Help on Derailleur Cable Routing
 

For a winter project I'm going to build up an early 80s touring frame, standard triple drivetrain. This one has no braze-ons, no bb guides or cable stops on the frame for derailleur cables until you get to the rear drop out - so I'd be running a bare cable from a downtube stop, top of the bb with a seattube clamp to the end of the chainstay I'm figuring. If you have time, could you show or describe how you've rigged the cables for the derailleurs with what clamps?...I scratching my head deciding which clamp style I need to acquire. Also, any real performance difference in the quality of the clamps, (Suntour, Duraace to Campy),or is it just aesthetics...

Much thanks.

The convention is to get the same brand cable guide clamp as the shifter you use. The cable guide at the bb clamps to the downtube, not the seattube. The Suntour guides are nicely finished and seem more robust than the the Campy guides.

Also, there are generic clamp on cable guides for the chainstay.

it all depends where the RD cable stop is located...if there is one.

If there's no RD cablr stop it doesnt matter what type of DT cable guide you use...
If the RD cable stop is above the chain stay centerline a DT cable guide is needed.
If the RD cable stop is below the chain stay centerline then an under the BB guide is needed.

Campy, Suntour, Shimano...they all work.

So that's it, the RD frame stop is directly above the chainstay CL. So, the DT cable guide is located at the bottom of the DT, making a fairly straight run to the chainstay stop. But what about the FD, that cable will run through the same clamp but left side channel and up behind starting from the left side for a pull down FD...correct? So you'd have to be sure the left side guide is long enough to get the cable positioned behind the ST coming of the guide, yeah?

Google images for derailleur cable guide.

When I mentioned chainstay centerline I should have clarified centerline from the side..... You RD stop is above that centerline so yes, you need a DT mounted guide.

Someone can correct me if I wrong but I think all double DT cable guides are designed to properly position the FD cable around the back side of the ST. And they can be bend to better optimize routing.

Some of the Huret and Suntour guides use cable housing for the FD, but yes, they all are set up to get the FD cable around the backside of the ST.

I assume that the ones that take cable housing would need an FD that has a built in cable stop?

I've always used the Campy ones, but yes, you do need to be careful installing/removing them as the metal in the band fatigues over time. If you never remove them, probably not an issue.

Grazie

given you've chosen a dt cable guide for the rd, the specific one (campy, suntour, etc) you choose will be determined by the fd used. campy doesn't use fd housing. suntour does. you can't mix and match.

I don't know how the Campagnolo guides could possibly be more robust or have better chrome plating. Do you have a picture of a Suntour guide?

I have snapped a Campy guide by spreading it too quickly as I opened it up to install it without scratching the frame. That's not to say the same thing wouldn't have happened with a SunTour guide, of course.

Too busy with the holidays, maybe after.

umm ... google?

http://www.porkchopbmx.com/images/De...ableGuide1.jpg

I'm not impressed.

Just wondering.

Somebody posted a picture of a part and I stated my opinion. It's a crude-looking stamping with thin looking chrome that appears to be peeling. Nobody disagreed with me yet. It's okay if they do.

You're just trying to start something with me....again. I'm not interested.

This is just one data point, but when I rebuilt my Raleigh recently, it had a Suntour cable stop at the top of the DT for the barend shifters and a Campy cable guide at the bottom of the DT for the bare cables to make the bend around the BB. When I went to re-install them after removing them to clean up, the Campy band failed and broke in half and the Suntour did not show any fatigue.

Had both been installed/removed the same number of times? Yes, the Campy ones will fail after 6-8 remove/install cycles, particularly if you don't take it easy with them. They still look the best, and I have a couple of spares, so will continue using them. I might start just loosening but not removing for cleaning.

I couldn't say for sure in my case, but neither of them had been removed in 33 years (that is how long I have owned the bike). I could tell the Campy was ready to fail before I put it back on. I bought a used one to replace it on eBay and that one was also showing some fatigue in the same location. I am not sure why, but I took a picture of it after it broke. You can see it failed where the band becomes narrower.

http://bikeforums.net/attachment.php...hmentid=423966

Yep, that looks familiar :)

I had found an ebay seller in TX a couple of years ago that was selling NOS ones for pretty cheap ($20/ea), so I bought a couple of them. Last time I overhauled the Raleigh, the one I was using failed in just such a fashion, so I am down to 1 left.

I've owned this frame since new (1973 frame, bought in 1974). I would guess the one that last broke was maybe the 3rd one I had replaced? I guess there's always braze-ons...

Another option, if you happen to find a guide that's rear-only (I believe these exist), is to run the fd cable under the bottom bracket in a short piece of housing, with no guide. My '73 Gran Sport had a braze-on for the rear and nothing for the front, so that's how I did it for years, until I had it painted and added a fd cable guide braze-on.

You can also use a rear only and install a modern under the BB cable guide for the FD if you want to use one without housing stops. I have a frame around here that has this setup from the factory except the under BB guide is brazed on instead of using a screw.

Glenn