Abstract: A bicycle transmission has drive pedals connected through a pedal shaft disposed in a pedal shaft hub on a bicycle frame. The shaft is selectively engageable with a series of gear pawls which are positioned to selectively engage one of a series of gears disposed about the pedal shaft. The gears are selectively engaged with an output sprocket meshed to a rear wheel sprocket. The pedal shaft includes a series of angled slots therein, in which a cam follower pin is disposed. The cam follower includes an actuator arm to cause one of the gears to engage the pedal shaft. The slots are sized so that reverse pedal rotation will cause the cam follower to axially actuate about the pedal shaft to cause disengagement and engagment of the gears.