Patent ID: 6591929
Filing Date: 2003-07-15
Classification: B60Y,B62J,B62M

Abstract:
A motor-assisted bicycle having a power unit for inputting an assist power into a chain according to a depression force input from a pedal into said chain, comprising:a plurality of bicycle frames, each of said plurality of bicycle frames having a plurality of flanges for fixing said power unit thereon; said power unit having a plurality of boss forming spaces for forming bosses to be fixed to said plurality of bicycle frames, said plurality of boss forming spaces being first, second, and third boss forming spaces defined so that line segments connecting said first, second, and third boss forming spaces form a phantom triangle, said bosses being selectively formed in at least some of said boss forming spaces; and means for fixedly connecting some of said bosses of said power unit to said flanges, wherein said power unit is fixed to said plurality of bicycle frames separately from a pedal-powered crankshaft of said bicycle, and wherein said flanges on each of said plurality of bicycle frames are constructed differently from each other, and said bosses are selectively formed to accommodate said flanges.