Effect of Tire Wear on Tire Force and Moment Characteristics

In repeated physical testing of vehicles at or near their handling limit, shoulder wear occurs that is not typical of normal customer use. It has been observed for decades that this type of severe cornering induced tire wear can have a significant effect on the force and moment characteristics of tires. In this study, this shoulder wear effect was isolated by testing tires in a controlled environment and objectively assessed for a number of tires of various brands and sizes. This testing shows how a tire's lateral force and overturning moment capacities increase significantly as the number of runs on a tire accumulates. Additionally, one particular tire make and model was placed on a vehicle to acquire 1000 miles of normal customer driving and then evaluated under the same simulated load conditions. The results confirmed that, irrespective of a tire break-in procedure, the increases in lateral forces of the tire in repeated limit handling maneuvers were a product of the test induced atypical shoulder wear generated during the limit handling maneuver.