Originally Posted by
fuzz2050
I have a bike with a half step plus granny. Thats 52/48/28. I admit shifting from the middle to the inner is a bit hairy, you don't really have to do it that often. You know when your going to need that bailout gear, so you can anticipate when to shift better
+1. I shift over a 45/42/24 using a FD-5500 double front derailleur with stated capacity of only 15t, but it works fine. The stated capacity of a double front derailleur relates to shifting between outer and middle; since the cage moves down as it moves toward the frame, that stated capacity can be exceeded a bit when a double FD shifts over a triple. With such a big jump you need a chain watcher to keep from dropping the chain when going to the granny. A ramped and pinned middle ring is a big help for the upshift.
A wide range double with a wide cassette is a good practical setup. You spend most of your time in the big ring, only using the granny for extreme climbs. It avoids the problem of a compact double where the flatland riding range straddles between the two gears and you have to shift the front all the time.