What Is Wheel Runout?
What is wheel runout? And what does it have to with an out of round tire? The terms wheel runout and out of round are used to refer to any component of a wheel or tire assembly that is not perfectly round. There are two measurements that are used when evaluating the roundness or a wheel or tire: radial runout and lateral runout.
Radial runout is where the radius of the tire is not consistent from the wheel midpoint to any point on the rim. Too much radial runout can cause up and down vibrations, which means there will be up and down hopping when it spins. Excessive radial runout is generally felt in the suspension system of the vehicle, and is one of several wheel and tire malformations that can cause unacceptable vibration or a bumpy ride. Radial runout is measured by placing a dial indicator on the inside edge of the rim or tire tread.
Lateral runout is the amount of sideways motion or the amount of “wobble” in a wheel or tire as it rotates. It is usually measured by holding a dial indicator against the face of the rim or tire sidewall. A wheel with too much lateral runout will wobble back and forth as it rotates, creating a shimmy that is generally felt in the steering system.
The following are "industry standard" specifications, and only apply to unloaded tire and wheel assemblies on the vehicle.
|Radial Runout||0.060 inch (1.524mm)||0.050 inch (1.27mm)|
|Lateral Runout||0.060 inch (1.524mm)||0.050 inch (1.27mm)|
At OE Wheels, we maintain much stricter standards, and only allow a tolerance of .030 for both radial runout and lateral runout. That's almost half the acceptable tolerance, and another reason why OE Wheels has developed such a quality reputation.