DE102017223877A1 - Rear Bicycle Sprocket Assembly and Bicycle Sprocket Assembly - Google Patents

Abstract

The rear bicycle sprocket assembly 28 includes the first sprocket 28C, the second sprocket 28D and a plurality of first connecting portions 31B. The first sprocket 28C has the first root diameter R1. The second sprocket 28D has the second root diameter R2, which is smaller than the first root diameter R1. The plurality of first connecting portions 31B connect the first sprocket 28C and the second sprocket 28D in the axial direction with each other. The first sprocket 28C, the second sprocket 28D and the plurality of first connection portions 31B are integrally formed as a unitary one-piece member. The total number of the plurality of first connecting portions 31B is smaller than the total number of teeth of the second sprocket 28D.

Description

The technology disclosed herein relates to a rear bicycle sprocket assembly and a bicycle sprocket assembly.

Cycling is becoming an increasingly popular form of recreational activity as well as a means of transport. Moreover, cycling has become a very popular competitive sport for both amateurs and professionals.

Whether the bicycle is used as a pastime, for transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One bicycle component that has been comprehensively redesigned is the bicycle sprocket assembly. The bicycle sprocket assembly is mounted to the bicycle frame, such as a bicycle hub assembly.

According to the present invention, a rear bicycle sprocket assembly has a rotational center axis and a hub engagement profile. The hub engagement profile is configured to engage a bicycle hub assembly in the assembled condition where the rear bicycle sprocket assembly is mounted to the bicycle hub assembly. The rear bicycle sprocket assembly includes a first sprocket, a second sprocket and a plurality of first connecting portions. The first sprocket has a first Zahnfußdurchmesser. The second sprocket has a second root diameter that is smaller than the first root diameter. The second sprocket adjoins the first sprocket in the axial direction with respect to the rotational center axis without another sprocket therebetween. The plurality of first connection portions are circumferentially spaced from each other with respect to the rotational center axis. The plurality of first connecting portions connect the first sprocket and the second sprocket in the axial direction with each other. The first sprocket, the second sprocket and the plurality of first connecting portions are integrally formed as a unitary one-piece member. The total number of the plurality of first connecting portions is smaller than the total number of teeth of the second sprocket.

In the case of such a rear bicycle sprocket assembly, the weight of the rear bicycle sprocket assembly can be reduced because the total number of the plurality of first connecting portions is smaller than the total number of teeth of the second sprocket.

According to a preferred aspect of the present invention, the rear bicycle sprocket assembly may include a third sprocket and a plurality of second connecting portions. The third sprocket has a third tooth root diameter that is smaller than the second root diameter. The third sprocket abuts the second sprocket in the axial direction without another sprocket therebetween. The plurality of second connecting portions are spaced apart in the circumferential direction. The plurality of second connecting portions connect the second sprocket and the third sprocket in the axial direction with each other. The total number of the plurality of second connecting portions is smaller than the total number of teeth of the third sprocket. In the case of such a rear bicycle sprocket assembly, the weight of the rear bicycle sprocket assembly including three sprockets or more can be reduced because the total number of the plurality of second connecting portions is smaller than the total number of teeth of the third sprocket.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that the second sprocket, the third sprocket and the plurality of second connecting portions are integrally formed as a unitary one-piece member. In the case of such a rear bicycle sprocket assembly, the weight of the rear bicycle sprocket assembly including three sprockets or more can be further reduced.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may further comprise a fourth sprocket and a plurality of third connecting portions. The fourth sprocket has a fourth tooth root diameter that is larger than the first root diameter. The fourth sprocket abuts the first sprocket in the axial direction without another sprocket therebetween. The plurality of third connection portions are spaced from each other in the circumferential direction. The plurality of third connecting portions connect the first sprocket and the fourth sprocket in the axial direction with each other. The total number of the plurality of third connecting portions is smaller than the total number of teeth of the first sprocket. In the case of such a rear bicycle sprocket assembly, the weight of the rear bicycle sprocket assembly including four sprockets or more can be reduced because the total number of the plurality of third connecting portions is smaller than the total number of teeth of the first sprocket.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that the first sprocket, the fourth sprocket, and the plurality of third connecting portions are integrally formed as a unitary one-piece member. In the case of such a rear bicycle sprocket assembly, the weight of the rear bicycle sprocket assembly including four sprockets or more can be further reduced.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that the first sprocket diameter of the first sprocket in the rear bicycle sprocket assembly is the largest. In the case of such a rear bicycle sprocket assembly, the weight of the rear bicycle sprocket assembly on the side of the larger sprocket (i.e., the lowest gear side) of the rear bicycle sprocket assembly can be effectively reduced.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that the first sprocket has a different hub engagement profile. In the case of such a rear bicycle sprocket assembly, in addition to the reduction in the weight of the rear bicycle sprocket assembly, torque can be reliably transmitted to the bicycle hub assembly.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that the second sprocket diameter of the second sprocket in the rear bicycle sprocket assembly is the smallest. In the case of such a rear bicycle sprocket assembly, the weight of the rear bicycle sprocket assembly on the side of the smallest sprocket (i.e., the highest gear side) of the rear bicycle sprocket assembly can be effectively reduced.

According to another aspect of the present invention, a bicycle sprocket assembly has a rotational center axis. The bicycle sprocket assembly includes a first sprocket assembly and a second sprocket assembly. The first sprocket assembly includes a plurality of first drive sprockets. The plurality of first drive sprockets are integrally formed as a unitary one-piece component. The second sprocket assembly includes a plurality of second drive sprockets. The plurality of second drive sprockets are integrally connected to each other by a plurality of attachment components. The first sprocket unit and the second sprocket unit are connected together. Each of the above aspects can be linked to the latter aspect. In the case of such a rear bicycle sprocket assembly, the rear bicycle sprocket assembly can be manufactured efficiently and its weight reduced. That is, the bicycle sprocket assembly includes a first sprocket unit formed as a unitary one-piece member and a second sprocket unit integrally formed by a plurality of fastening members, and the first sprocket unit and the second sprocket unit are connected to each other ,

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that each of the plurality of attachment components is a separate component from the plurality of second drive sprockets. In the case of such a rear bicycle sprocket assembly, the rear bicycle sprocket assembly can be manufactured efficiently and its weight reduced. This is because each of the plurality of attachment components is a separate component from the plurality of second drive sprockets.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that the plurality of first drive sprockets include a sprocket having the smallest tooth root diameter in the bicycle sprocket assembly. In the case of such a rear bicycle sprocket assembly, the weight of the rear bicycle sprocket assembly on the side of the smaller sprocket (i.e., the highest gear side) of the rear bicycle sprocket assembly can be effectively reduced.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that the plurality of first drive sprockets include a sprocket having the largest tooth root diameter in the bicycle sprocket assembly. In the case of such a rear bicycle sprocket assembly, the weight of the rear bicycle sprocket assembly on the side of the larger sprocket (i.e., the lowest gear side) of the rear bicycle sprocket assembly can be effectively reduced.

According to another preferred aspect of the present invention, the rear bicycle Sprocket assembly may be formed so that the plurality of second drive sprockets includes a sprocket with the smallest Zahnfußdurchmesser in the bicycle sprocket assembly. In the case of such a rear bicycle sprocket assembly, the weight of the rear bicycle sprocket assembly on the side of the smaller sprocket (ie, the highest gear side) of the rear bicycle sprocket assembly can be effectively reduced.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that the plurality of second drive sprockets include a sprocket having the largest tooth root diameter in the bicycle sprocket assembly. In the case of such a rear bicycle sprocket assembly, the weight of the rear bicycle sprocket assembly on the side of the larger sprocket (i.e., the lowest gear side) of the rear bicycle sprocket assembly can be effectively reduced.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that the plurality of first drive sprockets have a first average tooth root diameter. The plurality of second drive sprockets have a second average root diameter greater than the first average root diameter. In the case of such a rear bicycle sprocket assembly, the rear bicycle sprocket assembly can be efficiently manufactured on the side of the larger sprocket (ie, the lowest gear side) of the rear bicycle sprocket assembly, whereas the weight of the rear bicycle sprocket Sprocket assembly on the side of the smaller sprocket (ie, the side of the highest gear) of the rear bicycle sprocket assembly can be effectively reduced.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that the plurality of first drive sprockets have a first average tooth root diameter. The plurality of second drive sprockets have a second average root diameter that is less than the first average root diameter. In the case of such a rear bicycle sprocket assembly, the rear bicycle sprocket assembly can be efficiently manufactured on the side of the smaller sprocket (ie, the highest gear side) of the rear bicycle sprocket assembly, while the weight of the rear bicycle sprocket Sprocket assembly on the side of the larger sprocket (ie, the lowest gear side) of the rear bicycle sprocket assembly can be effectively reduced.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that the first sprocket assembly and the second sprocket assembly are interconnected by a plurality of additional attachment components. In the case of such a rear bicycle sprocket assembly, the rear bicycle sprocket assembly, except that its weight can be effectively reduced, can be manufactured efficiently.

