I really don't have any problem riding in the 20's F with the gear that I have. That problem that I am facing is ice and frost. I know that a lot of you commute in these temperatures a lot more than I do (I'm in Portland, OR). Do you all have Nokians or is the humidity so low that the roads are dry at those temps?
I have always been cautious, but I had a pretty good crash last week on some black ice. I have not commuted this week because both mornings so far have been in the 20's F and everything is covered in frost, including the road. There has been no precipitation to speak of, but there is often fog that makes everything pretty slick when the temperature drops. I'm also a little jittery from last weeks crash. This weather isn't typically around for a long time here in Portland, so I can't justify studded tires. Do I just hang up the bike in these conditions?
By the way, I start my commute at 5:30 am, and my work schedule is not flexible enough that I could wait until it warmed up to ride in.