the axially outer surface being closer to the rear hub abutment surface in the axial direction than the axially inner surface. An axial distance defined between the axially inner surface and the rear hub abutment surface in the axial direction is equal to or greater than 7 mm.

With the bicycle rear sprocket assembly according to the forty-sixth aspect, the axial distance enables the bicycle rear sprocket to have a wide range.

According to a seventeenth aspect of the present invention, the bicycle rear sprocket assembly according to the forty-sixth aspect is configured such that the axial distance is equal to or greater than 10 mm.

With the bicycle rear sprocket assembly according to the seventeenth aspect, the axial distance further enables a wider range of the bicycle rear sprocket.

According to a forty-eighth aspect of the present invention, the bicycle rear sprocket assembly according to the forty-sixth or forty-seventh aspect is configured such that the axially inner surface is located closer to an axial center plane of the bicycle hub assembly than the rear hub abutment surface in a state in which the bicycle rear sprocket assembly is mounted to the bicycle hub assembly.

With the bicycle rear sprocket assembly according to the forty-eight aspect, the axial distance enables a wider range of the bicycle rear sprocket.

According to a forty-ninth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the forty-sixth to forty-eighteenth aspects is configured such that the total number of the plurality of sprockets is 12.

With the bicycle rear sprocket assembly according to the forty-ninth aspect, the total number of the plurality of sprockets enables the bicycle rear sprocket to have a wide range.

According to a fifty-fifth aspect of the present invention, the bicycle rear sprocket assembly according to any one of the forty-sixth to forty-ninth aspects is configured such that the total number of teeth of the largest sprocket is equal to or greater than 39.

With the bicycle rear sprocket assembly according to the fifty-th aspect, the total number of teeth of the maximum sprocket enables the bicycle rear sprocket to have a wide range.

According to a fifty-first aspect of the present invention, the bicycle rear sprocket assembly according to any one of the forty-sixth to the forty-ninth aspects is configured such that the total number of teeth of the largest sprocket is equal to or greater than 45.

With the bicycle rear sprocket assembly according to the fifteenth aspect, the total number of teeth of the largest sprocket enables a wider range of the bicycle rear sprocket.

Drawings

A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

FIG. 1 is a schematic diagram of a bicycle drive train in accordance with one embodiment.

Fig. 2 is an exploded perspective view of the bicycle drive train illustrated in fig. 1.

FIG. 3 is another perspective view of the bicycle drive train illustrated in FIG. 2.

FIG. 4 is a cross-sectional view of the bicycle drive train taken along line IV-IV of FIG. 2.

FIG. 5 is an exploded perspective view of the bicycle hub assembly of the bicycle drive train illustrated in FIG. 2.

FIG. 6 is an enlarged cross-sectional view of the bicycle drive train illustrated in FIG. 4.

FIG. 7 is a perspective view of the sprocket support body of the bicycle hub assembly of the bicycle drive train illustrated in FIG. 2.

FIG. 8 is another perspective view of the sprocket support body of the bicycle hub assembly of the bicycle drive train illustrated in FIG. 2.

FIG. 9 is a side elevational view of the sprocket support body illustrated in FIG. 7.

FIG. 10 is a side elevational view of a sprocket support body of a bicycle hub assembly in accordance with a variation.

FIG. 11 is an enlarged cross-sectional view of the sprocket support body illustrated in FIG. 7.

FIG. 12 is a cross-sectional view of the sprocket support body illustrated in FIG. 7.

FIG. 13 is a perspective view of the bicycle hub assembly of the bicycle drive train illustrated in FIG. 2.

FIG. 14 is a side elevational view of the bicycle hub assembly of the bicycle drive train illustrated in FIG. 2.

FIG. 15 is a rear elevational view of the bicycle hub assembly of the bicycle drive train illustrated in FIG. 2.

FIG. 16 is a cross-sectional view of the bicycle hub assembly taken along line XVI-XVI of FIG. 5.

FIG. 17 is a side elevational view of the bicycle rear sprocket assembly of the bicycle drive train illustrated in FIG. 2.

Fig. 18 is an exploded perspective view of the bicycle rear sprocket assembly illustrated in fig. 17.

FIG. 19 is a partially exploded perspective view of the bicycle rear sprocket assembly illustrated in FIG. 17.

FIG. 20 is another partially exploded perspective view of the bicycle rear sprocket assembly illustrated in FIG. 17.

FIG. 21 is another partially exploded perspective view of the bicycle rear sprocket assembly illustrated in FIG. 17.

FIG. 22 is another partially exploded perspective view of the bicycle rear sprocket assembly illustrated in FIG. 17.

FIG. 23 is a perspective cross-sectional view of the bicycle rear sprocket assembly taken along line XXIII-XXIII of FIG. 17.

FIG. 24 is a perspective view of the smallest sprocket of the bicycle rear sprocket assembly illustrated in FIG. 17.

FIG. 25 is another perspective view of the smallest sprocket of the bicycle rear sprocket assembly illustrated in FIG. 17.

FIG. 26 is a side elevational view of the smallest sprocket of the bicycle rear sprocket assembly illustrated in FIG. 17.

FIG. 27 is a side elevational view of a smallest sprocket according to a variation.

FIG. 28 is an enlarged cross-sectional view of the smallest sprocket illustrated in FIG. 24.

FIG. 29 is a cross-sectional view of the smallest sprocket illustrated in FIG. 24.

FIG. 30 is a cross-sectional view of the sprocket support body and the smallest sprocket of the bicycle drive train illustrated in FIG. 2.

FIG. 31 is a partially exploded perspective view of the bicycle rear sprocket assembly illustrated in FIG. 17.

FIG. 32 is a perspective view of the sprocket support of the bicycle rear sprocket assembly illustrated in FIG. 17.

FIG. 33 is a side elevational view of a bicycle rear sprocket assembly in accordance with a modification.

FIG. 34 is a side elevational view of the first sprocket of the bicycle rear sprocket assembly illustrated in FIG. 33.

FIG. 35 is a partial perspective view of the first sprocket of the bicycle rear sprocket assembly illustrated in FIG. 33.

FIG. 36 is another side elevational view of the first sprocket of the bicycle rear sprocket assembly illustrated in FIG. 33.

FIG. 37 is another partial perspective view of the first sprocket of the bicycle rear sprocket assembly illustrated in FIG. 33.

FIG. 38 is an enlarged cross-sectional view of a sprocket support body according to a variation.

FIG. 39 is an enlarged cross-sectional view of a smallest sprocket according to a variation.

Detailed Description

Embodiments will now be described with reference to the drawings, wherein like reference numerals designate corresponding or identical elements throughout the several views.

Referring initially to FIG. 1, a bicycle drive train 10 in accordance with one embodiment includes a bicycle hub assembly 12 and a bicycle rear sprocket assembly 14. The bicycle hub assembly 12 is secured to the bicycle frame BF. The bicycle rear sprocket assembly 14 is mounted to the bicycle hub assembly 12. The bicycle brake rotor 16 is mounted on the bicycle hub assembly 12.

The bicycle drive train 10 further includes a crank assembly 18 and a bicycle chain 20. The crank assembly 18 includes a crank axle 22, a right crank arm 24, a left crank arm 26, and a front sprocket 27. A right crank arm 24 and a left crank arm 26 are fixed to the crank axle 22. The front sprockets 27 are fixed to at least one of the crank axle 22 and the right crank arm 24. The bicycle chain 20 engages the front sprocket 27 and the bicycle rear sprocket assembly 14 to transmit a pedaling force from the front sprocket 27 to the bicycle rear sprocket assembly 14. In the illustrated embodiment, the crank assembly 18 includes the front sprocket 27 as a single sprocket. However, the crank assembly 18 may include a plurality of front sprockets. The bicycle rear sprocket assembly 14 is a rear sprocket assembly. However, the structure of the bicycle rear sprocket assembly 14 can be applied to a front sprocket.

In this application, the following directional terms "forward", "rearward", "left", "right", "lateral", "upward" and "downward" as well as any other similar directional terms refer to those directions which are determined based on a user (e.g., a rider) seated on a saddle (not shown) of a bicycle facing a handlebar (not shown). Accordingly, these terms, as utilized to describe the bicycle drive train 10, the bicycle hub assembly 12, or the bicycle rear sprocket assembly 14 should be interpreted relative to a bicycle equipped with the bicycle drive train 10, the bicycle hub assembly 12, or the bicycle rear sprocket assembly 14 as used in an upright riding position on a horizontal surface.