According to another preferred aspect of the present invention, the rear bicycle sprocket assembly may be configured such that each of the plurality of additional attachment components is a separate component from the first sprocket assembly and the second sprocket assembly. In the case of such a rear bicycle sprocket assembly, the rear bicycle sprocket assembly, except that its weight can be effectively reduced, can be manufactured efficiently.

• 1 eine Seitenansicht eines Fahrrads gemäß einer ersten Ausführungsform der vorliegenden Erfindung ist;
• 2 eine perspektivische Außenansicht der hinteren Fahrrad-Kettenrad-Baueinheit gemäß der ersten Ausführungsform der vorliegenden Erfindung ist;
• 3A eine perspektivische Innenansicht der hinteren Fahrrad-Kettenrad-Baueinheit gemäß der ersten Ausführungsform der vorliegenden Erfindung ist;
• 3B eine teilweise vergrößerte perspektivische Innenansicht der hinteren Fahrrad-Kettenrad-Baueinheit gemäß der ersten Ausführungsform der vorliegenden Erfindung ist;
• 4 eine perspektivische Innenansicht der hinteren Fahrrad-Kettenrad-Baueinheit gemäß der ersten Ausführungsform der vorliegenden Erfindung (ohne ein erstes hinteres Kettenrad) ist;
• 5A eine teilweise vergrößerte perspektivische Ansicht von 4 ist;
• 5B eine teilweise vergrößerte perspektivische Ansicht als eine Variante der zusätzlichen Kettenrad-Verbindungsabschnitte ist;
• 6 eine perspektivische Außenansicht der hinteren Fahrrad-Kettenrad-Baueinheit als eine Variante der ersten Ausführungsform der vorliegenden Erfindung ist;
• 7A eine teilweise vergrößerte perspektivische Innenansicht der hinteren Fahrrad-Kettenrad-Baueinheit als eine Variante der ersten Ausführungsform der vorliegenden Erfindung ist;
• 7B eine teilweise vergrößerte perspektivische Innenansicht der hinteren Fahrrad-Kettenrad-Baueinheit als eine Variante der ersten Ausführungsform der vorliegenden Erfindung ist;
• 8 eine teilweise vergrößerte Querschnittsansicht der hinteren Fahrrad-Kettenrad-Baueinheit als eine Variante der ersten Ausführungsform der vorliegenden Erfindung ist;
• 9A eine perspektivische Außenansicht der hinteren Fahrrad-Kettenrad-Baueinheit gemäß der zweiten Ausführungsform der vorliegenden Erfindung ist;
• 9B eine perspektivische Außenansicht der hinteren Fahrrad-Kettenrad-Baueinheit gemäß der zweiten Ausführungsform der vorliegenden Erfindung ist;
• 9C eine teilweise vergrößerte perspektivische Außenansicht der hinteren Fahrrad-Kettenrad-Baueinheit gemäß der zweiten Ausführungsform der vorliegenden Erfindung ist; und
• 10 eine perspektivische Innenansicht der hinteren Fahrrad-Kettenrad-Baueinheit gemäß der zweiten Ausführungsform der vorliegenden Erfindung (ohne ein erstes hinteres Kettenrad) ist.

Embodiments of the present invention will now be described with reference to the drawings, which form a part of this original disclosure, wherein:

• 1 a side view of a bicycle according to a first embodiment of the present invention;
• 2 Fig. 11 is an external perspective view of the rear bicycle sprocket assembly according to the first embodiment of the present invention;
• 3A FIG. 12 is an inside perspective view of the rear bicycle sprocket assembly according to the first embodiment of the present invention; FIG.
• 3B a partially enlarged interior perspective view of the rear bicycle sprocket assembly according to the first embodiment of the present invention;
• 4 Fig. 12 is an inside perspective view of the rear bicycle sprocket assembly according to the first embodiment of the present invention (without a first rear sprocket);
• 5A a partially enlarged perspective view of 4 is;
• 5B a partially enlarged perspective view as a variant of the additional sprocket connecting portions;
• 6 an external perspective view of the rear bicycle sprocket assembly as a variant of the first embodiment of the present invention;
• 7A a partially enlarged interior perspective view of the rear bicycle sprocket assembly as a variant of the first embodiment of the present invention;
• 7B a partially enlarged interior perspective view of the rear bicycle sprocket assembly as a variant of the first embodiment of the present invention;
• 8th a partially enlarged cross-sectional view of the rear bicycle sprocket assembly as a variant of the first embodiment of the present invention;
• 9A Fig. 11 is an external perspective view of the rear bicycle sprocket assembly according to the second embodiment of the present invention;
• 9B Fig. 11 is an external perspective view of the rear bicycle sprocket assembly according to the second embodiment of the present invention;
• 9C a partially enlarged external perspective view of the rear bicycle sprocket assembly according to the second embodiment of the present invention; and
• 10 is an interior perspective view of the rear bicycle sprocket assembly according to the second embodiment of the present invention (without a first rear sprocket) is.

In the embodiments, the following directional terms "forward," "backward," "left," "right," "up," "down," "up," and "down," as well as other similar directional indications, refer to those directions that relate to FIG to a cyclist sitting on a bicycle saddle (not shown) of a bicycle facing the bicycle handlebar (not shown).

As in 1 shown contains a bicycle 1 a bicycle chain 9 a frame 11 , a handlebar 13 , a front and a rear wheel 17 . 19 , a switching device 24 and a drive section 25 ,

The frame 11 contains a frame body 11a and a front fork 11b , The front fork 11b is rotatable on the frame body 11a attached. The driver 13 is at the front fork 11b fixed. The front wheel 17 is rotatable on the front fork 11b attached. The rear wheel 19 is via a rear hub assembly 29 rotatable at a rear portion of the frame 11 (of the frame body 11a) attached. A front tire 17a is at the front wheel 17 attached. A rear tire 19a is at the rear wheel 19 attached.

The switching device 24 is on the handlebars 13 attached. The switching device 24 operates a rear derailleur 26 via a cable 22 , The rear derailleur 26 moves the bicycle chain 9 by a switching device 24 from a rear sprocket of a rear sprocket assembly 28 on another rear sprocket of the rear sprocket assembly 28 , The rear sprockets are in 1 simplified described. The rear derailleur 26 is for example at a rear portion of the frame 11 (the frame body 11a) attached.

The drive section 25 contains mainly a crank rod 27 and the rear sprocket assembly 28 , In particular, the drive section includes 25 mainly a crank rod 27 , a rear hub assembly 29 and a rear sprocket assembly 28 ,

The crank rod 27 is rotatable on a lower portion of the frame 11 (the frame body 11a ) stored. The crank rod 27 contains at least one front sprocket 35 , In this embodiment, the crank linkage contains 27 a front sprocket 35 in the bicycle chain 9 attacks.

The rear hub assembly 29 is at the rear section of the frame 11 (the frame body 11a) assembled. The rear hub assembly 29 carries the rear sprocket assembly 28 ,

As in the 2 and 3 is shown has the rear bicycle sprocket assembly 28 a rotational center axis C1 and a hub engagement profile 30 on. The hub engagement profile 30 is designed so that it in the assembled state, in which the rear bicycle sprocket assembly 28 at the bicycle hub assembly 29 is mounted in the bicycle hub assembly 29 attacks (see 1 ).

For example, the rear sprocket assembly becomes 28 rotatable from the rear hub assembly 29 carried. For example, the hub engagement profile is effective 30 with a keying engagement in an outer portion of the rear hub assembly 29 , Such wedging engagement may include a plurality of keyways.

In the hub engagement profile 30 it is a first hub engagement profile 30a and a second hub engagement profile 30b , The first and second hub engagement profiles 30a . 30b are described below.

