DE102020121721A1 - A BICYCLE BOTTOM BRACKET ASSEMBLY AND A CRANK AXLE FOR A BICYCLE CRANK ASSEMBLY - Google Patents

Abstract

A first outer race radial clearance (D11) is defined from the rotation center axis (C1) toward the first radially outermost surface (61d). A second outer race radial distance (D12) is defined from the rotational centerline (C1) toward the second radially outermost surface (62d). A first inner race radial clearance (D31, D131, D231) is defined from the rotational center axis (C1) toward the first radially innermost surface (61e, 161e). A second inner race radial distance (D32, D132, D232) is defined from the rotational centerline (C1) toward the second radially innermost surface (62e, 162e). At least one of the first outer race radial clearance (D11) and the first roller element radial clearance (D21) is different from a counterpart of the second outer race radial clearance (D12) and the second roller element radial clearance (D22). The first inner race radial running distance (D31, D131, D132) differs from the second inner race radial running distance (D32, D123, D232).

Description

The present invention relates to a bicycle bottom bracket assembly and a crank axle for a bicycle crank assembly.

The bicycle is becoming an increasingly popular form of recreation and as a means of transportation. In addition, cycling has become a very popular competitive sport among both amateurs and professionals.

Regardless of whether the bicycle is used for leisure, as a means of transport or in competition, the bicycle industry is constantly improving the various systems of the bicycle. A bicycle system that has undergone a major overhaul is a bicycle bottom bracket assembly and a crank axle for a bicycle crank assembly. The bicycle bottom bracket assembly and the crank axle for the bicycle crank assembly are mounted on a bicycle frame.

One such bicycle bottom bracket assembly is from U.S. 7,699,532 B2 and DE 10 2008 029 088 A1 famous. Based on such prior art, the object of the present invention is to provide a bicycle bottom bracket assembly balanced in terms of drive efficiency and rigidity. It is also an object of the present invention to provide a bicycle bottom bracket assembly capable of improving the assembly of the bicycle bottom bracket assembly to the bicycle frame. Furthermore, a corresponding crank axle for a bicycle crank assembly, for example, from U.S. 2005/0011304 A1 and the U.S. 2006/0053962 A1 famous. Based on such prior art, the aim of the present invention is to provide a crank axle that is balanced in terms of driving efficiency and rigidity.

According to a first aspect of the present invention, a bicycle bottom bracket assembly includes a first support member, a second support member, a first bearing unit, and a second bearing unit.

The first support member includes a first bracket mounting portion and a first bearing mounting portion. The first bracket mounting portion is configured to be mountable on a first axial end of a bracket part of a bicycle frame.

The second support member includes a second bracket mounting portion and a second bearing mounting portion. The second bracket mounting portion is configured to be mountable to a second axial end of the bracket part of the bicycle frame. The second axial end of the support member is opposite to the first axial end of the support member in the axial direction with respect to a rotational center axis of the bicycle bottom bracket assembly.

The first bearing unit includes a first outer race, a first inner race, and at least one first rolling element disposed between the first outer race and the first inner race in a radial direction with respect to the rotation center axis. The first outer race is configured to be attachable to the first bearing mounting portion of the first support member. The first outer race has a first radially outermost surface facing in the radial direction. The first inner race has a first radially innermost surface facing in the radial direction. The at least one first roller element has a first center point.

The second bearing unit includes a second outer race, a second inner race, and at least one second rolling element disposed between the second outer race and the second inner race in the radial direction. The second outer race is configured to be attachable to the second bearing mounting portion of the first support member. The second outer race has a second radially outermost surface facing radially. The second inner race has a second radially innermost surface facing in the radial direction. The at least one second roller element has a second center point.

A first outer race radial clearance is defined in a radial direction from the central axis of rotation toward the first radially outermost surface. A second outer race radial clearance is defined in a radial direction from the rotational center axis toward the second radially outermost surface. The first outer race radial clearance and the second outer race radial clearance are opposed to each other as counterparts.

A first roller element radial distance is defined from the rotational centerline to the first center point. A second roller element radial distance is defined from the rotational centerline to the second center point. The first radial rolling element spacing and the second radial rolling element spacing are opposed to each other as counterparts.

A first inner race radial clearance is defined in a radial direction from the rotational centerline toward the first radially innermost surface. A second inner race radial clearance is defined in a radial direction from the rotational centerline toward the second radially innermost surface. The first radial inner race gabstand and the second inner race radial clearance face each other as counterparts.

At least one of the first outer race radial clearance and the first roller element radial clearance is different than the respective counterpart of the second outer race radial clearance and the second roller element radial clearance. The first inner race radial clearance is different than the second inner race radial clearance.

In the bicycle bottom bracket assembly according to the first aspect, the first inner race radial spacing is different from the second inner race radial spacing.

As such, a crank axle mounted to the bicycle bottom bracket assembly may have a large-diameter portion and a small-diameter portion. In other words, the bicycle bottom bracket assembly is able to increase rigidity by the large-diameter portion of the crank axle and reduce weight by the small-diameter portion of the crank axle.

Also, a diameter of one of the first bearing unit and the second bearing unit is smaller than the diameter of the other of the second bearing unit and the first bearing unit. In other words, the rotation resistance of the smaller bearing unit is less than the rotation resistance of the larger bearing unit. As a result, the bicycle bottom bracket assembly is able to increase driving efficiency with the smaller one of the first and second bearing units while improving rigidity with the larger one of the first and second bearing units.

According to a second aspect of the present invention, the bicycle bottom bracket assembly according to the first aspect is configured such that the first support member and the second support member are formed as a unitary, one-piece member.

With the bicycle bottom bracket assembly according to the second aspect, it is possible to improve the assembly of the bicycle bottom bracket assembly to the bicycle frame. In addition, it is possible to improve dimensional accuracy of the bicycle bottom bracket assembly in an axial direction with respect to a rotational center axis of the bicycle bottom bracket assembly. This makes it possible to mount the first and second support members of the bicycle bottom bracket assembly to the bicycle frame without using spacers that eliminate unnecessary axial gaps.

According to a third aspect of the present invention, the bicycle bottom bracket assembly according to the first aspect is configured such that the first support member has a first axially inner end configured so that, in an assembled state in which the bicycle bottom bracket assembly is attached to the Bracket part of the bicycle frame is mounted, can be arranged within the bracket part of the bicycle frame. The second support member has a second axially inner end configured to be disposed within the mounting portion of the bicycle frame when assembled.

With the bicycle bottom bracket assembly according to the third aspect, it is possible to reduce the weight of the bicycle bottom bracket assembly and fix it to the bicycle frame with various dimensions.

According to a fourth aspect of the present invention, the bicycle bottom bracket assembly according to the third aspect is configured such that when assembled, the first axially inner end of the first support member and the second axially inner end of the second support member are separated from each other.

With the bicycle bottom bracket assembly according to the fourth aspect, it is possible to reduce the weight of the bicycle bottom bracket assembly and fix it to the bicycle frame with various dimensions.

According to a fifth aspect of the present invention, the bicycle bottom bracket assembly according to any one of the first to fourth aspects further includes a connecting tube member. The connecting tube member is configured to, when assembled, bridge an axial gap between the first axially inner end of the first support member and the second axially inner end of the second support member.

With the bicycle bottom bracket assembly according to the fifth aspect, the bicycle bottom bracket assembly is able to prevent intrusion of foreign matter such as water and mud and the like from a seat tube into the first bearing unit and the second bearing unit.

According to a sixth aspect of the present invention, the bicycle bottom bracket assembly according to the third aspect is configured such that the first axially inner end of the first support member has a first threaded portion. The second axially inner end of the second support member has a second threaded portion configured to, when assembled, engage with the first threaded portion of the first axially inner end can be screwed.

With the bicycle bottom bracket assembly according to the sixth aspect, it is possible to fix the bicycle bottom bracket assembly to the bicycle frame in various dimensions and prevent foreign matter such as water and mud and the like from entering the first bearing unit and into invade the second storage unit.

According to a seventh aspect of the present invention, the bicycle bottom bracket assembly of the third aspect is configured such that, in the assembled state, the first axially inner end of the first support member and the second axially inner end of the second support member are overlapped with each other by press fitting.

With the bicycle bottom bracket assembly according to the seventh aspect, it is possible to fix the bicycle bottom bracket assembly to the bicycle frame with various dimensions and prevent foreign matter such as water and mud and the like from a seat tube into the first bearing unit and into the reach the second storage unit.

According to an eighth aspect of the present invention, the bicycle bottom bracket assembly according to the third aspect is configured such that, when assembled, the first axially inner end of the first support member and the second axially inner end of the second support member overlap each other. In the assembled state, an elastic sealing element is arranged in the radial direction between the first axially inner end of the first support element and the second axially inner end of the second support element.

With the bicycle bottom bracket assembly according to the eighth aspect, it is possible to fix the bicycle bottom bracket assembly to the bicycle frame with various dimensions and prevent foreign matter, such as water and mud and the like, from a seat tube into the first bearing unit and into the second storage unit invade.

According to a ninth aspect of the present invention, the bicycle bottom bracket assembly according to any one of the first to eighth aspects further includes a tubular sealing member. The tubular sealing member is configured to bridge an axial gap between the first inner race of the first bearing assembly and the second inner race of the second bearing assembly when assembled.

With the bicycle bottom bracket assembly according to the ninth aspect, the bicycle bottom bracket assembly is able to prevent intrusion of foreign matter such as water and mud and the like from a seat tube into the first bearing unit and the second bearing unit.

According to a tenth aspect of the present invention, the bicycle bottom bracket assembly according to any one of the first to ninth aspects is configured such that the first inner race radial spacing is greater than the second inner race radial spacing. The first radially innermost surface defines a first opening. The second radially innermost surface defines a second opening.

The first opening and the second opening are configured such that a crank axle can be inserted into the bicycle bottom bracket assembly by axially moving the crank axle from the first opening toward the second opening and removed from the bicycle bottom bracket assembly. by moving the crank axle from the second opening in the axial direction toward the first opening.

With the bicycle bottom bracket assembly according to the tenth aspect, it is possible to increase the rigidity by the large-diameter portion of the crank axle and reduce the weight by the small-diameter portion of the crank axle in the bicycle bottom bracket assembly. The bicycle bottom bracket assembly makes it possible to increase drive efficiency by making the first and second bearing units smaller, while improving rigidity by making the first and second bearing units larger.

