| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve on-ice performance, without reducing dry maneuvering stability. <P>SOLUTION: Sipes are arranged in a crown land part, middle land parts and shoulder land parts partitioned by a pair of crown peripheral directional main grooves and a pair of shoulder peripheral directional main grooves. A land part width Wc of the crown land part and a land part width Wm of the middle land part are respectively 19-25% of a tread grounding width Tw, and the ratio Wc/Wm is 0.9-1.1. An average angle θc<SB POS="POST">0</SB>of the sipes arranged in the crown land part, an average angle θm<SB POS="POST">0</SB>of the sipes arranged in the middle land part and an average angle θs<SB POS="POST">0</SB>of the sipes arranged in the shoulder land part, satisfy the following expression. θc<SB POS="POST">0</SB><θs<SB POS="POST">0</SB><θm<SB POS="POST">0</SB>. <P>COPYRIGHT: (C)2013,JPO&INPIT |
