Abstract: A bicycle with a drive mechanism using reciprocal rectilinear pedal motion to propel a pinion gear against a crown gear face associated with a rear bicycle wheel, rotating the rear wheel. The pinion gear receives motion from a helical member surrounded by a slider. Each pedal is united with the slider which moves linearly along a guide or track, forcing rotation of the helical member as the slider is pushed rearwardly by a pedal. A freewheel or overrunning clutch permits power transfer only when the pedal moves rearwardly and allows freewheeling when the pedal is reset. Reciprocal, linear pedal strokes power the bicycle.