According to an eleventh aspect of the present invention, a bicycle bottom bracket assembly includes a first bearing unit and a second bearing unit.

The first bearing unit includes a first outer race, a first inner race, and at least one first roller element disposed between the first outer race and the first inner race in a radial direction with respect to a rotational center axis of the bicycle bottom bracket assembly. The first outer race is configured to be secured to a first axial end of a bracket portion of a bicycle frame. The first inner race has a first radially innermost surface facing in the radial direction.

The second bearing assembly includes a second outer race, a second inner race, and at least a second roller element positioned radially between the second outer Race and the second inner race is arranged. The second outer race is configured to be secured to a second axial end of the bracket portion of the bicycle frame. The second axial end of the support member is opposite to the first axial end of the support member in the axial direction with respect to a rotational center axis of the bicycle bottom bracket assembly. The second inner race has a second radially innermost surface facing in the radial direction.

A first inner race radial clearance is defined in an axial direction from the rotational centerline toward the first radially innermost surface. A second inner race radial clearance is defined in an axial direction from the rotational centerline toward the second radially innermost surface. The first inner race radial clearance differs from the second inner race radial clearance.

In the bicycle bottom bracket assembly according to the eleventh aspect, the bicycle bottom bracket assembly enables rigidity to be increased by the large-diameter portion of the crank axle and reduction in weight by the small-diameter portion of the crank axle. The bicycle bottom bracket assembly makes it possible to increase drive efficiency by making the first and second bearing units smaller, while improving rigidity by making the first and second bearing units larger. The bicycle bottom bracket assembly makes it possible to reduce its weight because the bicycle bottom bracket assembly is assembled without the first support member and the second support member.

According to a twelfth aspect of the present invention, the bicycle bottom bracket assembly of the eleventh aspect is configured such that the first inner race radial spacing is greater than the second inner race radial spacing. The first radially innermost surface defines a first opening. The second radially innermost surface defines a second opening.

The first opening and the second opening are configured such that a crank axle can be inserted into the bicycle bottom bracket assembly by axially moving the crank axle from the first opening toward the second opening and removed from the bicycle bottom bracket assembly. by moving the crank axle from the second opening in the axial direction toward the first opening.

With the bicycle bottom bracket assembly according to the twelfth aspect, the bicycle bottom bracket assembly enables rigidity to be increased by the large-diameter portion of the crank axle and weight reduction by the small-diameter portion of the crank axle. The bicycle bottom bracket assembly makes it possible to increase drive efficiency by making the first and second bearing units smaller, while improving rigidity by making the first and second bearing units larger.

According to a thirteenth aspect of the present invention, the bicycle bottom bracket assembly according to the eleventh or twelfth aspect is configured such that the first outer race is configured to be press-fittable to the first axial end of the mounting portion of the bicycle frame. The second outer race is configured to be press fit to a second axial end of the mounting portion of the bicycle frame.

With the bicycle bottom bracket assembly according to the thirteenth aspect, since the bicycle bottom bracket assembly is assembled without the first support member and the second support member, it is possible to reduce the weight of the bicycle bottom bracket assembly.

According to a fourteenth aspect of the present invention, a bicycle bottom bracket assembly includes a first support member, a second support member, a first bearing unit, and a second bearing unit.

The first support member includes a first bracket mounting portion and a first bearing mounting portion. The first bracket mounting portion is configured to be mountable on a first axial end of a bracket part of a bicycle frame.

The second support member includes a second bracket mounting portion and a second bearing mounting portion. The second bracket mounting portion is configured to be mountable to a second axial end of the bracket part of the bicycle frame. The second axial end of the support member is opposite to the first axial end of the support member in the axial direction with respect to a rotational center axis of the bicycle bottom bracket assembly.

The first bearing unit includes a first outer race, a first inner race, and at least one first roller element disposed between the first outer race and the first inner race in a radial direction with respect to the rotational center axis of the bicycle bottom bracket assembly. The first outer race is configured to be attachable to the first bearing mounting portion of the first support member. The first inner race has a first radially innermost surface facing in the radial direction and the first radially innermost surface defines a first opening

The second bearing unit includes a second outer race, a second inner race, and at least one second rolling element disposed between the second outer race and the second inner race in the radial direction. The second outer race is configured to be attachable to the second bearing mounting portion of the first support member. The second inner race has a second radially innermost surface facing in the radial direction. The second radially innermost surface defines a second opening.

The first opening and the second opening are configured such that a crank axle can be axially inserted into the bicycle bottom bracket assembly from one of the first opening and the second opening toward the other of the first opening and the second opening and out of the bicycle bottom bracket assembly. The bottom bracket assembly can be removed by axially moving the crank axle from the other of the first opening and the second opening toward the one of the first opening and the second opening. The first support member and the second support member are formed as a unitary, one-piece member.

With the bicycle bottom bracket assembly according to the fourteenth aspect, it is possible to improve the assembly of the bicycle bottom bracket assembly to the bicycle frame. In addition, it is possible to improve dimensional accuracy of the bicycle bottom bracket assembly in an axial direction with respect to a rotational center axis of the bicycle bottom bracket assembly. This makes it possible to mount the first and second support members of the bicycle bottom bracket assembly to the bicycle frame without using spacers that eliminate unnecessary axial gaps.

According to a fifteenth aspect of the present invention, the bicycle bottom bracket assembly of the fourteenth aspect is configured such that a first inner race radial clearance is defined in the axial direction from the rotational center axis toward the first radially innermost surface. A second inner race radial clearance is defined in an axial direction from the rotational centerline toward the second radially innermost surface. The first inner race radial clearance is equal to the second inner race radial clearance.

With the bicycle bottom bracket assembly according to the fifteenth aspect, it is possible to improve the mounting of the bicycle bottom bracket assembly to the bicycle frame. In addition, it is possible to improve dimensional accuracy of the bicycle bottom bracket assembly in an axial direction with respect to a rotational center axis of the bicycle bottom bracket assembly. This makes it possible to mount the first and second support members of the bicycle bottom bracket assembly to the bicycle frame without spacers that eliminate unnecessary axial gaps.

According to a sixteenth aspect of the present invention, the bicycle bottom bracket assembly of the fourteenth aspect is configured such that a first inner race radial clearance is defined in the radial direction from the rotational center axis toward the first radially innermost surface. A second inner race radial clearance is defined in a radial direction from the rotational centerline toward the second radially innermost surface. The first inner race radial clearance differs from the second inner race radial clearance.

With the bicycle bottom bracket assembly according to the sixteenth aspect, the bicycle bottom bracket assembly makes it possible to increase rigidity with the large-diameter portion of the crank axle and reduce weight with the small-diameter portion of the crank axle. The bicycle bottom bracket assembly makes it possible to increase drive efficiency by making the first and second bearing units smaller, while improving rigidity by making the first and second bearing units larger.

According to a seventeenth aspect of the present invention, the bicycle bottom bracket assembly according to the sixteenth aspect is configured such that the first inner race radial spacing is greater than the second inner race radial spacing. The first opening and the second opening are configured such that a crank axle can be inserted into the bicycle bottom bracket assembly by axially moving the crank axle from the first opening toward the second opening and removed from the bicycle bottom bracket assembly. by moving the crank axle from the second opening in the axial direction toward the first opening.

With the bicycle bottom bracket assembly according to the seventeenth aspect, the bicycle bottom bracket assembly enables rigidity to be increased by the large-diameter portion of the crank axle and weight reduction by the small-diameter portion of the crank axle. The bicycle bottom bracket assembly makes it possible to increase drive efficiency by making the first and second bearing units smaller, while improving rigidity by making the first and second bearing units larger.

According to an eighteenth aspect of the present invention comprises a crank axle for a bicycle crank assembly has a large diameter section, a small diameter section, and a transition stage.

The large diameter section includes a first bearing mounting section having a first bearing mounting diameter. The small diameter portion includes a second bearing mounting portion having a second bearing mounting diameter that is smaller than the first bearing mounting diameter. The transition stage is arranged between the large-diameter portion and the small-diameter portion in the axial direction with respect to a rotational center axis of the crank axle. The second bearing mounting portion is axially spaced from the transition stage.

With the crank axle for the bicycle crank assembly according to the eighteenth aspect, it is possible for the crank axle to increase rigidity through the large-diameter portion of the crank axle and to reduce the weight of the crank axle through the small-diameter portion. The crank axle makes it possible to increase drive efficiency through the small-diameter section while improving rigidity through the large-diameter section.

According to a nineteenth aspect of the present invention, the crank axle for the bicycle crank assembly according to the eighteenth aspect is configured to define an axial distance between the second bearing mounting portion and the transition step in the axial direction from 0.1 mm to 70 mm.

With the crank axle for the bicycle crank assembly according to the nineteenth aspect, it is possible for the crank axle to increase rigidity by the large-diameter portion of the crank axle and to reduce the weight of the crank axle by the small-diameter portion. The crank axle makes it possible to increase drive efficiency through the small-diameter section while improving rigidity through the large-diameter section.

According to a twentieth aspect of the present invention, a crank axle for a bicycle crank assembly includes a large-diameter portion, a small-diameter portion, and a transition stage.

The large diameter section includes a first bearing mounting section. The first bearing mounting portion has a first bearing mounting diameter.

The small diameter section includes a second bearing mounting section. The second bearing mounting portion has a second bearing mounting diameter that is smaller than the first bearing mounting diameter.

The transition stage is positioned between the large-diameter portion and the small-diameter portion in the axial direction with respect to a rotation center axis of the crank axle.

A difference in diameter between the first bearing mounting diameter and the second bearing mounting diameter is equal to or greater than 2 mm.

With the crank axle for the bicycle crank assembly according to the twentieth aspect, the crank axle makes it possible to increase the rigidity of the crank axle by the large-diameter portion and to reduce the weight of the crank axle by the small-diameter portion. The crank axle allows, through the small-diameter section, to increase propulsion efficiency while improving rigidity through the large-diameter section.

According to a twenty-first aspect of the present invention, the crank axle for the bicycle crank assembly according to the twentieth aspect is designed so that the difference in diameter is equal to or smaller than 60 mm.

With the crank axle for the bicycle crank assembly according to the twenty-first aspect, the crank axle makes it possible to reduce the weight of the crank axle by the small-diameter portion. The crank axle makes it possible to reduce the resistance to rotation of the crank axle.

