Yes you have a point about the tire moving faster, but because all of the measurements and contermeasures are taken at the wheel rim, the speed diffence is automatically compensated for in the measurements and in the final result. The exact weight of the heavy spot on the tire is not relevant, as we do not apply the lead counter weights to the tread of the tire. It is the EFFECT of the tires heavy spot as measured at the wheel rim which is important, as that is where the countermeasures (counterweights) are applied. I'm not a mathematician, so I'm not going to bother trying to work out the formula required by my above post, but common sense tells me that it shouldn't be terribly difficult, for someone with a good grasp of physics and algebra, to come up with a formula, which could then be built-in to an alignment machine's electronics or computer system.Ray Bell:
Yes, simple... overly simple, I think...
Because an out of balance point in the tyre would be of more import (greater speed etc) than one on the wheel.