So I’m embarrassingly unfamiliar with freewheels and associated gearing. I have a frame I’m building up and it’s looking like I’m going to use (mostly) parts I have on hand. Currently that’s Campy NR friction DT shifters and an English Campy freewheel set of wheels. I’m using an Athena crankset that can either be 52/42 or 52/39. I have a 6s 14-28 Suntour Perfect freewheel on a set of wheels I can steal from.
Which Campy rear derailleur should I be looking for that can handle this combo?