Tread Contribution to Tire Rolling Loss

Tires built from compounds with equal storage moduli but different loss moduli for tread and body were subjected to designed tests on both roadwheel and twin rolls. The results allowed computation of the tread contribution to the total rolling loss, at various loads and pressures. On twin rolls, the relative tread contribution was much higher than it was on the roadwheel (typically, 60% vs 30%). On both machines, the loss contribution of the tread depended strongly on its loss modulus and on tire load; the effect of inflation pressure was small.