| 摘要 |
A pneumatic tire, which is improved in high speed durability, maintaining the required tread rubber thickness for mud and snow tires, is disclosed. The tire comprises a radial carcass and a belt including a breaker. The breaker comprises an inner ply and an outer ply, each composed of steel cords laid at an angle of 16 to 26 degrees to the tire equator. The outer breaker ply has a width WB2 of 0.7 to 0.75 times the tire cross sectional width TW. The inner breaker ply has a width WB1 of 1.03 to 1.10 times said width WB2 of the radially outer breaker ply. The tread profile comprises a crown portion defined by a circular arc having a single radius Rc of curvature of 1.4 to 2.6 times the tire cross sectional width TW and having the center on the tire equatorial plane, and a pair of tread shoulder portions continuing from the axially outer ends of said tread crown portion, each defined by a circular arc having a single radius Rs of curvature of 0.10 to 0.20 times the tire cross sectional width TW. The tread rubber thickness Ts at the axially outer edges of the radially outer breaker ply to a tread rubber thickness Tc at the tire equator being 0.7 to 0.9. The tread portion is provided with a block pattern comprising circumferential grooves having a groove depth D of 9 to 13 mm. |
