To reduce the weight of a tire without worsening road noise nearby 300Hz.
The areal weight rata Mw of the reinforcing cord of a belt layer 8 is made not more than 6×10-6kg/mm2, the bending rigidity Dw is made not less than 220kg.mm, and the reinforcing cord of a carcass 4 is constituted out of fiber cord twisting organic fiber. In addition to this, in relation of the twist number T (times/10cm) to the total denier Dc, the twist coefficient K shown as K=T(Dc)1/2 is set in the range of 1000-2000, elongation of the fiber cord at 2.25g/d load is set under 6%, and the edge ends 4b of both end parts 4a of the carcass 4 folded back through bead cores 5 are set to be equal to the outer circumferential ends 6a of a bead filler 6 on the outer circumference of the bead cores 5, or on the side of a tire inner diameter.
IMAMIYA OSAMU
TAKAHASHI SHUJI