As seen in fig. 2 and 3, the bicycle hub assembly 12 and the bicycle rear sprocket assembly 14 have a center axis of rotation a 1. The bicycle rear sprocket assembly 14 is rotatably supported by the bicycle hub assembly 12 about a rotational center axis A1 with respect to the bicycle frame BF (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. During pedaling, the bicycle rear sprocket assembly 14 rotates in a driving rotational direction D11 about the center axis of rotation a 1. The driving rotational direction D11 is defined in a circumferential direction D1 of the bicycle hub assembly 12 or the bicycle rear sprocket assembly 14. The opposite rotational direction D12 is the opposite direction from the drive rotational direction D11 and is defined in the circumferential direction D1.

As seen in fig. 2, the bicycle hub assembly 12 includes a sprocket support body 28. The bicycle rear sprocket assembly 14 is mounted on the sprocket support body 28 to transmit a driving rotational force F1 between the sprocket support body 28 and the bicycle rear sprocket assembly 14. The bicycle hub assembly 12 also includes a hub axle 30. The sprocket support body 28 is rotatably mounted on the drum shaft 30 about a center axis of rotation a 1. The bicycle rear sprocket assembly 14 also includes a locking member 32. The locking member 32 is fixed to the sprocket support body 28 to retain the bicycle rear sprocket assembly 14 relative to the sprocket support body 28 in an axial direction D2 that is parallel to the rotational center axis a 1.

As seen in fig. 4, the bicycle hub assembly 12 is secured to the bicycle frame BF by a wheel securing structure WS. The hub axle 30 has a through hole 30A. The fixing rod WS1 of the wheel fixing structure WS extends through the through hole 30A of the hub axle 30. The drum shaft 30 includes a first shaft end 30B and a second shaft end 30C. The dram shaft 30 extends along a central axis of rotation a1 between a first shaft end 30B and a second shaft end 30C. The first shaft end portion 30B is disposed in the first recess BF11 of the first frame BF1 of the bicycle frame BF. The second shaft end 30C is disposed 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 the wheel securing structure WS. The wheel securing structure WS comprises a structure known in the bicycle art. Therefore, for the sake of brevity, it will not be described in detail herein.

As seen in fig. 4 and 5, the bicycle hub assembly 12 further includes a brake rotor support body 34. The brake rotor support body 34 is rotatably mounted on the drum shaft 30 about a center axis of rotation a 1. The brake rotor support body 34 is coupled to the bicycle brake rotor 16 (fig. 1) to transmit a braking rotational force from the bicycle brake rotor 16 to the brake rotor support body 34.

As seen in fig. 5, the bicycle hub assembly 12 further includes a hub body 36. The hub body 36 is rotatably mounted on the hub axle 30 about a center axis of rotation a 1. In this embodiment, the sprocket support body 28 is a separate member from the hub body 36. The brake rotor support body 34 is integrally provided as a one-piece, unitary member with the hub body 36. However, the sprocket support body 28 may be provided integrally with the hub body 36. The brake rotor support body 34 may be a separate component from the hub body 36.

The hub body 36 includes a first flange 36A and a second flange 36B. A first spoke (not shown) is coupled to the first flange 36A. A second spoke (not shown) is coupled to the second flange 36B. The second flange 36B is spaced from the first flange 36A along the axial direction D2. The first flange 36A is disposed between the sprocket support body 28 and the second flange 36B in the axial direction D2. The second flange 36B is disposed between the first flange 36A and the brake rotor support body 34 in the axial direction D2.

The locking member 32 includes an externally threaded portion 32A. The sprocket support body 28 includes an internal threaded portion 28A. The male threaded portion 32A is threadedly engaged with the female threaded portion 28A in a state where the locking member 32 is fixed to the sprocket support body 28.

As seen in fig. 6, the locking member 32 is configured to prevent at least one sprocket mounted on the bicycle hub assembly 12 from moving axially relative to the rotational center axis a1 of the bicycle rear sprocket assembly 14. As shown in fig. 5, the locking member 32 includes a tubular body portion 32C and a protruding portion 32B. The tubular body portion 32C has a central axis a 2. The projection portion 32B extends radially outward from the tubular body portion 32C relative to a central axis a2 of the tubular body portion 32C. The tubular body portion 32C has an externally threaded portion 32A configured to engage the internally threaded portion 28A of the bicycle hub assembly 12.

As shown in fig. 6, the projection 32B is configured to abut against at least one sprocket. In this embodiment, the projecting portion 32B is configured to abut against the sprocket SP 1. The tubular body portion 32C has a first outer diameter ED1 equal to or less than 26 mm. The first outer diameter ED1 is equal to or greater than 25 mm. In this embodiment, the first outer diameter ED1 is 25.45 mm. However, the first outer diameter ED1 is not limited to this embodiment and the ranges described above. The projection 32B has a second outer diameter ED2 equal to or less than 32 mm. The second outer diameter ED2 is equal to or greater than 30 mm. In this embodiment, the second outer diameter ED2 is 31.5 mm. However, the second outer diameter ED2 is not limited to this embodiment and the ranges described above.

As shown in fig. 5, the locking member 32 has a tool engaging portion 32D. The tool engaging portion 32D is provided on the inner peripheral surface 32C1 of the tubular body portion 32C to engage with a tool. The tool engaging portion 32D includes a plurality of tool engaging recesses 32D1 disposed on an inner peripheral surface 32C1 of the tubular body portion 32C. However, the structure of the tool engagement portion 32D is not limited to this embodiment. The tool engaging portion 32D may be omitted from the locking member 32 or may have another shape than the tool engaging portion 32D in the illustrated embodiment.

As seen in fig. 6, the bicycle hub assembly 12 further includes a ratchet structure 38. The sprocket support body 28 is operatively coupled to the hub body 36 by a ratchet structure 38. The ratchet structure 38 is configured to couple the sprocket support body 28 to the hub body 36 to rotate the sprocket support body 28 with the hub body 36 in the drive rotation direction D11 (fig. 5) during pedaling. The ratchet structure 38 is configured to allow the sprocket support body 28 to rotate in an opposite rotational direction D12 (fig. 5) relative to the hub body 36 during coasting. Thus, the ratchet structure 38 can be interpreted as a one-way clutch structure 38. The ratchet structure 38 comprises a structure known in the bicycle art. Therefore, they will not be described in detail herein for the sake of brevity.

The bicycle hub assembly 12 includes a first bearing 39A and a second bearing 39B. The first bearing 39A and the second bearing 39B are disposed between the sprocket support body 28 and the hub axle 30 to rotatably support the sprocket support body 28 about the rotational center axis a1 with respect to the hub axle 30.

In this embodiment, each of the sprocket support body 28, the brake rotor support body 34 and the hub body 36 is made of a metallic material such as aluminum, iron or titanium. However, at least one of the sprocket support body 28, the brake rotor support body 34 and the hub body 36 can be made of a non-metallic material.

As seen in fig. 7 and 8, the sprocket support body 28 includes at least one external spline tooth 40 configured to engage the bicycle rear sprocket assembly 14 (fig. 6). The sprocket support body 28 includes a plurality of external spline teeth 40 configured to engage the bicycle rear sprocket assembly 14 (fig. 6). That is, the at least one external spline tooth 40 includes a plurality of external spline teeth 40. The sprocket support body 28 includes at least nine externally splined teeth 40 configured to engage the bicycle rear sprocket assembly 14 (fig. 6). The sprocket support body 28 includes at least ten external spline teeth 40 configured to engage the bicycle rear sprocket assembly 14 (fig. 6).

The sprocket support body 28 includes a tubular base support 41. The base support 41 extends along a central axis of rotation a 1. The outer spline teeth 40 extend radially outward from the base support 41. The sprocket support body 28 includes a larger diameter portion 42, a flange 44 and a plurality of helical outer spline teeth 46. The larger diameter portion 42 and the flange 44 extend radially outward from the base support 41. The larger diameter portion 42 is disposed between the plurality of external spline teeth 40 and the flange 44 in the axial direction D2. The larger diameter portion 42 and the flange 44 are disposed between the plurality of external spline teeth 40 and the plurality of helical external spline teeth 46 in the axial direction D2. As seen in fig. 6, the bicycle rear sprocket assembly 14 is held between the larger diameter portion 42 and the projecting portion 32B of the locking member 32 in the axial direction D2. The larger diameter portion 42 may have an internal cavity such that a drive structure, such as a one-way clutch structure, may be received within the internal cavity. The larger diameter portion 42 can be omitted from the bicycle hub assembly 12 as desired.

