| 摘要 |
PROBLEM TO BE SOLVED: To increase traction on an ice surface while enhancing riding comfort simultaneously. SOLUTION: A heavy load studless tire with a block pattern maintains K to be 50 mm<2> or more, where K is a ratio of the cross-section secondary moment in a rotation direction R of the tire to a ground contact area of the tire of each main block 4' whose contact are 4x exceeds 1% of the total area of a tread face 1. The studless tire also maintains a ratio KA/KB in a range of 2.0-4.0, where KA is ratio of each main block 4'A allocated at a center area A comprising left and right areas between a center line CL and each of tire contact area edges E and extending as wide as not less than 0.3 times of a tread expanded width W, and KB is a ratio of each main block 4'B allocated at shoulder areas B on the both sides. |
