Whatever I do, however hard I try, the rear shifting on my road bike just doesn’t work properly. I’ve never had a problem setting up gears before, usually it’s just a case of setting the limit screws, clamp the cable and tweak with the barrel adjusters. The 08-09 era Ultegra shifter and 2013 105 derailleur (both 10sp) just don’t want to play at all. The first click barely moves the derailleur, the second isn’t much better. The only way to get it shifting is to put so much tension on the cable it won’t shift back down again.
The cables are new and there are no snags, the hanger is also pretty new and hasn’t been crashed on. The only things I can think of are that the shifter and mech aren’t compatible or one (or both) are knackered.
Any thoughts?