Tom, I would say to follow Ply33's instructions. At the same time you check for rim trueness, you can check the tires themselves (same procedure, just on the tire), though a dial indicator for the tires is overkill. Just use a stick and see how much the tires vary as they rotate. Place the stick horizontal relative to the tread, very close to the tread, and give the wheel a spin. If you see large variation in the gap between stick and tread, the tire needs to be shaved. Cheers, Tom