Abstract: A bicycle derailleur apparatus for controlling bicycle speed includes a bicycle chain guide and a pair of moldable wires. The guide has opposite sides receiving a bicycle chain therebetween and is pivotally movable in a lateral direction toward and away from a bicycle frame portion mounting the guide. The moldable wires, disposed side-by-side and spaced apart, are mounted to the bicycle frame portion and have respective outer end portions attached to one guide side. By applying a predetermined electric current to the moldable wires at separate times their outer end portions deform from pliable states to respective acute and obtuse angular shapes relative to respective main portions thereof and thereby move the guide to shift the bicycle chain into engagement with one or the other of inner and outer derailleur sprocket gears of different diameter sizes to change the bicycle speed relative to the pedal cadence of a rider.

Abstract: A bicycle derailleur apparatus for controlling bicycle speed includes a bicycle chain guide and a pair of moldable wires. The guide has opposite sides receiving a bicycle chain therebetween and is pivotally movable in a lateral direction toward and away from a bicycle frame portion mounting the guide. The moldable wires, disposed side-by-side and spaced apart, are mounted to the bicycle frame portion and have respective outer end portions attached to one guide side. By applying a predetermined electric current to the moldable wires at separate times their outer end portions deform from pliable states to respective acute and obtuse angular shapes relative to respective main portions thereof and thereby move the guide to shift the bicycle chain into engagement with one or the other of inner and outer derailleur sprocket gears of different diameter sizes to change the bicycle speed relative to the pedal cadence of a rider.