The outer portion is formed to be relative to a hub axle 51 (please refer 1 ) of the rear hub assembly 29 rotates. The hub axle 51 the rear hub assembly 29 is at the back section of the frame 11 (the frame body 11a) assembled.

For example, the rear sprocket assembly includes 28 ten or more rear sprockets. The rear sprocket assembly 28 can contain eleven or more rear sprockets. The rear sprocket assembly 28 may also include twelve or more rear sprockets.

As in the 2 and 3 is shown in this embodiment includes the rear sprocket assembly 28 twelve rear sprockets 28A to 28L , In other words, the rear sprocket assembly 28 contains a first to twelfth rear sprocket 28A to 28L ,

Each of the first to twelfth rear sprockets 28A to 28L is a rear sprocket. Each of the first to twelfth rear sprockets 28A to 28L is each formed substantially annular.

Each of the first to twelfth rear sprockets 28A to 28L Each contains a plurality of teeth for engagement in the bicycle chain 9 ,

The plurality of teeth are on an outer peripheral portion of each of the first to twelfth rear sprockets 28A to 28L intended. The number of teeth of each of the first to twelfth rear sprockets 28A to 28L is different.

As in 4 is shown contains the rear sprocket assembly 28 a plurality of first to tenth sprocket connection portions 31A to 31J , The plurality of first to tenth sprocket connection portions 31A to 31J is respectively at an inner peripheral portion of each of the first to twelfth rear sprocket 28A to 28L intended.

The second rear sprocket 28B is used as an example of a fourth sprocket. The third rear sprocket 28C is used as an example of a first sprocket. The fourth rear sprocket 28D is used as an example of a second sprocket. The fifth rear sprocket 28E is used as an example of a third sprocket.

The first sprocket connection section 31A is used as an example of a third sprocket connecting portion. The second sprocket connection section 31B is used as an example of a first sprocket connection portion. The third sprocket connection section 31C is used as an example of a second sprocket connecting portion.

In other words, the rear bicycle sprocket assembly 28 has the third rear sprocket 28C (an example of a first sprocket), the fourth rear sprocket 28D (an example of a second sprocket) and a plurality of second sprocket connecting portions 31B (an example of a plurality of first connection portions).

The rear bicycle sprocket assembly 28 also has the fifth rear sprocket 28E (an example of a third sprocket) and the plurality of third sprocket connecting portions 31C (an example of a plurality of second connection portions).

The rear bicycle sprocket assembly 28 also has the second rear sprocket 28B (an example of a fourth sprocket) and the plurality of first sprocket connecting portions 31A (an example of a plurality of third connection portions).

As in 2 Shown are the first to twelfth rear sprockets 28A to 28L side by side in the axial direction with respect to the rotational center axis C1 arranged. The axial direction coincides with or is parallel to the rotational center axis.

The first rear sprocket 28A is the largest rear sprocket in the rear sprocket assembly 28 , The first rear sprocket 28A is on the side of the rear wheel 19 in the axial direction with respect to the rotational center axis C1 arranged.

The twelfth rear sprocket 28L is the smallest rear sprocket in the rear sprocket assembly 28 , The twelfth rear sprocket 28L is on the side of the frame 11 (of the frame body 11a ), for example the side of the rear derailleur 26 , in the axial direction relative to the rotational center axis C1 arranged.

The second to eleventh rear sprocket 28B to 28K are between the first rear sprocket 28A and the twelfth rear sprocket 28L in the axial direction with respect to the rotational center axis C1 arranged.

In particular, the second rear sprocket adjoins 28B to the first rear sprocket 28A in the axial direction without another rear sprocket in between. The second rear sprocket 28B (the example of the fourth sprocket) is adjacent to the third rear sprocket 28C (the example of the first sprocket) in the axial direction without another rear sprocket in between.

The third rear sprocket 28C adjoins the second rear sprocket 28B in the axial direction without another rear sprocket in between. The fourth rear sprocket 28D (the example of the second sprocket) is adjacent to the third rear sprocket 28C (the example of the first sprocket) in the axial direction without another rear sprocket in between. The fifth rear sprocket 28E (the example of the third sprocket) is adjacent to the fourth rear sprocket 28D (the example of the second sprocket) in the axial direction without another rear sprocket in between.

The sixth rear sprocket 28F adjoins the fifth rear sprocket 28E in the axial direction without another rear sprocket in between. The seventh rear sprocket 28G borders on that sixth rear sprocket 28F without another rear sprocket in between. The eighth rear sprocket 28H adjoins the seventh rear sprocket 28G in the axial direction without another rear sprocket in between. The ninth rear sprocket 281 adjoins the eighth rear sprocket 28H without another rear sprocket in between.

The tenth rear sprocket 28J adjoins the ninth rear sprocket 281 in the axial direction without another rear sprocket in between. The eleventh rear sprocket 28K adjoins the tenth rear sprocket 28J in the axial direction without another rear sprocket in between. The twelfth rear sprocket 28L adjoins the eleventh rear sprocket 28K in the axial direction without another rear sprocket in between. The hub engagement profile 30b is preferably on the inner peripheral surface of the twelfth rear sprocket 28L educated.

As in 2 Shown have the first to twelfth rear sprocket 28A to 28L each different diameter. The diameter of the first rear sprocket 28A is the largest of the first to twelfth rear sprockets 28A to 28L , The diameter of the twelfth rear sprocket 28L is the smallest of the first to twelfth rear sprockets 28A to 28L ,

The diameter of each of the second to eleventh rear sprockets 28B to 28K decreases sequentially in the direction starting from the first rear sprocket 28A towards the twelfth rear sprocket 28L , In other words, the diameter of each of the first to twelfth rear sprockets 28A to 28L decreases starting from the first rear sprocket 28A towards the twelfth rear sprocket 28L ,

In this embodiment, the sprocket tooth root diameter defines the diameter of each sprocket. The sprocket tooth root diameter is defined by the distance between the rotational center axis C1 and the root of each of the first to twelfth rear sprockets 28A to 28L in the radial direction relative to the rotational center axis C1 , The root of the tooth corresponds to the nearest portion (eg, the nearest point) of the root of the tooth starting from the center of rotation C1 in the radial direction. The maximum tooth root diameter is selected as the sprocket root diameter, ie, the root diameter of the claims, when a plurality of sprocket tooth root diameters can be measured at a rear sprocket.

In particular, the first rear sprocket has 28A a first sprocket tooth root diameter R1 , which is the largest of the first to twelfth sprocket tooth diameter R 12 is. The second rear sprocket 28B has the second sprocket tooth diameter R2 which is smaller than the first sprocket tooth diameter R1 ,

The third rear sprocket 28C (the example of the first sprocket) has the third sprocket tooth root diameter R3 (an example of a first tooth root diameter). In particular, has the third rear sprocket 28C the third sprocket tooth diameter R3 which is smaller than the second sprocket tooth diameter R2 , In other words, the second rear sprocket 28B (the example of the fourth sprocket) has the second sprocket tooth root diameter R2 (an example of a fourth tooth root diameter) which is larger than the third sprocket tooth root diameter R3 (an example of the first tooth root diameter).

The fourth rear sprocket 28D (the example of the second sprocket) has the fourth sprocket tooth diameter R4 (an example of a second tooth root diameter) which is smaller than the third sprocket tooth root diameter R3 (the example for the first tooth root diameter). The fifth rear sprocket 28E (the example of the third sprocket) has the fifth sprocket tooth root diameter R5 (an example of a third tooth root diameter) which is smaller than the fourth sprocket tooth root diameter R4 (the example for the second Zahnfußdurchmesser).