• 1 eine Seitenansicht eines Fahrrads gemäß Ausführungsformen der vorliegenden Erfindung ist;
• 2A ein Querschnitt einer Fahrrad-Tretlagerbaugruppe gemäß einer ersten Ausführungsform der vorliegenden Erfindung ist;
• 2B ein Querschnitt einer Fahrrad-Tretlagerbaugruppe gemäß der ersten Ausführungsform der vorliegenden Erfindung ist;
• 2C ein Querschnitt einer Fahrrad-Tretlagerbaugruppe gemäß einer Variation einer ersten Ausführungsform der vorliegenden Erfindung ist;
• 2D ein Querschnitt einer Fahrrad-Tretlagerbaugruppe gemäß einer Variation einer ersten Ausführungsform der vorliegenden Erfindung ist;
• 3A ein Querschnitt einer Fahrrad-Tretlagerbaugruppe gemäß einer zweiten Ausführungsform der vorliegenden Erfindung ist;
• 3B ein Querschnitt einer Fahrrad-Tretlagerbaugruppe gemäß einer Variation der zweiten Ausführungsform der vorliegenden Erfindung ist;
• 4A ein Querschnitt einer Fahrrad-Tretlagerbaugruppe gemäß einer dritten Ausführungsform der vorliegenden Erfindung ist;
• 4B ein Querschnitt einer Fahrrad-Tretlagerbaugruppe gemäß einer Variation der dritten Ausführungsform der vorliegenden Erfindung ist;
• 4C ein Querschnitt einer Fahrrad-Tretlagerbaugruppe gemäß einer Variation der dritten Ausführungsform der vorliegenden Erfindung ist;
• 5 ein Querschnitt einer Fahrrad-Tretlagerbaugruppe gemäß einer vierten Ausführungsform der vorliegenden Erfindung ist;
• 6 ein Querschnitt einer Fahrrad-Tretlagerbaugruppe gemäß einer fünften Ausführungsform der vorliegenden Erfindung ist; und
• 7 ein Querschnitt einer Fahrrad-Tretlagerbaugruppe und einer Kurbelachse gemäß einer sechsten Ausführungsform der vorliegenden Erfindung ist.

A more complete understanding of the invention and many of the advantages attendant thereof is readily obtained by reference to the following detailed description when considered in connection with the accompanying drawings in which:

• 1 Figure 12 is a side view of a bicycle in accordance with embodiments of the present invention;
• 2A Figure 12 is a cross section of a bicycle bottom bracket assembly according to a first embodiment of the present invention;
• 2 B Figure 12 is a cross section of a bicycle bottom bracket assembly according to the first embodiment of the present invention;
• 2C Figure 12 is a cross section of a bicycle bottom bracket assembly according to a variation of a first embodiment of the present invention;
• 2D Figure 12 is a cross section of a bicycle bottom bracket assembly according to a variation of a first embodiment of the present invention;
• 3A Figure 12 is a cross section of a bicycle bottom bracket assembly according to a second embodiment of the present invention;
• 3B Figure 12 is a cross section of a bicycle bottom bracket assembly according to a variation of the second embodiment of the present invention;
• 4A Figure 12 is a cross section of a bicycle bottom bracket assembly according to a third embodiment of the present invention;
• 4B Figure 12 is a cross section of a bicycle bottom bracket assembly according to a variation of the third embodiment of the present invention;
• 4C Figure 12 is a cross section of a bicycle bottom bracket assembly according to a variation of the third embodiment of the present invention;
• 5 Figure 12 is a cross section of a bicycle bottom bracket assembly according to a fourth embodiment of the present invention;
• 6 Figure 12 is a cross section of a bicycle bottom bracket assembly according to a fifth embodiment of the present invention; and
• 7 Figure 12 is a cross section of a bicycle bottom bracket assembly and crank axle according to a sixth embodiment of the present invention.

Selected embodiments of the present invention will now be explained with reference to the drawings, in which like reference characters designate corresponding or identical elements in the different drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments of the present invention are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

In the following embodiments, when the plurality of elements and parts match, the corresponding elements and the corresponding parts are indicated with the same sign.

As in 1 is shown, a bicycle 1 comprises a bicycle chain 9, a bicycle frame 11, handlebars 13, front and rear wheels 17, 19, a switching device 24, a drive train 25 and a front fork 20. The bicycle 1 comprises a crank axle 51 for a bicycle crank assembly 27 and a bicycle bottom bracket assembly 53.

The bicycle frame 11 includes a mounting portion 11a. The bracket part 11a is provided at a lower and middle portion of the bicycle frame 11 . The holding part 11a is essentially tubular.

As in 2A As shown, the support portion 11a includes a first axial end 12a and a second axial end 12b. The mounting portion 11a further includes a body portion 12c.

The first axial end 12a is provided on one end side of the body part 12c. The second axial end 12b is provided on the other end side of the body part 12c.

The body portion 12c extends in an axial direction with respect to a rotational center axis C1 of the bicycle bottom bracket assembly 53. The body portion 12c is formed in a generally tubular shape. A rotational center axis of the crank axle 51 is coaxial with the rotational center axis C1 of the bicycle bottom bracket assembly 53.

The body portion 12c is provided between the first axial end 12a and the second axial end 12b. The body portion 12c is integrally formed with the first axial end 12a and the second axial end 12b. Body portion 12c, first axial end 12a and second axial end 12b are formed as a unitary, one-piece member.

As in 1 As shown, the front fork 20 is rotatably attached to the bicycle frame 11 . The handlebar 13 is attached to the front fork 20 . The front wheel 17 is rotatably attached to the front fork 20 . The rear wheel 19 is rotatably attached to a rear portion of the bicycle frame 11 via a rear bicycle hub assembly 29 . A front tire 17a is fixed to the front wheel 17 . A rear tire 19a is fixed to the rear wheel 19. As shown in FIG.

The switching device 24 is attached to the handlebar 13 . The shifting device 24 operates a bicycle rear derailleur 26 via a control cable. The bicycle rear derailleur 26 is fixed to a rear portion of the bicycle frame 11, for example.

The rear bicycle derailleur 26 moves the bicycle chain 9 with the aid of the shifting device 24 from one bicycle sprocket of a rear bicycle sprocket assembly 28 to another bicycle sprocket of the rear bicycle sprocket assembly 28. The bicycle sprockets are identified by simplified description in FIG 1 shown.

The drivetrain 25 mainly includes the bicycle crank assembly 27 and the bicycle rear sprocket assembly 28. Specifically, the drivetrain 25 mainly includes the bicycle crank assembly 27, the bicycle rear hub assembly 29 and the bicycle rear sprocket assembly 28. The bicycle chain 9 can also belong to the drive train 25 .

The bicycle crank assembly 27 is rotatably supported on a lower portion of the bicycle frame 11, for example, on the mounting portion 11a of the bicycle frame 11. The bicycle crank assembly 27 includes at least one bicycle front sprocket 35. In this embodiment, the bicycle - crank assembly 27 a single front bicycle sprocket 35 which meshes with bicycle chain 9. The bicycle crank assembly 27 may include a plurality of bicycle front sprockets between which the bicycle chain 9 is switched by a front derailleur.

The bicycle crank assembly 27 is mounted on the crank axle 51 . For example, the bicycle crank assembly 27 is non-rotatably attached to the crank axle 51 . In particular, the bicycle crank assembly 27 is non-rotatably attached to the crank axle 51 so that pedaling torque can be transmitted from the bicycle crank assembly 27 to the crank axle 51 .

The crank axle 51 is rotatably supported on a lower portion of the bicycle frame 11, for example on a mounting part 11a of the bicycle frame 11. The crank axle 51 is rotatable on the mounting part 11a of the bicycle frame 11, for example via the bicycle bottom bracket assembly 53 stored. The details of the bicycle bottom bracket assembly 53 will be described later.

The bicycle rear hub assembly 29 is mounted on the rear portion of the bicycle frame 11 . The bicycle rear hub assembly 29 rotatably supports the bicycle rear sprocket assembly 28 . The bicycle rear sprocket assembly 28 is mounted to the bicycle rear hub assembly 29 .

As in 1 As shown, the bicycle bottom bracket assembly 53 is mounted on the bracket portion 11a. As in 2A As shown, the bicycle bottom bracket assembly 53 includes a first support member 55, a second support member 57, a first bearing unit 61, and a second bearing unit 62.

The first support member 55 and the second support member 57 are formed as a unitary, one-piece member. Specifically, the first support member 55 and the second support member 57 are connected to each other by a connecting portion 59 .

The connecting portion 59 is arranged inside the mounting part 11a of the bicycle frame 11 . The connecting portion 59 is integrally formed with the first support member 55 and the second support member 57 . In other words, the connection portion 59, the first support member 55 and the second support member 57 are formed as a unitary, one-piece member. For example, the connecting portion 59 is formed into a tubular shape.

The first support member 55 includes a first bracket mounting portion 55a and a first bearing mounting portion 55b.

The first bracket mounting portion 55a is configured to be mountable on a first axial end 12a of the bracket part 11a of the bicycle frame 11 . The first bracket mounting portion 55a is arranged on a radially inner side of the first axial end 12a of the bracket part 11a of the bicycle frame 11 in a radial direction with respect to a rotational center axis C<b>1 of the bicycle bottom bracket assembly 53 . For example, the first bracket mounting portion 55a is formed into a tubular shape.

The first bearing mounting portion 55b is configured to mount the first bearing unit 61 . In this embodiment, the first bearing mounting portion 55b is arranged on an axially outer side of the first axial end 12a of the support member 11a in the axial direction with respect to the rotation center axis C<b>1 of the bicycle bottom bracket assembly 53 . For example, the first bearing mounting portion 55b is formed in a tubular shape. For example, the first bearing unit 61 is press-fitted to the first bearing mounting portion 55b.

The second support member 57 includes a second bracket mounting portion 57a and a second bearing mounting portion 57b.

The second bracket mounting portion 57a is configured to be mountable to a second axial end 12b of the bracket part 11a of the bicycle frame 11 . The second axial end 12b of the support part 11a is opposed to the first axial end 12a of the support part 11a in the axial direction with respect to a rotation center axis C<b>1 of the bicycle bottom bracket assembly 53 .

