Radnaben

Radnabe, or wheel hub, is the central component of a wheel that connects to the axle and houses the bearings. It enables the wheel to rotate around the axle while transmitting torque and supporting loads from the vehicle or bicycle frame. The hub also provides mounting interfaces for spokes in bicycles or for wheel studs and brake components in motor vehicles.

In bicycles, the hub comprises a hub shell, an axle (solid or hollow), bearings (cup-and-cone or cartridge), and end caps. The shell carries two flanges to which the wheel’s spokes are attached. The rear hub may include a freehub body or a freewheel, which engages the sprockets. Hubs are designed for front or rear use, and for different axle standards such as quick-release or through-axle. Some wheels mount a disc brake rotor directly to the hub; others use caliper brakes. Through-axle hubs are generally stiffer and align the wheel more precisely than traditional quick-release hubs. Some high-end hubs allow internal lubrication or ceramic bearings for reduced friction.

In automotive and motorcycle applications, the wheel hub assembly includes wheel bearings housed in a hub that bolts to the suspension or axle and provides a mounting surface for the wheel via studs or lug bolts. The hub region may include a reluctor ring for ABS, and the brake rotor is often mounted to the hub. Many modern hub assemblies integrate the bearings as a sealed unit and include components such as a tone ring or sensors, reducing maintenance but requiring replacement of the entire assembly when worn.

Maintenance involves checking bearing pre-load or play, inspection for wear or corrosion, ensuring fasteners are torqued to specification, and replacing worn bearings, seals, or the entire hub assembly when needed.