The sixth rear sprocket 28F has the sixth sprocket tooth diameter R6 which is smaller than the fifth sprocket tooth diameter R5 , The seventh rear sprocket 28G has the seventh sprocket tooth diameter R7 which is smaller than the sixth sprocket tooth diameter R6 , The eighth rear sprocket 28H has the eighth sprocket tooth diameter R8 which is smaller than the seventh sprocket tooth diameter R7 ,

The ninth rear sprocket 281 has the ninth sprocket tooth diameter R9 which is smaller than the eighth sprocket tooth diameter R8 , The tenth rear sprocket 28J has the tenth sprocket tooth diameter R10 which is smaller than the ninth sprocket tooth diameter R9 , The eleventh rear sprocket 28K has the eleventh sprocket tooth diameter R11 which is smaller than the tenth sprocket tooth diameter R10 , The twelfth rear sprocket 28L has the twelfth sprocket tooth diameter R12 which is smaller than the eleventh sprocket tooth diameter R11 ,

As in the 2 and 4 shown in the rear bicycle sprocket assembly 28 with the above configuration, the first rear sprocket 28A preferably the hub engagement profile 30a , The hub engagement profile 30a is at an inner peripheral portion of the first rear sprocket 28A educated. The hub engagement profile 30a engages in the assembled state, in which the rear bicycle sprocket assembly 28 at the bicycle hub assembly 29 is mounted in the bicycle hub assembly 29 , Consequently, the first rear sprocket becomes 28A used as a hub engagement sprocket. In other words, the rear bicycle sprocket assembly 28 may include a hub engagement sprocket with a hub engagement profile. In a preferred embodiment, the hub engagement profile is included 30a at least one keyway, more preferably a plurality of keyways.

As in the 2 and 3 is shown is the first rear sprocket 28A on the second rear sprocket 28B assembled. Such as in the 3 and 4 is shown, the first rear sprocket 28A by a plurality of additional sprocket connection portions 32 on the second rear sprocket 28B fixed (as described below).

As in the 4 and 5 Shown are the second to twelfth rear sprockets 28B to 28L and the first to tenth sprocket connecting portions 31A to 31J integrally formed as a unitary, one-piece component. In other words, the third rear sprocket 28C (the example of the first sprocket), the fourth rear sprocket 28D (the example of the second sprocket) and the plurality of second sprocket connecting portions 31B (The example of the plurality of first connecting portions) are integrally formed as a unitary, one-piece component.

The fourth rear sprocket 28D (the example of the second sprocket), the fifth rear sprocket 28E (the example of the third sprocket) and the plurality of third sprocket connecting portions 31C (The example of the plurality of second connecting portions) are integrally formed as a unitary, one-piece component.

The third rear sprocket 28C (the example of the first sprocket), the second rear sprocket 28B (the example of the fourth sprocket) and the plurality of first sprocket connecting portions 31A (The example of the plurality of third connecting portions) are integrally formed as a unitary one-piece member.

The second to twelfth rear sprocket 28B to 28L and the first to tenth sprocket connecting portions 31A to 31J are formed as one unit. For example, the second to twelfth rear sprockets 28B to 28L and the first to tenth sprocket connecting portions 31A to 31J made by cutting out a material like metal with a cutting machine.

As in 4 and 5 is shown connecting the plurality of first sprocket connecting portions 31A (the example of the plurality of third connecting portions) the third rear sprocket 28C (the example of the first sprocket) and the second rear sprocket 28B (the example of the fourth sprocket) in the axial direction with respect to the rotational center axis C1 together. The plurality of first sprocket connecting portions 31A (The example of the plurality of third connection portions) is in the circumferential direction with respect to the rotation center axis C1 spaced apart.

For example, each of the plurality of first sprocket connecting portions 31A arranged at intervals in the circumferential direction. The first sprocket connection section 31A is between the second rear sprocket 28B and the third rear sprocket 28C arranged in the axial direction.

The total number of the plurality of first sprocket connecting portions 31A (the example of the plurality of third connecting portions) is smaller than the total number of teeth of the third rear sprocket 28C (the example of the first sprocket, see 4 ). In this embodiment, the total number of the first sprocket connecting portions 31A Eighteenth, and the total number of teeth of the third rear sprocket 28C is thirty-six.

As in 5 is shown is the first sprocket connecting portion 31A integral with the second rear sprocket 28B and the third rear sprocket 28C educated. The first sprocket connection section 31A connects the inner peripheral portion of the second rear sprocket 28B and a side surface of the third rear sprocket 28C that the second rear sprocket 28B is facing.

Specifically, after the first sprocket connecting portion extends 31A from the inner periphery of the second rear sprocket 28B extends radially inwardly, the first sprocket-connecting portion 31A axially outward and connects to the side surface of the third rear sprocket 28C ,

As in the 4 and 5 is shown connecting the plurality of second sprocket connecting portions 31B (the example of the plurality of first connecting portions) the third rear sprocket 28C (the example of the first sprocket) and the fourth rear sprocket 28D (the Example of the second sprocket) in the axial direction with respect to the rotational center axis C1 together. The plurality of second sprocket connecting portions 31B (The example of the plurality of first connection portions) is in the circumferential direction with respect to the rotation center axis C1 spaced apart.

For example, each of the plurality of second sprocket connecting portions 31B arranged at intervals in the circumferential direction. The second sprocket connection section 31B is between the third rear sprocket 28C and the fourth rear sprocket 28D arranged in the axial direction.

The total number of the plurality of second sprocket connecting portions 31B (The example of the plurality of first connecting portions) is smaller than the total number of teeth of the fourth rear sprocket 28D (the example of the second sprocket) (see 4 ). In this embodiment, the total number of the second sprocket connecting portions 31B fifteen, and the total number of teeth of the fourth rear sprocket 28D is thirty-two.

As in 5 is shown is the second sprocket connection portion 31B integral with the third rear sprocket 28C and the fourth rear sprocket 28D educated. The second sprocket connection section 31B connects the inner peripheral portion of the third rear sprocket 28C and a side surface of the fourth rear sprocket 28D that the third rear sprocket 28C is facing.

Specifically, after the second sprocket connecting portion runs 31B from the inner periphery of the third rear sprocket 28C extends radially inwardly, the second sprocket-connecting portion 31B axially outward and connects to the side surface of the fourth rear sprocket 28D ,

As in 4 is shown connecting the plurality of third sprocket connecting portions 31C (the example of the plurality of second connecting portions) the fourth rear sprocket 28D (the example of the second sprocket) and the fifth rear sprocket 28E (the example of the third sprocket) in the axial direction with respect to the rotational center axis C1 together. The plurality of third sprocket connecting portions 31C (The example of the plurality of second connecting portions) is in the circumferential direction with respect to the rotational center axis C1 spaced apart.

For example, each of the plurality of third sprocket connecting portions 31C arranged at intervals in the circumferential direction. The third sprocket connection section 31C is between the fourth rear sprocket 28D and the fifth rear sprocket 28E arranged in the axial direction.

The total number of the plurality of third sprocket connecting portions 31C (the example of the plurality of second connecting portions) is smaller than the total number of teeth of the fifth rear sprocket 28E (the example of the third sprocket). In this embodiment, the total number of third sprocket connection portions is 31C fourteen, and the total number of teeth of the fifth rear sprocket 28E is twenty-eight.

The third sprocket connection section 31C is integral with the fourth rear sprocket 28D and the fifth rear sprocket 28E educated. The third sprocket connection section 31C connects the inner peripheral portion of the fourth rear sprocket 28D and a side surface of the fifth rear sprocket 28E that the fourth rear sprocket 28D is facing.

Specifically, after the third sprocket connecting portion runs 31C from the inner periphery of the fourth rear sprocket 28D extends radially inwardly, the third sprocket connection portion 31C axially outward and connects to the side surface of the fifth rear sprocket 28E ,

As in 4 is shown connecting the plurality of fourth sprocket connection portions 31D the fifth rear sprocket 28E and the sixth rear sprocket 28F in the axial direction with respect to the rotational center axis C1 together. The plurality of fourth sprocket connection portions 31D is in the circumferential direction with respect to the rotational center axis C1 spaced apart.

For example, each of the plurality of fourth sprocket connecting portions 31D arranged at intervals in the circumferential direction. The fourth sprocket connection section 31D is between the fifth rear sprocket 28E and the sixth rear sprocket 28F arranged in the axial direction.

The total number of the plurality of fourth sprocket connecting portions 31D is less than the total number of teeth of the sixth rear sprocket 28F , In this embodiment, the total number of the fourth sprocket connection portions is 31D twelve, and the total number of teeth of the sixth rear sprocket 28F is twenty four. The total number of the plurality of fourth sprocket wheels connecting sections 31D can equal the total number of teeth of the sixth rear sprocket 28F his.

The fourth sprocket connection section 31D is integral with the fifth rear sprocket 28E and the sixth rear sprocket 28F educated. The fourth sprocket connection section 31D connects the inner peripheral portion of the fifth rear sprocket 28E and a side surface of the sixth rear sprocket 28F that the fifth rear sprocket 28E is facing.

