Spoke: The part of the wheel that is installed and connected to the axle and supports the wheel assembly. 

Valve hole: The hole for installing the tire valve.

Tire bead seat: In contact with the tire bead, it supports the radial part of the tire's rim. 

Offset: The distance between the center plane of the wheel and the mounting surface of the spoke. There are positive offset, zero offset, and negative offset. 

Wheels: The part of the wheel that supports the tire assembly in coordination with the tire. 

Wheel rim: The part of the wheel that maintains and supports the direction of the tire. 

Groove bottom: For the convenience of tire assembly and disassembly, there are certain depth and width pits left on the wheel rim.