There’s something about French touring derailleurs after about 1960. Just one look at this Simplex SX610 GT is enough to make me feel utterly exhausted and dispirited. I can almost hear the chain hysterically clattering on the inaccurately cut teeth of the wide ratio Maillard freewheel as the SX610 GT pathetically attempts to find bottom gear. I can almost see the bemused expression on the face of the owner of a Peugeot tandem as I attempt to invent a reason why a seemingly rational company like Peugeot had chosen to fit his relatively demanding machine with a poorly constructed derailleur with a plastic inner parallelogram plate.
The basic idea for the Simplex SX610 GT was unoriginal but acceptable - Simplex thought they would just copy a mid range Shimano touring derailleur. The execution was terrible - it weighed a ton (tonne?), it looked dreadful, the springs lasted about 23 milliseconds, it had Simplex’s tedious hanger bolt system and it simply never quite worked right.
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