| 摘要 |
PROBLEM TO BE SOLVED: To prevent any early wear in a shoulder part from occurring by setting up two circumferential fine grooves in a tread position corresponding to a mean circumferential grounding length part at a grounding profile form at a time when the mass of maximum loading capacity is loaded upon filling up internal pressure corresponding to the maximum loading capacity in a radial tire inset in a standard applicable rim. SOLUTION: A tire is provided with four circumferential main grooves 1, having a mean grounding length part in a position of 45mm ranging from left to right in the cross direction from an equator line. Two fine grooves 2 of 12mm in depth are set up in a position of 45mm ranging from left to right in the cross direction from this equator line. An area of driving force being imposed on the tire and a branch line of this driving area are on the circumference where there is nearly means grounding length Lm, and if the driving force area and a braking force area are made to interfere with each other, abnormal abrasion is lible to occur there. Accordingly, if these fine grooves 2 are installed in the means grounding length part or the branch line of both driving force and braking force areas. These two areas are parted from each other and since they are made so as not to interfere with each other, each of their absolute values becomes lessened in addition to that any abnormal abrasion is hard to occur, and thus abrasion resistance is improved. |
