Tru-Balance Wheel Centering Products says that with older radial run-out gauges, there were numerous adjustments that needed to be made to get an accurate reading, but with its simple-to-use gauge, there are only two.
Radial run-out is an out-of-round condition in which the radius of the wheel or tire is not consistent from the wheel center to any point on the rim or the tread. Radial run-out is measured by placing a run-out gauge against a smooth section of the tread near the center of the tire and then rotating the wheel and tire by hand through one complete revolution. Tire and wheel radial run-out often are factors in troubleshooting ride and handling and in maintaining correct wheel balancing.
For more information, go to www.tru-bal.com.