Wheel dish doesn’t refer to those fancy disc wheels of mtb racing yesteryear.

Dish does refer to the relative placement of the rim over the hub. For a bike to track straight and handle correctly, the dish of the front and rear wheels had best be right.

The rim is centered over the axle, not the hub flanges. In the case of a rear wheel, the cassette necessitates that the right flange be pushed towards the center of the hub, making the rim sit off center between the hub flanges in order to be centered about the axle. The same effect is seen with a disc rotor mount – the flanges are often uneven distances from the axle ends yielding a “dished” wheel. When people speak of wheels without dish they are talking about wheels with hub flanges equidistant from the centerline of the hub, meaning that the rim is centered on the axle and the hub flanges.

It is important conceptually to understand that a wheel can be perfectly true, as in round, but out of dish by not being properly centered over the axle.

Next… How to check dish without tools.