A sprocket support body comprises at least ten external spline teeth including a plurality of external-spline driving surfaces. The plurality of external-spline driving surfaces each includes a radially outermost edge, a radially innermost edge, and a radial length. A total of the radial lengths of the plurality of external-spline driving surfaces is equal to or larger than 7 mm. At least one external-spline driving surface has a first external-spline-surface angle. The first external-spline-surface angle ranges from 0 degree to 10 degrees. One tooth of the at least ten external spline teeth having a first circumferential spline size. The other teeth of the at least ten external spline teeth each have a second circumferential spline size that is smaller than the first circumferential spline size. A total number of the other teeth of the at least ten external spline teeth being equal to or larger than nine.

An electronic automatically decoupling hub assembly is disclosed herein. The assembly has an axle and a hub shell rotationally positioned about the axle. A controller provides automatic activation/deactivation signals to an inductor. The assembly has a bearing rotationally positioned about the axle and a ratchet ring, having a plurality of teeth, rotationally positioned about the bearing. One or more pawls are provided to engage with at least some of the teeth of the ratchet ring and a seal is used to contain the pawls within the assembly. A cassette body assembly is coupled with the ratchet ring and an end cap is used to prevent a contaminant from entering into the decoupling hub assembly.

An electronic automatically decoupling hub assembly is disclosed herein. The assembly has an axle and a hub shell rotationally positioned about the axle. A controller provides automatic activation/deactivation signals to an inductor. The assembly has a bearing rotationally positioned about the axle and a ratchet ring, having a plurality of teeth, rotationally positioned about the bearing. One or more pawls are provided to engage with at least some of the teeth of the ratchet ring and a seal is used to contain the pawls within the assembly. A cassette body assembly is coupled with the ratchet ring and an end cap is used to prevent a contaminant from entering into the decoupling hub assembly.

A power transmission unit is used for generating auxiliary driving force for an electric bicycle, and includes a motor, an input structure, a speed reducer, a case, a bearing, and a bearing support portion. The motor includes a motor shaft. The input structure includes an input shaft and configured to rotate along with the input shaft, the input shaft being caused to rotate by external force transmitted thereto. Thea speed reducer mechanism is configured to transmit a rotational power of the motor shaft while reducing a rotational speed. The case houses the motor, the input structure, and the speed reducer mechanism. The case includes a first divided part and a second divided part. The bearing is located inside the case. The bearing supporting portion, to which the bearing is attached, supports the speed reducer mechanism. The bearing supporting portion is attached to the first divided part.

A freecoaster hub system for a bicycle allows the bicycle to coast freely in either a forward or backward direction. The freecoaster hub system includes a hub assembly having a hub and an axle, wherein the hub is interconnected to the rim of a wheel of the bicycle by a plurality of spokes. The freecoaster hub system for a bicycle also includes a transmission assembly at least partially mounted in the hub and operatively interconnected to the axle and the hub. The transmission assembly comprising a drive assembly and an engagement assembly, each of which operatively engage the axle and or hub.

A freecoaster hub system for a bicycle allows the bicycle to coast freely in either a forward or backward direction. The freecoaster hub system includes a hub assembly having a hub and an axle, wherein the hub is interconnected to the rim of a wheel of the bicycle by a plurality of spokes. The freecoaster hub system for a bicycle also includes a transmission assembly at least partially mounted in the hub and operatively interconnected to the axle and the hub. The transmission assembly comprising a drive assembly and an engagement assembly, each of which operatively engage the axle and or hub.

A coupling arrangement for coupling members as a gear change coupling in a gear mechanism unit includes a first member and a second member. The first member has a coupling toothing system. At least one locking body arrangement is mounted pivotably on the second member. The locking body arrangement can be pivoted into a coupling position, in the case of which a driving section on the locking body arrangement engages into the coupling toothing system. The locking body arrangement can be pivoted into a release position, in the case of which the driving section of the locking body arrangement does not engage into the coupling toothing system. The locking body arrangement has a locking body carrier which is mounted pivotably on the second member, and has a locking body member which is mounted pivotably on the locking body carrier and on which the driving section is configured.

A coupling arrangement for coupling members as a gear change coupling in a gear mechanism unit includes a first member and a second member. The first member has a coupling toothing system. At least one locking body arrangement is mounted pivotably on the second member. The locking body arrangement can be pivoted into a coupling position, in the case of which a driving section on the locking body arrangement engages into the coupling toothing system. The locking body arrangement can be pivoted into a release position, in the case of which the driving section of the locking body arrangement does not engage into the coupling toothing system. The locking body arrangement has a locking body carrier which is mounted pivotably on the second member, and has a locking body member which is mounted pivotably on the locking body carrier and on which the driving section is configured.

A wheel hub (10) comprises a main body (12) and a drive axle arrangement (14) extending through the main body (12). The main body (12) is rotatable about the drive axle arrangement (14). The wheel hub (10) further includes a transmission assembly comprising first and second transmission arrangements (44, 46). The first transmission arrangement (44) is provided on the drive axle arrangement (14), and the second transmission arrangement (46) is provided on the main body (12). The first transmission arrangement (44) is cooperable with the second transmission arrangement (46) to transmit a driving force from the drive axle arrangement (14) to the main body (12). The drive axle arrangement (14) comprises an axle portion (34) and a sprocket carrier (42). The axle portion (34) extends through the main body (12), and the sprocket carrier (42) is configured to carry at least one sprocket.

A wheel hub (10) comprises a main body (12) and a drive axle arrangement (14) extending through the main body (12). The main body (12) is rotatable about the drive axle arrangement (14). The wheel hub (10) further includes a transmission assembly comprising first and second transmission arrangements (44, 46). The first transmission arrangement (44) is provided on the drive axle arrangement (14), and the second transmission arrangement (46) is provided on the main body (12). The first transmission arrangement (44) is cooperable with the second transmission arrangement (46) to transmit a driving force from the drive axle arrangement (14) to the main body (12). The drive axle arrangement (14) comprises an axle portion (34) and a sprocket carrier (42). The axle portion (34) extends through the main body (12), and the sprocket carrier (42) is configured to carry at least one sprocket.