A bicycle derailleur mounting structure includes a base member and a stopper. The arm retainer includes a rigid arm tray having a connection stud protruding from the bottom side of the tray for connecting the tray to the articulatable support assembly, and the tray is provided with a pair of spaced openings for securement of a disposable arm support liner to the tray. An emitter electrode of the hetero junction bipolar transistor, a Schottky electrode of the Schottky diode and a resistance film of the resistance element are simultaneously formed using a same material.