Last time I rode my Paramount the force I exerted upshifting in the front caused the cable routing clamp to slip forward on the downtube mid-ride. I noticed that friction had caused the clamp to wear the paint down to the metal near the bolt but before returning home I slid it back down and tightened it in place again.

I don't think its a sustainable fix for a couple reasons. I've seen downtube braze-ons on other bikes presumably intended to prevent clamp sliding but this is not an option for me. The clamp needs to be as far down as possible to prevent the FD cable from flossing the seat tube paint off but as is it's starting to overlap the lug. In one of the pics below you can see some daylight between clamp and frame, possibly contributing to the clamp sliding.

So what advice do you guys have for 1) securing the clamp and 2) positioning it so the FD cable doesn't rub?

Could have posted to Mechanics but figured this is where the expertise would be.

Unlike the levers themselves these clamps rarely ever had sliding problems.

I suggest you remove the clamp, slide it out of the way, and clean the area completely to remove any possible oil film. Then remove the screw and work nut up and down the threads using some oil to clean them up and reduce any thread friction.

Then put it all back together and tighten to what you feel approaches the torque limit for a 5mm screw. (roughly 3nm max.)

If you don't feel it'll hold, go to your friendly auto mechanic and beg a tiny bit of lapping compound. Slide the clamp out of the way, apply some compound to the frame where you'll be putting the clamp, then with it fully loose put it where you want it and tighten. When the band is tight the grit in the compound will bite into both the clamp and frame, locking them together.

WARNING - when you use lapping compound this way, you cannot slide a slightly loose part to reposition it. You always have to loosen completely, move, then thighten.

In the second pic, of the bottom of the bottom bracket, that clamp sure looks loose. Unless the clamp is loosened up. Must be.
Here's is what I would do. FWIW. That paint looks awfully slick. FB's suggestion is a good one. Rough up the connection a bit, with a grit inter-face left in.
But if it were me, I'd coat the inside of the clamp with clear Plasti-dip. After cleaning it. It takes up some space, seems to grip well on paint, and keeps the metal of the clamp from marring the paint. I've done it on most of my bikes. A small can of Plastidip can be a bit hard to find, but handy to have on hand. Have to let it dry thoroughly before use.

I have seen a hose clamp used as a clamp on cable stop movement limit device. I have to admit that while I never liked the Campy BB guide is was the only method about often. The Shimano one was neat but not readily available. The Huret "cradle" type was to die for but also not too common. The SunTours and Simplexes, IIRC, were housing stops, not guides. I have also seen more then a few ft der cables routed around the seat tube using a casing stop and a zip tie to secure the free floating end of the casing to the backside of the seat tube. Andy.

With mounting it over the lug I think you are always going to have trouble due to the gap - not enough friction.
You could try a small piece of inner tube under the bolt and to help fill the gap. That will help increase the friction and protect the paint.
A piece of the plastic inner from shift housing over the cable at the back will protect the seat tube. It's translucent so wouldn't be too noticeable.

OH. I see. that second pic is with the clamp tightened!? Definite problem. You know, many fine bikes have lugs at the BB. With a Campy guide clamped just above the lug, that FD guide should still let the cable clear the back of the seat tube. I suspect that front derailleur cable guide on that example is bent a little bit. Believe I can see it in the third picture.
Try a new part, if you have one.

It's never going to work with the cable guide clamped over the lug points. Typically they need to be cranked down pretty tight, frankly enough to mar the paint. While it's true they don't slip nearly so easily as clamp on DT shifters, they do slip. (but not if they are cranked down properly) It's a moot point though because you have the wrong guide. Perhaps look at a Huret, or Simplex, or something else.

How old is this Paramount? If it's 60s it may be intended for first generation Record FD, or other, with a cable stop. I don't know what 1st gen campy FD are going for these days, but probably not cheap. There are numerous ways to solve this problem, but clamping the guide on tighter is IMO not one of them.

+1 this. Move the clamp off the bottom bracket shell so it can seat fully against the tube. Feel free to bend the cable tunnels to move the cable away from the paint.

Add to that.

I've often had the best results by bending the FD guide inward so it's jammed against the seat tube. This not only improves support and rigidity, but also leads the wire out better positioned to clear the seat tube.

However, every once in a while the wire will rub, and I deal with that with a small spot of muffler tape on the offending spot.

Thanks for your recommendations guys. Next I'll try scooting the clamp so it clears the lug and bending the FD cable tunnel out and closer to the frame to see if it will clear the seat tube. I'll see if the LBS has some clear cable lining tube to protect the paint in case of rubbing.

It seems as though I would have to move the clamp about a centimeter up the tube to clear the lug points. But if I did this, the FD guide would have to be dramatically bent to make it around the seat tube. Is this why you say it's the wrong guide?

It's from 1966 but the FD/RD are early 70s if I recall.

OK, that's why then. Early Campy record front derailleurs used a cable stop. I believe they were like this until 1967, though that may be off slightly.

In 1966 they would have used a derailleur like this:


And a cable stop like this, with a piece of housing going to the front derailleur:



If you want to be super accurate, that's the way to do it. Might cost you a bit though. You could also try a Huret guide, as IIR they don't clamp as close to the BB shell, and it wouldn't look out of place at all. There are other older derailleurs from the 60s and 70s that also had housing going to a stop rather than a free cable in space.

Normally I would agree with the cheap and cheerful solution of bending the guide, but I don't think you have enough room in this case.

I'd like to go the functional, inexpensive route. A quick google of Huret guides brought up a bunch that looked just like the mid-60s Campy guide you just posted above but those won't be compatible with my FD. Did Huret or Simplex make a clamp with an extra long FD cable guide instead of a cable stop that would work? Thanks!

I just strip some out of shift housing. Always some short pieces around. Use a knife to cut the outer sheath and it just falls apart and you can pull the inner out.
I keep meaning to buy some off Ebay but never get around to it. I asked at a bunch of LBS and they had no idea.

Keep in mind that you have another option.

You can use a RD only guide and route the FD wire under the BB, as it is on modern bikes. If you wish you can glue on a guide, or as we did BITD, just run the wire and let it find it's own path, then apply a strip of muffler tape where it rubs. On one of my old road bikes, I just laid the wire on the paint, and it took 5 years to wear through a few coats..

The only problem with DIY under the BB routing is that the wire won't be parallel with the rear one at the downtube.

However, I'm sure you'll find that you can make the current 626/a clamp work for you if you're a bit patient. The key is to clamp it as far down the tube as possible short of touching the lug, and not obsess over a bit of incidental rubbing (if you have any).

I was thinking of the Huret 2236. They are usually available on ebay. To be honest, I can't tell you for certain that it will clear your lug points without trying it, but I think there's a pretty good chance.

It's kind of wedged in by the V of the seat tube and downtube, so it's not going to slip.



OR, you could bend the 626 guide as much as possible, and run housing liner over the cable through the guide and behind the seat tube. A little cheezy and the cable will probably still touch, but it will protect the frame from rubbing.

I had the problem of cable rubbing the frame with a 1968 Lygie. I simply took some MTB cable covers which are used to keep dirt off the cables and installed it as shown. It not only protects the frame from rubbing but also allow smoother operation of the shifter due to reduced friction. Its easy, cheap and works well!