The sprocket hub is a central component that connects the sprocket to the motorcycle's wheel or drive assembly. It is typically a metal disc or plate with a central mounting area that aligns with the wheel's hub or drive shaft. The sprocket hub ensures proper alignment and stability of the sprocket, which is crucial for efficient power transfer from the engine to the rear wheel. It may include features for mounting bolts or securing mechanisms and is designed to withstand the forces and vibrations experienced during riding.