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.sup.2), the modulus thereof when the
elongation thereof is 2% is represented by M (unit: N/mm.sup.2), the band
cord arrangement density per cm of the band ply is represented by D
(unit: cord number/cm). K=S.times.M.times.D/100 (1)