Rolling Friction Calculator

Rolling friction is the resistance encountered by a wheel or ball when rolling over a surface. It is much smaller than sliding friction, which is why wheels are used to move heavy objects. The resistance comes from deformation of the wheel and surface at the contact point.

Car tires on asphalt have a Crr of about 0.01 to 0.015. Bicycle tires on smooth pavement range from 0.002 to 0.005. Train wheels on steel rails are about 0.001. Rubber on concrete is around 0.01 to 0.02.

At low speeds, rolling friction is relatively constant. At higher speeds, it can increase due to factors like tire deformation, heat buildup, and aerodynamic effects. For most practical calculations at normal speeds, the coefficient is treated as constant.

Higher tire pressure generally reduces rolling friction because it reduces the contact area and deformation of the tire. However, very high pressure can reduce grip and ride comfort. The optimal pressure balances low rolling resistance with adequate traction.