TANDEM BICYCLE PROPULSION SYSTEM UTILIZING A SHARED FOOTPEDAL AND CRANK ASSEMBLY

摘要

A kit of detachable parts which modify a single rider bicycle such that it accom modates two riders. Each rider applies propulsive force to a common crank-arm and chainwheel assembly by means of two shared footpedal assemblies which transmit both riders' foot pressu re onto the same pedal bearing spindles. Each of said footpedal assemblies is comprised of u pper and lower footpedal members upon which the front and rear riders respectively apply propul sive foot pressure. The upper (non-rotateable) footpedal member is affixed to the lower (r otateable) footpedal member and extends outwards from the bicycle, thereby permitting eithe r heel or toe pressure to be applied by the front rider. The upper pedal is suspended above th e lower pedal by means of compression members disposed such that the rear tandem rider can insert the forepart of each foot between the pedal members to exert foot pressure onto the lower, ro tateable footpedal member. Said lower member has a rearward extension used by the rear ri der to stabilize the pedal assembly against torque induced by the front rider's eccentr ic point of pressure application. The rear tandem rider's seat is adjustably affixed onto a support rail assembly at a location behind and substantially lower than the front rider's sea t. An adjustable support mechanism permits the front rider's seat to be both raised and advanced with respect to its single rider location such that the legs of the closely coupled riders do no t interfere with each other during pedaling activity.