The second bracket mounting portion 57a is arranged on the radially inner side of the second axial end 12b of the bracket part 11a in the radial direction with respect to the rotation center axis C<b>1 of the bicycle bottom bracket assembly 53 . For example, the second bracket mounting portion 57a is formed into a tubular shape.

The second bearing mounting portion 57 b is configured to mount the second bearing unit 62 . In this embodiment, the second bearing mounting portion 57b is arranged on the radially inner side of the second axial end 12b of the support member 11a in the radial direction with respect to the rotational center axis C<b>1 of the bicycle bottom bracket assembly 53 . For example, the second bearing unit 62 is press-fitted to the second bearing mounting portion 57b.

The first bearing unit 61 rotatably supports the crank axle 51 . The first bearing unit 61 includes a first outer race 61a, a first inner race 61b and at least one first roller element 61c. The at least one first rolling element 61c is arranged between the first outer race 61a and the first inner race 61b in the radial direction with respect to the rotation center axis C1.

The first outer race 61a is configured to be attachable to the first bearing mounting portion 55b of the first support member 55 . The first outer race 61a has a first radially outermost surface 61d facing in the radial direction.

The first inner race 61b faces the crank shaft 51 in the radial direction. The first inner race 61b rotates together with the crank axle 51. The first inner race 61b has a first radially innermost surface 61e facing in the radial direction. The first radially innermost surface 61e is formed in a circular shape as viewed in the axial direction with respect to the rotation center axis C1.

The at least one first roller element 61c has a first center point P1. The first center point P1 is defined on a circular line extending in the circumferential direction with respect to the rotation center axis C1. Preferably, the at least one first roller element 61c includes a plurality of first roller elements 61c in the circumferential direction.

The second bearing unit 62 rotatably supports the crank axle 51 . The second bearing unit 62 includes a second outer race 62a, a second inner race 62b and at least one second roller element 62c. The at least one second roller element 62c is arranged in the radial direction between the second outer race 62a and the second inner race 62b.

The second outer race 62a is configured to be attachable to the second bearing mounting portion 57b of the first support member 55 . The second outer race 62a has a second radially outermost surface 62d facing radially.

The second inner race 62b faces the crank shaft 51 in the radial direction. The second inner race 62b rotates together with the crank axle 51.

A seal protector 67 may be interposed between the first inner race 61b and the crank axle 51 in the radial direction. The seal protector 67 rotates together with the first inner race 61b and the crank axle 51. The seal protector 67 can be omitted as required.

A seal protector 68 may be interposed between the second inner race 62b and the crank axle 51 in the radial direction. The seal protector 68 rotates together with the second inner race 62b and the crank axle 51. The seal protector 68 can be omitted as required.

The second inner race 62b has a second radially innermost surface 62e facing radially. The second radially innermost surface 62e is formed in a circular shape as viewed in the axial direction with respect to the rotation center axis C1.

The first radially innermost surface 61e defines a first opening S1. The second radially innermost surface 62e defines a second opening S2. The crank axis 51 passes through the first opening S1 and the second opening S2.

The first opening S1 and the second opening S2 are configured so that the crank axle 51 can be inserted into the bicycle bottom bracket assembly 53 by axially moving the crank axle 51 from the first opening S1 toward the second opening S2.

The first opening S1 and the second opening S2 are configured such that the crank axle 51 can be removed from the bicycle bottom bracket assembly 53 by axially moving the crank axle 51 from the second opening S2 toward the first opening S1.

For example, a diameter DS1 of the first opening S1 is larger than a diameter DS2 of the second opening S2. An inside diameter of radially innermost surface of seal guard 67 is greater than an inner diameter of radially innermost surface of seal guard 68. An inner diameter of first radially innermost surface 61e of first inner race 61b is greater than an inner diameter of second radially innermost surface 62e of second inner race 62b.

The at least one second roller element 62c has a second center point P2. The second center point P2 is defined on a circular line extending in the circumferential direction with respect to the rotation center axis C1. Preferably, the at least one second roller element 62c includes a plurality of second roller elements 62c in the circumferential direction.

As in 2 B 1, a first outer race radial clearance D11 is defined in a radial direction from the rotation center axis C1 toward the first radially outermost surface 61d. A second outer race radial clearance D12 is defined in a radial direction from the rotation center axis C1 toward the second radially outermost surface 62d. The first outer race radial clearance D11 and the second outer race radial clearance D12 face each other as counterparts.

A first rolling element radial distance D21 is defined from the rotation center axis C1 toward the first center point P1. A second rolling element radial distance D22 is defined from the rotation center axis C1 toward the second center point P2. The first rolling element radial pitch D21 and the second rolling element radial pitch D22 are opposed to each other as counterparts.

A first inner race radial clearance D31 is defined in a radial direction from the rotation center axis C1 toward the first radially innermost surface 61e. A second inner race radial clearance D32 is defined in the radial direction from the rotation center axis C1 toward the second radially innermost surface 62e. The first inner race radial clearance D31 and the second inner race radial clearance D32 face each other as counterparts.

At least one of the first outer race radial clearance D11 and the first roller element radial clearance D21 differs from its respective counterpart of the second outer race radial clearance D12 and the second roller element radial clearance D22.

For example, the first outer race radial clearance D11 differs from the second outer race radial clearance D12. The first rolling element radial spacing D21 differs from the second rolling element radial spacing D22. The first outer race radial clearance D11 may be equal to the second outer race radial clearance D12. The first rolling element radial spacing D21 may be equal to the second rolling element radial spacing D22.

Specifically, the first outer race radial clearance D11 is greater than the second outer race radial clearance D12. The first rolling element radial spacing D21 is greater than the second rolling element radial spacing D22.

The first inner race radial clearance D31 is different than the second inner race radial clearance D32. For example, the first inner race radial clearance D31 is greater than the second inner race radial clearance D32. The first inner race radial distance D31 may be equal to the second inner race radial distance D32.

In the above bicycle bottom bracket assembly 53, the first bracket mounting portion 55a is bolted to the first axial end 12a of the bracket part 11a of the bicycle frame 11. As shown in FIG. The second bracket mounting portion 57a is threadedly engaged with the second axial end 12b of the bracket part 11a of the bicycle frame 11 .

An engaging portion of the first bracket mounting portion 55a and the first axial end 12a is in Figs 2A and 2 B marked by a thick line. An engaging portion of the second bracket mounting portion 57a and the second axial end 12b is in Figs 2A and 2 B marked by a thick line.

As a variation of the first embodiment, the bicycle bottom bracket assembly 53 can be configured as follows.

The first bracket mounting portion 55a may be press-fitted to the first axial end 12a of the bracket part 11a of the bicycle frame 11 . In other words, the engaging portion of the first bracket mounting portion 55a and the first axial end 12a which is in the 2A and 2 B denoted by the heavy line are press-fitted.

For example, an outer peripheral surface of the first bracket mounting portion 55a is unthreadedly pressed to the inner peripheral surface of the first axial end 12a.

Preferably, the inner diameter of an inner peripheral surface of the first axial end 12a is larger than the smaller diameter of an internally threaded portion of the second axial end 12b.

Preferably, the outer diameter of the first bracket mounting portion 55a of the first support member 55 is larger than the smaller diameter of a male screw portion of the second bracket mounting portion 57a of the second support member 57.

In this case, the second bracket mounting portion 57 is bolted to the second axial end 12b of the bracket part 11a of the bicycle frame 11 . Thus, the second bracket mounting portion 57a is screwed into the second axial end 12b of the bracket part 11a of the bicycle frame 11 .

As a variation of the first embodiment, the bicycle bottom bracket assembly 53 can be configured as follows.

The second bracket mounting portion 57a may be press-fitted to the second axial end 12b of the bracket part 11a of the bicycle frame 11 . In other words, the engaging portion of the second bracket mounting portion 57a and the second axial end 12b inserted in the 2A and 2 B denoted by the heavy line are press-fitted.

For example, the outer peripheral surface of the second bracket mounting portion 57a is press-fitted to the inner peripheral surface of the second axial end 12b without thread engagement.

Preferably, a smaller diameter of the first internally threaded portion of the first axial end 12a is larger than an inner diameter of the inner peripheral surface of the second axial end 12b. Preferably, an outer peripheral surface of the second bracket mounting portion 57a of the second support member 57 is smaller than a larger diameter of a male screw portion of the first bracket mounting portion 55a of the first support member 55. Preferably, the outer peripheral surface of the second bracket mounting portion 57a of the second support member 57 is smaller than the smaller diameter of the first female screw portion of the first axial end 12a.

In this case, the first bracket mounting portion 55a is bolted to the first axial end 12a of the bracket part 11a of the bicycle frame 11 . Thus, the first bracket mounting portion 55a is screwed into the first axial end 12a of the bracket part 11a of the bicycle frame 11 .

As a variation of the first embodiment, the bicycle bottom bracket assembly 53 can be configured as follows. The first bracket mounting portion 55a and the second bracket mounting portion 57a may be press-fitted to the first axial end 12a of the bracket part 11a and the second axial end 12b of the bracket part 11a, respectively.

As a variation of the first embodiment, the bicycle bottom bracket assembly 53 can be configured as follows.

As in 2C As illustrated, the bicycle bottom bracket assembly 53 may additionally include a tubular sealing member 69 . The tubular sealing member 69 is configured so that there is an axial gap between the first inner race 61b of the first bearing unit 61 and the second inner race in the assembled state in which the bicycle bottom bracket assembly 53 is mounted on the bracket part 11a of the bicycle frame 11 62b of the second bearing unit 62 is bridged.

In this embodiment, the tubular sealing member 69 covers the first bearing unit 61 . The tubular seal member 69 covers the second inner race 62b of the second bearing unit 62. The tubular seal member 69 engages the seal protector 68 in a concave-convex manner.

The tubular sealing element 169 can be configured as shown in FIG 2D is shown. The tubular sealing member 169 covers the first bearing unit 61 . The tubular seal member 169 concave-convexly engages the second inner race 62b of the second bearing unit 62 . The second bearing unit 62 is covered by the seal protector 68 .

The tubular sealing member 69, 169 is disposed radially inward of the first support member 55 and the second support member 57 with respect to the rotational center axis C<b>1 of the bicycle bottom bracket assembly 53 . For example, the tubular sealing member 69, 169 is disposed radially inward of the first support member 55, the second support member 57, and the first connecting portion 59 with respect to the rotational center axis C1 of the bicycle bottom bracket assembly 53.

