| 摘要 |
PROBLEM TO BE SOLVED: To control decrease in hydroplaning performance after abrasion than before. SOLUTION: On both sides of a first circumferential direction groove 22 having a bottom face side formed wider than a tread face side, a second circumferential direction groove 24 having the tread face side wider than the bottom face side is formed to relieve a compressive force acting on tread rubber (rubber that a top of a first rib part 18 of a mold 10 forces it to be pushed aside) between the first circumferential direction groove 22 and the second circumferential direction groove 24. Thereby, a vulcanized pneumatic tire 12 has a good mold releasing property to control breakage of a land part 26. Consequently, a width of bottom side of the first circumferential direction groove 22 can be set wide to control decrease in hydroplaning after tread abrasion than before. |
