Simplex FD loose. Does shimming work?
 

This is on my late 70's PX 10. The FD allen nut is tight, yet it slips down on the seat tube when you try to shift up to the larger ring. Unfortunately it's the half plastic, half chrome model. Does shimming work on these? Is it a viable solution, or does it continue to get worse until it breaks?,,,,BD

I've had a Campagnolo FD slip on my PX10, but never a Simplex. I wonder if they made them in two clamp sizes, one for French bikes with 28mm seat tubes and one for the 28.6mm tubes on the Raleighs and other bikes that used them. Which model Simplex do you have? The lowly Prestige didn't have a Chrome clamp.

Buy a can of Plasti-Dip. Paint the inside of your clamp with it and let it dry overnight. It will tighten up the clamp and keep it from marring the paint on your seat tube. I haven't tried it, but it's what I plan to do with a Campagnolo NR if I ever get my PX10 frame back from Dr. Deltron. I got the idea from him.

Allen nut?

Pretty sure it's a nut, kind of like the back of a recessed brake? Maybe not? It has a large dome capped head. This looks to be all original equipment, the back half is black plastic, and it has a half round hinged chrome part that goes across the front. I have a can of plasti dip, believe it or not, lol. I will give it a try, thanks. maybe a strip of inner tube could do it too. With 35+ bikes around, I have my share of old tubes.,,,,BD

I think you have a Simplex Competition. That was original equipment on my PX10. I've never seen one of those on anything but a PX10, so my "two sizes" theory doesn't fly. There have been a couple on eBay in the last few months. I search eBay for Simplex almost daily. Don't ask me why. Maybe I need to get a life.

I may go the Campagnolo replacement route for once. It already has campy hubs on Matrix wheels from a Raleigh SC, so maybe I will keep an eye out for the "Victory" that Kurt seems fond of. The factory will go in a drawer. From the looks of the RD, that's the reason the bike weighs so much to begin with. It's massive!,,,,BD

A Campagnolo clamp is made for a 26.8mm tube. Your tube is 26mm. You think that switching to a Capagnolo FD will solve your slipping problem? Using anything but a Simplex rear derailer on a '70s PX10 requires fairly major surgery to the derailer hanger. My PX10 is all Campagnolo, so I have some experience.

Cheap solution might be to trim down a strip or two of ordinary kitchen foil and put it between the fd and the frame. If the fd is intact, and not fractured like so many of those plastic Simplex fd's become over time, it may work for you.

Plastic, sheesh!

Well, I removed the bolt to inspect it and the part that holds the pin fell out in two pieces, plus the main
plastic piece. I guess there's no choice now. I have a golden arrow group, would that be an acceptable replacement? A small strip of inner tube should take up the slack. I hope.,,,,BD

I also have a 600 FD from the same era.

Keep it French.

http://www.velo-orange.com/si102frde.html

That is a reasonable price for a quality part. The logo also matches the RD. Best of all, NO PLASTIC, lol. Thanks!,,,,BD

About to go on the test ride with the 600 FD. Looks like it will fill the gap while I wait on the Simplex.

Wow, it's a nice riding bike. I sometimes forget how sweet it is. Feels vintage, yet rides like a dream. The 600 shifted without a single hiccup. Problem solved for now.,,,,BD

I have the same problem on a 1972 Mercier 300 (similar to PX10 or Gitane TDF). When I get around to overhauling that bike, I'll most likely do what most of the others have done and go with an LJ setup...after getting bent over a barrel. BOHICA

Real riders use beer cans...

Neither works when your derailleur is plastic, ;):p. The FD model was a Super Competition for anyone interested in that sort of thing. Were all these companies trying to save weight or what? Plastic is not something you want taking the place of metal in a stressed part, especially not 1970's plastic. The newer
stuff is scary strong, but back then, nuh uh.,,,,BD

Those plastics used back then were new, and lightweight. They didn't test things out to any great degree back then, at least apparantley not with bicycle parts. Guess it's a good they weren't sending up astronauts, huh?


That velo orange shop is just down the road from me. Next time I'm up in Nap-town I'll try and stop in.