Preferably, the tubular sealing element 69, 169 is arranged so that no contaminants such as mud and water can enter the first bearing unit 61, for example the first roller element 61c. The tubular sealing member 69, 169 is arranged to prevent ingress of contaminants such as mud and water into the second bearing unit 62, for example the second roller member 62c.

The configuration of the bicycle 1 of the second embodiment is basically the same like that of the first embodiment. The explanation of the identical features is omitted for the second embodiment. The same reference numerals as in the above embodiments are assigned to the elements of the same configuration.

The bicycle bottom bracket assembly 53 may be configured as follows. As in 3A As shown, the bicycle bottom bracket assembly 53 further includes a locking member 70. The locking member 70 is configured to hold the first support member 55 and the second support member 57. As shown in FIG. Specifically, the locking member 70 is configured to hold the first support member 55, the second support member 57, and the first connecting portion 59. As shown in FIG.

The locking member 70 includes a stopper portion 70a and a projection portion 70b. The stopper part 70a abuts on the second axial end 12b of the support part 11a of the bicycle frame 11 in the axial direction with respect to the rotation center axis C1 of the bicycle bottom bracket assembly 53 . For example, the stopper portion 70a is tubular.

The projection part 70b protrudes from the stopper part 70a. The projection part 70b is formed into a tubular shape, for example. The outer diameter of the projection part 70b is smaller than the outer diameter of the stopper part 70a.

The projection part 70b is arranged between the second axial end 12b of the bracket part 11a and the second bracket mounting portion 57a in the radial direction with respect to the rotation center axis C1. In this embodiment, the second bracket mounting portion 57a may be fixed to the locking member 70 by press fitting.

The projection part 70b is screwed to the second axial end 12b of the support part 11a. A male-threaded portion of a radially outer side of the boss part 70b is screwed into a female-threaded portion of a radially inner side of the second axial end 12b. A thread engagement portion of the projection part 70b and the second axial end 12b is indicated by the thick line in FIG 3A marked.

The projection part 70b is press-fitted with the second bracket mounting portion 57a. For example, an inner peripheral surface of the stopper part 70a and an inner surface of the projection part 70b are press-fitted into the second bracket mounting portion 57a. A press-fitting portion of the projection part 70b and the second bracket mounting portion 57a is indicated by the thick line in FIG 3A marked.

In this case, the first bracket mounting portion 55a may have the same configuration as in the first embodiment above. For example, the first bracket mounting portion 55a may be screwed into the first axial end 12a of the bracket part 11a. The first bracket mounting portion 55a may be press-fit into the first axial end 12a of the bracket part 11a.

As a variant of the second embodiment, the bicycle bottom bracket assembly 53 can be configured as follows.

The locking member 70 may be used instead of the press fitting between the second bracket mounting portion 57a and the locking member 70 in the second embodiment shown above in FIG 3A be screwed to the second bracket mounting portion 57a. In this case, female thread parts of a radially inner portion of the stopper part 70a and the projection part 70b are screwed into male thread parts of a radially outer portion of the second bracket mounting portion 57a.

The first bracket mounting portion 55a may be screwed into the first axial end 12a of the bracket part 11a. The first bracket mounting portion 55a may be press-fitted into the first axial end 12a of the bracket part 11a instead of the thread engagement between the first bracket mounting portion 55a and the first axial end 12a of the bracket part 11a.

As a variant of the second embodiment, the bicycle bottom bracket assembly 53 can be configured as follows.

The locking member 70 may be press fit into the second axial end 12b of the bracket part 11a and screwed to the second bracket mounting portion 57a instead of being threadedly engaged (see FIG 3A) .

In this case, the outer peripheral surface of the projection part 70b is press-fitted onto the inner peripheral surface of the second axial end 12b. The female thread parts of the stopper part 70a and the projection part 70b are screwed into the male thread part of the second bracket mounting portion 57a.

The first bracket mounting portion 55a may be screwed into the first axial end 12a of the bracket part 11a. The first bracket mounting portion 55a may be press-fit into the first axial end 12a of the bracket part 11a.

As a variant of the second embodiment, the bicycle bottom bracket assembly 53 can be configured as follows.

As in 3B As shown, the locking member 70 may be screwed to the second bracket mounting portion 57a. For example, in the state where the second bracket mounting portion 57a is bolted to the second axial end 12b of the bracket part 11a, the locking member 70 is bolted to the second bracket mounting portion 57a.

In this case, the locking member 70 includes the stopper portion 70a without the projection portion 70b. A male thread portion of a radially outer portion of the second bracket mounting portion 57a is screwed into a female thread portion of a radially inner portion of the second axial end 12b of the bracket portion 11a. A female thread portion of a radially inner portion of the stopper portion 70a is screwed into a male thread portion of a radially outer portion of the second bracket mounting portion 57a.

The first bracket mounting portion 55a may be screwed into the first axial end 12a of the bracket part 11a. The first bracket mounting portion 55a may be press-fit into the first axial end 12a of the bracket part 11a.

As a variation of the second embodiment, the bicycle bottom bracket assembly 53 of the type described above in 3B variant shown can be configured as follows.

The locking member 70 may be screwed to the second bracket mounting portion 57a. For example, the locking member 70 includes the stopper portion 70a without the projection portion 70b. The stopper part 70a of the locking member 70 is screwed to the second bracket mounting portion 57a in a state where the second bracket mounting portion 57a is press-fitted into the second axial end 12b of the bracket part 11a.

The first bracket mounting portion 55a may be screwed into the first axial end 12a of the bracket part 11a. The first bracket mounting portion 55a may be press-fit into the first axial end 12a of the bracket part 11a.

As a variation of the second embodiment, the bicycle bottom bracket assembly 53 of the type described above in 3B variant shown can be configured as follows.

The stopper part 70a of the locking member 70 can be press-fitted into the second bracket mounting portion 57a in a state where the second bracket mounting portion 57a is press-fitted to the second axial end 12b of the bracket part 11a.

The first bracket mounting portion 55a may be screwed into the first axial end 12a of the bracket part 11a. The first bracket mounting portion 55a may be press-fit into the first axial end 12a of the bracket part 11a.

The configuration of the bicycle 1 of the third embodiment is similar to that in the above embodiments. The explanation of the identical features is omitted for the third embodiment. The same reference numerals as in the above embodiments are assigned to the elements of the corresponding embodiment.

As in 4A As shown, the first support member 55 has a first axially inner end 55c. The first axially inner end 55c is configured to be attachable to the mounting portion 11a of the bicycle frame 11 in an assembled state in which the bicycle bottom bracket assembly 53 is mounted to the mounting portion 11a of the bicycle frame 11 .

The first axially inner end 55c is provided as part of the first bracket mounting portion 55a. The first axially inner end 55c is tubular.

The first support member 55 also has a first stop surface 55d. The first stop surface 55d borders on the first axial end 12a of the mounting part 11a of the bicycle frame 11 .

The second support member 57 has a second axially inner end 57c. The second axially inner end 57c is configured to be attachable to the mounting portion 11a of the bicycle frame 11 in the assembled state in which the bicycle bottom bracket assembly 53 is mounted to the mounting portion 11a of the bicycle frame 11 .

The second axially inner end 57c is provided as part of the second bracket mounting portion 57a. The second axially inner end 57c is tubular.

The second support member 57 also has a second stop surface 57d. The second stop face 57d borders on the second axial end 12b of the mounting part 11a of the bicycle frame 11 .

The mounting part 11a of the bicycle frame 11 is in the assembled state in which the bicycle bottom bracket assembly part 53 is mounted on the mounting part 11a of the bicycle frame 11, between the first stop surface 55d and the second stop surface 57d arranged. For example, in a state where the first stopper surface 55d and the second stopper surface 57d abut the first axial end 12a and the second axial end 12b of the bracket part 11a of the bicycle frame 11, respectively, the first bracket mounting portion 55a and the second bracket mounting portion 55a 57a mounted on the mounting part 11a of the bicycle frame 11.

The first bracket mounting portion 55a of the first support member 55 can be mounted on the first axial end 12a of the bracket part 11a of the bicycle frame 11 in the same manner as the above embodiments. The second bracket mounting portion 57a of the second support member 57 can be mounted on the second axial end 12b of the bracket part 11a of the bicycle frame 11 in the same manner as the above embodiments.

The first axially inner end 55c of the first support member 55 and the second axially inner end 57c of the second support member 57 are separated from each other in the axial direction in the assembled state in which the bicycle bottom bracket assembly 53 is mounted on the bracket portion 11a of the bicycle frame 11.

For example, the first axially inner end 55c of the first support member 55 and the second axially inner end 57c of the second support member 57 are arranged at a predetermined distance from each other in the axial direction.

The bicycle bottom bracket assembly 53 further includes a second connecting tube member 60. The second connecting tube member 60 is configured such that when assembled there is an axial gap between the first axially inner end 55c of the first support member 55 and the second axially inner end 57c of the second support member 57 bridged.

The connecting pipe member 60 is arranged inside the mounting part 11a of the bicycle frame 11 . The connecting pipe member 60 is mounted on the first axially inner end 55c of the first support member 55 and the second axially inner end 57c of the second support member 57 .

At least one elastic sealing member such as an O-ring may be interposed between the first axially inner end 55c of the first support member 55 and the connecting pipe member 60 in the radial direction with respect to the rotation center axis C1. Preferably, a plurality of elastic sealing members such as O-rings may be arranged between the first axially inner end 55c of the first support member 55 and the connecting pipe member 60 in the radial direction with respect to the rotation center axis C<b>1 .

At least one elastic sealing member such as an O-ring may be interposed in the radial direction between the second axially inner end 57c of the second support member 57 and the connecting pipe member 60 . Preferably, a plurality of elastic sealing members such as O-rings may be interposed in the radial direction between the second axially inner end 57c of the second support member 57 and the connecting pipe member 60 .

Preferably, the connecting tube member 60 is press-fit assembled at the first axially inner end 55c and the second axially inner end 57c. The connection tube member 60 may be fixed to the first axially inner end 55c and the second axially inner end 57c by adhesive bonding.

The connection pipe member 60 is formed in a tubular shape. Preferably, the connecting pipe member 60 is molded from a resin. The connection tube member 60 may be formed of a metallic material.

An engagement portion of the first axial end 12a of the bracket member 11a and the first bracket mounting portion 55a is indicated by the thick line in FIG 4A marked. The first axial end 12a of the bracket member 11a and the first bracket mounting portion 55a are engaged with each other at the engaging portion in the same manner as in the above embodiment.

