| 摘要 |
PURPOSE:To maintain the high speed durability of a motorcycle and improve its high speed running stability by providing each layer with a specific cord path between a tread and a carcass in a preset inclined cord arrangement and arranging the constrained layer of an organic fiber cord layer up to the maximum width section. CONSTITUTION:A crown constrained layer 5 is formed between a tread and a carcass 1 by stacking two or more organic fiber cord layers 51 and 52 with the widths W1 and W2 within the range of 50-120% of the tread width W centering around the equator so that cords can be intersected mutually. The cord angle of this constrained layer 5 is set to 5-25 deg. for the equator and the cord angle for the direction in parallel to the equator from the position of the equator to the side end direction of the constrained layer 5 is increased gradually within the range of 2.5-15 deg.. As a result of this structure, the high speed durability of a new motorcycle can be maintained and its high speed stability can be improved. |
