Sorry, forgot to say, my commute is 5 miles each way and I tend to ride as aggressively as I can without getting sweaty. I usually take it pretty easy on the uphill part of the bridge though. It typically takes me about 30 minutes if I hit an average amount of lights, but my record is 21 minutes on the way home basically sprinting the whole way. I have tried using a very thin North Face rain shell with pit zips on days where it is in the low 50s, but again my forearms are and back get no air and I get very sweaty on the bridge climb.