Flexing Resistance
The deformation (flexion) of a pneumatic tyre as a result of static compression and expansion, results in a loss work because of internal friction. If the tyre rolls under a load, the process of compression and expansion continually repeats for each circumferential point on the tyre. This is illustrated by a wheel replacement system whose circumference is shored up against the rim by linear spring-and-damper elements. In addition, the tyre tread can also be imagined to include a composition of elemental springs and dampers. These springs and dampers come into play when the tyre contact patch is run through (tyre contact patch on the road). By this, additional frictional influences are created that have to be ascribed to the flexing resistance. The spring and damper characteristics of the tyre tread also have an effect on the tyre's tractive power on the road. The choice of a low-damping running band mixture simultaneously leads to a deterioration of the tractive friction.
When the replacement model rotates, in each of the "elementary vibration dampers" work is transformed into heat. The resulting flexing resistance corresponds to the quotient of accomplished damping work and the covered distance:



Experience has shown that when comparing tyres with the same ply material the tyre with the larger number of plies has the higher damping, since the relative motion of the plies in relation to each other generates damping work.