The part of a bicycle that allows the wheel to rotate around the axle is called the hub. Typically, a hub consists of a central body that houses the bearings, which enable smooth rotation. Flanges on either side of the hub provide attachment points for the spokes, connecting the hub to the wheel rim. The hub is mounted onto the axle, which is secured to the bicycle frame or fork, allowing the wheel to spin freely while supporting the rider’s weight.
It functions as the central rotating component of the wheel, much like the axle of a car. It sits at the center of the wheel and fits between the dropouts of the fork (or frame in the rear). As the wheel spins, bearings inside the hub allow smooth rotation around the axle. When force is applied—such as from pedaling or braking—the hub transfers that energy through the spokes to the rim, keeping the motion efficient and stable.