A method of forming a rib 60 on a power transmission belt 10 including the steps of providing an endless belt body 14 having an elastic material to define at least part of a longitudinal rib on a completed power transmission belt, providing a grinding wheel 46 with a peripheral cutting surface 56, rotating the grinding wheel in a first rotational direction, pressing the peripheral cutting surface of the grinding wheel against the belt body and grinding the body to define a rib thereon with an exposed surface defined by the elastic material, and altering the rotational velocity of the peripheral cutting surface to compensate for wear on the grinding wheel.