Base-cap tread

摘要

A pneumatic tire having a tread of a lug type pattern is disclosed. In this type of the tire, the tread rubber has a composite structure of a cap rubber and a base rubber having a heat build-up property lower than that of the cap rubber and arranged on at least a shoulder portion of the tread just beneath the cap rubber. The base rubber has a thickness that an average thickness just beneath the lug is larger than that just beneath the lug groove in a conical plane imaged by taking as a general line a normal line drawn from the tread end to the inner surface of the tire in the radial section inclusive of a rotational axis of the tire.