I am a clyde and I just converted a bike boom 10 speed (29 lbs. with its original freewheel and derailleurs) to SS. I live in a hilly area and I'm running about 73 gear inches (46t chainring, 17t freewheel, 27 1 1/4" tires) and it works fine.

However, this bike has a steep seat tube which lets me stomp hard. I think I would probably want to go with lower gearing if I was riding a more relaxed geometry.