Dual and single seat composite bicycle frames and fabrication methods therefore

A bicycle frame connecting a steering support means for a rotating front fork assembly, at least one seat assembly support means, at least one pedal assembly support means, and a rear wheel assembly support means, said frame comprising:

• a straight, elongate, generally hollow main beam having an innermost shell comprising layers of fibrous material impregnated with synthetic resin, said layers forming an integrated everywhere continuous wall thereof symmetrical about a vertical plane, said innermost shell having everywhere continuous top and bottom surfaces both extending continuously from the steering support means to a rearmost end of said innermost shell;
• an elongate, generally hollow, tubular seat support post having an innermost shell comprising layers of fibrous material impregnated with synthetic resin, said innermost shell being bonded to the top surface of the main beam innermost shell to upstand therefrom;
• an elongate, generally hollow, tubular pedal support post having an innermost shell comprising layers of fibrous material impregnated with synthetic resin, said innermost shell being bonded to the bottom surface of the main beam innermost shell to downstand therefrom oppositely from the seat support post innermost shell;
• and
• an outermost layer comprising wrappings of fibrous material impregnated with synthetic resin overlapped to integrally cover and adhere to the outside surfaces of the innermost shells of the main beam, seat support post and pedal support post to form therewith an integral, load bearing frame structure.

A method of manufacture of a bicycle frame for connecting a steering support means for a rotating front fork assembly, at least one seat assembly support means, at least one pedal assembly support means, and a rear wheel assembly support means, said method comprising the steps:

• providing a main beam male mandrel;
• providing a male mandrel with a metallic seat tube removably attached thereto for an upstanding rear seat support post;
• providing a male mandrel with a metallic pedal hub sleeve removably attached thereto, for a downstanding rear pedal support post;
• overwrapping the main beam mandrel with a layer of fibrous material impregnated with synthetic resin, curing said layer using an external vacuum bag, and withdrawing the main beam mandrel from the cured main beam innermost shell;
• overwrapping the rear seat support post mandrel and the attached metallic seat tube sleeve with a layer of fibrous material impregnated with synthetic resin, curing said layer using an external vacuum bag and withdrawing the mandrel leaving the metallic seat tube within the cured innermost shell;
• overwrapping the rear pedal post support mandrel and the attached metallic hub sleeve with a layer of fibrous material impregnated with synthetic resin, curing said layer using an external vacuum bag, and withdrawing the mandrel leaving the metallic hub sleeve within the cured rear pedal post innermost shell;
• bonding the rear seat support innermost shell and the rear pedal support post innermost shell in place upon the main beam innermost shell;
• providing a metallic head tube sleeve secured to the foremost end of the main beam innermost shell;
• everywhere overwrapping the assembled frame innermost shell and the metallic head tube with an outermost layer of fibrous material impregnated with synthethic resin;
• and
• curing the outermost layer using an external vacuum bag.

A method of manufacture of a bicycle frame for connecting a steering support means for a rotating front fork assembly, at least one seat assembly support means, at least one pedal assembly support means, and a rear wheel assembly support means, said method comprising the steps:

• providing split female external molds for innermost shells of a main beam, a rear seat support post, a rear pedal support post, a front seat support post, a front pedal support post, and a pair of rear wheel stay side members;
• lining each of said molds with a layer of at least one ply of fibrous material impregnated with synthetic resin;
• curing each layer while applying internal pressure thereto using an inflated internal bladder;
• and
• removing each mold from about each cured innermost shell.