Braze-on mech cable rubbing on frame.

I have a braze on front mech on my Orange road bike, circa 1994. I've just noticed that the front mech cable is touching slightly on the frame where it comes up between the chainstays.
When I look at the guide under the BB the cable does seem to be pulling slightly to the side of the direction the guide aims at. The mech I'm using is a fairly modernish ultegra one, but looking at pics of older, period mechs I don't see any apparent difference in how far over the cable clamp is.

The mech is centred in the curve of the braze-on and shifting is fine but I don't want the cable sawing at my frame each time I shift so I was thinking about feeding the cable through a bit of rubber pipe to protect the frame.

Has anyone else experienced this? If so any tips?

if you're worried about rubbing, get a section of derailleur housing and with a razor blade whittle away the plastic outer till you can cut out a short section of the inner liner. I do that all the time.

Sounds odd - the reach/overhang of the cable pinch bolt doesn't differ much between front derailleurs for double/chset, and presumably your Orange had something like 105 derailleurs back in '94 which is the same as Ultegra ?

Can the cable guide be removed from under the BB ? Sometimes they're bolted on. If so, you could remove it and try drilling a new hole off to one side, and refit it. This could be a way of centering the front gear cable a bit (I'm assuming it's rubbing against the drive-side chainstay ?) as long as it doesn't then put the rear gear cable too close to the tyre.

I wouldn't worry about the cable rubbing on the underside of the bracket shell, all it will do is possibly leave a line in the paint. I (as did many people BITD) used to run the front changer cable in this way as a matter of course before guides were invented. It is actually a very smooth way of doing it as there is nothing to hinder the cable run.

Cheers guys. I don't fancy drilling holes in my frame but it's good point about the guide - I''ve only been assuming it's the original one. It is the drive side chainstay it's rubbing on - right where it joins the BB shell.

Not sure what gear the bike originally had - I picked it up frame only. I think it was 105 because the downtube shifter mounts have the curved bit built in, meaning the shifters have a flat surface to mount to (I understand they usually have a curved spacer - I had to file this down on mine to get them on). I was told this was a one off feature of 105 shifters at this time.

For the moment I've put a bit of plastic tubing over the cable between the guide and derailleur. There's a guy who runs a maintenance shop in town who keeps loads of old bits and pieces - I'll pop in and see if he another guide that looks a better fit.

Daft question, but have you clamped the cable on the wrong side of the bolt?

Nope -I checked that as it was my first thought too! It's going in from the inside (furthest point towards the frame) and there's a little guide groove in the clamp to lay the cable in.