Rolling Resistance – What exactly is rolling resistance?
Rolling resistance is the energy that is lost when the tire is rolling and the main reason for loss of energy is the constant deformation of the tire. In addition to rolling resistance, there are also other resistances that have to be overcome when riding a bicycle. Air resistance rises squared with increased speed. At a straight-line speed of 20 km/h on the flat, air resistance is the main resistance force. Energy is also required to accelerate. For instance, the weight of the wheels is of great importance when this mass has to be brought up to rotation. When riding uphill, the main resisting force to overcome is the gradient resistance (descending force). In addition to these, there are other friction resistances in the chain and all of the other moving parts. Yet in a well-serviced bicycle, these represent a very minor part of the total resistance.
