Originally Posted by slisk
I'm thinking about a bike build in the near future and have heard a bit about front derailleur issues so here is the deal. 2006 Look 585 w/dura ace (rear wheel is Shimano) so no Campy on this one. The plan is to use FSA Carbon Compact Megaexo & BB and run a 48/34 ring combo instead of the 50. I'm trying to gain low gears and doubt very seriously I will ever run a 48/12 at more than 90 rpm for long. Will using the 48 solve any potential shifting issues with a Dura ace 10 front derailleur. I'd rather use that derailleur instead of an FSA or other.
Slisk
I doubt that using a 48 large ring would make a lick of difference in shifting performance as compared to a 50. But if that's what you want to do, there's no reason it won't work.
BTW, compacts do not require a special FD, if that is your concern. They do perhaps require that you pay a bit more attention to installing and adjusting them properly, since you're kind of pushing the stated limits a little bit. But plenty of people are running 50/34 with standard FDs; they work fine.