As shown in fig. 9, the total number of at least ten external spline teeth 40 is equal to or greater than 20. The total of at least ten external spline teeth 40 is equal to or greater than 25. In this embodiment, the total number of at least ten external spline teeth 40 is 26. However, the total number of the external spline teeth 40 is not limited to this embodiment and the above range.

At least ten of the external spline teeth 40 have a first external pitch angle PA11 and a second external pitch angle PA 12. At least two of the plurality of external spline teeth 40 are circumferentially arranged at a first external pitch angle PA11 relative to the center axis of rotation A1 of the bicycle hub assembly 12. At least two of the plurality of external spline teeth 40 are circumferentially arranged at a second external pitch angle PA12 relative to the rotational center axis a1 of the bicycle hub assembly 12. In this embodiment, the second outer pitch angle PA12 is different from the first outer pitch angle PA 11. However, the second outer pitch angle PA12 may be substantially equal to the first outer pitch angle PA 11.

In this embodiment, the plurality of external spline teeth 40 are arranged at a first external pitch angle PA11 in the circumferential direction D1. Two 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 external spline teeth 40 may be arranged at additional external pitch angles in the circumferential direction D1.

The first outer pitch angle PA11 ranges from 10 degrees to 20 degrees. The first outer pitch angle PA11 ranges from 12 degrees to 15 degrees. The first outer pitch angle PA11 ranges from 13 degrees to 14 degrees. In this embodiment, the first outer pitch angle PA11 is 13.3 degrees. However, the first external pitch angle PA11 is not limited to this embodiment and the above range.

The second outer pitch angle PA12 ranges from 5 degrees to 30 degrees. In this embodiment, the second outer pitch angle PA12 is 26 degrees. However, the second outer pitch angle PA12 is not limited to this embodiment and the above range.

The external spline teeth 40 have substantially the same shape as each other. The external spline teeth 40 have substantially the same spline dimensions as each other. The external spline teeth 40 have substantially the same profile as each other when viewed along the rotational center axis a 1. However, as shown in fig. 10, at least one of the at least ten external spline teeth 40 may have a first spline shape that is different from a second spline shape of another one of the at least ten external spline teeth 40. At least one of the at least ten external spline teeth 40 may have a first spline dimension that is different from a second spline dimension of another of the at least ten external spline teeth 40. At least one of the at least ten external spline teeth 40 may have a profile that is different from a profile of another one of the at least ten external spline teeth 40 when viewed along the rotational center axis a 1. In fig. 10, one of the external spline teeth 40 has a spline shape different from the spline shape of the other teeth of the external spline teeth 40. One of the external spline teeth 40 has a spline size that is different from the spline size of the other of the external spline teeth 40. When viewed along the rotational center axis a1, one of the external spline teeth 40 has a different profile than the other teeth of the external spline teeth 40.

As shown in fig. 11, each of the at least ten externally splined teeth 40 has an externally splined driving surface 48 and an externally splined non-driving surface 50. The plurality of externally splined teeth 40 include a plurality of externally splined drive surfaces 48 to receive a driving rotational 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-drive surfaces 50. The externally splined driving surface 48 is contactable with the bicycle rear sprocket assembly 14 to receive a driving rotational force F1 from the bicycle rear sprocket assembly 14 (fig. 6) during pedaling. The externally splined drive surface 48 faces in the opposite rotational direction D12. The externally splined non-drive surface 50 is disposed on an opposite side of the externally splined drive surface 48 in the circumferential direction D1. The externally splined non-driving surface 50 faces in the driving rotation direction D11 and does not receive the driving rotation force F1 from the bicycle rear sprocket assembly 14 during pedaling.

At least ten of the external spline teeth 40 each have a circumferential maximum width MW 1. The plurality of external spline teeth 40 each have a circumferential maximum width MW 1. The circumferential maximum width MW1 is defined as the maximum width that receives the thrust F2 applied to the external spline teeth 40. The circumferential maximum width MW1 is defined as the linear distance based on the externally splined drive surface 48.

The plurality of externally splined drive surfaces 48 each include a radially outermost edge 48A and a radially innermost edge 48B. The externally splined drive surface 48 extends from a radially outermost edge 48A to a radially innermost edge 48B. A first reference circle RC11 is defined on the radially innermost edge 48B and is centered on the rotational center axis a 1. A first reference circle RC11 intersects male spline non-driving surface 50 at reference point 50R. Circumferential maximum width MW1 extends linearly in circumferential direction D1 from radially innermost edge 48B to reference point 50R.

The plurality of externally splined non-driving surfaces 50 each include a radially outermost edge 50A and a radially innermost edge 50B. The externally splined non-driving surface 50 extends from a radially outermost edge 50A to a radially innermost edge 50B. A reference point 50R is disposed between the radially outermost edge 50A and the radially innermost edge 50B. However, reference point 50R may coincide with radially innermost edge 50B.

The sum of the circumferential maximum widths MW1 is equal to or greater than 55 mm. The sum of the circumferential maximum widths MW1 is equal to or greater than 60 mm. The sum of the circumferential maximum widths MW1 is equal to or greater than 65 mm. In this embodiment, the sum of the circumferential maximum widths MW1 is 68 mm. However, the sum of the circumferential maximum widths MW1 is not limited to this embodiment and the above range.

As shown in fig. 12, at least one of the externally splined teeth 40 has an externally splined top diameter DM 11. The external spline crest diameter DM11 is equal to or greater than 25 mm. The external spline crest diameter DM11 is equal to or greater than 29 mm. And the external spline top diameter DM11 is equal to or less than 30 mm. In this embodiment, the external spline crest diameter DM11 is 29.6 mm. However, the external spline crest diameter DM11 is not limited to this embodiment and the ranges described above.

At least one of the externally splined teeth 40 has an externally splined bottom diameter DM 12. The at least one external spline tooth 40 has an external spline root circle RC12, the external spline root circle RC12 having an external spline base diameter DM 12. However, the outer spline root circle RC12 may have another diameter than the outer spline base diameter DM 12. The external spline bottom diameter DM12 is equal to or less than 28 mm. The external spline base diameter DM12 is equal to or greater than 25 mm. The external spline base diameter DM12 is equal to or greater than 27 mm. In this embodiment, the external spline base diameter DM12 is 27.2 mm. However, the outer spline bottom diameter DM12 is not limited to this embodiment and the ranges described above.

The larger diameter portion 42 has an outer diameter DM13 that is larger than the external spline crest diameter DM 11. The outer diameter DM13 ranged from 32mm to 40 mm. 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. 11, plurality of externally splined drive surfaces 48 each include a radial length RL11 defined from radially outermost edge 48A to radially innermost edge 48B. The sum of the radial lengths RL11 of the plurality of externally splined drive surfaces 48 is equal to or greater than 7 mm. The sum of the radial lengths RL11 is equal to or greater than 10 mm. The sum of the radial lengths RL11 is equal to or greater than 15 mm. In this embodiment, the sum of the radial lengths RL11 is 19.5 mm. However, the sum of the radial lengths RL11 is not limited to this embodiment.

The plurality of external spline teeth 40 have a radial length RL 12. The radial lengths RL12 are respectively defined from the outer spline root circle RC12 to the radially outermost ends 40A of the plurality of outer spline teeth 40. The sum of the radial lengths RL12 is equal to or greater than 12 mm. In this embodiment, the sum of the radial lengths RL12 is 31.85 mm. However, the sum of the radial lengths RL12 is not limited to this embodiment.

At least one of the at least nine external spline teeth 40 has an asymmetrical shape with respect to the circumferential tip centerline CL 1. The circumferential addendum center line CL1 is a line connecting the rotation center axis a1 and the circumferential center point CP1 of the radially outermost end 40A of the external spline tooth 40. However, at least one of the male spline teeth 40 may have a symmetrical shape with respect to the circumferential crest center line CL 1. At least one of the at least nine externally splined teeth 40 includes an externally splined driving surface 48 and an externally splined non-driving surface 50.

