On the topic of broken Simplex Front Derailleurs
 

On the topic of broken Simplex Front Derailleurs...

I've seen altogether too many of these. That poorly-designed black plastic derailleur body part that cracks open when the front bracket is over-tightened is the first thing I look for when I find older Peugeots that were prematurely retired.

Both of the two Peugeot SuperSports with the close chain rings I picked up had broken front Simplex derailleur bodies and I went through my entire selection of salvaged road bike derailleurs looking for something that would shift cleanly and exactly duplicate the throw of the Simplex FD.

The good news is that the Shimano FE front derailleur derailleur is a perfect fit and easily replaces the Simplex.

https://dl.dropboxusercontent.com/u/...olida35.59.jpg

The need to cut costs to make Bikes cheap enough go be sellable in mass numbers continues ..

the French Problem .. 28.0 frame tube to mount a FD on when the rest of the Planet uses 28.6 ie 1.125".

the holdouts finally had to fall back in the crowd..

Just about anything made for a 28.6 mm seat tube and similar-sized chainrings should be a workable replacement. You might have to shim down to 28.0, but that's no big deal. I'm running a SunTour Compe-V on my old Peugeot UO-8 whose Delrin (plastic) Simplex derailleur cracked.

Back in the mid '70s I had no difficulty mounting a Suntour FD on my PX10. The
Suntour RD was pretreated with a run through of the hanger threads with a 10Mx1 tap but
the threading difference is minor and a Campy NR with 26.4 TPI fit fine.

I bought a NOS VeloSolex St. Tropez in 1977, had them replace the Simplex with Suntour derailleurs and shifters before it left the shop. Only problem was the Simplex dropout did not have a notch for the B-screw. Had to file one and bend the screw a little so it would catch. Still have and ride the bike with the same setup.

I wonder if it would be worthwhile to digitize that Simplex FD Delrin piece to get it CNC'ed or 3D printed. I have a friend who makes replacement Delrin parts for Saab heater vent controls with his tabletop CNC machine. Might be a project he could take on.