Specifically, after the fourth sprocket connecting portion runs 31D from the inner periphery of the fifth rear sprocket 28E extends radially inwardly, the fourth sprocket-connecting portion 31D axially outwardly and connects to the side surface of the sixth rear sprocket 28F ,

As in 4 is shown connecting the plurality of fifth to eighth sprocket connecting portions 31E to 31H the rear sprockets from the sixth to the tenth rear sprocket 28F to 28J which adjoin each other in the axial direction. The fifth to eighth sprocket connection sections 31E to 31H are in the same manner as the above first to fourth sprocket connecting portions 31A to 31D arranged.

The total number of each group of fifth to eighth sprocket connection sections 31E to 31H is equal to the total number of teeth of the smaller rear sprocket of the rear sprockets, which are arranged on both sides of each group. The total number of each group of fifth to eighth sprocket connection sections 31E to 31H may be smaller than the total number of teeth of the smaller rear sprocket from the rear sprockets arranged on both sides of each group.

As in 4 is shown connecting the plurality of ninth and tenth sprocket connection portions 311 . 31J the rear sprockets from the tenth to twelfth rear sprockets 28J to 28L which adjoin each other in the axial direction.

Each of the ninth and tenth sprocket connecting portions 31I . 31J is formed substantially annular.

The ninth sprocket connection section 311 is integral with the tenth rear sprocket 28J and the eleventh rear sprocket 28K educated. The ninth sprocket connection section 311 connects the inner peripheral portion of the tenth rear sprocket 28J and a side surface of the eleventh rear sprocket 28K that the tenth rear sprocket 28J is facing.

The tenth sprocket connection section 31J is integral with the eleventh rear sprocket 28K and the twelfth rear sprocket 28L educated. The tenth sprocket connection section 31J connects the inner peripheral portion of the eleventh rear sprocket 28K and a side surface of the twelfth rear sprocket 28L that the eleventh rear sprocket 28K is facing.

The tenth sprocket connection section 31J preferably includes the hub engagement profile 30b , The hub engagement profile 30b is at an inner peripheral portion of the tenth sprocket connection portion 31J educated. The hub engagement profile 30b engages in the assembled state, in which the rear bicycle sprocket assembly 28 at the bicycle hub assembly 29 is mounted in the bicycle hub assembly 29 , In a preferred embodiment, the hub engagement profile is included 30b at least one keyway, more preferably a plurality of keyways.

As in the 3B and 5 is shown connecting the plurality of additional sprocket connection portions 32 the first rear sprocket 28A and the second rear sprocket 28B in the axial direction. The plurality of additional sprocket connection sections 32 is at intervals in the circumferential direction (see 4 ) arranged. The additional sprocket connection section 32 can be attached to the first rear sprocket 28A and the second rear sprocket 28B be attached as a separate component.

As in the 3A . 3B and 5A is shown, each of the additional sprocket connection sections 32 integral with the second rear sprocket 28B formed as a unitary, one-piece component. The pen section 32a the additional sprocket connection section 32 is from the second rear sprocket 28B in the direction of the first rear sprocket 28A in the axial direction. The positioning section 32b as a spacer is at the base end of the pin portion 32a the additional sprocket connection section 32 intended. The positioning section 32b is between the first rear sprocket 28A and the second rear sprocket 28B intended.

As in 3B is shown, in this state, each of the pin portions 32a the additional sprocket connection sections 32 in each of the bolt holes 33 of the first rear sprocket 28A introduced. The first rear sprocket 28A is through fixation sections 32c on the second rear sprocket 28B fixed. Each of the fixation sections 32c is done by caulking the distal end of the pin sections 32a educated.

As in 5B 2, each of the additional sprocket connection sections may be shown 32 one from the second rear sprocket 28B be separate component. In this case, the spacers 34 in place of the positioning section 32b used. Each of the spacers 34 is between the first rear sprocket 28A and the second rear sprocket 28B arranged in the axial direction. For example, the spacer is 34 around the pen section 32a the additional sprocket connection section 32 and between the first rear sprocket 28A and the second rear sprocket 28B arranged in the axial direction.

In this state, each of the pin sections 32a the additional sprocket connection sections 32 in each of the bolt holes 33 of the first rear sprocket 28A and the second rear sprocket 28B introduced (see 3B and 5B) , The first rear sprocket 28A is about the spacer 34 through the fixation sections 32c on the second rear sprocket 28B fixed. Each of the fixation sections 32c is made by caulking both ends of each of the pin sections 32a educated.

The additional sprocket connection section 32 and the spacer 34 can be integrally formed as a unitary, one-piece component. Alternatively, the additional sprocket connecting portion 32 and the spacer 34 be separate from each other components.

As a variant of the first embodiment, the rear bicycle sprocket assembly 28 the second to eleventh rear sprocket 28B to 28K and the plurality of second to tenth sprocket connection portions 31B to 31J without the first rear sprocket 28A and the additional sprocket connection portions 32 respectively.

The second rear sprocket 28B (an example of a first sprocket) may be the largest rear sprocket in the rear bicycle sprocket assembly 28 his. In other words, the second sprocket tooth diameter R2 (an example of a first Zahnfußdurchmesser) of the second rear sprocket 28B (the example of the first sprocket) is the largest in the rear bicycle sprocket assembly 28 ,

In this case, the first rear sprocket 28A from the rear bicycle sprocket assembly 28 omitted, and a hub engagement member having a hub engagement profile is of the second rear sprocket 28B based on the rotational center axis C1 arranged radially inward. The hub engagement member is so on the second rear sprocket 28B attached that it is the second rear sprocket 28B in the radial direction and the pedaling moment on the bicycle hub assembly 29 transfers. Consequently, the second rear sprocket 28B (the example of the first sprocket) have a different hub engagement profile. The second rear sprocket 28B is used as an example of a first sprocket.

The third rear sprocket 28C is used as an example of a second sprocket. The fourth rear sprocket 28D is used as an example of a third sprocket.

As a variant of the first embodiment, the ninth sprocket connecting portion 311 of a plurality of ninth sprocket connecting portions 311 like the first to eighth sprocket connection sections 31A to 31H to be formed. Likewise, the tenth sprocket connection portion 31J of a plurality of tenth sprocket connecting portions 31J like the first to eighth sprocket connection sections 31A to 31H to be formed.

In this case, the twelfth sprocket tooth diameter is R1 (an example of a second tooth root diameter) of the twelfth rear sprocket 28L (an example of a second sprocket) is the smallest in the rear bicycle sprocket assembly 28 , The majority of the ninth and tenth sprocket connection sections 311 . 31J is in the circumferential direction with respect to the rotational center axis C1 spaced apart. The total number of ninth sprocket connection sections 31I is less than the total number of teeth of the eleventh rear sprocket 28K , The total number of tenth sprocket connection sections 31J is less than the total number of teeth of the twelfth rear sprocket 28L ,

In this case, the tenth rear sprocket 28J used as an example of a fourth sprocket. The eleventh rear sprocket 28K is used as an example of a first sprocket. The twelfth rear sprocket 28L is used as an example of a second sprocket.

As in 6 As a variant of the first embodiment, the rear bicycle sprocket assembly may be shown 128 Furthermore, an additional rear sprocket 28M respectively.

The additional rear sprocket 28M adjoins the first rear sprocket 28A in the axial direction with respect to the rotational center axis C1 , The first rear sprocket 28A is between the extra rear sprocket 28M and the second rear sprocket 28B arranged in the axial direction.

As in 7A In this case, each of the additional sprocket connecting portions may be shown 32 integral with the second rear sprocket 28B be formed as a unitary, one-piece component. The pen section 32a the additional sprocket connection section 32 is from the second rear sprocket 28B in the direction of the first rear sprocket 28A and the additional rear sprocket 28M in the axial direction. The positioning section 32b as the spacer is at the base end of the pin section 32a the additional sprocket connection section 32 intended. The positioning section 32b is between the first rear sprocket 28A and the second rear sprocket 28B arranged.

In this condition is the spacer 34 between the additional rear sprocket 28M and the first rear sprocket 28A arranged in the axial direction. In particular, the spacer is 34 around the pen section 32a the additional sprocket connection section 32 arranged as in the first embodiment.

Each of the pin sections 32a from the additional sprocket connection sections 32 gets into each of the bolt holes 33 the additional rear sprocket 28M introduced. The additional rear sprocket 28M gets over the first rear sprocket 28A and the spacers 34 through the fixation sections 32c on the second rear sprocket 28B fixed. The fixation sections 32c are made by caulking the distal end of the pin sections 32a educated.

