Louis seems to have solved his immediate problem as someone advised the Huret clamps have a M5 x 0.9 thread that it is said is easily tapped to Campy M5 x 0.8.
However, having started to explore this I pulled out my Simplex shifter stash to investigate.
My recollection was that Simplex Retrofriction Brazeon and Clampon levers were not interchangeable, which indeed they are not. Disassembled a pair of clampon Retrofrictions this morning and confimed my recollection. The ID of the Clampon lever barrel is too small to go over a Campy brazeon, i.e. the clampon Retrofriction clamps have a post smaller than a Campy brazeon post. This means that the clampon levers cannot be used on a frame made for Campy brazeons. It also means that brazeon Retrofriction levers cannot be converted to clampon by mounting them on a Retrofriction clamp.
However, - and this is what I have done in the past - the Retrofriction brazeons will fit on the clamp from the old cheap plastic Simplex Prestige shifters found on UO-8's and the like. These clamps are really quite nice, although the plastic levers are crap.
However, there is also the matter of the retaining screw thread. My recollection was that the thread of the Prestige clamps did not match the Campy thread of the Retrofriction brazeon shifters, so I recall finding an SAE stainless socket head cap screw at the hardware store which although technically a different thread, did work. I blieve the original Prestige screws were probably too short for the thick Retrofriction levers.
Well, my recollection was correct - PARTLY. This morning just within my stash, I found that the Brazons version of the Retrofrictions used two different threads. Some of the brazeon levers have Campy compatible screws, so they will work with Campy brazeons bosses, but not with Simplex Prestige clamps. Others had a thread that works with the Prestige clamps but not with Campy brazeon bosses.
Now here is another weird bit. The clampon Retrofrictions have Campy compatible thread, although the post diameter is different.
Now one place my memory may have been wrong is that I thought that I had tried mounting brazeon Retrofrictions on the clamps from Simplex Creterium shufters, found on PX-10 and the like, and this did not work, although the Prestige clamps did (though perhaps with different screws). But today I find that at least the two set of clampon Citeriums I tried had both the same post and the same thread as the Prestige clamps. Perhaps not all Criteriums through the yeras used the same clamps, or perhaps the Simplex clamps I tried unsuccessfully in the past were not Criterium as I thought them, but some other model.
So to summarize:
A) Clampon Retrofrictions, or at least all the ones I have seen, have the same thread as Campy brazeon posts, but a smaller post diameter, so they cannot be used on Campy brazon fittings. The clamps also have a smaller post than Simplex Prestige and at least some Criterium shiters, though there may be some other Simplex clamps that are interchangeable with Retrofrictions clamps.
B) Brazeon Retrofriction levers, or at least all those I have seen, fit the Campy brazeons post size. Some, probably most, also have fixing screws with Campy compatible thread, but others have fixing screws that don't work with Campy brazeons posts but do work with Simplex Prestige and at least some Criterium clamps.
C) Simplex Prestige and at least some Creierium shifters have clamps with the same post size as Campy brazeon posts, but a different thread. All Brazon Retrofriction lever with fit on clamps from these Prestige and at least some Criterium shifters. But only some Retrofriction brazeons have screws comaptible with Prestige and Criterium clamps, while most have Campy-compatible screws. This means brazeon Retrofiction levers can be converted to clampon using Prestige and at least some Criterium clamps. Some can be adapted using the original fixing screws, but for most, one must find Simplex campatible screws. This also means Simplex Prestige and at least some Citerium shifters can probably be used with Campy brazeon posts, though one has to find some Campy-compatible screws to do so. Now personally I can't image anyone deranged enough to want to mount the crappy Prestige levers on a frame with Campy brazeons, although the Criterium levers might make perfect sense.
Can anyone, perhaps a framebuilder, explain the Retrofriction brazeon levers with the non-Campy screw thread? Did Simplex or Huret make brazon posts with the same diamter but different thread from Campy?
The one thing that remains is a trip to the hardware store to see what SAE thread works with Simplex clamps. Also want to pick up a couple of standard 5 x .8 button head screws and confirm these match the Campy thread.
Regards,
Jerry Moos
Big Spring, Texas, USA
> From: Louis Schulman <louiss@gate.net>
\r?\n> Subject: [CR] Clamp-on shift lever bosses (or, Zut Alors!)
\r?\n> To: "Classic Rendezvous" <classicrendezvous@bikelist.org>
\r?\n> Date: Thursday, June 25, 2009, 9:24 PM
\r?\n> Recently, there was a discussion
\r?\n> about different threading on shifter bosses. My
\r?\n> problem is that I have a set of Sachs-Huret levers for
\r?\n> standard braze-ons, so they won't go on my Huret clamp-on
\r?\n> bosses, which have the different French threads. Zut
\r?\n> alors! C'est ironique, n'est-ce pas? I do not
\r?\n> want to switch out the special fixing screws.
\r?\n>
\r?\n> Here is the question. Is there a clamp with bosses,
\r?\n> where the bosses are the same as braze-on bosses? That
\r?\n> is, the bosses have the standard square bases and round
\r?\n> shafts with normal threads? I have several clamp-on
\r?\n> shifters, but the clamps are all unique to the shifters.
\r?\n>
\r?\n> If there is such a thing, does anyone have one they would
\r?\n> like to part with?
\r?\n>
\r?\n> Thanks,
\r?\n>
\r?\n> Louis Schulman
\r?\n> Tampa, Florida USA