An engagement portion of the second axial end 12b of the bracket member 11a and the second bracket mounting portion 57a is indicated by the thick line in FIG 4A marked. The second axial end 12b of the bracket member 11a and the second bracket mounting portion 57a are engaged with each other at the engaging portion in the same manner as in the above embodiment.

As a variant of the second embodiment, the bicycle bottom bracket assembly 53 can be configured as follows.

As in 4B As shown, the first axially inner end 55c of the first support member 55 has a first threaded portion 55e. The first screw portion 55e is provided on an inner peripheral surface of the first axially inner end 55c. The first threaded portion 55e is an internally threaded part.

The second axially inner end 57c of the second support member 57 has a second threaded portion 57e. The second threaded portion 57e is configured to be threadedly engaged with the first threaded portion 55e of the first axially inner end 55c in the assembled state in which the bicycle bottom bracket assembly 53 is mounted to the mounting portion 11a of the bicycle frame 11 .

The second thread portion 57e is provided on an outer peripheral surface of the second axially inner end 57c. The second threaded portion 57e is a male threaded portion. An engaging part of the first threaded portion 55e and the second threaded portion 57e is indicated by the thick line in FIG 4B marked.

As a variation of the second embodiment, the bicycle bottom bracket assembly 53 of the type described above in 4B variant shown can be configured as follows.

The first axially inner end 55c of the first support member 55 and the second axially inner end 57c of the second support member 57 may be press-fitted to overlap each other in the assembled state in which the bicycle bottom bracket assembly 53 is mounted on the bracket portion 11a of the bicycle frame 11.

Concretely, the first axially inner end 55c and the second axially inner end 57c are arranged so as to oppose each other in the radial direction with respect to the rotation center axis C<b>1 of the bicycle bottom bracket assembly 53 . The first axially inner end 55c and the second axially inner end 57c overlap each other when assembled without the first threaded portion 55e and the second threaded portion 57e in an interference fit.

The engagement portion of the first threaded portion 55e and the second threaded portion 57e indicated by the thick line in 4B is a portion where the first axially inner end 55c and the second axially inner end 57c can overlap with each other.

As a variant of the second embodiment, the bicycle bottom bracket assembly 53 can be configured as follows.

As in 4C As shown, the first axially inner end 55c of the first support member 55 and the second axially inner end 57c of the second support member 57 overlap with each other in the assembled state in which the bicycle bottom bracket assembly 53 is mounted on the bracket portion 11a of the bicycle frame 11 with an interference fit .

An elastic sealing member 63 is located in the radial direction between the first axially inner end 55c of the first support member 55 and the second axially inner end 57c of the first support member 55 in the assembled state in which the bicycle bottom bracket assembly 53 is mounted on the mounting portion 11a of the bicycle frame 11 second support element 57 is arranged.

Concretely, the first axially inner end 55c and the second axially inner end 57c are arranged so as to oppose each other in the radial direction with respect to the rotation center axis C<b>1 of the bicycle bottom bracket assembly 53 . The elastic sealing element 63 is arranged in a recess of the first axially inner end 55c and in a recess of the second axially inner end 57c. For example, the elastic sealing member 63 includes an O-ring.

The configuration of the bicycle 1 of the fourth embodiment is similar to the above embodiments. The explanation of the identical features is omitted for the fourth embodiment. The same reference numerals as in the above embodiments are assigned to the elements of the same configuration.

As in 5 As shown, the support portion 11a includes the first axial end 12a and the second axial end 12b. The mounting portion 11a further includes the body portion 12c. The bracket part 11a includes a third bearing mounting portion 12d and a fourth bearing mounting portion 12e.

The third bearing mounting portion 12d is configured to mount a first bearing unit 161 . The third bearing mounting portion 12d is provided at the first axial end 12a of the bracket part 11a of the bicycle frame 11 . The third bearing mounting portion 12d is formed integrally with the first axial end 12a of the bracket part 11a of the bicycle frame 11 . For example, the third bearing mounting portion 12d is formed into a tubular shape.

The fourth bearing mounting portion 12e is configured to mount a second bearing unit 162 . The fourth bearing mounting portion 12e is provided at the second axial end 12b of the bracket part 11a of the bicycle frame 11 . The fourth bearing mounting portion 12e is formed integrally with the second axial end 12b of the bracket part 11a of the bicycle frame 11 . For example, the fourth bearing mounting portion 12e is formed into a tubular shape.

The body portion 12c is integrally formed with the first axial end 12a and the second axial end 12b. In particular, the body portion 12c integrally formed with the first axial end 12a, the second axial end 12b, the third bearing mounting portion 12d and the fourth bearing mounting portion 12e.

A bicycle bottom bracket assembly 153 includes the first bearing unit 161 and the second bearing unit 162. The configurations of the first bearing unit 161 and the second bearing unit 162 may be the same as the above embodiments.

The first bearing unit 161 is mounted on the third bearing mounting portion 12d of the bracket part 11a of the bicycle frame 11 . The first bearing unit 161 includes the first outer race 161a, the first inner race 161b, and the at least one first rolling element 161c positioned radially with respect to the rotational center axis C1 of the bicycle bottom bracket assembly 153 between the first outer race 161a and the first inner race 161b is arranged.

The first outer race 161a is configured to be fixed to the first axial end 12a of a bracket part 11a of the bicycle frame 11 . For example, the first outer race 161a is configured to be press-fittable to the first axial end 12a of the mounting portion 11a of the bicycle frame 11 . Specifically, the first outer race 161a is configured to be press-fittable to the third bearing mounting portion 12d. The first inner race 61b has the first radially innermost surface 161e facing in the radial direction.

The second bearing unit 162 is mounted on the fourth bearing mounting portion 12e of the bracket part 11a of the bicycle frame 11 . The second bearing unit 162 includes the second outer race 162a, the second inner race 162b, and the at least one second roller element 162c, which is arranged in the radial direction between the second outer race 162a and the second inner race 162b.

The second outer race 162a is configured to be fixed to the second axial end 12b of the bracket part 11a of the bicycle frame 11 . For example, the second outer race 162a is configured to be press-fittable to a second axial end 12b of the mounting portion 11a of the bicycle frame 11 . In particular, the second outer race 162a is configured to be press-fittable to the fourth bearing mounting portion 12e. The second inner race 162b has the second radially innermost surface 162e facing in the radial direction.

The second axial end 12b of the support part 11a is opposed to the first axial end 12a of the support part 11a in the axial direction with respect to the rotational center axis C1 of the bicycle bottom bracket assembly 153 . The second inner race 62b has the second radially innermost surface 62e facing in the radial direction with respect to the rotational center axis C<b>1 of the bicycle bottom bracket assembly 153 .

The first inner race radial clearance D131 is defined in the radial direction from the rotation center axis C1 toward the first radially innermost surface 161e. The second inner race radial clearance D132 is defined in the radial direction from the rotation center axis C1 toward the second radially innermost surface 162e. The first inner race radial clearance D131 and the second inner race radial clearance D132 face each other as counterparts.

The first inner race radial clearance D131 is different than the second inner race radial clearance D132. For example, the first inner race radial clearance D131 is greater than the second inner race radial clearance D132. The first radially innermost surface 161e defines the first opening S1. The second radially innermost surface 62e defines the second opening S2.

The first opening S1 and the second opening S2 are configured such that the crank axle 51 is inserted into the bicycle bottom bracket assembly 153 by moving the crank axle 51 from the first opening S1 in the axial direction toward the second opening S2, and by moving the crank axle 51 from the second opening S2 can be removed from the bicycle bottom bracket assembly 153 in the axial direction toward the first opening S1.

The configuration of the bicycle 1 of the fourth embodiment is similar to the above embodiments. The explanation of the identical features is omitted for the fifth embodiment. The same reference numerals as in the above embodiments are assigned to elements of the same configuration.

As described in the embodiment above, the first opening S1 is defined by the first radially innermost surface 61e, 161e. The second opening S2 is defined by the second radially innermost surface 62e, 162e.

As in 6 As shown, the first opening S1 and the second opening S2 are configured so that the crank axle 51 can be inserted into the bicycle bottom bracket assembly 253 by moving the crank axle 51 from one of the first opening S1 and the second opening S2 to the other in the axial direction is moved toward the first opening S1 and the second opening S2. An insertion direction of Crank axis 51 is in 6 indicated by a hatched arrow.

The first opening S1 and the second opening S2 are configured so that the crank axle 51 can be removed from the bicycle bottom bracket assembly 253 by moving the crank axle 51 from the other of the first opening S1 and the second opening S2 in the axial direction toward one of the the first opening S1 and the second opening S2. A disassembling direction of the crank axle 51 is in 6 marked by a white arrow.

The first opening S1 and the second opening S2 are configured so that the crank axle 51 can be inserted into the bicycle bottom bracket assembly 253 by axially moving the crank axle 51 from the first opening S1 toward the second opening S2.

The first opening S1 and the second opening S2 are configured such that the crank axle 51 can be removed from the bicycle bottom bracket assembly 253 by axially moving the crank axle 51 from the second opening S2 toward the first opening S1.

In this embodiment, as in 6 shown, an inner diameter of the first bearing unit 261 of the bicycle bottom bracket assembly 253 is equal to an inner diameter of the second bearing unit 262 of the bicycle bottom bracket assembly 253.

For example, an inner diameter of the first radially innermost surface 61e of the first inner race 61b is equal to an inner diameter of the second radially innermost surface 62e of the second inner race 62b. In other words, a diameter of the first opening S1 is equal to a diameter of the second opening S2.

Specifically, a first inner race radial clearance D231 is defined in the axial direction from the rotation center axis C1 toward the first radially innermost surface 61e. A second inner race radial clearance D232 is defined in the axial direction from the rotational center axis C1 toward the second radially innermost surface 62e. The first inner race radial clearance D231 is equal to the second inner race radial clearance D232.

The third inner race radial clearance D231 corresponds to "a first inner race radial clearance" in claim 15. The fourth inner race radial clearance D232 corresponds to "a second inner race radial clearance" in claim 15.

The configuration of the bicycle 1 of the fourth embodiment is similar to the above embodiments. The explanation of the identical features is omitted for the sixth embodiment. The same reference numerals as in the above embodiments are assigned to the elements of the same configuration.

