Originally Posted by
Reynolds
I like to cover the cable with a small length of thin inner housing lininig under the BB.
+1
This is what I do with both my bikes that route under the bb on steel guides. I go into this habit after having my rear shifter seemingly malfunction far from home. It locked up, and refused to pull cable.
Turns out, the cable guide on the bb shell had gotten gooked up with debris, and the cable was stuck. A little liner that extends an inch or two on either side fixed that issue, and it has never happened again.
Just go to the LBS and ask for some. It is dirt cheap.