The resistance that occurs when a round object such as a ball or tire rolls on a flat surface.
The tyre is deflected as it enters the contact patch
The tyre is deflected as it enters the contact patch. Energy is dissipated in this deflection and is not recovered as the tyre recovers it′s shape as it exits the contact area.
Rolling resistance can be minimised by reducing the deflection of the tyre. One method is to increase the tyre pressure.
F = Rolling resistance [N]
Crr = Coefficient of rolling resistance [dimensionless]
N = Force normal to road surface [N] = mass x gravity
|train wheel on rail||0.001 to 0.0025|
|bicycle tyre||0.0022 to 0.005|
|low rolling resistance car tyre||0.006|
|ordinary car tyre||0.01|
|car tyre on sand||0.3|