| 摘要 |
PROBLEM TO BE SOLVED: To accurately evaluate carcass durability within a short test time by reproducing damage caused by rubbing of a carcass cord with a bead core within a short test time.SOLUTION: The evaluation method of carcass durability includes the running step of running a test tire on a drum, and the evaluation step of evaluating carcass durability at a bead part. In the running step, the test tire is run in the inner pressure P of 160 to 260% of normal inner pressure P, in the load F of 350 to 450% of a normal load F, at the traveling speed V of 15 to 40 km/h, and in a predetermined distorted state. The distorted state is a distorted state where a difference (&thetas;-&thetas;) between the value &thetas;of the angle &thetas; of the tire in the normal inner pressure state of no load and the value &thetas;of the angle &thetas; of the tire in the running step is within the range of 5 to 15°, where &thetas; is an angle of a reference line X passing through the innermost point of the tire axial direction of the bead core and the tire axial maximum width point of a carcass ply with respect to the tire axial direction. |
