The wheel frame of the hub is as follows:

1. Rim: Matched with tire assembly to support wheel part of tire.

2. Spoke: it is installed and connected with the axle hub to support the wheel part of the rim.

3. Offset: the distance between the center surface of the rim and the spoke mounting surface. There are positive offset, zero offset, negative offset.

4. Rim: The part of the rim that holds and supports the tire direction.

5. Tire seat: also known as the mounting surface, which contacts with the tire ring and supports the rim in the direction of the tire radius.

6, groove bottom: For the convenience of tire assembly and disassembly, a certain depth and width of the crater on the rim.

7. Valve hole: The hole through which to install the tire valve.