Tire balance

When tires are fitted to wheels at the point of sale, they are measured again on a balancing machine, and correction weights are applied to counteract their combined unbalance.

In tire manufacturing factories, static balancers use sensors mounted to the spindle assembly.

[1] These forces are resolved into static and couple values for the inner and outer planes of the wheel, and compared to the unbalance tolerance (the maximum allowable manufacturing limits).

In tire retail shops, tire/wheel assemblies are checked on a spin-balancer, which determines the amount and angle of unbalance.

[3] Dynamic balancing has traditionally required removing the wheel from the vehicle, but sensors installed in modern cars, such as for anti-lock brakes, could enable estimating the imbalance while driving.

In some cases, losing a counterweight or bumping the curb hard can lead to wheel unbalance.

[8] According to the United States Environmental Protection Agency, these total more than 20,000 tonnes of lead worldwide every year,[9] and therefore the use of less-toxic materials is encouraged.