Maybe I'm just immune to the cold from living in the PNW for my whole life, but I get by with layering under a set of warmups I picked up from Wal-Mart for $20 or so. I wear wool socks inside my shoes, and if it gets really cold I can wear long johns. Right now I'm riding in shorts & long-sleeved shirt under my warmups in the morning (35-45F) and just shorts and long-sleeve shirt in the afternoon (55-75F). Then again, here in the PNW everywhere you need to go is a 1000' climb from where you're at, or so it seems!