I'm running two Schwinns, a Paramount and a Super Sport, with Campy NR FDs and tripilizers.

The Paramount is currently set up at 50-42-31 and runs a 16-20-25-30-34-38 freewheel and a Sachs-Huret RD.



The Super Sport runs 50-42-30 TA rings on the NR crank with the NR FD and a 13-30 freewheel. Currently it runs a Nuovo Gran Sport with a [MENTION=130750]HenryIII[/MENTION] made long cage.





I doubt that you will have any trouble running a 28T granny. If you do try dropping down to a 50T big ring.