Patent ID: 7832439

Claim:
A pneumatic tire comprising: a tread portion having a row of shoulder blocks which are aligned along a ground contact edge and which are defined by a circumferential shoulder groove extending continuously in the circumferential direction of the tire on a side closest to a ground contact edge and a plurality of lateral shoulder grooves extending from said circumferential shoulder groove to the ground contact edge, wherein said pneumatic tire has a square shoulder such that a radially outer surface of each said shoulder block intersects, at said ground contact edge, with a buttress face extending radially inwardly and axially outwardly to form a substantial edge substantially an edge, and each said shoulder block provided with a circumferential sipe extending in the circumferential direction in a region ranging from a distance of 2 mm or more axially inwardly from said ground contact edge to a distance of 10 mm or less axially inwardly from said ground contact edge, said buttress face is provided with a recess extending in the circumferential direction and having a depth of 0.5 to 3 mm measured from said buttress face in at least a part of a projection region obtained by projecting each said circumferential sipe onto said buttress face along the axial direction of the tire so that, the radially innermost end of said recess is located in a region ranging from 50 to 100% of the depth of said circumferential sipe, and wherein said buttress face includes an outer slope extending radially inwardly and axially outwardly from said ground contact edge, a middle slope which is continuous with said outer slope and extends radially inwardly from the outer slope with an inclination smaller than that of the outer slope, and an inner slope which is continuous with said middle slope and extends from the middle slope substantially parallel to the outer slope, and said recess is disposed in said middle slope.