I have a couple of nice folding bikes, a great city bike and a Marin hybrid that I converted. It now has a Shimano Nexus 8 ratio hub transmission with two chain wheels; 16 'speeds'. It is a tremendous tour machine. All my bikes now have this type of rear hub, either bought that way or I've changed them. They are great for 'bents, as they simplify the complicated chain system. I was a nice front drive, rear steering 'bent on Youtube a few years ago, but haven't seen anything like it since. All the chain on 'bents is a problem.