Modular composite bicycle frame

A bicycle comprising:

• (a) a frame formed of composite material, said frame including at least two separately-formed body units, said body units each having a center section, a head section, and a chain stay extending rearward from said center section;
• (b) a seat assembly including a seat support beam attached to said head section, said seat support beam extending rearwardly from said head section, and a seat attached to a portion of said seat support beam distal from said head section;
• (c) a from wheel assembly including a front fork assembly rotatably coupled to said head section, a front wheel attached to said front fork assembly below said head section, and a handlebar assembly attached to said front fork assembly above said head section;
• (d) a rear wheel rotatably coupled to said chain stays;
• and
• (e) a drivetrain assembly including a free gear secured to said rear wheel, a crank assembly secured to said center section of said body units, and a drive chain connecting said crank assembly to said free gear.

A bicycle frame comprising:

• (a) a head section having means for mounting a seat support beam and means for securing a front fork assembly;
• (b) a center section extending downwardly from said head section, the lower end of said center section having means for coupling a crank assembly;
• and
• (c) at least one chain stay extending rearwardly from said center section, said chain stay including means for attaching a rear wheel;
• wherein said head section and said center section include a generally centrally located body beam providing the main support and the basic shape of said head section and said center section and support ribs projecting outwardly from said body beam, said support ribs extending across said body beam in a plurality of directions.

A bicycle frame assembly comprising:

• (a) a first body unit comprising a first outer shell with an inside surface and first internal ribs, said first internal ribs projecting from said inside surface of said first outer shell to form a first support structure, said first body unit including a chain stay;
• and
• (b) a second body unit comprising a second outer shell with an inside surface and second internal ribs, said second internal ribs projecting from said inside surface of said second outer shell to form a second support structure, said first and second body units being arranged and configured to mate together, said first outer shell being configured to mate along at least a portion of its perimeter with the perimeter of said second outer shell and at least a portion of said first internal ribs configured to mate with at least a portion of said second internal ribs;
• wherein at least one of said first and second body units includes a center section, said center section having a bottom bracket bore disposed within a lower portion of said center section, said chain stay extending rearwardly of said center section, said second body unit terminating at the bottom of said center section near said bottom bracket such that said second body unit does not include a chain stay.

A bicycle comprising:

• (a) a frame formed of composite material, said frame including at least two body units, said body units each having a center section, a head section including a head tube extending longitudinally through said head section and a chain stay extending rearward from said center section;
• (b) a seat assembly including a seat support beam attached to hid head section, said seat support beam extending rearwardly from said head section, and a seat attached to a portion of said seat support beam distal from said head section;
• (c) a front wheel assembly including a front fork assembly rotatably coupled to said head tube of said head section, a front wheel attached to said front fork assembly below said head section, and a handlebar assembly attached to said front fork assembly above said head section;
• (d) s rut wheel rotatably coupled to said chain stays;
• (e) a drivetrain assembly including a free gear secured to said rear wheel, a bottom bracket assembly including a sleeve extending longitudinally through said center section of said body units, crank assembly rotatably mounted to said bottom bracket assembly of said body units, and a drive chain connecting said crank assembly to said free gear;
• and
• (f) a front derailleur and rear brake assembly attached to said body units adjacent said crank assembly, said front derailleur and rear brake including a front derailleur having a chain guide disposed around said drive chain and a brake disposed around said rear wheel, wherein said from derailleur and rear brake assembly includes a mount secured to said body units and said front derailleur is connected to said assembly mount to pivot about said assembly mount.