CUSTOM WHEELS HANDLING

For decades, it was common practice in the aftermarket to mount a tire so its red dot aligned with the wheel's valve stem, since the valve stem area was normally assumed to be the wheel's lowest point of radial run out. Aligning the tires high point to the wheel's low point (theoretically) reduces or eliminates the chance of developing a radial force variation (RFV) in the tire/wheel assembly.' RFV (again, an issue of runout, not imbalance) can cause a vibration that might be mistakenly diagnosed as an imbalance problem.

Times change. With the advent of styled custom wheels, the valve stem location may no longer indicate the wheel's low radial run out spot. In other words, it may no longer be viable to assume that aligning a tire's.red dot to the wheel's valve stem will address any potential RFV issues.

Consequently, a procedure that was once easy has now become complicated. The only way to accurately match mount a tire to a wheel is to actually measure tire and wheel runout. The end goal remains the same: to align the tire's high point to the wheel's low point. The wheel itself can be easily checked for radial run out by mounting it to a hub and slowly rotating it while monitoring the rim edge with a rigidly mounted dial gauge. However, the only acceptable method to check the assembled tire/wheel package for radial uniformity under load is to use a state-of-the-art wheel balancing machine that features a load-roller that applies road-simulated load to the inflated tire. Such a machine will not only check for dynamic balance but will also locate the tire's high spot. If this high spot doesn't correlate to the wheel's low spot, the machine will let you know where to relocate the tire on the wheel to minimize RFV

If you don't have access to a road wheel type of balancing machine, and you don't know where a wheel's lowest radial run out spot is located, you can default to using the Weight Method, which involves aligning the tire's yellow dot to the wheel's valve stem.