I recently picked up a pair of braze on Simplex retrofriction shifters. I'd like to use these on a 64 Peugeot PX10. Is there a clamp that could be used for these to fit onto? As a follow up am I wrong about this one being braze on?

I'm contemplating the same thing for the PX10 on which I am currently working! I did a test fit last night of the retrofriction shifters (just like yours) onto the simplex clamp that came with the PX10 and they seemed to fit just fine. Since I am re-painting the frame I won't get to test their function for a few weeks but I didn't see any problem with the fit.
Brent

Those are braze ons. This sort of clamp is what you need, but I couldn't say where to find them:



There are also some horrid looking Problem Solvers hinged aluminum ones.

The key appears to be the square hole in each shift lever assembly having a matching square protrusion to lock onto.

Just to make things interesting, Simplex actually found it necessary to have a different thread pitch for the mounting bolts used on the clamped on version of the Retrofrictions to the brazed on ones.
Strange , but at least they had the right bolt threads on the brazed on version, so they will screw on to "standard" brazed shifter lugs on most bikes........ but not on to Simplex mounting bands....

I put this Flickr album together in 2011 when I was faced with the same problem. Don't let the title fool you, it makes sense after you read on.

Scroll down below the photos for explanations and instructions.

https://www.flickr.com/photos/282672...7627163433202/

I'm finishing up a 1983 Peugeot PSV-10 that I bought as a partial bike a few years ago. I have 6-7 sets of Simplex Retrofriction levers in my parts collection.

When I tried to mount one set this evening, I discovered that the mounting screws were about 3-4mm too short. They must have come off of a clamp on band but with 5mm x .8mm mounting screws.

Most of the band mounted Retrofriction levers use obsolete French bâtard 5mm x 1.0mm screw. See my Flickr album for more details.

Le Roi Bâtard du Simplexia

I think the band versions had the older thread standard so they work with old-fashioned Simplex bands. The braze-on versions were designed to mount to standard Campy fittings, and thus used the correct threading for them.

Simplex band clamps are on ebay, but prices are a bit more than I'd like to spend, and you still have the threading issue. There must be other band clamps that match the square-based Campy braze-ons, though I have yet to find one.

Fortunately, the fix is just and easy trip to a well stocked hardware store for a couple the proper stainless steel button headed socket bolts to replace the ones with the obsolete French threading....
It is good to replace the original slotted head bolts anyway on all the retrofrictions, as the chrome finish on them tended to rust and flake off very badly.

I did this sort of conversion last year: Had a set of Simplex braze-on downtube shifters (retrofiction? I'm not sure) and a Simplex shifter clamp from somewhere. They matched perfectly:

What's really strange is the retrofriction shift levers that came with the mounting band had a larger inner bore diameter. They will go on brazed on bosses without a problem if you change out the mounting bolts, but the brazed on version of the shifters will not fit over the retrofriction clamp on band bosses because of this. You will have to make sure the Simplex clamp-on band will not have the larger diameter step on the bosses to do so.
Found this out when I transferred a set of clamp-on Retrofriction shift levers, on to brazed-on bosses on a project bike.

Some French bikes had different threading in the braze ons, too.

I don't think those screws were plated at all, I have a NOS set and they look like bare steel to me. I wax them regularly. Button head socket bolts would be out of place on my early seventies bikes.

Yes, they were all plated. I have like 8 sets of Retrofrictions bought used and NOS, and all of them had original mounting screws that are plated. As I noted, the plating flakes off really easy, so you will see a lot of them out there that looks like bare steel. I think some of them has such bad plating that they flaked off even just in storage and not in use.
As for button headed socket bolts, I use them on my Retrofrictions to ease taking them off and installing them for servicing/cleaning, plus, I think they look pretty good on the later version of the levers with the cutout, issued in the 80's when a lot of components were going over to allen socket headed fasteners

I just installed some later Simplex shifters on my bike, and it seemed like the mounting bolts were captive. Is there a trick to removing them?

There's a captive plastic washer inside of the barrel well that screws on to the threads of the bolt. Just push the bolt out with a thin rod or other screw from the well side of the barrel and the bolt should slip out of the lever body, leaving the plastic washer inside the well. I usually reinstall the plastic washer when I put the lever back together so the lever assembly all stays together before I install it on a bike or if I store the levers in my stash. You can do this by pushing it back on to the mounting bolt with an appropriate sized metal or rigid plastic tube.

I still don't think mine were ever chrome plated.

Some of the later ones came with socket head screws. They suit the later style levers. Mine are the very early shifters with the little nub on the bottom.



I don't understand what you are saying about replacing the screw with the obsolete French 5mm x 1mm thread with a standard 5mm x .8mm screw. The threads don't even come close to matching. It would be like trying to put a coarse threaded nut on a fine threaded bolt.

He's talking about how to convert them to braze on.


Chombi, thanks for the tip. I might consider replacing my slotted screws with hex.

From my reading of a few of these messages it seems all that is needed is the correct length of the appropriate threaded Batard French M5x1.0 screws to attach the braze on Retrofriction shifters on a Simplex clamp. Indeed, I attempted to attach one of my Retrofriction shifters on a set of Criterium shifters just now. What I found was the Retrofriction shifters fit onto the simnplex band perfectly. However, the Retrofriction screw did not fit into the clamp and the original Simplex clamp screw was not long enough.

Is it really possible to find a french threaded bolt at a hardware store as @Chombi1 suggested? That would seem to be the easiest solution if it is possible. If a fix is that easy I will do so and post a full set of directions.

So let me rephrase. Any idea where longer french threaded bolts could be found? Otherwise it seems like the choice is possible tethreading a bracket or using a different clamp.

Drill out the M5 holes from the inside, fit a 5.3mm M4 T-nut from the inside and use a wide headed M4 screw or standard M4 with a washer?

Well here is what I did. I ordered a cheap NOS Huret clamp from eBay. It also turned out to have French threads but it is sturdy and nice and shiny. I then took it to a friend at a LBS who rethreaded the clamp to standard. It all works well now.

When did Simplex start using the "sun" logo?

I have a set of Spidel branded Retrofrictions on a sun logo clamp.

I enjoyed [MENTION=61614]verktyg[/MENTION]'s Flickr page.

Simplex levers on a Huret clamp??...... Blasphemy!.
That's like a Coke and Pepsi combinstion!

SB Greg-

Peugeot used the M5 x 1.0 obsolete thread for non-Retrofriction clamp-on and braze-on shifter bosses as I discovered when refurbishing a PB 12. The solution was to use an M5 x0.8 tap to re-thread the PB 12's braze-on bosses to take the modern screw in the Retrofriction shift lever. Perhaps you can re-thread the original PX 10 clamp-on band bosses to accept the newer standard Retrofriction threading.

I’m very happy with the nos Huret clamp. Done and done.