Patent ID: 6991014

Claim:
A pneumatic tire comprising a tread portion with a tread face and a tread width the tread portion including a grooved portion, a pair of sidewall portions, a pair of bead portions, a carcass extending between the bead portions, a belt made of cords disposed radially outside the carcass in the tread portion, a tread rubber disposed radially outside the belt and including a cap tread rubber defining said tread face and a base tread rubber disposed radially inside the cap tread rubber, said base tread rubber including a central base tread rubber centered on the tire equator and a side base tread rubber disposed on each side of the central base tread rubber so as to extend from a position axially inwards to a position axially outwards of an axial edge of the belt, the tread rubber having the following hardness distribution: the cap tread rubber having a hardness of from 53 to 63 degrees, the central base tread rubber having a hardness of from 45 to 60 degrees, and the side base tread rubber having a hardness of from 65 to 75 degrees; wherein the hardness is measured with a type-A durometer according to Japanese Industrial Standard K6253, said belt including a band formed by spirally winding at least one cord at a small angle with respect to the tire equator, the band comprising a pair of axially spaced edge band plies, said side base tread rubber extending on the radially outside of the belt from a position axially inward of one of the edge band plies to a position axially outward of the edge band ply, while covering the entire width of the edge band ply, wherein the central base tread rubber has a substantially constant thickness, the thickness of the central base tread rubber is substantially the same as the thickness of the side base tread rubber at a boundary between the central base rubber and the side base tread rubber, and the cap tread rubber has a substantially constant thickness except for the grooved portion, and when measured at the tire equator, the thickness of the cap tread rubber is in a range of from 0.70 to 0.90 times the overall thickness of the tread rubber.