Heavy duty radial tire including a tread having reentrants

A heavy duty radial tire comprising a tread wherein the tread is defined by a rib pattern comprising a plurality of circumferential grooves and a plurality of ribs formed therebetween, each of said grooves having a depth H and being of a trapezoidal configuration in cross-section with groove edges extending straight in a circumferential direction of said tire and slant groove walls which decrease a groove width toward a groove bottom, wherein a plurality of reentrants in a form of trigonal pyramid which increase in width and depth toward the groove bottom are formed in a circumferential direction of said tire with triangular slant groove walls remaining therebetween on the slant groove walls of at least a pair of grooves, the ratio of circumferential pitch P of said reentrants to the depth H being within the range of 0.3 and 1.5 wherein the circumferential pitch P of said reentrants is the distance between adjacent apexes of the triangular slant groove walls, and the reentrants formed in a form of trigonal pyramid on one groove wall and the triangular slant groove walls formed on the other groove wall face each other.