Quote Originally Posted by lph View Post
PS. Barrel adjusters work by lengthening the housing, i.e. giving the cable a longer way to travel, ie. tightening the cable, when you screw them out. So start by screwing the barrel adjusters all the way in, clockwise* (you can see them growing longer or shorter after a few turns, you want them as short as possible) before you start tightening the cable by hand. If you've screwed them a bit too far out in advance they de-attach and can be a little fiddly to re-attach. Check by wiggling it sideways.

(*I get the feeling I may be confusing barrel adjusters on brake and gear wires here. Please correct me if I'm remembering wrong, fellow mechanics )
Barrel adjusters work the same on brakes and gears. Your explanation is totally correct, LPH.

If the cable is slack between the bb and the shifter and tight between the bb and derailleur, then it is somehow binding in the BB. Check if the cable slides freely around the BB. If not, you need to fix or replace the cable guide. To check for a fraying cable in the shifter, shift to the inner front ring, pull the brake lever open, and look inside it with a flashlight. If you see any individual strands or sharp wire sticking out, then the cable needs to be replaced. Also look for strands of sharp wire sticking out of either end of the cable housing.