Front mech cable issue

mattbrown

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I've just cabled up a Klein Quantum Race, and noticed that the front mech cable rubs on the front mech, when its in the smallest front chain ring. It shifts fine, but that contact cant be right can it?

The cable also slightly rubs on the frame where it exits from the bb cable guide as well. As far as I know, all of the parts are original and I cant see that it would have rubbed before (I picked this up as a frame so didn't see it built up before I built it).

Link to the photo below.

http://photos.app.goo.gl/HuF1extnF9LuqRi39
 
I've seen the cable rub the mech like that before, on bikes with fat seat tubes and/or short bottom bracket axles. Not a problem (that grey plastic sleeve might even be there for that reason, along with covering the spring).

Cable rubbing the frame doesn't seem right - are you running smaller chainrings, hence a lower front mech and more acute cable angle?
 
The cable position on the frame looks a little odd - does it have a cable guide fitted under the bottom bracket? The rest looks OK, although I wonder if the chainline is right - the front mech is very close to the seat tube. It can look like this with fat seat tubes though.
 
Re:

I've had the same issue with the cable touching the front mech spring but only with a Shimano Ultegra 6500 front mech. It only just touched the spring when fitted to a skinny tubed steel frame, but I've never had the same problem with any Campagnolo front mech I've fitted as there has always been clearance between the cable and spring, so maybe it's just a Shimano thing?

As for the cable rubbing on the bottom bracket shell, it might be down to the type of cable guide you have. Some tend to have a slightly longer length for the front mech cable route which guides it round the bottom bracket shell. The Amazon link shows a Campagnolo guide with a longer tail that extends round further than some versions.
https://www.amazon.co.uk/Campagnolo-Ant ... 9273&psc=1
 
Re:

Yes I think the cable guide doesn't quite have a long enough guide for the front mech cable. it is one of those that has two positions, but neither is perfect. I might invest in a new guide for peace of mind.

The bottom bracket is the correct length for the chainset according to Sheldon Brown and other sites.
 
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