TYRE WITH IMPROVED TREAD

摘要

Tyre (10) comprising a tread (40) having a mean radial height HB, an outer edge (45) and an inner edge (46), the axial distance between the outer edge (45) and the inner edge (46) defining the axial width L of the tread, the tread comprisinga first portion (411) made of a first rubber compound, extending from the outer edge (45) to a first axial position at an axial distance from the outer edge of between 20% and 40% of the axial width; a second portion (412) made of a second rubber compound, extending from said first axial position to a second axial position at an axial distance from the outer edge of between 50% and 60% of the axial width L; a third portion (413) made of a third rubber compound extending from said second axial position to a third axial position at an axial distance from the outer edge of between 80% and 90% of the axial width L; and a fourth portion (414) made of a fourth rubber compound, extending from said third axial position to the inner edge (46) of the tread, wherein said first and third rubber compounds are predominantly filled with carbon black filler, wherein said second and fourth rubber compounds are predominantly filled with non carbon black filler, and wherein said first rubber compound and said third rubber compound have a value for tand at 0°C, at a stress of 0.7 MPa, that is lower than that of said second rubber compound and said fourth rubber compound.