PJB1

Hello All!
I have a CCM Concorde from 1973 that I would like to bring as close to all original equipment as possible. Other than tires & brake pads, the last item is the front derailleur.

In the 1990's, the front derailleur's dreaded Delrin cracked. I was working a billion hours, so I took the bike to a shop for a replacement. They were able to fit a Shimano FD-TY25 and make it work kinda-sorta good. (Not all gear combinations are available.) But, in the interest of authenticity, I'd like to put an original Simplex Prestige AV 223 back on, assuming I can find one for a reasonable cost. (I know the next question: "Are you Crazy?")

But, I cannot remember the original cabling system.

The front shifter cable has no jacket. As far as I can tell, the Simplex Prestige uses the cable jacket to push the actuating arm, rather than pulling it. The inner cable gets secured to the Prestige derailleur's body, thus does not move. (I have a wrong size one to study. It's for a 28.0mm tube) The Shimano on the rear simply uses the wire rope to pull the derailleur into position, so that didn't give me clues.
There is a pair of cable guides on the down tube. The front & rear cables (both bare- no jackets), pass under them.

Should the 'new' Prestige be fed with a shifter cable that has the 'exit' end clamped under the guide? It looks like a 4mm OD jacket will fit under the exit side of the guide. The entrance side has a smaller hole. I'm assuming the cable jacket will terminate in the moving 'actuator' arm. It does not have a set screw, but rather a larger hole on the 'enter' side than the 'exit' side.

The next question is- Does the jacket require ferrules, or does it simply go into the guide and shifter boss with a raw end?

I can't quite grasp the Bowden cable concept, so The Million Dollar Question is:
How does the cable jacket move the lever if the wire is fixed & does not move? When shifting, wouldn't the wire simply bend between the lever & the cable guide since one end of the jacket is clamped by the guide & the other end is pushing against the piston spring? Or, did I get the whole cable jacket being clamped under the guide part all wrong? I haven't found a photo of a Prestige that's installed, showing the jacket on the frame of the bicycle.

Please pardon my terms, such as "boss" and "actuator arm". I could not (yet) find out the real names of the parts.

Thanks for your help & for not beating me up too badly for wanting a Prestige. (OK- Go ahead. I deserve it!)
Paul

SkyDog75

You ARE crazy. It's obvious. No need to ask the question. ;-)

Too bad the Simplex Prestige derailleur from my old Peugeot is for a 28 mm seat tube; otherwise you could have it for the cost of shipping.

dabac

Maybe some clues here:Simplex - l'ensemble Prestige scan 1

As for your million dollar question: take a look at how interrupter brake levers work. When used as interrupters, they push at the casing. If the wire is fixed at both ends, and you push the casing back&forth, or if the casing is fixed and you pull at the cable doesn't matter. One is moving in relation to the other, and that can be used to make other parts move.
Pushing cables is very rare on bikes, AFAIK only used by Shimano Positron. But they're a single strand piano wire. Although the boating industry use it a lot on small/mid sized outboard motors.

PJB1

Thank You Dabac & SkyDog75 for taking the time to reply. I appreciate your help & offer of a derailleur! Very generous, indeed!

I looked at the linked Disraeli pages. They are very helpful. (I could spend far too many hours reading on that site. It's cool.)
Your tip, Debac, about looking at interrupter levers really cleared up how Bowden cables work in a similar situation.

After reading, my thinking is that the cable jacket should not be clamped under the cable guide, but rather be free floating under it.

My Theory of Operation now is-
1) The shifter lever is moved by hand.
2) The inner wire is pushed by that lever.
3) Because the inner wire is fixed to the stationary derailleur housing at the other end, the cable jacket is forced to slide under the cable guide toward the derailleur.
4) The movement of the cable jacket pushes the derailleur's actuating arm, thus extending the piston.

Reverse-
1) The shifter lever is moved back where it was before Step 1, above.
2) The tension on the wire is diminished or released completely.
3) The cable jacket now slides back where it began & is under minimal or no tension
4) The spring in the derailleur moves the arm back to its starting position.

Did I get it correct or am I still wonky?

Some pictures of the guides & a similar (28mm- wrong size) derailleur are attached. I somehow goofed attaching them to my first post.

Thanks Again!
Paul

Grand Bois

The same clamp size front derailers were used on both 28mm and 28.6mm seat tubes. Some people say they have slippage on french tubes, but I have never had that problem. My Peugeot PX10 has a Campagnolo Nuovo Record front derailer.

Simply loop the housing from the stop on the down tube over the bottom bracket to the stop on the derailer, push the shifter all the way forward, insert the inner cable, pull the slack out and clamp it. The stranded inner cable can never push, only pull and release. The outer housing can push. It's simple. I think you are over-thinking this.

I have replaced the Prestige on a couple of my French bikes with this one:

VeloBase.com - Component: Simplex SJA 102

My Jeunet still has the Prestige FD. It works fine, but it's only a matter of time before the old, brittle Delrin cracks. The last time that happened, I bought a NOS replacement on Ebay for not much money.

PJB1

Thank You Grand Bois!
The guy I bought the Prestige from also mentioned they fit both sizes. But this one is visibly too small for my seat tube. The radius does not match. I used a vernier caliper on my CCM's tube just to be sure my bike's not goofy sized. it is 28.664mm

Another oddity is that, on this derailleur, the 'hub' (stop?) that the cable jacket goes into is on the opposite side of the other Prestiges I've seen. It faces the front of the bike. There might be a seat tube conflict on my CCM. I also noticed that the derailleur I bought by mistake defaults by spring to the inner (smaller) ring on the crank set. It has to be pushed very hard to go to the larger ring.