As in 7B In this state, each of the additional sprocket connection portions can be shown 32 one from the second rear sprocket 28B be separate component. In this case, the spacers 34a in place of the positioning section 32b used. Each of the spacers 34a is around the pen section 32a the additional sprocket connection section 32 and between the first rear sprocket 28A and the second rear sprocket 28B arranged in the axial direction. A spacer 34b is around the pen section 32a the additional sprocket connection section 32 and between the additional rear sprocket 28M and the first rear sprocket 28A arranged in the axial direction.

Each of the pin sections 32a from the additional sprocket connection sections 32 gets into each of the bolt holes 33 the additional rear sprocket 28M , the first rear sprocket 28A and the second rear sprocket 28B introduced. The additional rear sprocket 28M gets over the first rear sprocket 28A and the spacers 34a . 34b through the fixation sections 32c on the second rear sprocket 28B fixed. The fixation sections 32c are made by caulking both end portions of the pin sections 32a educated.

As in 8th As a variant of the above embodiment, the additional rear sprocket may be shown 28M over the first rear sprocket 28A without the spacer 34 on the second rear sprocket 28B be fixed.

In this case, a radially inner portion 28Ma of the additional rear sprocket 28M designed so that it is against a side surface of the first rear sprocket 28A encounters. A radially outer section 28MB the additional rear sprocket 28M is from the side surface of the first rear sprocket 28A by bending the additional rear sprocket 28M spaced. A plurality of teeth are on an outer peripheral portion of the radially outer portion 28MB intended.

As a variant can with the rear bicycle sprocket assembly 28 . 128 the above feature is achieved when the total number of the at least one group of the first to tenth sprocket connecting portions 31A to 31J is smaller than the total number of teeth of the smaller rear sprocket of the rear sprockets, on both sides of the at least one group of the first to tenth sprocket connecting portions 31A to 31J are arranged.

As in the 9A . 9B and 10 is shown has the rear bicycle sprocket assembly 228 (An example of a bicycle sprocket assembly) of the second embodiment has substantially the same configuration as the rear bicycle sprocket assembly 28 the first embodiment.

In the second embodiment, a more detailed explanation of substantially the same configuration will be omitted and the description of the first embodiment applies to the second embodiment with reference to the description omitted below.

As in the 9A . 9B and 10 is shown has the rear bicycle sprocket assembly 228 the rotational center axis C1 on. The rear bicycle sprocket assembly 228 has a first sprocket unit U1 and a second sprocket unit U2 on.

The first sprocket unit U1 is one of the second sprocket unit U2 separate unit. The first sprocket unit U1 and the second sprocket unit U2 are connected.

As in the 9A and 9B shown has the first sprocket unit U1 a first average sprocket tooth root diameter AR1 , The second sprocket unit U2 has a second average sprocket tooth diameter AR2 which is larger than the first average sprocket tooth root diameter AR1 ,

The rear bicycle sprocket assembly 228 contains twelve rear sprockets. In other words, the rear bicycle sprocket assembly includes the first to twelfth rear sprockets 228A - 228L , However, the total number of rear sprockets is not limited to this embodiment.

As in the 9A and 9B is shown contains the first sprocket unit U1 a plurality of rear sprockets (an example of a plurality of first drive sprockets). In the second embodiment, the first sprocket unit includes U1 nine rear sprockets, especially the fourth to twelfth rear sprockets 228D to 228L (the example of the plurality of first drive sprockets). The total number of the plurality of rear sprockets (the example of the plurality of first drive sprockets) is not limited to the second embodiment.

The fourth to twelfth rear sprockets 228D to 228L (The example of the plurality of first drive sprockets) are integrally formed as a unitary, one-piece component.

The fourth to twelfth rear sprockets 228D to 228L (The example of the plurality of first drive sprockets) include a sprocket having the smallest sprocket tooth diameter in the rear bicycle sprocket assembly 228 , In the second embodiment, the twelfth rear sprocket has 228L the smallest sprocket tooth root diameter from the fourth to twelfth rear sprockets 228D to 228L ,

The fourth to twelfth rear sprockets 228D to 228L (the example of the plurality of first drive sprockets) have the first average sprocket tooth root diameter AR1 (an example of a first average tooth root diameter). The first average sprocket tooth diameter AR1 is done by averaging the sprocket tooth diameter R4 to R12 the fourth to twelfth rear sprocket 228D to 228L calculated.

The fourth to twelfth rear sprockets 228D to 228L have substantially the same configuration as the fourth to twelfth rear sprockets 28D to 28L the first embodiment.

As in 10 is shown contains the first sprocket unit U1 a plurality of sprocket connecting portions. In other words, the first sprocket unit U1 Also includes the plurality of first to eighth sprocket connection portions 131A to 131H ,

The plurality of first to eighth sprocket connecting portions 131A to 131H is integral with the fourth to twelfth of the rear sprockets 228D to 228L formed as a unitary, one-piece component. For example, the first to eighth sprocket connection portions become 131A to 131H and the fourth to twelfth of the rear sprockets 228D to 228L made by cutting out a material like metal with a cutting machine.

The plurality of first to sixth sprocket connecting portions 131A to 131F has substantially the same configuration as the third to eighth sprocket connecting portions 31C to 31H the first embodiment. The seventh and eighth sprocket connection sections 131G to 131H have substantially the same configuration as the ninth and tenth sprocket connection portions 311 to 31J the first embodiment.

In the second embodiment, the total number of each group is the first to sixth sprocket connection portions 131A to 131F equal to the total number of teeth of the smaller rear sprocket from the rear sprockets arranged on both sides of each group.

The total number of each group of the first to sixth sprocket connection portions 131A to 131F may be smaller than the total number of teeth of the smaller rear sprocket from the rear sprockets arranged on both sides of each group.

As in the 9A and 9B is shown contains the second sprocket unit U2 a plurality of rear sprockets (an example of a plurality of second drive sprockets). In the second embodiment, the second sprocket unit includes U2 three rear sprockets, in particular the first to third rear sprockets 228A to 228C (the example of the plurality of second drive sprockets). Each of the first to third rear sprockets 228A to 228C is a separate component.

The first to third rear sprockets 228A to 228C (The example of the plurality of second drive sprockets) includes a sprocket having the largest sprocket tooth diameter in the rear bicycle sprocket assembly 228 , In The second embodiment has the first rear sprocket 228L the largest sprocket tooth root diameter from the first to third rear sprockets 228A to 228C ,

The first to third rear sprockets 228A to 228C (the example of the plurality of second drive sprockets) have the second average sprocket tooth root diameter AR2 (the example of the second average tooth root diameter) which is larger than the first average sprocket tooth root diameter AR1 (the example for the first average tooth root diameter). The second average sprocket tooth diameter AR2 is done by averaging the sprocket tooth diameter R1 to R3 the first to third rear sprocket 228A to 228C calculated.

As in the 9A and 9B Shown are the first to third rear sprockets 228A to 228C (The example of the plurality of second drive sprockets) by a plurality of fixing members 36 integrally connected with each other. Each of the plurality of fastening components 36 is one of the first to third rear sprockets 228A to 228C (the example of the plurality of second drive sprockets) separate component.

As in the 9A . 9B and 10 is shown contains the plurality of fastening components 36 a plurality of first fastening components 36a and a plurality of second fastening components 36b ,

The plurality of first fastening components 36a connects the first rear sprocket 228A and the second rear sprocket 228B , The plurality of first fastening components 36a is between the first rear sprocket 228A and the second rear sprocket 228B arranged. The plurality of first fastening components 36a is in the circumferential direction with respect to the rotational center axis C1 spaced apart.

Specifically, each of the plurality of first fastening components 36a formed essentially bolt-shaped. As in 9C is shown, each of the plurality of first fastening components 36a in each of the bolt holes 37a of the first rear sprocket 228A and every bolt hole 38a the second rear sprocket 228B introduced.

In this state, for example, both end portions of each of the first attachment components 36a caulked. This will be the first rear sprocket 228A and the second rear sprocket 228B fixed to each other at a distance in the axial direction.

As in 10 can be shown, at least one spacer such as in 7 shown spacers 34 between the first rear sprocket 228A and the second rear sprocket 228B to be ordered. For example, the spacer may be around each of the plurality of first fastening components 36a and between the first rear sprocket 228A and the second rear sprocket 228B arranged or integrally formed as a unitary, one-piece component.

