| 摘要 |
PURPOSE:To improve control stability and wear resistance by placing a rubber composition different from that in a center portion with a preset thickness at the peripheral portion of a block or a rib and specifying the coefficient of loss, hardness and strength of tensile break of rubbers at the center and peripheral portions, respectively. CONSTITUTION:In the periphery of the center portion 2 of a block 1 which is formed at a tire tread, a peripheral portion 3 is formed with the rubber composition different from that in the center portion 2 and the thickness Q1-Q4 of 0.3-10mm. Then, the coefficient of loss of respective rubber compositions is set to 0.4 or more at the center portion 2 and to 0.2 or more at the peripheral portion 3 and the JIS hardness at 25 deg.C to less than 65 at the center portion 2 and to 65 or more at the peripheral portion 3, respectively. Also, the strength of tensile break at 25 deg.C at the peripheral portion 3 is set to 200kg/cm<2> or more. Such constitution permits the improvement of control stability, wear resistance and high-speed durability. |
