A bicycle rear sprocket adapter comprises a plurality of external spline teeth and a plurality of internal spline teeth. The plurality of external spline teeth is configured to engage with a bicycle rear sprocket assembly. The plurality of internal spline teeth is configured to engage with a bicycle hub assembly. At least two internal spline teeth of the plurality of internal spline teeth are circumferentially arranged at a first internal pitch angle with respect to a rotational center axis of the bicycle hub assembly. The first internal pitch angle ranges from 10 degrees to 20 degrees.

A bicycle rear sprocket adapter comprises a plurality of external spline teeth and a plurality of internal spline teeth. The plurality of external spline teeth is configured to engage with a bicycle rear sprocket assembly. The plurality of internal spline teeth is configured to engage with a bicycle hub assembly. At least two internal spline teeth of the plurality of internal spline teeth are circumferentially arranged at a first internal pitch angle with respect to a rotational center axis of the bicycle hub assembly. The first internal pitch angle ranges from 10 degrees to 20 degrees.

A mobile vehicle is disclosed herein. It comprises a car body having four wheels and a chassis bracket at a bottom thereof, and at least one drive motor disposed on a front side or a rear side or both of the chassis bracket and each of which has a motor body and a rotational shaft passing through a center of the motor body for driving the four wheels to rotate through a driver assembly.

A mobile vehicle is disclosed herein. It comprises a car body having four wheels and a chassis bracket at a bottom thereof, and at least one drive motor disposed on a front side or a rear side or both of the chassis bracket and each of which has a motor body and a rotational shaft passing through a center of the motor body for driving the four wheels to rotate through a driver assembly.

A motive wheel and selectively attachable/detachable hub motor for an electric vehicle comprises an axle comprising an axle axis, outer end, and cylindrical axle hub; a wheel comprising an outer wheel surface, inner wheel surface, wheel hub configured for reversible rotatable disposition on the axle, and wheel rim configured to receive a tire; and a hub motor disposed proximate the outer wheel surface and configured for selective attachment to/detachment from the wheel and axle and comprising a cylindrical rotor and cylindrical stator, the cylindrical rotor configured for selective attachment to/detachment from the axle, the cylindrical stator extending away from the cylindrical rotor and configured for selective attachment to/detachment from the wheel hub, the hub motor configured for reversible rotation of the wheel and cylindrical stator, wherein upon attachment of the hub motor a motive wheel is provided, and wherein upon detachment of the hub motor a non-motive wheel is provided.

A motive wheel and selectively attachable/detachable hub motor for an electric vehicle comprises an axle comprising an axle axis, outer end, and cylindrical axle hub; a wheel comprising an outer wheel surface, inner wheel surface, wheel hub configured for reversible rotatable disposition on the axle, and wheel rim configured to receive a tire; and a hub motor disposed proximate the outer wheel surface and configured for selective attachment to/detachment from the wheel and axle and comprising a cylindrical rotor and cylindrical stator, the cylindrical rotor configured for selective attachment to/detachment from the axle, the cylindrical stator extending away from the cylindrical rotor and configured for selective attachment to/detachment from the wheel hub, the hub motor configured for reversible rotation of the wheel and cylindrical stator, wherein upon attachment of the hub motor a motive wheel is provided, and wherein upon detachment of the hub motor a non-motive wheel is provided.

The present disclosure relates to structures and associated systems for connecting a hub apparatus to a wheel. In some embodiments, the hub apparatus includes (1) a housing assembly having an outer radius; and (2) a mounting portion circumferentially provided on at least one side surface of the housing assembly. The mounting portion is formed with a plurality of coupling structures configured to couple the hub apparatus to a wheel rim. The mounting portion defines a first radius smaller than the outer radius.

The present disclosure relates to structures and associated systems for connecting a hub apparatus to a wheel. In some embodiments, the hub apparatus includes (1) a housing assembly having an outer radius; and (2) a mounting portion circumferentially provided on at least one side surface of the housing assembly. The mounting portion is formed with a plurality of coupling structures configured to couple the hub apparatus to a wheel rim. The mounting portion defines a first radius smaller than the outer radius.

A bicycle rear sprocket assembly is configured to be mounted to a sprocket support body of a bicycle rear hub assembly. The bicycle rear sprocket assembly comprises a plurality of bicycle sprockets. The plurality of bicycle sprockets comprises a first sprocket and a second sprocket. The first sprocket includes a first opening having a first minimum diameter that is smaller than a minimum outer diameter of the sprocket support body of the bicycle rear hub assembly. The second sprocket includes a second opening and at least ten internal spline teeth. The second opening has a second minimum diameter that is equal to or larger than the minimum outer diameter of the sprocket support body of the bicycle rear hub assembly. The at least ten internal spline teeth are configured to engage with the sprocket support body of the bicycle rear hub assembly.

A bicycle rear sprocket assembly is configured to be mounted to a sprocket support body of a bicycle rear hub assembly. The bicycle rear sprocket assembly comprises a plurality of bicycle sprockets. The plurality of bicycle sprockets comprises a first sprocket and a second sprocket. The first sprocket includes a first opening having a first minimum diameter that is smaller than a minimum outer diameter of the sprocket support body of the bicycle rear hub assembly. The second sprocket includes a second opening and at least ten internal spline teeth. The second opening has a second minimum diameter that is equal to or larger than the minimum outer diameter of the sprocket support body of the bicycle rear hub assembly. The at least ten internal spline teeth are configured to engage with the sprocket support body of the bicycle rear hub assembly.