This paper develops a simple model for the behavior of a pneumatic tire when vertically loaded. The model is based on the behavior of a thick-skinned spherical membrane (like a basketball) being compressed between two flat plates. The model is reasonably accurate for bicycle, motorcycle, truck, general purpose, and early model automobile tires which all have a circular cross-section. However modern automobile tires have a wide aspect ratio when unloaded, have unloaded line contact with the ground across the tread width, and have relatively stiff sidewalls that contribute to the tire’s load carrying capability (and in the case of run-flat tires can totally support the car’s weight). Thus the analysis in this paper is quantitatively representative for tires of initially round cross-section, like a typical motorcycle tire, but provides only a qualitative idea of the tire support mechanism for modern automobile tires.
Department, Program, or Center
Manufacturing and Mechanical Engineering Technology (CAST)
Sutherland, George, "Simplified Explanation of Pneumatic Tire Behavior" (2008). Accessed from
RIT – Main Campus