The rim is an extrusion that is butted into itself to form a circle. Most rims are made of aluminum alloy, while some very high-end rims are made of carbon fiber, and some old or very low-end rims are made of steel. Rims have even been made of wood[1] and thermoplastic.
Rims designed for use with rim brakes provide a smooth parallel braking surface, while rims meant for use with disc brakes or hub brakes sometimes lack this surface.
The Westwood rim is designed for use with rod-actuated brakes, which press against the inside surface of the rim. These rims cannot be used with caliper rim brakes.
Rims can either have a single-wall or double-wall cross section. Single-wall rims are usually less expensive and weaker or heavier; double-wall rims tend to be stronger and more expensive. Double-wall rims may have a deep profile either to reduce aerodynamic drag or for additional strength or rigidity, especially for wheels with fewer spokes.
Aluminum rims are reinforced with either steel washers, single eyelets, or double eyelets. A single eyelet reinforces the spoke hole much like a hollow rivet. A double eyelet is a cup that is riveted into both walls of a double-walled rim.
The number of spoke holes on the rim normally matches the number of spoke holes in the hub. For a double-walled rim there are usually holes for spokes in both walls, although some factory built wheels have rim designs without holes in the wall that contacts the tire. For example Campagnolo road rims and the Velocity
Answered by
Sunny
at
11:34 AM on March 29, 2008
