| 摘要 |
PURPOSE:To exhibit steering stability beyond a tire with a belt layer using a conventional steel cord while enhancing a reduction in weight by using an aramid fiber cord in belt structure. CONSTITUTION:In a pneumatic radial tire comprising a plurality of grooves extending at least in the tire circumferential direction on a tread surface and two belt layers disposed in the tread in such a manner their belt cords are mutually crossed, the groove depth of the groove is set within the range of 6.0-8.5mm, and the groove under rubber thickness from the groove bottom to the surface belt layer is within the range of 0.5-2.0mm. This belt layer is disposed without turning up both the end parts, and at least one layer is formed from aramid fiber cord. Further, at least both the end parts of the belt layer is covered with a belt cover layer having a cord angle to the tire circumferential direction not more than 30 deg.. The belt cover layer is formed from an organic fiber cord with a cord diameter not more than 0.7mm, and its placing density is 35-90%. |
