Originally Posted by
tarsi
I guess the real question is, how close can I get to a compact (50/34) setup? Will it be possible to match the gearing rations of a compact with an 11-25, 11-28, 11-32?
You seem to be asking different questions.
You can run an 8 speed crank with any kind of chain, including 11 speed, so you can use it with an 11 speed cassette.
A Campy 53/39 crank's smallest possible chainring is 39T because the bolt circle diameter is 135mm.
The maximum cassette range you can combine with that crank is going to be based on the rear derailleur, nothing else.