Re: [CR] Clamp-on shift lever boss threading

(Example: Bike Shops:R.E.W. Reynolds)

Date: Sat, 27 Jun 2009 14:55:38 -0700
From: Jerome & Elizabeth Moos <jerrymoos@sbcglobal.net>
To: Classic Rendezvous <classicrendezvous@bikelist.org>, Louis Schulman <louiss@gate.net>
Subject: Re: [CR] Clamp-on shift lever boss threading


Well, made my trip to the hardware store - on the 1962 Superior.

First, a standard M5 x 0.8 bolt does match Campy brazeon bosses, which opens a lot of possibilities for replacement screws for Campy or other brazeon shifters.

Second, the SAE (or is it USS?) thread that works with the Simplex Prestige clamp is a 10-24. It's just maybe a bit loose in the Simplex thread, which it has been suggested is an M5 x 0.9, but it works fine for an application like securing shift levers. For the extra thick Simplex Retrofriction levers you need an 18 to 20 mm thread length. With normal levers, one probably needs a thread length similar to Campy fixing screws, which are 12 mm.

I also tried the 10-24 screws on Huret clampon shifter clamps, among a large lot of miscellaneous Huret stuff I bought from Ted Ernst a few years ago. The 10-24 screw works with the Huret clamp, and the fixing screws for the Huret shifters work on the Simplex Prestige clamp as well. So it appears there was a fairly common French shift lever thread, perhaps M5 x 0.9, which won't work with Campy brazon bosses, but which is a decent match for a 10-24.

I've used stainless 10-24 (as it turns out) socket head cap screws in the past to secure brazeon Retrofrictions to Simplex Prestige clamps to convert them to clampon use. The stainless bolts look pretty good, and the socket head can be adjusted with a hex wrench in a typical multitool many of us carry. Actually a better adjusting mode than the original retrofriction bolts which typically used a straight blade screw driver and were much easier to damage. What might look more elegant yet would be button head screws. Now that I know the Campy thread and the 10-24 thread that will work for Simplex and Huret clamps, I will see if I can find some stainess or chromed button head screws in those sizes.

Regards,

Jerry Moos
Big Spring, Texas, USA


--- On Sat, 6/27/09, Jerome & Elizabeth Moos wrote:


> From: Jerome & Elizabeth Moos <jerrymoos@sbcglobal.net>

\r?\n> Subject: Re: [CR] Clamp-on shift lever bosses - Now Simplex Strangness

\r?\n> To: "Classic Rendezvous" <classicrendezvous@bikelist.org>, "Louis Schulman" <louiss@gate.net>

\r?\n> Date: Saturday, June 27, 2009, 2:19 PM

\r?\n>

\r?\n> Louis seems to have solved his immediate problem as someone

\r?\n> advised the Huret clamps have a M5 x 0.9 thread that it is

\r?\n> said is easily tapped to Campy M5 x 0.8.

\r?\n>

\r?\n> However, having started to explore this I pulled out my

\r?\n> Simplex shifter stash to investigate.

\r?\n>

\r?\n> My recollection was that Simplex Retrofriction Brazeon and

\r?\n> Clampon levers were not interchangeable, which indeed they

\r?\n> are not.  Disassembled a pair of clampon Retrofrictions

\r?\n> this morning and confimed my recollection.  The ID of

\r?\n> the Clampon lever barrel is too small to go over a Campy

\r?\n> brazeon, i.e. the clampon Retrofriction clamps have a post

\r?\n> smaller than a Campy brazeon post.  This means that the

\r?\n> clampon levers cannot be used on a frame made for Campy

\r?\n> brazeons.  It also means that brazeon Retrofriction

\r?\n> levers cannot be converted to clampon by mounting them on a

\r?\n> Retrofriction clamp.

\r?\n>

\r?\n> However, - and this is what I have done in the past - the

\r?\n> Retrofriction brazeons will fit on the clamp from the old

\r?\n> cheap plastic Simplex Prestige shifters found on UO-8's and

\r?\n> the like.  These clamps are really quite nice, although

\r?\n> the plastic levers are crap.

\r?\n>

\r?\n> However, there is also the matter of the retaining screw

\r?\n> thread.  My recollection was that the thread of the

\r?\n> Prestige clamps did not match the Campy thread of the

\r?\n> Retrofriction brazeon shifters, so I recall finding an SAE

\r?\n> stainless socket head cap screw at the hardware store which

\r?\n> although technically a different thread, did work. I blieve

\r?\n> the original Prestige screws were probably too short for the

\r?\n> thick Retrofriction levers.

\r?\n>

\r?\n> Well, my recollection was correct - PARTLY.  This

\r?\n> morning just within my stash, I found that the Brazons

\r?\n> version of the Retrofrictions used two different

\r?\n> threads.  Some of the brazeon levers have Campy

\r?\n> compatible screws, so they will work with Campy brazeons

\r?\n> bosses, but not with Simplex Prestige clamps.  Others

\r?\n> had a thread that works with the Prestige clamps but not

\r?\n> with Campy brazeon bosses.