The plurality of second fastening components 36b connects the second rear sprocket 228B and the third rear sprocket 228C , The plurality of second fastening components 36b is between the second rear sprocket 228B and the third rear sprocket 228C arranged. The plurality of second fastening components 36b is in the circumferential direction with respect to the rotational center axis C1 spaced apart.

Specifically, each of the plurality of second fastening components 36b formed essentially bolt-shaped. As in 9C is shown, each of the plurality of second fastening components 36b in each of the bolt holes 38b the second rear sprocket 228B and every bolt hole 39a of the third rear sprocket 228C introduced.

At least one spacer like the one in 7 shown spacers 34 can in the same manner as in the case of the first fastening components 36a between the second rear sprocket 228B and the third rear sprocket 228C to be ordered.

As in 10 are shown in the case of the first sprocket unit U1 and the second sprocket unit U2 with the above configuration, the first sprocket unit U1 and the second sprocket unit U2 by a plurality of additional fastening components 39 connected with each other.

Each of the plurality of additional fastening components 39 is one of the first sprocket unit U1 and the second sprocket unit U2 separate component. The majority of additional fastening components 39 is on the fourth rear sprocket 228D arranged.

The majority of additional fastening components 39 is on a side surface of the fourth rear sprocket 228D arranged the third rear sprocket 228C is facing. For example, the additional fastening component may be integral with the fourth rear sprocket 228D formed or on the fourth rear sprocket 228D be attached as a separate component. The majority of additional fastening components 39 Has essentially the same configuration as in FIG 5 shown additional sprocket connection portion 32 ,

As a variant of the second embodiment, the fourth to twelfth rear sprockets 228D to 228L (An example of a plurality of second drive sprockets) may be integrally connected to each other by the plurality of attachment members instead of the sprocket connection portions.

In this case, a unit becomes the fourth to twelfth rear sprocket 228D to 228L used as an example of a second sprocket unit. A unit from the first to the third rear sprocket 228A to 228C is used as an example of a second sprocket unit.

The majority of the fourth to twelfth rear sprockets 228D to 228L (An example of a plurality of second drive sprockets) includes a sprocket having the smallest sprocket tooth diameter in the rear bicycle sprocket assembly 228 , In particular, the twelfth rear sprocket has 228L the smallest sprocket tooth diameter in the rear bicycle sprocket assembly 228 ,

The first to third rear sprockets 228A to 228C (An example of a plurality of first drive sprockets) are integrally formed with the plurality of sprocket connecting portions as a unitary one-piece member. In this case, a unit becomes the first to third rear sprocket 228A to 228C used as an example of a first sprocket unit.

The first to third rear sprockets 228A to 228C (an example of a plurality of first drive sprockets) include a sprocket having the largest sprocket tooth diameter in the rear bicycle sprocket assembly 228 , In particular, the first rear sprocket has 228A the largest sprocket tooth diameter in the rear bicycle sprocket assembly 228 ,

In another embodiment, the fourth to twelfth rear sprockets 228D to 228L (the example of the first drive sprockets) have a third average sprocket tooth root diameter (an example of a plurality of first average sprocket diameters). The first to third rear sprockets 228A to 228C (Example of the second drive sprockets) may have a fourth average sprocket tooth root diameter (an example of a plurality of second average sprocket diameters) smaller than the third average sprocket tooth root diameter (the example of the plurality of first average tooth root diameters). The third and fourth average sprocket tooth root diameters are calculated in the same manner as in the second embodiment.

In the second embodiment, the rear bicycle sprocket assembly becomes 228 as an example of a bicycle sprocket assembly. The above embodiment can also be applied to a front sprocket assembly.

As a variant of the above embodiment, the rear bicycle sprocket assembly 28 . 228 be formed as follows.

In the above embodiments, a switching facilitation area is not specifically described. At least one of the first to twelfth rear sprockets 28A to 28L . 228A to 228L and the additional rear sprocket 28M can contain the switching facilitating area. The switching facilitating area may include an upshift facilitating area and a downshift facilitating area.

In the case of a rear bicycle sprocket, the term "upshift facilitating area" as used herein means a predetermined area formed in a chain engagement structure of such a rear bicycle sprocket. The upshift facilitating area is intentionally configured to shift a bicycle chain from the rear bicycle sprocket to a smaller sprocket adjacent the rear bicycle sprocket without another sprocket between the smaller sprocket and the rear bicycle sprocket. The upshift facilitating portion may include a toggle facilitating tooth on which a upshift facilitating recess is formed.

The term "downshift facilitating area" in the case of a rear bicycle sprocket as used herein means a predetermined area formed in a chain-engaging structure of a rear bicycle sprocket. The downshift facilitating area is intentionally configured to shift a bicycle chain from a smaller sprocket adjacent to the rear sprocket without another sprocket between the smaller sprocket and the rear sprocket to the rear bicycle sprocket. The downshift facilitation area may include a downshift facilitating tooth on which a downshift facilitating recess is formed.

In the case of a front bicycle sprocket, the term "downshift facilitating area" as used herein means a predetermined area formed in a chain engagement structure of such a front bicycle sprocket. The downshift facilitating area is intentionally configured to shift a bicycle chain from the front bicycle sprocket to a smaller sprocket adjacent the front bicycle sprocket without another sprocket between the smaller sprocket and the front bicycle sprocket.

The downshift facilitating area may include a downshift facilitating protrusion and / or a downshift facilitating tooth on which a downshift facilitating chamfer is formed. As used herein, the term "upshift facilitating area" in the case of a front bicycle sprocket is to be understood as a predetermined area formed in a chain engagement structure of the front bicycle sprocket. The upshifting facilitation area is intentionally configured to shift a bicycle chain from a smaller sprocket adjacent the front bicycle sprocket to the front bicycle sprocket without another sprocket between the smaller sprocket and the bicycle sprocket. The upshifting facilitation area may include an upshift facilitating protrusion and / or an upshift facilitating tooth on which an upshift facilitating chamfer is formed.

In the above embodiments, a tooth profile of each of the first to twelfth rear sprockets 28A to 28L . 228A to 228L and the additional rear sprocket 28M not specifically described. The tooth profile may be a conventional tooth profile and / or a narrow-width tooth profile.

Specifically, as the narrow / wide tooth profile, the teeth of the rear sprocket may also include at least a first tooth having a first axially maximum chain engagement width and at least one second tooth having a second axially maximum chain engagement width smaller than the first axial maximum chain engagement width.

The first axially maximum chain engagement width is greater than an axial inner strap space defined by a pair of inner link plates of a bicycle chain and smaller than an outer axial strap space defined by a pair of outer link plates of the bicycle chain, wherein the pair of outer link plates are axially referenced on the rotational center axis of the rear sprocket facing each other when the bicycle chain is engaged with the rear sprocket.

The second axially maximum chain engagement width is smaller than the axial inner link space defined by the pair of inner link plates of the bicycle chain. Thus, the first teeth are formed so as to grip a pair of outer link plates of the bicycle chain, the pair of outer link plates axially facing each other when the bicycle chain is engaged with the rear sprocket, and the second teeth are formed that they engage in a pair of inner link plates of the bicycle chain, wherein the pair of inner link plates in the axial direction facing each other. Preferably, the first teeth and the second teeth are alternately arranged on the outer circumference of the rear sprocket.

In the above embodiments, the relationship between the front sprocket 35 and the rear sprockets 28A to 28L . 228A to 228L not specifically described. Preferably, the weight of the drive section 25 be reduced when the front sprocket 35 is a single or single front sprocket. As used herein, the term "single sprocket" means a bicycle sprocket mounted on a bicycle frame without any other sprocket between the bicycle sprocket and the bicycle frame in the axial direction with respect to the rotational centerline of the bicycle sprocket is arranged except that another sprocket is disposed on the opposite side of the bicycle frame with respect to the bicycle sprocket in the axial direction.

In the above embodiments, explanation will be given as an example in which the hub engagement profile 30 the first hub engagement profile 30a and the second hub engagement profile 30b includes. Instead, the hub engagement profile 30 either the first hub engagement profile 30a or the second hub engagement profile 30b include.

