Wicking base layer (long sleeve shirt, long underwear). T-shirt and shorts. Nylon sweatpants with fleece liner. Sweatshirt. Canari poly outer shell (only bike-specific piece of clothing I own). If it's cold (<15F), double socks. Balaclava with a skull cap hat. For hands, a thin pair of wool gloves over a pair of leather work gloves down to 20F. Under that, the thin wool gloves with a pair of insulated leather work gloves over them. I've done this down to 5F, with a wind chill of -10F, and not the least bit cold. Don't know how low it would take me but for St Louis, that will get me through the winter no problem.