I was looking at the picture of the Suntour "Spirt" front derailleur, and it brought back memories of a Suntour I tried on my PX10 in 73ish when the Simplex broke. It was a nice enough piece, but the operation was backwards, using the spring to push the chain up onto the large ring. Or should I say try to push the chain up, as it would fail to shift if any more than a trivial amount of force were being applied to the pedals. Downshifted right smartly though! Also gave the levers an operational symmetry that appealed to me; forward for fast, rearward for slow. Did any other manufacturers use this method, and did Suntour abandon it before the end of their days?