PURPOSE: To resolve problems which conventional steel has, achieve light weight and favorable rim fit property, and prevent deterioration of the rim fit property or strength of beam material even when a bicycle is folded and carried for a long period.
CONSTITUTION: In a bead material for a tire of a bicycle comprising a core- sheath type composite wire body composed of a reinforcement fiber bundle at a core part impregnated and coated with thermoplastic resin, it includes the core part comprising the reinforcement fiber bundle by 60-95 weight %, and a sheath part of the thermoplastic resin by 40-5 weight %, where the sheath part thermoplastic resin is impregnated in a surface layer of the reinforcement fiber bundle of the core part, with a surface of the sheath part PFL-processed.
TAKADA TADAHIKO
OKAMOTO TETSUO
