I've got around 120 miles on my new bike, Jamis Nova, with a 50x34 up front (FSA Gossamer Compact), with 105 brifters, rear derailleur, front derailleur, and 12x25 10 sp. cassette.
My issue is this: I know that when I am in the big chain ring up front, I cannot (or should not) use the big chain ring on the back. I am unable, however, to use even the 3rd or 4th largest chain rings on the back. When I try to shift to these chainrings, the chain is constantly slipping, so much so that I have a hard time pedaling up any sort of a decent hill at all. Yes, I know, HTFU, sure. Doesn't help me now.
I took the bike back to the shop and had them realign the RD, but I have been having the same issues, and its really frustrating. Is this just what I should expect using a compact double? From the big chain ring, which rings should I be able to use in the back? How about from the small chainring?
Thank you in advance.