The externally splined drive surface 48 has a first externally splined surface angle AG 11. A first external spline surface angle AG11 is defined between external spline drive surface 48 and a first radial line L11. The first radial line L11 extends from the rotational center axis a1 of the bicycle hub assembly 12 to the radially outermost edge 48A of the externally splined drive surface 48. A first outer pitch angle PA11 or a second outer pitch angle PA12 is defined between adjacent first radial lines L11 (see, e.g., fig. 9).

The externally splined non-driving surface 50 has a second externally splined surface angle AG 12. A second male spline surface angle AG12 is defined between the male spline non-drive surface 50 and a second radial line L12. The second radial line L12 extends from the rotational center axis a1 of the bicycle hub assembly 12 to the radially outermost edge 50A of the externally splined non-driving surface 50.

In this embodiment, second externally splined surface angle AG12 is different from first externally splined surface angle AG 11. The first externally splined surface angle AG11 is less than the second externally splined surface angle AG 12. However, first external spline surface angle AG11 may be equal to or greater than second external spline surface angle AG 12.

The first external spline surface angle AG11 ranges from 0 degrees to 10 degrees. The second externally splined surface angle AG12 ranges from 0 degrees to 60 degrees. In this embodiment, the first external spline surface angle AG11 is 5 degrees. The second externally splined surface angle AG12 is 45 degrees. However, first and second externally splined surface angles AG11, AG12 are not limited to this embodiment and the ranges described above.

As seen in fig. 13 and 14, the brake rotor support body 34 includes at least one additional external spline tooth 52 configured to engage the bicycle brake rotor 16 (fig. 4). In this embodiment, the brake rotor support body 34 includes an additional base support 54 and a plurality of additional external spline teeth 52. The additional base support 54 has a tubular shape and extends from the hub body 36 along the rotational center axis a 1. Additional outer spline teeth 52 extend radially outward from an additional base support 54. The total number of additional external spline teeth 52 is 52. However, the total number of additional external spline teeth 52 is not limited to this embodiment.

As shown in fig. 14, at least one additional external spline tooth 52 has an additional external spline crest diameter DM 14. As shown in fig. 15, the additional external spline crest diameter DM14 is greater than the external spline crest diameter DM 11. The additional external spline crest diameter DM14 is substantially equal to the external diameter DM13 of the larger diameter portion 42. However, the additional outer spline crest diameter DM14 may be equal to or less than the outer spline crest diameter DM 11. The additional external spline crest diameter DM14 may be different from the external diameter DM13 of the larger diameter portion 42.

As shown in fig. 16, the hub axle 30 includes an axial contact surface 30B1 to contact the bicycle frame BF. In this embodiment, the axial contact surface 30B1 is contactable with the first frame BF1 of the bicycle frame BF. The first frame BF1 includes a frame contact surface BF 12. In a state where the bicycle hub assembly 12 is fixed to the bicycle frame BF by the wheel fixing structure WS, the axial contact surface 30B1 is in contact with the frame contact surface BF 12.

The first axial length AL11 is defined in the axial direction D2 relative to the rotational center axis a1 from the axial contact surface 30B1 to the larger diameter portion 42. The first axial length AL11 ranges from 35mm to 41 mm. The first axial length AL11 may be equal to or greater than 39 mm. The first axial length AL11 may also range from 35mm to 37 mm. In this embodiment, the first axial length AL11 is 36.2 mm. However, the first axial length AL11 is not limited to this embodiment and the ranges described above.

The larger diameter portion 42 has an axial end 42A that is farthest from the axial contact surface 30B1 in the axial direction D2. The second axial length AL12 is defined in the axial direction D2 from the axial contact surface 30B1 to the axial end 42A. The second axial length AL12 ranges from 38mm to 47 mm. The second axial length AL12 may range from 44mm to 45 mm. The second axial length AL12 may also range from 40mm to 41 mm. In this embodiment, the second axial length AL12 is 40.75 mm. However, the second axial length AL12 is not limited to this embodiment and the ranges described above.

The axial length AL13 of the larger diameter portion 42 ranges from 3mm to 6 mm. In this embodiment, the axial length AL13 is 4.55 mm. However, the axial length AL13 is not limited to this embodiment and the ranges described above.

As seen in fig. 17, the bicycle rear sprocket assembly 14 includes at least one sprocket. The at least one sprocket includes a plurality of sprockets. The at least one sprocket includes at least ten sprockets. The at least one sprocket includes at least eleven sprockets. The at least one sprocket includes at least twelve sprockets. The plurality of sprockets includes a largest sprocket SP 12. The largest sprocket has a tip diameter TD 1. The plurality of sprockets also includes a smallest sprocket SP 1. The smallest sprocket SP1 can also be referred to as sprocket SP 1. The largest sprocket SP12 can also be referred to as sprocket SP 12. In this embodiment, the at least one sprocket further comprises sprockets SP2 to SP 11. The sprocket SP1 corresponds to the high gear. The sprocket SP12 corresponds to the low gear. In this embodiment, the total number of the plurality of sprockets is 12. However, the total number of sprockets of the bicycle rear sprocket assembly 14 is not limited to this embodiment.

The smallest sprocket SP1 includes at least one sprocket tooth SP 1B. The total number of the at least one sprocket teeth SP1B of the smallest sprocket SP1 is equal to or less than 10. In this embodiment, the total number of the at least one sprocket tooth SP1B of the smallest sprocket SP1 is 10. However, the total number of the at least one sprocket tooth SP1B of the minimum sprocket SP1 is not limited to the embodiment and the above range.

The largest sprocket SP12 includes at least one sprocket tooth SP 12B. The total number of teeth of the largest sprocket SP12 is equal to or greater than 39. The total number of teeth of the largest sprocket SP12 is equal to or greater than 45. The total number of the at least one sprocket tooth SP12B of the largest sprocket SP12 is equal to or greater than 46. The total number of the at least one sprocket tooth SP12B of the largest sprocket SP12 is equal to or greater than 50. In this embodiment, the total number of the at least one sprocket tooth SP12B of the largest sprocket SP12 is 51. However, the total number of the at least one sprocket tooth SP12B of the largest sprocket SP12 is not limited to the embodiment and the above range. The tooth tip diameter TD1 is the diameter of the circle defined by the tooth tip portion of the sprocket tooth SP 12B.

The sprocket SP2 includes at least one sprocket tooth SP 2B. The sprocket SP3 includes at least one sprocket tooth SP 3B. The sprocket SP4 includes at least one sprocket tooth SP 4B. The sprocket SP5 includes at least one sprocket tooth SP 5B. The sprocket SP6 includes at least one sprocket tooth SP 6B. The sprocket SP7 includes at least one sprocket tooth SP 7B. The sprocket SP8 includes at least one sprocket tooth SP 8B. The sprocket SP9 includes at least one sprocket tooth SP 9B. The sprocket SP10 includes at least one sprocket tooth SP 10B. The sprocket SP11 includes at least one sprocket tooth SP 11B.

The total number of the at least one sprocket teeth SP2B is 12. The total number of the at least one sprocket teeth SP3B is 14. The total number of the at least one sprocket teeth SP4B is 16. The total number of the at least one sprocket teeth SP5B is 18. The total number of the at least one sprocket teeth SP6B is 21. The total number of the at least one sprocket teeth SP7B is 24. The total number of the at least one sprocket teeth SP8B is 28. The total number of the at least one sprocket teeth SP9B is 33. The total number of the at least one sprocket teeth SP10B is 39. The total number of the at least one sprocket teeth SP11B is 45. At least one sprocket has a total number of teeth equal to or greater than 15. For example, the sprocket SP4 has a total tooth count of 16. The total number of teeth of the sprocket SP5 is 18. The total number of teeth of the sprocket SP6 is 21. The total number of teeth of the sprocket SP7 is 24. The total number of teeth of the sprocket SP8 is 28. The total number of teeth of the sprocket SP9 is 33. The total number of teeth of the sprocket SP10 is 39. The total number of teeth of the sprocket SP11 is 45. The total number of teeth of the sprocket SP12 is 51. The total number of sprocket teeth of each of the sprockets SP2 to SP11 is not limited to this embodiment. At least one of the sprockets SP1 to SP12 can include a total number of teeth equal to or greater than 15.