As in 7 As shown, the bicycle crank assembly 27 is assembled to the crank axle 51 . The crank axle 51 for the bicycle crank assembly 27 is rotatably supported on the first bearing unit 361 via the seal protector 67 . The crank axle 51 for the bicycle crank assembly 27 is rotatably supported by the second bearing unit 362 . In this embodiment, a bushing element 168 is arranged in the radial direction between the second bearing unit 362 and the seal guard 68 . The seal protector 68 may be disposed on a radially inner portion of the second radially innermost surface 62e of the second bearing unit 362 without the bushing member 168 .

The crank axle 51 for the bicycle crank assembly 27 has an elongated shape in one direction. The crank axle 51 for the bicycle crank assembly 27 has a rotational center axis C2 of the crank axle 51. The rotational center axis C2 of the crank axle 51 is coaxial with the rotational center axis C1 of the bicycle bottom bracket assembly 53 when the bicycle crank assembly 27 is assembled.

The crank axle 51 for the bicycle crank assembly 27 includes a large-diameter portion 51a, a small-diameter portion 51b, and a transition step 51c. The crank axle 51 for the bicycle crank assembly 27 has a difference in diameter.

The large-diameter portion 51a is preferably formed in a cylindrical or tubular shape. The large-diameter portion 51a includes a first bearing mounting portion 51d. The first bearing mounting portion 51d has a first bearing mounting diameter.

The first bearing mounting portion 51d faces the first inner race 61b, for example, the first radially innermost surface 61e of the first inner race 61b, in the radial direction with respect to the rotational center axis C1 of the bicycle bottom bracket assembly 53. Specifically, the first bearing mounting portion 51d is pressed to the first radially innermost surface 61e of the first inner race 61b.

The small-diameter portion 51b is preferably formed into a cylindrical shape or a tubular shape. The small-diameter portion 51b includes a second bearing mounting portion 51e. The second bearing mounting portion 51e has a second bearing mounting diameter smaller than the first bearing mounting diameter.

The second bearing mounting portion 51e faces the second inner race 62b, for example, the second radially innermost surface 62e of the second inner race 62b, in the radial direction with respect to the rotational center axis C1 of the bicycle bottom bracket assembly 53. Specifically, the second bearing mounting portion 51e is press-fitted via the seal protector 67 to the second radially innermost surface 62e of the first inner race 61b.

The transition step 51c is positioned between the large-diameter portion 51a and the small-diameter portion 51b in the axial direction with respect to the rotation center axis C2 of the crank axle 51 .

The transition step 51c is provided on a plane intersecting with the rotation center axis C2 of the crank axle 51 . For example, the transition step 51c is provided on a plane perpendicular to the rotation center axis C2 of the crank axle 51 . The transition step 51c may be provided on a plane inclined to the rotation center axis C2 of the crank axle 51 .

The transition step 51c is spaced from the second bearing mounting portion 51e in the axial direction. In other words, the second bearing mounting portion 51e is spaced from the transition step 51c in the axial direction. There is an axial clearance between the transition step 51c and the second bearing mounting portion 51e in the axial direction.

Preferably, the axial distance in the axial direction between the second bearing mounting portion 51e and the transition step 51c is defined in the range of 0.1 mm to 70 mm. Preferably, the difference in diameter between the first bearing mounting diameter and the second bearing mounting diameter is equal to or greater than 2 mm. The diameter difference is equal to or less than 60mm.

reference list

1

bicycle

9

bicycle chain

11

bike frame

11a

bracket part

12a

first axial end

12b

second axial end

12c

body part

12d

third bearing assembly section

12e

fourth bearing assembly section

13

handlebars

17

front wheel

17a

front tire

19

rear wheel

19a

rear tire

20

front fork

24

switching device

25

powertrain

26

rear bicycle derailleur

27

Bicycle crank assembly

28

rear bicycle sprocket assembly

29

rear bicycle hub assembly

35

front bike sprocket assembly

51

crank axle

51a

Large diameter section

51b

Small diameter section

51c

transition stage

51d

first bearing assembly area

51e

second bearing assembly area

53

Bicycle bottom bracket assembly

55

first support element

55a

first bracket mounting section

55b

first bearing assembly section

55c

first axially inner end

55d

first stop surface

55e

first thread section

57

second support element

57a

second bracket mounting section

57b

second bearing assembly section

57c

second axially inner end

57d

second stop surface

57e

second thread section

59

connection section

60

connecting tube element

61

first storage unit

61a

first outer race

61b

first inner race

61c

first role element

61d

first radially outermost surface

61e

first radially innermost surface

62

second storage unit

62a

second outer race

62b

second inner race

62c

second role element

62d

second radially outermost surface

62e

second radially innermost surface

63

elastic sealing element

67

seal protection

68

seal protection

69

tubular sealing element

70

locking element

70a

stop part

70b

projection part

153

Bicycle bottom bracket assembly

161

first storage unit

161a

first outer race

161b

first inner race

161c

first role element

161e

first radially innermost surface

162

second storage unit

162a

second outer race

162b

second inner race

162c

second role element

162e

second radially innermost surface

168

socket element

169

tubular sealing element

253

Bicycle bottom bracket assembly

261

first storage unit

262

second storage unit

361

first storage unit

362

second storage unit

C1

center axis of rotation

D11

first outer race radial clearance

D12

second outer race radial clearance

D21

first radial roller element spacing

D22

second radial roller element spacing

D31

first inner race radial clearance

D32

second inner race radial clearance

D131

first inner race radial clearance

D132

second inner race radial clearance

D231

first inner race radial clearance

D232

second inner race radial clearance

DS1

Diameter of the first opening S1

DS2

Diameter of the second opening S2

P1

first midpoint

p2

second midpoint

S1

first opening

S2

second opening

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US7699532B2 [0004]
• DE 102008029088 A1 [0004]
• US 2005/0011304 A1 [0004]
• US 2006/0053962 A1 [0004]

Claims (21)

