PNEUMATIC RADIAL TIRE

摘要

A pneumatic radial tire in which only two wide straight main grooves are arranged on the left and right sides of an equator of the tire to define a region, which lies between these two main grooves, as a rib, lug grooves and/or sipes which extend in the widthwise direction of the tire being arranged in shoulder regions on the outer sides of the main grooves to form rows of blocks in which the blocks are lined in the circumferential direction of the tire, a distance a between the equator and an equatorside portion of a main groove and a width b of the main grooves being set in the following ranges with respect to a ground contact half-width W respectively of a tread surface. 0.10 ? a/W ? 0.38 0.17 ? b/W ? 0.25