Car manufacturers have been using road force wheel balancers for decades because even the best tires are not perfect. It’s done at the factory on every tire/wheel assembly to create that ever so important new car ride.
Road Force Balancers
So what does a road force balancer actually do? Road force balancers, in addition to performing a traditional spin balance, measure both the wheel and tire by pressing a large roller against the tread of the spinning tire. The roller applies 1,200 to 1,400 pounds of pressure to simulate the weight of the vehicle on the tire as it rolls down the road.
A computer in the machine, along with various sensors, determines variations of tire stiffness, radial runout and anything in the tire’s construction (such as inconsistencies in the belt package) that would prevent the tire from rolling smoothly when it is weighted by the car. By measuring both the wheel and tire, the road force balancer tells the technician where to move the tire around on the wheel until the effective high spot of the tire (when it is rolling on the car) matches the low spot of the wheel – a more sophisticated method of match mounting.
It’s actually more complicated than that, but for practical purposes, that is what a road force balancer does. If necessary, in extreme cases, the road force balancer can be used to run several tires across different wheels to find the best possible wheel and tire combinations.
Use of a road force balancer can provide consumers with the same level of ride comfort previously only available to OEMs.