Originally Posted by
RoadTire
I'll speculate this is one of your first bikes of that caliber, so take what I'm saying in that context. Minor shifting issues are normal with all bikes as cables and components settle in, then as they wear down. Minor, tweaking, following a procedure, not random changes are par for the course. You should be able to have the LBS tweak the cable tension, or better yet learn to do it yourself.
First, is it the Front or Rear derailleur that is giving you problems? Next, shifting up is going to a harder faster gear. So that would be larger chainring on the FD, smaller cogs on the RD. Which is it?
Loose cables on the FD will interfere with shifting up into the large chainring.
Overly tight cables on the RD may interfere with shifting into the small cogs.
My previous bike was a Fuji Absolute 3.0 with Aliveo shifters. They worked perfectly for the five years I had the bike. The problem is with the rear dérailleur, and break in could be part of the issue, but I am going to pull the cable and apply a light lubricant. I'm also going to inspect for clean housing cuts, snags, kinks, etc. as Andy recommended.
The problem does seem to be worse on the faster gears, so cable tension could be an issue. Any advice on how to adjust the tension would be appreciated. And I really appreciate the feedback. Thanks!