| 摘要 |
PROBLEM TO BE SOLVED: To raise durability of a pneumatic tire by preventing a cut separation trouble from happening. SOLUTION: A central area A with a center line CL of a tread 14 as a center is formed so that a land part 16 extending along the circumferential direction of the tread 14 becomes a land part line there. A sub-ditch 20 is provided along the circumferential direction of the tread 14 to become a pattern. The sub-ditch 20 has a structure consisting of an upper and a lower two steps having a different width. Width W1 of an upper ditch part 20A which is an upper side part of the sub-ditch 20 is made larger than that of the tread by 2% to 10%, and the width W2 of a lower ditch part which is made to be a lower side part of the sub-ditch 20 is made larger than the tread width by 1% to 10%. The depth D1 of the upper ditch part 20A is made to be 10% to 50% deep of the main ditch depth while the entire depth of the sub-ditch 20 is made to be 50% to 100% of the main ditch depth. |