A bicycle bottom bracket assembly (53, 153, 253) comprising: a first support member (55) having a first bracket mounting portion (55a) and a first bearing mounting portion (55b), the first bracket mounting portion (55a) being configured to be attached to a first axial end (12a) of a bracket part (11a) of a bicycle Frame (11) can be mounted; a second support member (57) having a second bracket mounting portion (57a) and a second bearing mounting portion (57b), the second bracket mounting portion (57a) being configured to be mounted to a second axial end (12bb) of the bracket portion (11a) of the bicycle frame (11), the second axial end (12b) of the support part (11a) facing the first axial end (12a) of the support part (11a) in an axial direction with respect to a rotational center axis (C1) of the bicycle bottom bracket assembly (53, 153, 253); a first bearing unit (61, 161, 261, 361) having a first outer race (61a, 161a), a first inner race (61b, 161b) and at least one first roller element (61c, 161c) sandwiched between the first outer race (61a, 161a) and the first inner race (61b , 161b), wherein the first outer race (61a) 161a) is configured to be attached to the first bearing mounting portion (55b) of the first support member (55), the first outer race (61a, 161a) having a first radial outermost surface (61d) facing in the radial direction, and the first inner race (61a, 161a) has a first radially innermost surface (61e, 161e) facing in the radial direction, wherein the at least one first roller element ( 61c, 161c) has a first center point (P1); and a second bearing assembly (62, 162, 262, 362) having a second outer race (62a, 162a), a second inner race (62b, 162b) and at least one second roller element (62c, 162c) arranged in the radial direction between the second outer race (62a, 162a) and the second inner race (62b, 162b), the second outer race (62a, 162a) configured to be attachable to the second bearing mounting portion (57b) of the first support member (55), the second outer race (62a, 162a) having a second radially outermost surface (62d), facing in the radial direction, and the second inner race (62b, 162b) has a second radially innermost surface (62e, 162e) facing in the radial direction, the at least one second roller element (62c, 162c) having a second center point (P2) has; wherein a first outer race radial clearance (D11) is defined in a radial direction from the rotation center axis (C1) toward the first radially outermost surface (61d); wherein a second outer race radial clearance (D12) is defined in a radial direction from the rotational center axis (C1) to the second radially outermost surface (62d), the first outer race radial clearance (D11) and the second outer race radial clearance (D12) being opposed to each other; a first roller element radial distance (D21) being defined from the rotation center axis (C1) toward the first center point (P1); a second rolling element radial pitch (D22) being defined from the rotational center axis (C1) toward the second center point (P2), the first rolling element radial pitch (D21) and the second rolling element radial pitch (D22) being opposed to each other; wherein a first inner race radial clearance (D31, D131, D231) is defined in a radial direction from the rotation center axis (C1) toward the first radially innermost surface (61e, 161e); wherein a second inner race radial clearance (D32, D132, D232) is defined in a radial direction from the rotation center axis (C1) toward the second radially innermost surface (62e, 162e), wherein the first inner race radial clearance (D31, D131, D231) and the second inner race radial clearance (D32, D132, D231) face each other as counterparts; wherein the first outer race radial spacing (D11) and/or the first roller element radial spacing (D21) differs from the respective counterpart of the second outer race radial spacing (D12) and/or the second roller element radial spacing (D22); and wherein the first inner race radial clearance (D31, D131, D231) differs from the second inner race radial clearance (D32, D132, D231). The bicycle bottom bracket assembly (53, 153, 253). claim 1 wherein the first support member (55) and the second support member (57) are formed as a unitary, one-piece member. The bicycle bottom bracket assembly (53, 153, 253). claim 1 , wherein the first support member (55) has a first axially inner end (55c) configured to, in an assembled condition in which the bicycle bottom bracket assembly (53, 153, 253) is mounted on the mounting portion (11a) of the Bicycle frame (11) mounted, can be arranged within the mounting part (11a) of the bicycle frame (11); and the second support member (57) has a second axially inner end (57c) configured to be disposed within the mounting portion (11a) of the bicycle frame (11) when assembled. The bicycle bottom bracket assembly (53, 153, 253). claim 3 , wherein in the assembled state the first axially inner end (55c) of the first support element (55) and the second axially inner end (57c) of the second support element (57) are separated from one another in the axial direction. The bicycle bottom bracket assembly (53, 153, 253) according to any one of Claims 1 until 4 further comprising: a connecting tube member (60) configured to, when assembled, define an axial gap between the first axially inner end (55c) of the first support member (55) and the second axially inner end (57c) of the second support member ( 57) bridged. The bicycle bottom bracket assembly (53, 153, 253). claim 3 wherein the first axially inner end (55c) of the first support member (55) has a first threaded portion (55e); and the second axially inner end (57c) of the second support member (57) has a second threaded portion (57e) configured to threadably engage the first threaded portion (55e) of the first axially inner end (57c) when assembled. stands. The bicycle bottom bracket assembly (53, 153, 253). claim 3 wherein when assembled, the first axially inner end (55c) of the first support member (55) and the second axially inner end (57c) of the second support member (57) are overlapped with each other in an interference fit. The bicycle bottom bracket assembly (53, 153, 253). claim 3 wherein, in the assembled state, the first axially inner end (55c) of the first support member (55) and the second axially inner end (57c) of the second support member (57) overlap each other; and when assembled, an elastic sealing element (63) is arranged in the radial direction between the first axially inner end (55c) of the first support element (55) and the second axially inner end (57c) of the second support element (55). The bicycle bottom bracket assembly (53, 153, 253) according to any one of Claims 1 until 8th further comprising: a tubular sealing member (69) configured to seal an axial gap between the first inner race (61b, 161b) of the first bearing unit (61, 161, 261, 361) and the second inner race when assembled (62b, 162b) of the second bearing unit (62, 162, 262, 362) bridged. The bicycle bottom bracket assembly (53, 153, 253) according to any one of Claims 1 until 9 wherein the first inner race radial clearance (D31, D131, D231) is greater than the second inner race radial clearance (D32, D132, D232); the first radially innermost surface (61e, 161e) defines a first opening (S1); the second radially innermost surface (62e, 162e) defines a second opening (S2); and the first opening (S1) and the second opening (S2) are configured so that a crank axle (51) can be inserted into the bicycle bottom bracket assembly (53, 153, 253) by removing the crank axle (51) from the first opening (S1) is moved in the axial direction toward the second opening (S2), and can be removed from the bicycle bottom bracket assembly (53, 153, 253) by moving the crank axle (51) from the second opening (S2) in the axial direction is moved to the first opening (S1). A bicycle bottom bracket assembly (53, 153, 253) comprising: a first bearing unit (61, 161, 261, 361) having a first outer race (61a, 161a), a first inner race (61b, 161b) and at least one first roller element (61c, 161c) sandwiched between the first outer race (61a, 161a) and the first inner race (61b, 161b) in a radial direction with respect to a rotational center axis (C1) of the bicycle bottom bracket assembly (53, 153, 253). is arranged, wherein the first outer race (61a, 161a) is configured to be attached to a first axial end (12a) of a mounting part (11a) of a bicycle frame (11), wherein the first inner race (61b, 161b ) has a first radially innermost surface (61e, 161e) facing in the radial direction; and a second bearing unit (62, 162, 262, 362) having a second outer race (62a, 162a), a second inner race (62b, 162b) and at least one second roller element (62c, 162c) positioned radially between the second outer race (62a, 162a) and the second inner race (62b 162b), the second outer race (62a, 162a) being configured to be attached to a second axial end (12b) of the support part (11a) of the Bicycle frame (11) with the second axial end (12b) of the support member (11a) in an axial direction with respect to a rotational center axis (C1) of the bicycle bottom bracket assembly (53, 153, 253) the first axial end (12a) of the support member (11a), the second inner race (62b, 162b) having a second radially innermost surface facing in the radial direction (62e, 162e); wherein a first inner race radial clearance (D31, D131, D231) is defined in a radial direction from the rotation center axis (C1) toward the first radially innermost surface (61e, 161e); wherein a second inner race radial distance (D32, D132, D232) in the radial direction from the rotation center axis (C1) to the second radially innermost surface (62e, 162e) is defined towards; and wherein the first inner race radial clearance (D31, D131, D231) differs from the second inner race radial clearance (D32, D132, D232). The bicycle bottom bracket assembly (53, 153, 253). claim 11 wherein the first inner race radial clearance (D31, D131, D231) is greater than the second inner race radial clearance (D32, D132, D232); the first radially innermost surface (61e, 161e) defines a first opening (S1); the second radially innermost surface (62e, 162e) defines a second opening (S2); and the first opening (S1) and the second opening (S2) are configured so that a crank axle (51) can be inserted into the bicycle bottom bracket assembly (53, 153, 253) by removing the crank axle (51) from the first opening (S1) is moved in the axial direction toward the second opening (S2), and can be removed from the bicycle bottom bracket assembly (53, 153, 253) by moving the crank axle (51) from the second opening (S2) in the axial direction is moved to the first opening (S1). The bicycle bottom bracket assembly (53, 153, 253). claim 11 or 12 wherein the first outer race (61a, 161a) is configured to be press-fittable to the first axial end (12a) of the mounting portion (11a) of the bicycle frame (11); and the second outer race (62a, 162a) is configured to be press-fittable to a second axial end (12b) of the mounting portion (11a) of the bicycle frame (11). A bicycle bottom bracket assembly (53, 153, 253) comprising: a first support member (55) having a first bracket mounting portion (55a) and a first bearing mounting portion (55b), the first bracket mounting portion (55a) being configured to be attached to a first axial end (12a) of a bracket part (11a) of a bicycle Frame (11) can be mounted; a second support member (57) having a second bracket mounting portion (57a) and a second bearing mounting portion (57b), the second bracket mounting portion (57a) being configured to be mounted to a second axial end (12b) of the bracket portion (11a) of the bicycle frame (11), the second axial end (12b) of the support member (11a) opposed to the first axial end (12a) of the support member (11a) in an axial direction with respect to a rotational center axis (C1) of the bicycle bottom bracket assembly (53, 153, 253); a first bearing unit (61, 161) having a first outer race (61a, 161a), a first inner race (61b, 161b), and at least one first roller member (61c, 161c) rotating in a radial direction with respect to a rotation center axis ( C1) the bicycle bottom bracket assembly (53, 153, 253) is disposed between the first outer race (61a, 161a) and the first inner race (61b, 161b), the first outer race (61a, 161a) being configured so that it can be attached to the first bearing mounting portion (55b) of the first support member (55), the first inner race (61b, 161b) having a first radially innermost surface (61e, 161e) facing in the radial direction, the first radially innermost surface (61e, 161e) defines a first opening (S1); and a second bearing assembly (62, 162) having a second outer race (62a, 162a), a second inner race (62b, 162b), and at least one second roller element (62c, 162c) spaced radially between the second outer race (62a , 162a) and the second inner race (62b, 162b), the second outer race (62a, 162a) being configured to be attached to the second bearing mounting portion (57b) of the first support member (55), the second the inner race (62b, 162b) has a second radially innermost surface (62e, 162e) facing in the radial direction, the second radially innermost surface (62e, 162e) defining a second opening (S2); wherein the first port (S1) and the second port (S2) are configured such that a crank axis (51) in the axial direction extends from one of the first port (S1) and the second port (S2) toward the other of the first port ( S1) and the second opening (S2) can be inserted into the bicycle bottom bracket assembly (53, 153, 253), and by moving the crank axis (51) in the axial direction from the other of the first opening (S1) and the second opening ( S2) to which one of the first opening (S1) and the second opening (S2) can be removed from the bicycle bottom bracket assembly (53, 153, 253); and wherein the first support member (55) and the second support member (57) are formed as a unitary, one-piece member. The bicycle bottom bracket assembly (53, 153, 253). Claim 14 wherein a first inner race radial clearance (D31, D131, D231) is defined in the axial direction from the rotation center axis (C1) toward the first radially innermost surface (61e, 161e); a second inner race radial clearance (D32, D132, D231) is defined in the axial direction from the rotation center axis (C1) toward the second radially innermost surface (62e, 162e); and the first inner race radial clearance (D31, D131, D231) is equal to the second inner race radial clearance (D32, D132, D232). The bicycle bottom bracket assembly (53, 153, 253). Claim 14 wherein a first inner race radial clearance (D31, D131, D231) is defined in a radial direction from the rotation center axis (C1) toward the first radially innermost surface (61e, 161e); a second inner race radial clearance (D32, D132, D232) is defined in a radial direction from the rotational center axis (C1) toward the second radially innermost surface (62e, 162e); and the first inner race radial clearance (D31, D131, D231) differs from the second inner race radial clearance (D32, D132, D232). The bicycle bottom bracket assembly (53, 153, 253). Claim 16 wherein the first inner race radial clearance (D31, D131, D231) is greater than the second inner race radial clearance (D32, D132, D232); and the first opening (S1) and the second opening (S2) are configured so that a crank axle (51) can be inserted into the bicycle bottom bracket assembly (53, 153, 253) by removing the crank axle (51) from the first opening (S1) is moved in the axial direction toward the second opening (S2), and can be removed from the bicycle bottom bracket assembly (53, 153, 253) by moving the crank axle (51) from the second opening (S2) in the axial direction is moved to the first opening (S1). A crank axle (51) for a bicycle crank assembly (27), the crank axle (51) comprising: a large diameter portion (51a) having a first bearing mounting area (51d) with a first bearing mounting diameter; a small diameter portion (51b) having a second bearing mounting area (51e) with a second bearing mounting diameter smaller than the first bearing mounting diameter; and a transition stage (51c) disposed between the large-diameter portion (51a) and the small-diameter portion (51b) in an axial direction with respect to a rotational center axis (C1) of the crank axle (51); wherein the second bearing mounting portion (51e) is axially spaced from the transition step (51c). The crank axle (51) for the bicycle crank assembly (27). Claim 18 wherein an axial distance defined in the axial direction between the second bearing mounting portion (51e) and the transition step (51c) is in the range of 0.1 mm to 70 mm. A crank axle (51) for a bicycle crank assembly (27), the crank axle (51) comprising: a large diameter portion (51a) having a first bearing mounting portion (51d) with a first bearing mounting diameter; a small diameter portion (51b) having a second bearing mounting portion (51e) with a second bearing mounting diameter smaller than the first bearing mounting diameter; and a transition stage (51c) disposed between the large-diameter portion (51a) and the small-diameter portion (51b) in an axial direction with respect to a rotational center axis (C1) of the crank axle (51); wherein a difference in diameter between the first bearing mounting diameter and the second bearing mounting diameter is equal to or greater than 2 mm. The crank axle (51) for the bicycle crank assembly (27). claim 20 , where the diameter difference is equal to or less than 60 mm.

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