\r?\n>

\r?\n> Now here is another weird bit.  The clampon

\r?\n> Retrofrictions have Campy compatible thread, although the

\r?\n> post diameter is different.

\r?\n>

\r?\n> Now one place my memory may have been wrong is that I

\r?\n> thought that I had tried mounting brazeon Retrofrictions on

\r?\n> the clamps from Simplex Creterium shufters, found on PX-10

\r?\n> and the like, and this did not work, although the Prestige

\r?\n> clamps did (though perhaps with different screws).  But

\r?\n> today I find that at least the two set of clampon Citeriums

\r?\n> I tried had both the same post and the same thread as the

\r?\n> Prestige clamps.  Perhaps not all Criteriums through

\r?\n> the yeras used the same clamps, or perhaps the Simplex

\r?\n> clamps I tried unsuccessfully in the past were not Criterium

\r?\n> as I thought them, but some other model.

\r?\n>

\r?\n> So to summarize:

\r?\n>

\r?\n> A) Clampon Retrofrictions, or at least all the ones I have

\r?\n> seen, have the same thread as Campy brazeon posts, but a

\r?\n> smaller post diameter, so they cannot be used on Campy

\r?\n> brazon fittings. The clamps also have a smaller post than

\r?\n> Simplex Prestige and at least some Criterium shiters, though

\r?\n> there may be some other Simplex clamps that are

\r?\n> interchangeable with Retrofrictions clamps.

\r?\n>

\r?\n> B) Brazeon Retrofriction levers, or at least all those I

\r?\n> have seen, fit the Campy brazeons post size.  Some,

\r?\n> probably most, also have fixing screws with Campy compatible

\r?\n> thread, but others have fixing screws that don't work with

\r?\n> Campy brazeons posts but do work with Simplex Prestige and

\r?\n> at least some Criterium clamps.

\r?\n>

\r?\n> C) Simplex Prestige and at least some Creierium shifters

\r?\n> have clamps with the same post size as Campy brazeon posts,

\r?\n> but a different thread.  All Brazon Retrofriction lever

\r?\n> with fit on clamps from these Prestige and at least some

\r?\n> Criterium shifters.  But only some Retrofriction

\r?\n> brazeons have screws comaptible with Prestige and Criterium

\r?\n> clamps, while most have Campy-compatible screws.  This

\r?\n> means brazeon Retrofiction levers can be converted to

\r?\n> clampon using Prestige and at least some Criterium

\r?\n> clamps.  Some can be adapted using the original fixing

\r?\n> screws, but for most, one must find Simplex campatible

\r?\n> screws. This also means Simplex Prestige and at least some

\r?\n> Citerium shifters can probably be used with Campy brazeon

\r?\n> posts, though one has to find some Campy-compatible screws

\r?\n> to do so.  Now personally I can't image anyone deranged

\r?\n> enough to want to mount the crappy Prestige levers on a

\r?\n> frame with Campy brazeons, although the Criterium levers

\r?\n> might make

\r?\n> perfect sense.

\r?\n>

\r?\n> Can anyone, perhaps a framebuilder, explain the

\r?\n> Retrofriction brazeon levers with the non-Campy screw

\r?\n> thread? Did Simplex or Huret make brazon posts with the same

\r?\n> diamter but different thread from Campy?

\r?\n>

\r?\n> The one thing that remains is a trip to the hardware store

\r?\n> to see what SAE thread works with Simplex clamps.  Also

\r?\n> want to pick up a couple of standard 5 x .8 button head

\r?\n> screws and confirm these match the Campy thread.

\r?\n>

\r?\n> Regards,

\r?\n>

\r?\n> Jerry Moos

\r?\n> Big Spring, Texas, USA     

\r?\n>

\r?\n>

\r?\n>

\r?\n>

\r?\n>

\r?\n>

\r?\n>

\r?\n> --- On Thu, 6/25/09, Louis Schulman <louiss@gate.net>

\r?\n> wrote:

\r?\n>

\r?\n> > From: Louis Schulman <louiss@gate.net>

\r?\n> > Subject: [CR] Clamp-on shift lever bosses (or, Zut

\r?\n> 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

\r?\n> for

\r?\n> > standard braze-ons, so they won't go on my Huret

\r?\n> 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? 

\r?\n> That

\r?\n> > is, the bosses have the standard square bases and

\r?\n> round

\r?\n> > shafts with normal threads?  I have several clamp-on

\r?\n> > shifters, but the clamps are all unique to the

\r?\n> shifters.

\r?\n> >

\r?\n> > If there is such a thing, does anyone have one they

\r?\n> would

\r?\n> > like to part with?

\r?\n> >

\r?\n> > Thanks,

\r?\n> >

\r?\n> > Louis Schulman

\r?\n> > Tampa, Florida USA