I'm working on a 3 speed roadbike conversion now. I'm using one of the new SA hubs. It has an aluminum shell with thicker flanges so you don't snap spokes. Aebike is selling them for $53 with shifter and cable. I'm going to try a 21t cog and a 52t ring and see how it works for me. That will give me 49.7, 66.3 and 88.3 gear inches with a 700X28.
