TIRE TREAD WITH SEVERAL WEARING PLIES

摘要

FIELD: transport.SUBSTANCE: tire tread has at least two wearing plies including outer wearing ply and at least one inner wearing ply located at mid tread under outer wearing ply, and at least one outer groove located in outer wearing ply. Besides, said tread features volumetric cavity ratio of 0.25-0.40 in sound state and of about 0.25-0.40 in worn-out state. External side interacting with ground extends along one of inner wearing ply in worn-out tread. Additionally, said tread features contact surface ratio of 0.66-0.72 in sound state and of about 0.56-0.66 in worn-out state.EFFECT: enhanced performances.15 cl, 19 dwg