| 摘要 |
PROBLEM TO BE SOLVED: To enhance shape holding performance, so as to prevent a bead material from easily slipping off from a tire molding former, by forming a linear composite material by three layers of an innermost layer, an intermediate layer and an outermost layer, concerning a bead material for a bicycle tire, formed of a linear composite material formed by impregnating and coating thermoplastic resin in a reinforcing fiber bundle. SOLUTION: A bead material for a bicycle tire is composed of a linear composite material formed by impregnating resin into a reinforcing organic fiber bundle and coating the front surface, and this linear composite material is formed of three layers of an innermost layer formed of only reinforcing fibers, an intermediate layer in which resin is impregnated among single fibers for constituting a reinforcing fiber bundle 1, and an outermost layer formed of only coating resin. The radius of the innermost layer and the thickness of the intermediate layer and the outermost layer are respectively set in the range of 0.20 to 0.95 times, 0.04 to 0.50 times, and 0.01 to 0.30 times of radii of respective linear composite materials. The ratio of the minimum radius of curvature of the linear composite material and the radius of the bead material is set to 150 or less, para-Aramid fiber is suitable for a fiber for constituting the reinforcing organic fiber bundle, and the total size is in the range of 4000 to 20000 denier. |
