WHICH FACTORS AFFECT ROLLING RESISTANCE?
Tire pressure, tire diameter, tire width, tire construction, tire tread and other factors all have an effect on rolling resistance.
On a completely smooth surface the following applies: The higher the inflation pressure, the inferior the tire deformation and thus rolling resistance.
Off road it is exactly the reverse: The lower the inflation pressure, the lower the rolling resistance. This applies equally on hard gravel roads and soft forest tracks. Explanation: A tire with low inflation pressure can adapt better to a rugged surface. It sinks into the ground less and the whole rotational mass is held back much less by the uneven surface.
Tires with a smaller diameter have a higher rolling resistance with the same inflation pressure, because tire deformation is proportionally greater. The tire is flattened more and is “less round”.
Wider tires roll better than narrower tires. This statement generally invokes skepticism, nevertheless, with tires at the same pressure a narrower tire deflects more and so deforms more.
Obviously, tire construction also has an effect on rolling resistance. By using less material, less material can be deformed. And the more flexible the material is, such as the rubber compound, the less energy is lost through deformation.
Generally, smooth treads roll better than coarse treads. Tall lugs and wide gaps usually have a detrimental effect on rolling resistance.
