When a spherical or round body rolls across the surface of across a surface, the resistance in motion which arises is rolling friction.
The general equation to calculate rolling friction is,
Following are some typical coefficients of rolling friction we come across in our everyday life.
|Everyday usage scenarios||Rolling Resistance Coefficients|
|Railroad steel wheels on steel rails||0.001 – 0.002|
|Bicycle tire on the wooden track||0.001|
|Low resistance tubeless tires||0.002 – 0.005|
|Bicycle tire on concrete||0.002|
|Bicycle tire on asphalt||0.004|
|Dirty tram rails||0.005|
|The truck tire on asphalt||0.006 – 0.01|
|Bicycle tire on a roughly paved road||0.008|
|Ordinary car tires on concrete and new asphalt||0.01 – 0.015|
|Car tires on tar or asphalt||0.02|
|Car tires on gravel||0.02|
|Car tires on cobbles||0.03|
|Car tires on solid sand||0.04 – 0.08|
|Car tires on loose sand||0.2 – 0.4|
There are many factors that subtly influence rolling friction, like the shape of the wheel, type of surfaces, speed of the wheel and pressure on the wheel.