I am starting to wonder if this is a Prestige or if it is a totally different (and opposite) model that happens to look very similar.

Thanks for your great explanation of the cable routing and operation. I sure do appreciate your help.

I'm positive that when I get a replacement in my hands the operation will penetrate my thick skull. And, yes I probably am over-thinking it. Gotta know how everything works. Lots of clocks & watches suffered an early demise when I was a kid because of that curiosity! My Excuse? I was raised by a very, very German engineer. It's in the blood!

Thanks Again & I Hope Today Is Great!
Paul

sekaijin

Hello! I went looking and found this thread because I'm about to cable up a Simplex Prestige FD, and I'm having the same state of disbelief that you had, PJB1 - Really? The housing, not the cable, pushes the FD spring-arm? And that works? Really?

I knew someone must have had this discussion here already. And here it is. I love BF C&V.

So Paul, I'm wondering - how did it work? And, did you use a ferrule at the FD cable stop?

PJB1

Hello Sekaijin!
I hesitate to admit this, but I have not yet installed the front derailleur. It took a long time to find the correct sized one for my 28.6mm downtube and then winter showed up. So I'm still riding with the aftermarket. (Winter riding's fun, but winter fixing--- Not so much)

Studying the part, although still not installed, does illustrate what Grand Bois explained about the jacket doing the pushing. But, i still can't visualize how it will be guided on my bicycle. The existing replacement is using the inner wire to do the work, so that's no help. I wonder what will keep the cable assembly from simply flexing sideways when I operate the shift lever.

About The Size & Clamp Differences I Found Between The 28mm & 28.6mm Versions:
When I had both sizes in my possession, I checked them with radius gauges and measured manually. The two clamps are, indeed, different and the part that the cable jacket butts into (Part 1953B on the attached drawing) are facing opposite directions. The 28mm version faces the front of the bicycle & the 28.6mm faces rear. It would be interesting to find someone with an old 28.0mm bike & see if their Part 1953B also faces front.

The 26.0mm version I had absolutely did not fit the 28.6mm tube. I gave it to someone who swore it would fit his 28.6mm. It didn't.
The radius of the clamp and body were too small. To better explain what I mean, picture taking a pipe coupling for 3/4" pipe and slicing it lengthwise into 2 halves. They will lay nicely over the 3/4" pipe, but not 1" pipe because the radius is different.
But, just as Grand Bois said, the 28.6 model does fit the 28mm tube and the 28.6 size. There is plenty of range in the clamp to grip. It isn't perfectly flush with the 26mm tubing wall due to the larger radius of the clamp, but it held fine on a test piece of 26mm tubing.

So....
With luck, I will install this derailleur soon & can report back with more details & photos.
After I read your post, I went outside to the garage & took a fresh look at the bike's setup. Unfortunately the new snow I walked through to get to the garage is telling me I have a less fun thing to do today.

Some photos are attached & hopefully they will help you with your project.

Enjoy Today!
Paul

fietsbob

Yes Going thru that plastic piece (1st/2nd picture) with the bare cable and adding a short piece of Housing

from the plastic Piece to the housing stop and actuating lever on the FD has the housing push the Front derailleur cage outward .

relative to the cable .. give the section of housing a smooth curve and don't make it too Short .

corrado33

It's one of... those... derailleurs. The two times I've encountered this type of derailleur they were broken (where the nut was set into the plastic.) Finding a replacement derailleur was a royal PAIN because those derailleurs can get really close to the seat tube IIRC.

Although you don't often see new FDs with cable stops, the ones that do generally have a few different types of cable housing locations. They basically fall into two categories.

Under the BB.



And over the BB.



Sometimes the over the BB is on the other side of the seat tube.

In general, if I must use a housing for the FD, I'll choose the path that results in the least bent (widest radius) housing. If the stop for the housing on that derailleur is on the drive side, I'd run the FD cable down the DS of the bike. You MAY be missing an old style clamp on cable housing stop they had back in the day.

RubeRad

How weird is that?

I would just replace with some other vintage FD that deals in cable pull rather than housing push.

sekaijin

I just cabled up the Simplex Prestige FD. Works fine. OK then! Thanks all!

sekaijin

Update - that just happened. I was re-positioning the Prestige FD on the seat tube, to improve the shifting, and pop!

I have a gen-1 Suntour Cyclone FD on hand, so I swapped that in.

Grand Bois

Why?

RubeRad

Because it would be easier to cable up, OP would not have the problems that prompted his OP.

Grand Bois

There is nothing difficult about the cabling once you know how. The system works well. It was used on more than a few bikes. I have four that work that way.

PJB1

Thanks for the photos Corrado33.
They are helpful for me when I try to visualize the project. It still might be a while before I decide to install the unit. Every time I go near the bike to work on it, I end up riding it.
Regarding using a pull derailleur, that's what is on there now. The goal for the AV 223 is simply to put the bicycle "back to factory"- faults and all.
Thanks Again All for helping me out. I'll post when the job's successfully completed.
Paul

SkyDog75

I'm not a fan of the Simplex delrin derailleurs, but I've also got a few bikes that use the 'housing push' actuation method for the front derailleur. It's just as simple as the usual method and works fine ...especially if you replace the plastic derailleur with something like a SunTour Compe-V or Spirt.