As shown in fig. 18, the sprockets SP1 to SP12 are members separate from each other. However, at least one of the sprockets SP1 to SP12 can be at least partially integrally provided with another one of the sprockets SP1 to SP 12. The bicycle rear sprocket assembly 14 further includes a sprocket support 56, a plurality of spacers 58, a first ring 59A and a second ring 59B. In the illustrated embodiment, a plurality of sprockets SP 1-SP 12 are attached to the sprocket support 56. For example, the plurality of sprockets SP 1-SP 12 are attached to the sprocket support 56 with an adhesive.

As shown in fig. 19, the sprocket SP1 includes a sprocket body SP1A and a plurality of sprocket teeth SP 1B. A plurality of sprocket teeth SP1B extend radially outward from the sprocket body SP 1A. The sprocket SP2 includes a sprocket body SP2A and a plurality of sprocket teeth SP 2B. A plurality of sprocket teeth SP2B extend radially outward from the sprocket body SP 2A. The sprocket SP3 includes a sprocket body SP3A and a plurality of sprocket teeth SP 3B. A plurality of sprocket teeth SP3B extend radially outward from the sprocket body SP 3A. The sprocket SP4 includes a sprocket body SP4A and a plurality of sprocket teeth SP 4B. A plurality of sprocket teeth SP4B extend radially outward from the sprocket body SP 4A. The sprocket SP5 includes a sprocket body SP5A and a plurality of sprocket teeth SP 5B. A plurality of sprocket teeth SP5B extend radially outward from the sprocket body SP 5A. The first ring 59A is disposed between the sprocket SP3 and the sprocket SP 4. The second ring 59B is disposed between the sprocket SP4 and the sprocket SP 5.

As shown in fig. 20, the sprocket SP6 includes a sprocket body SP6A and a plurality of sprocket teeth SP 6B. A plurality of sprocket teeth SP6B extend radially outward from the sprocket body SP 6A. The sprocket SP7 includes a sprocket body SP7A and a plurality of sprocket teeth SP 7B. A plurality of sprocket teeth SP7B extend radially outward from the sprocket body SP 7A. The sprocket SP8 includes a sprocket body SP8A and a plurality of sprocket teeth SP 8B. A plurality of sprocket teeth SP8B extend radially outward from the sprocket body SP 8A.

As shown in fig. 21, the sprocket SP9 includes a sprocket body SP9A and a plurality of sprocket teeth SP 9B. A plurality of sprocket teeth SP9B extend radially outward from the sprocket body SP 9A. The sprocket SP10 includes a sprocket body SP10A and a plurality of sprocket teeth SP 10B. A plurality of sprocket teeth SP10B extend radially outward from the sprocket body SP 10A. The sprocket SP11 includes a sprocket body SP11A and a plurality of sprocket teeth SP 11B. A plurality of sprocket teeth SP11B extend radially outward from the sprocket body SP 11A. The sprocket SP12 includes a sprocket body SP12A and a plurality of sprocket teeth SP 12B. A plurality of sprocket teeth SP12B extend radially outward from the sprocket body SP 12A.

As shown in fig. 22, the sprocket support 56 includes a hub engaging portion 60 and a plurality of support arms 62. A plurality of support arms 62 extend radially outward from the hub engagement portion 60. The support arm 62 includes first to eighth attachment portions 62A to 62H. The plurality of spacers 58 includes a plurality of first spacers 58A, a plurality of second spacers 58B, a plurality of third spacers 58C, a plurality of fourth spacers 58D, a plurality of fifth spacers 58E, a plurality of sixth spacers 58F, and a plurality of seventh spacers 58G.

As shown in fig. 23, the first spacer 58A is disposed between the sprocket SP5 and the sprocket SP 6. The second spacer 58B is disposed between the sprocket SP6 and the sprocket SP 7. The third spacer 58C is disposed between the sprocket SP7 and the sprocket SP 8. The fourth spacer 58D is disposed between the sprocket SP8 and the sprocket SP 9. The fifth spacer 58E is disposed between the sprocket SP9 and the sprocket SP 10. The sixth spacer 58F is disposed between the sprocket SP10 and the sprocket SP 11. The seventh spacer 58G is disposed between the sprocket SP11 and the sprocket SP 12.

The sprocket SP6 and the first spacer 58A are attached to the first attachment portion 62A by a bonding structure such as an adhesive. The sprocket SP7 and the second spacer 58B are attached to the second attachment portion 62B by a bonding structure such as an adhesive. The sprocket SP8 and the third spacer 58C are attached to the third attachment portion 62C by a bonding structure such as an adhesive. The sprocket SP9 and the fourth spacer 58D are attached to the fourth attachment portion 62D by a bonding structure such as an adhesive. The sprocket SP10 and the fifth spacer 58E are attached to the fifth attachment portion 62E by a bonding structure such as an adhesive. The sprocket SP11 and the sixth spacer 58F are attached to the sixth attachment portion 62F by a bonding structure such as an adhesive. The sprocket SP12 and the seventh spacer 58G are attached to the seventh attachment portion 62G by a bonding structure such as an adhesive. The sprocket SP5 and the second ring 59B are attached to the eighth attaching portion 62H by a bonding structure such as an adhesive. The hub engaging portion 60, the sprocket SP1 through the sprocket SP4, the first ring 59A and the second ring 59B are held between the larger diameter portion 42 and the protruding portion 32B of the locking member 32 in the axial direction D2.

In this embodiment, each of the sprockets SP1 to SP12 is made of a metal material such as aluminum, iron or titanium. Each of the sprocket support 56, the first to seventh spacers 58A to 58G, the first ring 59A and the second ring 59B is made of a non-metallic material such as a resin material. The sprocket support 56 is made of a non-metallic material including a resin material. However, at least one of the sprockets SP1 to SP12 can be at least partially made of a non-metallic material. At least one of the sprocket support 56, the first through seventh spacers 58A through 58G, the first and second rings 59A and 59B may be at least partially made of a metallic material such as aluminum, iron, or titanium.

At least one sprocket includes at least one internally splined tooth configured to engage the bicycle hub assembly 12. As seen in fig. 24 and 25, at least one sprocket includes at least ten internal spline teeth configured to engage the bicycle hub assembly 12. The at least one internal spline tooth includes a plurality of internal spline teeth. Thus, at least one sprocket includes a plurality of internal spline teeth configured to engage the bicycle hub assembly 12. In this embodiment, the sprocket SP1 includes at least ten internal spline teeth 64 configured to engage the bicycle hub assembly 12. In this embodiment, the sprocket SP1 includes internal spline teeth 64 configured to mesh with the external spline teeth 40 of the sprocket support body 28 of the bicycle hub assembly 12. The sprocket body SP1A has a ring shape. The inner spline teeth 64 extend radially inward from the sprocket body SP 1A.

As shown in fig. 26, the total number of at least ten internal spline teeth 64 is equal to or greater than 20. The total number of the at least ten internal spline teeth 64 is equal to or greater than 25. In this embodiment, the total number of internal spline teeth 64 is 26. However, the total number of the internal spline teeth 64 is not limited to this embodiment and the above range.

At least ten of the internal spline teeth 64 have a first internal pitch angle PA21 and a second internal pitch angle PA 22. At least two of the plurality of internal spline teeth 64 are circumferentially arranged at a first internal pitch angle PA21 relative to the rotational center axis A1 of the bicycle rear sprocket assembly 14. At least two of the plurality of internal spline teeth 64 are circumferentially arranged at a second internal pitch angle PA22 relative to the central axis of rotation a 1. In this embodiment, the second internal pitch angle PA22 is different from the first internal pitch angle PA 21. However, the second inner pitch angle PA22 may be substantially equal to the first inner pitch angle PA 21.

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

The first internal pitch angle PA21 ranges from 10 degrees to 20 degrees. The first inner pitch angle PA21 ranges from 12 degrees to 15 degrees. The first internal pitch angle PA21 ranges from 13 degrees to 14 degrees. In this embodiment, the first internal pitch angle PA21 is 13.3 degrees. However, the first internal pitch angle PA21 is not limited to this embodiment and the above range.

