Wire wheel 6 rigid spokes began to appear in the Olympic Games and professional racing: these have advantages in specialized applications, such as time trials, but wire-spoked wheels are used for most purposes. The reaction to a radial load of a well-tensioned wire spoked wheel, such as by a rider sitting on a bicycle, is that the wheel flattens slightly near the ground contact area. The rest of the wheel remains approximately circular. The tension of all the spokes does not increase significantly. Instead, only the spokes directly under the hub decrease their tension. The issue of how best to describe this
Bicycle wheel of center. "Vertical truing" refers to adjustments of local deviations (known as hop) of the radius, the distance from the rim to the center of the hub. "Dish" refers to the left-right centering of the plane of the rim between the lock nuts on the outside ends of the axle. This plane is itself determined as an average of local deviations in the lateral truing. For most rim-brake bicycles, the dish will be symmetrical on the front wheel. However, on the rear wheel, because most bicycles accommodate a rear sprocket (or group of them), the dishing will often be asymmetrical: