front derailleur cable rubs against bulky weld behind bottom

[bmatson]

Aluminium frame, TIG welds (very bulky). The plastic cable guide is present but does not extend far enough to stop the cable from rubbing against the weld at the back of the shell. There's no slot in the metal or other means of locating and stabilizing the cable - it slips sideways when shifting.

I'm mostly concerned about the cable sawing into the metal, as well as the shifting considerations.

I'm considering 1) a short length of cable housing (how long would this last ?)
2) durable plastic film, e.g. the kind used to protect chainstays 3) glue (?) another nylon cable guide to the back of the bb shell 4) glue some other material to protect the shell.
5) suggestions ?

I noticed this after I had the LBS eliminate the crossover under the teardrop downtube. The cables were crossed where the third water bottle would mount (that can't be right?) and rubbed the downtube (that can't be right ?). I looked at other Mikado touring bikes, non of them had crossed cables.

I doubt it's related - I don't see how crossing the cables would change how the cable bends around the back of the bb shell.

Thanks for your help.

[quadbox]

Perhaps the BB guide is mounted backwards?

-Or-

If not, perhaps the screw for the guide is too far forward. If so, unscrew, rotate the guide in the x-y plane towards the rear until the right clearance for the cables is obtained. Drill a pilot hole, tap for the screw, then fasten.

[yoda]

The crossover makes for a nicer run for the shifter housing. Less rubbing on the HT. Some bikes it works, some it doesn't, depends on where the bosses are mounted. My C-dale mtn bike was always run this way with no problems, but my road bikes are not.