Force and Moment Characteristics of a Low Aspect Ratio Asymmetrically Worn Passenger Car Tire

Many vehicles are equipped with independent suspension systems on the front and/or rear axle. As opposed to a DeDion or beam axle, independent suspension systems have the potential to generate camber and toe changes as the suspension strokes from full jounce to full rebound. Each vehicle suspension design presents unique camber and toe curves to the tire. To improve handling, manufacturers often set static camber on such vehicle suspension systems to nonzero values so that when cornering, the outside suspension will deflect so as to maximize cornering power and vehicle stability. Then, under straight driving conditions, the tires tend to predominantly wear their inside shoulder edges, producing the phenomenon known as camber wear. In the present work, three identical tires had their force and moment characteristics measured on the T.I.R.F. ( TIr e R esearch F acility), Calspan Corporation, Buffalo, NY: a brand new tire, a ½-evenly-worn tire and an asymmetrically-worn (camber-worn) tire. Results showed that camber wear can actually improved certain tire performance characteristics under dry weather conditions.