The second internal pitch angle PA22 ranges from 5 degrees to 30 degrees. In this embodiment, the second internal pitch angle PA22 is 26 degrees. However, the second internal pitch angle PA22 is not limited to this embodiment and the above range.

At least one of the at least ten internal spline teeth 64 has a first spline shape that is different from a second spline shape of another of the at least ten internal spline teeth 64. At least one of the at least ten internal spline teeth 64 has a first spline dimension that is different from a second spline dimension of another of the at least ten internal spline teeth 64. At least one of the at least ten internal spline teeth 64 has a cross-sectional shape that is different from a cross-sectional shape of another of the at least ten internal spline teeth 64. However, as shown in fig. 27, the internal spline teeth 64 may have the same shape as each other. The internal spline teeth 64 may have the same dimensions as one another. The internal spline teeth 64 may have the same cross-sectional shape as each other.

As shown in fig. 28, at least one internally splined tooth 64 includes an internally splined driving surface 66 and an internally splined non-driving surface 68. The at least one internal spline tooth 64 includes a plurality of internal spline teeth 64. The plurality of internal spline teeth 64 include a plurality of internal spline drive surfaces 66 to receive a driving rotational force F1 from the bicycle hub assembly 12 (fig. 6) during pedaling. The plurality of internal spline teeth 64 includes a plurality of internal spline non-drive surfaces 68. The internally splined drive surface 66 is contactable with the sprocket support body 28 to transfer a driving rotational force F1 from the sprocket SP1 to the sprocket support body 28 during pedaling. The internally splined drive surface 66 faces in the drive rotational direction D11. The internally splined non-drive surface 68 is disposed on an opposite side of the internally splined drive surface 66 in the circumferential direction D1. The internally splined non-drive surface 68 faces in the opposite rotational direction D12, and the driving rotational force F1 is not transferred from the sprocket SP1 to the sprocket support body 28 during pedaling.

At least ten of the internal spline teeth 64 each have a circumferential maximum width MW 2. The plurality of internal spline teeth 64 each have a circumferential maximum width MW 2. The circumferential maximum width MW2 is defined as the maximum width that receives the thrust F3 applied to the internal spline teeth 64. The circumferential maximum width MW2 is defined as the linear distance based on the internally splined drive surface 66.

The internally splined drive surface 66 includes a radially outermost edge 66A and a radially innermost edge 66B. The internally splined drive surface 66 extends from a radially outermost edge 66A to a radially innermost edge 66B. A second reference circle RC21 is defined on the radially outermost edge 66A and is centered on the rotational center axis a 1. A second reference circle RC21 intersects the internally splined non-driving surface 68 at reference point 68R. The circumferential maximum width MW2 extends linearly in the circumferential direction D1 from the radially innermost edge 66B to the reference point 68R.

The inner splined non-driving surface 68 includes a radially outermost edge 68A and a radially innermost edge 68B. The inner splined non-driving surface 68 extends from a radially outermost edge 68A to a radially innermost edge 68B. Reference point 68R is disposed between radially outermost edge 68A and radially innermost edge 68B.

The sum of the circumferential maximum widths MW2 is equal to or greater than 40 mm. The sum of the circumferential maximum widths MW2 is equal to or greater than 45 mm. The sum of the circumferential maximum widths MW2 is equal to or greater than 50 mm. In this embodiment, the sum of the circumferential maximum widths MW2 is 50.8 mm. However, the sum of the circumferential maximum widths MW2 is not limited to this embodiment.

As shown in fig. 29, at least one of the internally splined teeth 64 has an internally splined bottom diameter DM 21. The at least one inner spline tooth 64 has an inner spline root circle RC22, the inner spline root circle RC22 having an inner spline base diameter DM 21. However, the inner spline root circle RC22 may have another diameter than the inner spline base diameter DM 21. The internal spline base diameter DM21 is equal to or less than 30 mm. The internal spline base diameter DM21 is equal to or greater than 25 mm. The internal spline base diameter DM21 is equal to or greater than 29 mm. In this embodiment, the internal spline base diameter DM21 is 29.6 mm. However, the internal spline base diameter DM21 is not limited to this embodiment and the ranges described above. In this embodiment, the ratio of the internal spline base diameter DM21 to the tooth tip diameter TD1 ranges from 0.1 to 0.2. The crest diameter TD1 (FIG. 1) of the largest sprocket SP12 ranges from 183.7mm to 207.9 mm. The ratio of the internal spline base diameter DM21 to the tooth tip diameter TD1 ranges from 0.14 to 0.17. However, the ratio of the internal spline base diameter DM21 to the tooth tip diameter TD1 is not limited to the above range.

At least one of the internal spline teeth 64 has an internal spline crest diameter DM22, the internal spline crest diameter DM22 is equal to or less than 28 mm. The internal spline crest diameter DM22 is equal to or greater than 25 mm. The internal spline crest diameter DM22 is equal to or greater than 27 mm. In this embodiment, the internal spline crest diameter DM22 is 27.7 mm. However, the internal spline crest diameter DM22 is not limited to this embodiment and the ranges described above.

As shown in fig. 28, the plurality of internally splined drive surfaces 66 includes a radially outermost edge 66A and a radially innermost edge 66B. The plurality of inner spline drive surfaces 66 each include a radial length RL21 defined from a radially outermost edge 66A to a radially innermost edge 66B. The sum of the radial lengths RL21 of the plurality of internal spline drive surfaces 66 is equal to or greater than 7 mm. The sum of the radial lengths RL21 is equal to or greater than 10 mm. The sum of the radial lengths RL21 is equal to or greater than 15 mm. In this embodiment, the sum of the radial lengths RL21 is 19.5 mm. However, the sum of the radial lengths RL21 is not limited to this embodiment and the ranges described above.

The plurality of internal spline teeth 64 have an additional radial length RL 22. Additional radial lengths RL22 are defined from the inner spline tooth root circle RC22 to the radially innermost ends 64A of the plurality of inner spline teeth 64, respectively. The sum of the additional radial lengths RL22 is equal to or greater than 12 mm. In this embodiment, the sum of the additional radial lengths RL22 is 27.95 mm. However, the sum of the additional radial lengths RL22 is not limited to this embodiment and the ranges described above.

At least one of the internal spline teeth 64 has an asymmetrical shape with respect to the circumferential tip centerline CL 2. The circumferential tip center line CL2 is a line connecting the rotational center axis a1 and the circumferential center point CP2 of the radially innermost end portion 64A of the inner spline tooth 64. However, at least one of the internal spline teeth 64 may have a symmetrical shape with respect to the circumferential tip center line CL 2. At least one of the internally splined teeth 64 includes an internally splined driving surface 66 and an internally splined non-driving surface 68.

The internally splined drive surface 66 has a first internally splined surface angle AG 21. A first internal spline surface angle AG21 is defined between internal spline drive surface 66 and a first radial line L21. The first radial line L21 extends from the rotational center axis a1 of the bicycle rear sprocket assembly 14 to the radially outermost edge 66A of the internally splined driving surface 66. A first internal pitch angle PA21 or a second internal pitch angle PA22 is defined between adjacent first radial lines L21 (see, e.g., fig. 26).

The internally splined non-drive surface 68 has a second internally splined surface angle AG 22. A second internally splined surface angle AG22 is defined between internally splined non-drive surface 68 and a second radial line L22. The second radial line L22 extends from the rotational center axis a1 of the bicycle rear sprocket assembly 14 to the radially outermost edge 68A of the inner splined non-driving surface 68.

In this embodiment, second internally splined surface angle AG22 is different from first internally splined surface angle AG 21. First internal spline surface angle AG21 is less than second internal spline surface angle AG 22. However, first internal spline surface angle AG21 may be equal to or greater than second internal spline surface angle AG 22.

The first internal spline surface angle AG21 ranges from 0 degrees to 10 degrees. Second internal spline surface angle AG22 ranges from 0 degrees to 60 degrees. In this embodiment, first internally splined surface angle AG21 is 5 degrees. Second internally splined surface angle AG22 is 45 degrees. However, first and second internal spline surface angles AG21 and AG22 are not limited to this embodiment and the ranges described above.

