| 摘要 |
Inside a tread portion and outside a belt layer along the radius direction thereof is formed a belt layer comprising a band ply formed by winding spirally a tape- and belt-form ply wherein one ore plural band cords are stretched and arranged to be embedded in a topping rubber. In this band ply, the elongation resistance value K (unit: N° cord number/cm) specified by the following equation is set within the range of 99 to 700 when the sectional area of the band cord or each of the band cords is represented by S (unit: mm<2>), the modulus thereof when the elongation thereof is 2% is represented by M (unit: N/mm<2>), the band cord arrangement density per cm of the band ply is represented by D (unit: cord number/cm). K=SxMxD/100 (1) |
