I've talked about gear choice extensively with my friends. From what they say and my own experience, having just started riding SS, the best gear in back to start with, IMO, is 20t. Now, this all depends on where you're gonna be riding. From the get go, if you're going to ride rail trails or tow paths, I'd say drop down to an 18t. If you are going to do any technical riding or plan to ride where there are steep climbs, maybe 22t is a good starting point. Trouble is, changing gears involves a little work, so maybe at first it's best to find a middle ground. I started out running 32:18, which is tall for a beginner, but muscled through it. After training all winter on that setup at places like Skyline, Ringwood, MD, and LM, I recently popped on a 20t cog that I will be racing on this season. WOW! What a difference two teeth made! The strength I built from the 18t made the 20t feel like a granny gear and is going to make me much faster climbing. But then again, I spin out at 15mph! Hope this helps! BTW, that Paddy Wagon is effing sweeeet!