As shown in fig. 30, the internal spline teeth 64 mesh with the external spline teeth 40 to transmit the driving rotational force F1 from the sprocket SP1 to the sprocket support body 28. The internally splined drive surface 66 is contactable with the externally splined drive surface 48 to transfer a driving rotational force F1 from the sprocket SP1 to the sprocket support body 28. With the inner spline drive surfaces 66 in contact with the outer spline drive surfaces 48, the inner spline non-drive surfaces 68 are spaced from the outer spline non-drive surfaces 50.

As shown in fig. 31, the sprocket SP2 includes a plurality of internal spline teeth 70. The sprocket SP3 includes a plurality of internally splined teeth 72. The sprocket SP4 includes a plurality of internally splined teeth 74. The first ring 59A includes a plurality of internal spline teeth 76. As shown in fig. 32, the hub engaging portion 60 of the sprocket support 56 includes a plurality of internal spline teeth 78. The plurality of internal spline teeth 70 have substantially the same structure as the plurality of internal spline teeth 64. The plurality of internal spline teeth 72 have substantially the same structure as the plurality of internal spline teeth 64. The plurality of internal spline teeth 74 have substantially the same structure as the plurality of internal spline teeth 64. The plurality of internal spline teeth 76 have substantially the same structure as the plurality of internal spline teeth 64. The plurality of internal spline teeth 78 have substantially the same structure as the plurality of internal spline teeth 64. Therefore, they will not be described in detail herein for the sake of brevity.

As seen in fig. 6, the bicycle rear sprocket assembly 14 further includes a rear hub abutment surface 80. The rear hub abutment surface 80 is configured to abut against the bicycle hub assembly 12 in the axial direction D2 with respect to the rotational center axis a1 of the bicycle rear sprocket assembly 14 in a state where the bicycle rear sprocket assembly 14 is mounted to the bicycle hub assembly 12. In this embodiment, the rear hub abutment surface 80 abuts against the larger diameter portion 42 of the sprocket support body 28 in the axial direction D2. The rear hub abutment surface 80 is disposed on the hub engaging portion 60 of the sprocket support 56. However, the position of the rear hub abutment surface 80 is not limited to this embodiment.

The largest sprocket SP12 has an axially inner surface SP12C and an axially outer surface SP12D, the axially outer surface SP12D being disposed on an opposite side of the axially inner surface SP12C in the axial direction D2 with respect to the rotational center axis a1 of the bicycle rear sprocket assembly 14. The axially outer surface SP12D is closer to the rear hub abutment surface 80 in the axial direction D2 than the axially inner surface SP 12C.

As seen in fig. 15, the bicycle hub assembly 12 has an axial center plane CPL that bisects the bicycle hub assembly 12 in the axial direction D2. The axial center plane CPL of the bicycle hub assembly 12 is perpendicular to the rotational center axis a 1. As seen in fig. 6, the axially inner surface SP12C is positioned closer to the axial center plane CPL of the bicycle hub assembly 12 than the rear hub abutment surface 80 in the state where the bicycle rear sprocket assembly 14 is mounted to the bicycle hub assembly 12. The axial distance AD1 defined between the axially inner surface SP12C and the rear hub abutment surface 80 in the axial direction D2 is equal to or greater than 7 mm. The axial distance AD1 is equal to or greater than 10 mm. However, the axial distance AD1 is not limited to the above range.

As shown in fig. 9 and 10, the sprocket support body 28 includes a hub indicator 28I provided at an axial end of the base support 41. When viewed along the rotational center axis a1, the hub indicator 28I is disposed in the area of the second outer pitch angle PA 12. In this embodiment, the hub indicator 28I includes dots. However, the hub indicator 28I may include other shapes such as a triangle and a line. Further, the hub indicator 28I may be a separate member that is attached to the sprocket support body 28, for example, by a bonding structure such as an adhesive. The position of the hub indicator 28I is not limited to this embodiment.

As seen in fig. 26 and 27, the sprocket SP1 includes a sprocket indicator SP1I disposed at an axial end of the sprocket body SP 1A. The sprocket indicator SP1I is disposed in the area of the second inner pitch angle PA22 when viewed along the rotational center axis a 1. In this embodiment, sprocket indicator SP1I comprises dots. However, sprocket indicator SP1I can comprise other shapes such as triangles and lines. Further, the sprocket indicator SP1I can be a separate member that is attached to the sprocket SP1, for example, by a bonding structure such as an adhesive. The position of the sprocket indicator SP1I is not limited to this embodiment. The sprocket indicator SP1I may be provided to any one of the other sprockets SP2 to SP 12. Sprocket indicator SP1I can also be provided to sprocket support 56.

Variants

Fig. 33 shows a bicycle rear sprocket assembly 214 in accordance with a modification of the bicycle rear sprocket assembly 14. As seen in fig. 33, the bicycle rear sprocket assembly 214 includes a sprocket SP1 and a plurality of sprockets SP202 to SP 212. The sprockets SP202 to SP212 have substantially the same structure as the sprockets SP2 to SP 12. As shown in fig. 33 and 34, for example, the sprocket SP212 includes a sprocket body SP12A and a plurality of sprocket teeth SP 12B.

One of the sprockets SP202 to SP212 can also be referred to as a first sprocket. The other sprocket adjacent to the first sprocket may also be referred to as a second sprocket. That is, the at least one sprocket of the bicycle rear sprocket assembly 214 includes a first sprocket and a second sprocket. The first sprocket has a first total number of teeth. The second sprocket has a second total tooth number less than the first total tooth number. The second sprocket is adjacent the first sprocket in the axial direction D2 without an additional sprocket between the first and second sprockets.

As shown in fig. 33, for example, the first total number of teeth of the first sprocket SP212 is 51. The second total tooth number of the second sprocket SP211 is 45. The sprockets SP212 and SP211 can also be referred to as a first sprocket SP212 and a second sprocket SP 211. The sprockets SP211 and SP210 can also be referred to as a first sprocket SP211 and a second sprocket SP 210. The sprockets SP210 and SP209 can also be referred to as a first sprocket SP210 and a second sprocket SP 209. The sprockets SP209 and SP208 can also be referred to as a first sprocket SP209 and a second sprocket SP 208. The sprockets SP208 and SP207 can also be referred to as a first sprocket SP208 and a second sprocket SP 207. The sprockets SP207 and SP206 can also be referred to as a first sprocket SP207 and a second sprocket SP 206. The sprockets SP206 and SP205 can also be referred to as a first sprocket SP206 and a second sprocket SP 205. The sprockets SP205 and SP204 can also be referred to as a first sprocket SP205 and a second sprocket SP 204. The sprockets SP204 and SP203 can also be referred to as a first sprocket SP204 and a second sprocket SP 203. The sprockets SP203 and SP202 can also be referred to as a first sprocket SP203 and a second sprocket SP 202. The sprockets SP202 and SP1 can also be referred to as a first sprocket SP202 and a second sprocket SP 1.

As seen in fig. 34, for example, the first sprocket SP212 includes at least one first shift facilitating area SP212X to facilitate a first shifting operation of the bicycle chain 20 from the second sprocket SP211 to the first sprocket SP 212. The first sprocket SP212 includes at least one second shift facilitating area SP212Y to facilitate a second shifting operation of the bicycle chain 20 from the first sprocket SP212 to the second sprocket SP 211. In this embodiment, the first sprocket SP212 includes a plurality of first shift facilitating areas SP212X to facilitate a first shifting operation of the bicycle chain 20 from the second sprocket SP211 to the first sprocket SP 212. The first sprocket SP212 includes a plurality of second shift facilitating areas SP212Y to facilitate a second shifting operation of the bicycle chain 20 from the first sprocket SP212 to the second sprocket SP 211.

The first sprocket SP212 includes a plurality of first shift facilitating recesses SP212X1 and a plurality of second shift facilitating recesses SP212Y 1. The first shift facilitation concave portion SP212X1 is provided in the first shift facilitation area SP 212X. The second shift promoting recess SP212Y1 is provided in the second shift promoting region SP 212Y.

As seen in fig. 35, the first shift facilitating recess SP212X1 is provided on the axially outer surface SP12D to reduce interference between the first sprocket SP212 and the bicycle chain 20 (fig. 33) in the first shifting operation. The second shift facilitating recess SP212Y1 is provided on the axially outer surface SP12D to reduce interference between the first sprocket SP212 and the bicycle chain 20 (fig. 33) in the second shifting operation. The second shift promoting recess SP212Y1 is spaced from the first shift promoting recess SP212X1 in the circumferential direction D1.