LIST OF REFERENCE NUMBERS

AR1

first average sprocket tooth root diameter

AR2

second average sprocket tooth diameter

C1

Central axis of rotation

R1

first sprocket tooth root diameter

R2

second sprocket tooth root diameter

R3

third sprocket tooth diameter

R4

fourth sprocket tooth diameter

R5

fifth sprocket tooth diameter

R6

sixth sprocket tooth diameter

R7

seventh sprocket tooth diameter

R8

Eighth sprocket tooth diameter

R9

Ninth sprocket tooth diameter

R10

tenth sprocket tooth diameter

R11

eleventh sprocket tooth diameter

R12

twelfth sprocket tooth diameter

U1

first sprocket unit

U2

second sprocket unit

1

bicycle

9

bicycle chain

11

frame

11a

frame body

11b

frame fork

13

handlebars

17

front

19

rear wheel

19a

rear tire

24

switching device

25

driving section

26

rear derailleur

27

crank linkage

28; 128; 228 28A to 28L,

rear sprocket assembly

228A to 228L

first to twelfth rear sprockets

28A, 228A

first rear sprocket

28B, 228B

second rear sprocket

28C, 228C

third rear sprocket

28D, 228D

fourth rear sprocket

28E, 228E

fifth rear sprocket

28F, 228F

sixth rear sprocket

28G, 228G

seventh rear sprocket

28H, 228H

Eighth rear sprocket

28I, 228I

ninth rear sprocket

28J, 228J

tenth rear sprocket

28K, 228K

eleventh rear sprocket

28L, 228L

twelfth rear sprocket

28M, 228M

additional rear sprocket

28MB

radially outer section

29

rear hub assembly

30a

Hub engagement profile

30b

Hub engagement profile

31A to 31J,

131A to 131J

first to tenth sprocket connection sections

31A, 131A

first sprocket connection section

31B, 131B

second sprocket connecting portion

31C, 131C

third sprocket connection section

31D, 131D

fourth sprocket connection section

31E, 131E

fifth sprocket connection section

31F, 131F

sixth sprocket connection section

31G, 131G

seventh sprocket connection section

31H, 131H

eighth sprocket connection section

31I, 131I

ninth sprocket connection section

31J, 131J

tenth sprocket connection section

32

additional sprocket connection section

32b

positioning section

32c

fixing sections

34

spacer

34a

spacer

35

front sprocket

36

Plurality of fastening components

36a

Plurality of first fastening components

36b

Plurality of second fastening components

37a

bolt hole

37b

bolt hole

38b

bolt hole

39a

bolt hole

39

Plurality of additional fastening components

51

hub axle

Claims (18)

A rear bicycle sprocket assembly (28; 128; 228) having a center axis of rotation (C1) and a hub engagement profile (30a, 30b) adapted to engage in the assembled state in which the rear bicycle sprocket assembly (28 128, 228) is mounted on the bicycle hub assembly (29), engages a bicycle hub assembly, the rear bicycle sprocket assembly (28; 128; 228) comprising: a first sprocket (28A, 228A) having a first root diameter (R1); a second sprocket (28B, 228B) having a second root diameter (R2) that is smaller than the first root diameter (R1), the second sprocket (28B, 228B) having no other sprocket in the axial direction with respect to the rotational center axis (C1) therebetween adjacent to the first sprocket (28A, 228A); and a plurality of first connecting portions (31A, 131A) circumferentially spaced from each other with respect to the rotational center axis (C1), the plurality of first connecting portions (31A, 131A) including the first sprocket (28A, 228A) and the second sprocket (28B , 228B) interconnects in the axial direction; in which the first sprocket (28A, 228A), the second sprocket (28B, 228B) and the plurality of first connecting portions (31A, 131A) are integrally formed as a unitary one-piece member; and the total number of the plurality of first connecting portions (31A, 131A) is smaller than the total number of teeth of the second sprocket (28B, 228B). Rear bicycle sprocket assembly (28; 128; 228) according to Claim 1 , further comprising: a third sprocket (28C, 228C) having a third root diameter (R3) smaller than the second root diameter (R2), the third sprocket (28C, 228C) being connected to the other in the axial direction without another sprocket therebetween second sprocket (28B, 228B) adjacent; and a plurality of second connecting portions (31B, 131B) spaced apart in the circumferential direction, wherein the plurality of second connecting portions (31B, 131B) axially connect the second sprocket (28B, 228B) and the third sprocket (28C, 228C) Connecting direction; wherein the total number of the plurality of second connection portions (31B, 131B) is smaller than that Total number of teeth of the third sprocket (28C, 228C). Rear bicycle sprocket assembly (28; 128; 228) according to Claim 2 wherein the second sprocket (28B, 228B), the third sprocket (28C, 228C), and the plurality of second connecting portions (31B, 131B) are integrally formed as a unitary one-piece member. Rear bicycle sprocket assembly (28; 128; 228) according to any one of Claims 1 to 3 , further comprising: a fourth sprocket (28D, 228D) having a fourth root diameter (R4) greater than the first root diameter (R1), the fourth sprocket (28D, 228D) being axially connected therewith without another sprocket therebetween first sprocket (28A, 228A) adjoins; and a plurality of third link portions (31C, 131C) spaced apart in the circumferential direction, wherein the plurality of third link portions (31C, 131C) axially connect the first sprocket (28A, 228A) and the fourth sprocket (28D, 228D) Connecting direction; wherein the total number of the plurality of third connecting portions (31C, 131C) is smaller than the total number of teeth of the first sprocket (28A, 228A). Rear bicycle sprocket assembly (28; 128; 228) according to Claim 4 wherein the first sprocket (28A, 228A), the fourth sprocket (28D, 228D) and the plurality of third connecting portions (31C, 131C) are integrally formed as a unitary, one-piece member. Rear bicycle sprocket assembly (28; 128; 228) according to any one of Claims 1 to 5 wherein the first root diameter (R1) of the first sprocket (28A, 228A) in the rear sprocket assembly (28; 128; 228) is the largest. The rear bicycle sprocket assembly (28; 128; 228) of any one of the preceding claims, wherein the first sprocket (28A, 228A) has a different hub engagement profile (30a, 30b). A rear bicycle sprocket assembly (28; 128; 228) according to any one of the preceding claims, wherein said second sprocket diameter (R2) of said second sprocket (28B, 228B) in said rear bicycle sprocket assembly (28; 128; 228) of smallest is. A bicycle sprocket assembly having a rotational centerline (C1), the bicycle sprocket assembly comprising: a first sprocket unit (U1) including a plurality of first drive sprockets, the plurality of first drive sprockets integrally formed as a unitary one-piece member; and a second sprocket assembly (U2) including a plurality of second drive sprockets, wherein the plurality of second drive sprockets are integrally connected to each other by a plurality of attachment members (36); in which the first sprocket unit (U1) and the second sprocket unit (U2) are interconnected. Bicycle sprocket assembly according to Claim 9 wherein: each of the plurality of mounting members (36) is a separate component from the plurality of second drive sprockets. Bicycle sprocket assembly according to Claim 9 or 10 wherein: the plurality of first drive sprockets includes a sprocket with the smallest sprocket diameter in the bicycle sprocket assembly. Bicycle sprocket assembly according to Claim 9 or 10 wherein: the plurality of first drive sprockets includes a largest sprocket diameter sprocket in the bicycle sprocket assembly. Bicycle sprocket assembly according to Claim 9 or 10 wherein: the plurality of second drive sprockets include a sprocket with the smallest sprocket diameter in the bicycle sprocket assembly. Bicycle sprocket assembly according to Claim 9 or 10 wherein: the plurality of second drive sprockets includes a largest sprocket diameter sprocket in the bicycle sprocket assembly. Bicycle sprocket assembly according to Claim 9 wherein: the plurality of first drive sprockets have a first average tooth root diameter and the plurality of second drive sprockets have a second average tooth root diameter greater than the first average tooth root diameter. Bicycle sprocket assembly according to Claim 9 or 10 wherein: the plurality of first drive sprockets have a first average tooth root diameter and the plurality of second drive sprockets have a second average tooth root diameter which is smaller than the first average Zahnfußdurchmesser. Bicycle sprocket assembly according to Claim 9 or 10 wherein: the first sprocket assembly (U1) and the second sprocket assembly (U2) are interconnected by a plurality of additional attachment components (39). Bicycle sprocket assembly according to Claim 17 wherein: each of the plurality of additional attachment components (39) is a separate component from the first sprocket assembly (U1) and the second sprocket assembly (U2).

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