Pneumatic tire including non-directional tread pattern

Abstract

A pneumatic tire which comprises a tread portion provided on each side of the tire equator with axial grooves extending axially inwardly from the tread edges, the axial grooves inclined to one direction with respect to the tire axial direction to form a non-directional tread pattern, and the inclination angle of the axial grooves to the tire circumferential direction is decreased from the axially outer end to the axially inner end thereof so as to have a minimum inclination angle &bgr;min of less than 45 degrees, and a maximum inclination angle of from 60 to 85 degrees. Preferably, the radially outermost belt ply has a cord angle a of 10 to 35 degrees to the tire equator and the axial grooves inclined in the reverse direction to the belt cords, and |&bgr;min−&agr;|≦25 degrees. The tread block has a toe edge and a heel edge both inclined to the same direction with respect to the tire axial direction so that each of the edges has a far end and a near end, and the inclination angle of the side face of the block gradually increases from the near end to the far end. The number of the axially inner blocks is a one half of the axially outer blocks.