As shown in fig. 36, the plurality of sprocket teeth SP12B of the first sprocket SP212 include a plurality of shift facilitating teeth SP212B1 to SP212B 3. The shift promoting teeth SP212B1 through SP212B3 are disposed in the second shift promoting region SP 212Y. As seen in fig. 34, the second shift promoting region SP212Y is defined by a second shift promoting recess SP212Y1 and shift promoting teeth SP212B3 in the circumferential direction D1.

As shown in fig. 37, the shift facilitation tooth SP212B1 includes a facilitation recess SP212R 1. The shift facilitation tooth SP212B2 includes a facilitation recess SP212R 2. The shift facilitation tooth SP212B3 includes a facilitation recess SP212R 3. The facilitating recess SP212R1 is provided on the axially inner surface SP12C to facilitate disengagement of the bicycle chain 20 from the first sprocket SP212 in the second shifting operation. The facilitating recess SP212R2 is provided on the axially inner surface SP12C to facilitate disengagement of the bicycle chain 20 from the first sprocket SP212 in the second shifting operation. The facilitating recess SP212R3 is provided on the axially inner surface SP12C to facilitate disengagement of the bicycle chain 20 from the first sprocket SP212 in the second shifting operation.

Each of the sprockets SP202 to SP211 has a first shift facilitation area and a second shift facilitation area having substantially the same structure as the first shift facilitation area SP212X and the second shift facilitation area SP212Y of the first sprocket SP212, respectively. For the sake of brevity, they will not be described in detail here. The term "shift facilitating area" as used herein is intended to be an area intentionally designed to facilitate a shifting operation of a bicycle chain from one sprocket to another axially adjacent sprocket in the area.

As shown in fig. 38, in the above-described embodiment, the externally splined teeth 40 may include a groove 40G disposed in the circumferential direction D1 between the externally splined driving surface 48 and the externally splined non-driving surface 50. The slots 40G reduce the weight of the bicycle hub assembly 12.

As shown in fig. 39, in the above-described embodiment, the internally splined teeth 64 may include grooves 64G disposed in the circumferential direction D1 between the internally splined driving surface 66 and the internally splined non-driving surface 68. The slots 64G reduce the weight of the bicycle rear sprocket assembly 14.

The term "comprises/comprising" and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers, and/or steps. This concept also applies to words of similar meaning, e.g., the terms "having," "including," and their derivatives.

The terms "member," "section," "portion," "element," "body" and "structure" when used in the singular can have the dual meaning of a single part or a plurality of parts.

Ordinal numbers such as "first" and "second" recited in this application are merely labels, but do not have other meanings, e.g., a particular order, etc. Further, for example, the term "first element" does not itself imply the presence of "second element", and the term "second element" does not itself imply the presence of "first element".

The term "pair" as used herein may include configurations in which a pair of elements have different shapes or structures from each other, except for configurations in which a pair of elements have the same shape or structure as each other.

The terms "a", "an", "one or more" and "at least one" may be used interchangeably herein.

Finally, terms of degree such as "substantially", "about" and "approximately" as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. All numerical values described in this application may be construed to include terms such as "substantially", "about" and "approximately".

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

Claims (20)

1. A bicycle rear sprocket assembly comprising:

at least one sprocket having a total number of teeth equal to or greater than 15, the at least one sprocket comprising at least ten internal spline teeth configured to engage a bicycle hub assembly,

wherein the at least ten internal spline teeth comprise a plurality of internal spline drive surfaces to transfer driving rotational force to the bicycle hub assembly during pedaling,

the plurality of internally splined drive surfaces each comprise

The radially outermost edge of the outer casing is,

the radially innermost edge, and

a radial length defined from the radially outermost edge to the radially innermost edge, an

The sum of the radial lengths being equal to or greater than 7mm, and

at least one of the plurality of inner spline drive surfaces has a first inner spline surface angle defined between the at least one of the plurality of inner spline drive surfaces and a first radial line extending from a center axis of rotation of the bicycle rear sprocket assembly to the radially outermost edge of the at least one of the plurality of inner spline drive surfaces, and

the first internal spline surface angle ranges from 0 degrees to 10 degrees.

2. The bicycle rear sprocket assembly according to claim 1, wherein

The total number of the at least ten internal spline teeth is equal to or greater than 20.

3. The bicycle rear sprocket assembly according to claim 2, wherein

The total number of the at least ten internal spline teeth is equal to or greater than 25.

4. The bicycle rear sprocket assembly according to claim 1, wherein

The at least ten internal spline teeth have a first internal pitch angle and a second internal pitch angle different from the first internal pitch angle.

5. The bicycle rear sprocket assembly according to claim 1, wherein

The at least one sprocket includes at least ten sprockets.

6. The bicycle rear sprocket assembly according to claim 1, wherein

The at least one sprocket includes at least eleven sprockets.

7. The bicycle rear sprocket assembly according to claim 1, wherein

The at least one sprocket includes at least twelve sprockets.

8. The bicycle rear sprocket assembly according to claim 1, wherein

The at least one sprocket includes a plurality of sprockets and at least one internally splined tooth configured to engage a bicycle hub assembly,

the plurality of sprockets including a largest sprocket having a crest diameter,

the at least one internal spline tooth has an internal spline base diameter, an

The ratio of the bottom diameter of the internal spline to the top diameter of the tooth is in the range of 0.1 to 0.2.

9. The bicycle rear sprocket assembly according to claim 1, wherein

The at least one sprocket comprises:

a first sprocket having a first total tooth number; and

a second sprocket having a second total number of teeth less than the first total number of teeth, the first sprocket comprising:

at least one first shift facilitating area to facilitate a first shift operation of a bicycle chain from the second sprocket to the first sprocket, and

at least one second shift facilitation area to facilitate a second shift operation of the bicycle chain from the first sprocket to the second sprocket.

10. The bicycle rear sprocket assembly of claim 1, further comprising

A locking member configured to prevent axial movement of the at least one sprocket mounted on the bicycle hub assembly relative to a rotational center axis of the bicycle rear sprocket assembly, wherein

The locking member includes:

a tubular body portion having a central axis; and

a projection extending radially outward from the tubular body portion relative to a central axis of the tubular body portion,

the tubular body portion has an externally threaded portion configured to engage an internally threaded portion of the bicycle hub assembly, an

The protruding portion is configured to abut against the at least one sprocket.

11. The bicycle rear sprocket assembly according to claim 10, wherein

The tubular body portion has a first outer diameter equal to or less than 26 mm.

12. The bicycle rear sprocket assembly according to claim 11, wherein

The first outer diameter is equal to or greater than 25 mm.

13. The bicycle rear sprocket assembly according to claim 10, wherein

The protruding portion has a second outer diameter equal to or less than 32 mm.

14. The bicycle rear sprocket assembly according to claim 13, wherein

The second outer diameter is equal to or greater than 30 mm.

15. The bicycle rear sprocket assembly according to claim 10, wherein

The locking member has a tool engaging portion.

16. The bicycle rear sprocket assembly of claim 1, further comprising

Sprocket support of which

The at least one sprocket includes a plurality of sprockets attached to the sprocket support.

17. The bicycle rear sprocket assembly according to claim 16, wherein

The plurality of sprockets are attached to the sprocket support by an adhesive.

18. The bicycle rear sprocket assembly according to claim 16, wherein

The sprocket support is made of a non-metallic material that includes a resin material.

19. The bicycle rear sprocket assembly of claim 1, further comprising

A rear hub abutment surface configured to abut against the bicycle hub assembly in an axial direction with respect to a rotational center axis of the bicycle rear sprocket assembly in a state in which the bicycle rear sprocket assembly is mounted to the bicycle hub assembly, wherein

The at least one sprocket comprises a plurality of sprockets including a largest sprocket having an axially inner surface and an axially outer surface disposed on an opposite side of the axially inner surface in the axial direction, the axially outer surface being closer to the rear hub abutment surface in the axial direction than the axially inner surface, and

an axial distance defined between the axially inner surface and the rear hub abutment surface in the axial direction is equal to or greater than 7 mm.

20. The bicycle rear sprocket assembly according to claim 19, wherein

The axial distance is equal to or greater than 10 mm.

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