Bicycle frame

Claim 1

An improved bicycle having a frame, a pair of wheels supporting said frame, and a pedal crankshaft journaled to said frame for propelling one of said wheels, said frame including: a rear frame member including a generally vertical center post positioned within an imaginary, generally vertical plane extending along a longitudinal axis of said bicycle; a front frame member including a generally horizontal crossbar positioned within said generally vertical, longitudinal plane; flex means for flexibly interconnecting said frame members so as to allow vertical relative flexing of said frame members generally along said generally vertical, longitudinal plane and to minimize relative flexing of said frame members out of said generally vertical, longitudinal plane; said crossbar comprising a single, horizontally extending hollow tubular member having a length with a generally elliptical cross-section and axis and major axis which is oriented in said imaginary generally vertical plane for a major portion of the length of said crossbar, for minimizing twisting of said crossbar, said hollow tubular member receiving said flex means at a rearward end thereof; said flex means comprising a generally flat spring having a horizontally oblong lateral cross-section; said tubular member tapering into a generally triangularly-shaped cross-section thus defining a transition area near said rearward end of said tubular member and adjacent said flex means; and said triangularly-shaped cross-section abruptly necking into an opening having a second major axis generally perpendicular to said first major axis and similarly shaped in lateral cross-section to said generally flat spring and defining a fitting receiving said generally flat spring.