Problems indexing gears I have a Boardman CX Team 2014 with some indexing issues. It's running a Shimano Sora ST-3500 9 speed shifter with a Shimano Sora rear mech.

The gears had not been running all that smoothly and, as I was changing the bars, I figured I'd also re-cable everthing with new housing. The gears are now shifting a lot better, but there is a small problem with the indexing on the rear derailleur.

When fine turing with the barrel adjuster I can get wonderfully smooth shifting on the smallest 4-5 cogs, but after that it gets a little less smooth.

Can anyone give me some pointers on what to check to get it working smoothly?

EDIT:

Photo showing cable connected to rear mech
B-tension issues rarely pop up spontaneously. Once it's set, you usually don't have to ever touch it unless you change to a much larger or smaller cassette. Unless you messed with it already...

I see the scrapes on the derailler and think your DR hanger is probably bent. This can cause irregular shifting issues like you mentioned-- good in the lows but bad in the highs, or vice versa. 

Or, your cassette/ chain might be worn out. Do you usually ride in the big cogs? If so, those will be the first to wear out and they might not shift right, while the unworn smaller cogs still have the sharp ramps to shift well.