US Patent 7395845 Pneumatic radial tire

A belt layer is provided at its outer side with a band layer comprising edge bands on left and right sides. When a cross sectional area of one band cord is defined as S (unit; mm2) and a modulus of the band cord when its elongation is 2% is defined as M (unit; N/mm2) and disposition density of the band cord per 1 cm of the band layer is defined as D (unit; the number of band cords/cm), an elongation resistance value K (unit; N·the number of band cords/cm) of the band layer which is determined by the following equation (1) is set to 270 or higher and 830 or lower:K=S×M×D/100.  (1)An elongation percentage T(%) of the band cord in a tire in its natural state in which the tire is not assembled to a rim is set to 0.75% or higher and 1.2% or lower.