Bicycle wheel rims meant for use with disc brakes or hub brakes sometimes lack this surface. The Westwood pattern rim was one of the first rim designs, and rod-actuated brakes, which press against the inside surface of the rim were designed for this rim. These rims cannot be used with caliper rim brakes. The cross-section of a rim can have a wide range of geometry, each optimized for particular performance goals. Aerodynamics, mass and inertia, stiffness, durability, tubeless tire compatibility, brake compatibility, and cost are all considerations. If the part of the cross-section of the rim is hollow where the spokes attached,
Wheel hub assembly A roller bearing between the axle hub and axle shaft ensures easy rotation of the non-drive wheels. On the axle side, it is mounted to the holding bracket from the chassis; on the disc side, the wheel is mounted to the bolts of the WHA. When replacing, a wheel hub assembly should be torqued to the vehicle's specifications to prevent failure. Wheel hub assembly A wheel hub assembly (WHA), also referred to as hub assembly, wheel hub unit, wheel hub bearing, etc., is an automotive part used in most cars, passenger vehicles, and light and heavy trucks. The WHA is