Pneumatic radial tire.

摘要

It is intended to improve cut growth resistivity at side portions of a pneumatic radial tire for a construction vehicle without affecting durability. A pneumatic radial tire, particularly for a construction vehicle, has a carcass ply (2) arranged toroidally between a pair of bead cores (1), containing rubber coated steel cords disposed radially therein, being turned up around the bead core from the inside to the outside of the tire and the turn-up portion (3) of which extends to around 1/2 height of the tire height H, characterized in that when the length of an overlapping portion of the turn-up portion (3) of the carcass ply and the main carcass ply (2) is h1 and the thickness of the overlapping portion is w1 within a range of +/- 0.1 H having half height H/2 of the tire height H as the center, the length h and the thickness w of a reinforcing rubber material (20) arranged between the turn-up portion (3) of the carcass ply and the main ply (2) satisfy the following formulae (1) 0.2w1 at 300% elongation and a rebound resilience coefficient R is 0.4 < R < 0.7.