| 摘要 |
PURPOSE:To reduce noise level at the time of grounding without sacrificing a function at the time of wet condition. CONSTITUTION:On a tread part 12 of a pneumatic tire 10, a rubber material 22 (e.g. the one with 20% modulus value of 8X10<8>dyn/cm<2>) which is softer than a rubber material 21 (e.g. the one with 20% modulus value of 13X10<8>dyn/cm<2>) that forms a tread hill part 20, is provided on the entire part of the inner circumference of a main groove 14, while a ratio D of the 20% modulus value of the rubber material 22 that forms the inner circumferential part of the main groove 14, to the 20% modulus value of the rubber material 21 that forms the tread hill part 20 is 0.1<=D<=0.9, or 0.62 for example. The thickness of the rubber material 22 is not less than 0.2mm and not more than 0. 5mm, or 1mm for example. |
