An improved apparatus and method are provided for cutting a tire surface to remove selected portions of rubber from the tire surface while the tire is rotating. The apparatus and method are especially useful in removing tread material from the tire to improve the force variation and runout characteristics of the tire. The material is removed by a cutting device such as a grinding wheel and a positioning device which holds the cutting device in a fixed cutting position for an incremental period of time while a corresponding incremental segment of the tire circumference, for instance a segment equal to 1/100 of the circumference (3.6.degree.), passes by the cutter. A sensing device measures a characteristic of the tire, such as its radial forced variation, and radial run-out of the tire is also measured. Based on these measurements, a computing device determines the amount of material to be removed from each incremental segment of the tire circumference and controls the positioning device so that the cutter is located in the correct position for removing the desired amount of material from each incremental segment of the tire circumference.