ive always been very pickey about having clean cable routing on all my bikes. my current one has been troublesome however. i am starting to think its a combination of the parts used and i am going to have to live with it. if i leave enough cable to not restrict the steering the cables rub the stem of all things. the rubbing is not a huge deal but it does give the bike "self correcting" steering

setup:
130mm stem (very large diameter)
one 5mm spacer under the stem.
wing shape bars with no tape on the top
campagnolo levers (shift cables crossed)
tall head tube

the cable was originally cut with a 10mm spacer under the stem so that explains some of the rubbing but not all of it. right now the rear brake cable is VERY tight when the bars are turned, but when the bars are straight, it rubs the bottom of the stem.

it would make sense that the long stem requires extra cable that has "no where to go" when the bars are turned. my "vintage" ride is set up with relatively the same fit, but i think the lower head tube and much thinner stem (half as thick) stem let me get by with it.

any advice?

only pic i have of the afflicted bike. you can kinda see the red housing hitting the clamp:


"vintage" ride with almost identical reach, saddle drop, and cable routing method (clean routing/no rubbing)

I'm not sure I understand the problem--if the cable's too tight, you need it to be longer. If that makes it rub on something, you might be able to route it a slightly different way, bring it out from under the tape a wrap earlier or later, or run it along a different part of the bar's circumference, in front rather than underneath or vice versa. I always have to mess with routing when I change things around, but there always seems to be a solution I can live with.

the rear brake cable is routed on the bottom of the bar (where the only groove is), its almost too short when the bar is turned, but when its straight it rubs the stem. i could try and route it outside the groove, but that would require wrapping the bars all the way up. i prefer the tops bare with winged bars.

Hard to tell from the picture but it looks like you have the rear brake cable coming out of the bar tape too high. Mine is taped so it's on the bottom of the bar when it comes out, but yours looks like it's on the back-middle when it comes out. Maybe switching that a bit could help give a bit better angle to curve.

it was out of the "bottom middle" but it migrates to the "bottom back" by itself over time. the bar tape is very tight, but the groove is so wide it doesnt hold the cable real well.

The front brake cable should be closest to the head tube. The rear brake cable should be just in front of the front brake cable and long enough that it does not rub the head tube. The shift cables should be in front of the brake cables. You need to use fiberglass reinforced strapping tape to hold the cable housings in place. Your rear brake cable should exit the tape at the center, near the stem.

My bars have no grooves at all, but I have no trouble routing both cable housings under the bar and keeping them in place.

The shift cable housing rubbing on the head tube is normal unless the head tube has cable guides, or you deliberately route the right cable over to the left side cable stop and the left cable over to the right cable stop, then cross the cables under the down tube. I used to do that, but with some frames the cables hit the down tube and rattle or wear the paint off unless you make a small bumper to keep the cable off the down tube. I've done that with small pieces of stainless steel sheetmetal, attached with silicone adhesive/caulk.

Some kind of space filler is in order, seems like. A strip of old decommissioned tape, run inline with the cable housing, over the housing underneath the tape, or "next to" the cable in the groove, might keep the housing from migrating. And indeed, it seems like if the housing exits from the bar right at the bottom rather than toward the rear, the radius curve going around the stem should be more "graceful", hopefully sans the rub.

I have low bars and a longish stem (110, not as long as yours) but I use Nokons which can easily make tight bends, and do the double cross for the shift cables (cross in front of head tube and again under down tube) so that the arc is more fluid. I have a picture of it somewhere...

i am using the double cross as wall (always have) its more the rear brake cable thats causing the issues...

Go search bike pics at cyclingnews.com for setup ideas. See, for instance, Voeckler's Campy equipped Colnago. He's using wing top bars.

Make the cable longer and use the fiberglass strapping tape. You'll have no more problems.

thanks guys. i think the strapping tape and "filler" is the winning idea. somewhere i have some rubber thats made to plug the "extra" groove in bars when you use shat shimano stuff