Abstract

Phenomena occurring at the interface between the tread compound and the road surface are responsible for at least two main tire characteristics: traction capability and wear resistance. Both depend on the road surface geometry, the presence of thin films of water, local contact pressure, tread element stiffness, temperature, tangential slip, etc. To discount the effect of tire construction, a laboratory test using a small solid rubber wheel has been considered. A rig is designed to easily change the “road” surface, and convert it from wet to dry conditions, run the rubber wheel on such surfaces under high braking or driving torque, and measure torque against longitudinal slip. The rig features a flat disk on which different surfaces can be simulated and two separate electric motors driving the disk and the test wheel in order to control slip instead of torque and to avoid instability at high driving or braking torques. Results show longitudinal characteristics versus slip in different test conditions and simulation of severe abrasion conditions leading to typical abrasion patterns.