C-40 said:
Of course you can get a compact that's not wide-spaced, like a 50/36 or 48/34 but why bother unless Campy's 13-29 isn't low enough? There is no advantage.
Isn't it little simplistic to say that there's no advantage? A compact with a conventionally sized rear will weigh a bit less (on both ends) than a conventional crank and pie-plate rear. Takes a link or two less chain, for the real weight weenies. It's a matter of opinion but for me, a conventional rear cluster provides better gear spacing than a wide-range rear can yield, and wide-ratio rears aren't exactly the smoothest shifters.
The compact is arguably more versatile, as well. Put on an 11-tooth rear, and you're higher than a 12-tooth standard setup. Put on a 29-tooth rear, and you're down with the low gearing of a triple with a standard cluster. You'd have to play with the chain (and maybe use a longer cage) to use all of these ranges, but it's a possibility. Most folks would probably choose one end or the other, which would minimize conversion issues.
The extra rear shift needed when making a front can be an issue. On the other hand, the extra range (per chainring) that extra shift affords means that front shifts have to happen proportionally less often, so it's something of a wash. There is a certain speed (for me, it's around 16mph) where I can't seem to settle on a ring. If that's a frequent spot in the ride profile, a compact can be a hassle. But if the course is flattish enough (or hillish enough), it's my opinion that the compact has some advantages. It's not right for everyone's style, but it's good by me.
Some folks have had setup and shifting problems with compact fronts, but that's not been my experience. Because of the jump (and the extra rear shift) it can take a front upshift a fraction longer to wrap the ring. A racer desiring only one setup may not like a compact. A recreational rider looking for versatility or a racer looking for a climber might find them just the ticket.
OP: If you do decide that a compact is in your future, I can't really suggest a specific cluster, but think you'd need a pretty good reason to stray from standard (12-25 or 12-27) as a starting point.
