I have less than 500mi on a brand-new bike with Ultegra FD, RD, chain, and cassette, and an FSA triple crank. Problem: During climbs, when shifting from the middle ring to the smallest ring, I occasionally encounter a condition where the chain "skates" on top of the smallest ring, not engaging it at all, leaving the crank to basically freewheel while the chain remains stationary. This immediate and complete loss of resistance in the drivetrain is a Bad Thing. It is scary, disorienting, hard on my knees and the disruption to the ride has about gotten me killed a couple of times.
This thread has a picture of my exact problem (I have one as well, taken just today, if it would help)
This thread seems to indicate that the smallest ring might be installed...backwards? The same thing is suggested here as well for a Champy setup. Seems strange to me that a ring would be asymmetrical and installable either way, but I'm awfully new at this.
This thread suggests a worn chain as the culprit, but the whole drivetrain is so new on my bike that this seems unlikely...?
I am going to take the bike back to the LBS that assembled it and ask them what they think (they include a tune-up once the cables stretch a bit), but frankly I'm just as interested if any of you have insights!
Thanks in advance for any ideas...this has got to get fixed before it causes me a serious problem.