Patent ID: 8851128

Claim:
A pneumatic radial tire having a thin groove continuous in a tire circumferential direction at a buttress formed between a shoulder of a tread and a sidewall, comprising: a tire contour portion that is formed between an end portion of the shoulder and a groove floor of the thin groove, and at least one circumferential direction groove, wherein the groove floor of the thin groove is positioned radially inwardly of a groove floor of the at least one circumferential direction groove; wherein a tire transverse direction outermost portion at a shoulder side curved portion is disposed further toward a tire radial direction inner side than a sidewall side end portion of a sidewall side groove wall surface of the thin groove, such that the tire transverse direction outermost portion and the sidewall side end portion are located in the same radial plane perpendicular to the axis of rotation of the tire, wherein the tire contour portion includes an inclined portion from the end portion of the shoulder toward the thin groove and a shoulder side groove wall surface of the thin groove, wherein the tire transverse direction outermost portion is an intersection of the inclined portion and the shoulder side groove wall surface at the shoulder side curved portion, wherein the end portion of the shoulder is closer to a width center of the tire in a width direction than the entire thin groove, wherein said sidewall side end portion of the sidewall side groove wall surface of the thin groove is radially inside said end portion of said shoulder, wherein the sidewall side groove wall surface of the thin groove is formed further to a tire radial direction outer side than the shoulder side curved portion of the tire contour portion, and includes a sidewall side curved portion at a position facing the shoulder side curved portion of the tire contour portion, and wherein said sidewall side end portion of the sidewall side groove wall surface of the thin groove contacts said inclined portion when the buttress is deformed by a lateral force.