I have a 09 Felt Z35 with 105 group. Compact 50/34, 11/25 cassette. I have had continual probs with the RD when climbing in the small chainring--skipping around on the cassette intermittently. I have 2500 miles on the bike, mostly commuting flat roads.
It has been back to the LBS 4 times, and is fine until I get up out of the saddle or power hard in the small ring during weekend climbing. The shop is very good (Wheelworks in Davis CA) and I don't doubt they know what they're doing, but is something else other than a finicky RD going on? Stretched chain?
Just frustrated, and looking for some advice before I go in yet again and feel like a petty anal complainer. I can't stand the skipping.