Originally Posted by SteveE
You may need to shift to a smaller cog concurrent with shifting to the smaller chain ring. This is to avoid too big a jump when going from the 50-tooth to the 34-tooth chainring.
That is a factor? The mechanic didn't refer to that being a possible problem - just the 50/34 factor itself because it is about at the limit of what the derailer can handle. Even then, he said his comments were based on just some comments from a few users who may not be representative.
Based on the Felt bikes in the shop this year, it looks like 34/50 is becoming their standard. It does seem strange that they would do that on so many bikes if there were problems, but still, it may be. That's why I hope to find a number of posters with experience with them.