Well, this morning it was 46. A gun to my head and i wouldn't get on the bike at 46! Of course i also won't put on 96 layers of clothing and electric gloves and all that to ride either. I have no doubt it would be doable, but to me riding is only fun when it's not a major chore or painful, and in that temp it's gonna be one or both. The coldest i ever ride is mid 50's, and thats only to commute if the ride home will be warm. Even then i'm numb by the time i get to work.