| 摘要 |
PURPOSE:To increase braking property on ice by increasing the ratio SIGMAXi/SIGMAYj of the sum SIGMAXi of length of component in lateral direction of siping arranged at ground contact face to the sum SIGMAYj of length of component in radial direction up to a specific scope. CONSTITUTION:Siping K which has groove width of 0.3mm or more and 1.5mm or less is provided on blocks B0, B1, B2. The ratio of the sum SIGMAXi of the length Xi of component in lateral direction which is the length in peripheral direction of tire of siping K arranged on the ground contact face on which tread face contacts the ground when normal load is applied on tire to the sum SIGMAYj of the length Yj of component in radial direction which is the length in axial direction of tire, SIGMAXi/SIGMAYj, should be 0.70 or more and 1.2 or less. The ratio of the sum SIGMAXi to the width of the ground contact lace in axial direction of tire of the ground contact face, TW, SIGMAXi/TW, should be 4.0 or more and 10.0 or less. Thus, it is possible to optimize the balance and increase braking property on ice while reducing the length of component in radial direction. |
