Bicycle wheel how well the wheel transmits propulsive and braking forces, if applied at the hub, as in the case of hub or disc brakes. Several factors affect these stiffnesses to varying degrees. These include wheel radius, rim bending and torsional stiffness, number of spokes, spoke gauge, lacing pattern, hub stiffness, hub flange spacing, hub radius. In general lateral and radial stiffness decreases with the number of spoke crossings and torsional stiffness increases with the number of spoke crossings. One factor that has little influence on these stiffnesses is spoke tension. Too much spoke tension, however, can lead to catastrophic failure in
Rim (wheel) object. Some authors are careful to use "rim" for only the outer portion of a wheel, where the tire mounts, just as the rim of a coffee cup or a meteor crater does not refer to the entire object. One engineering text says "alloy wheels [are] often incorrectly called aluminum rims". Others use "rim" to mean the entire metal part to which the tire mounts, because the rim and the wheel are often cast or stamped from a single piece of metal instead of being distinct as with wire wheels. At the same time, "wheel" may refer to the entire