I find my self much slower in the cold especially in the mornings, even when there is no snow. But i hear ya yesterday i was running late to an appt. after work so i rode hard the whole trip there (5mi) not only did it take 30min but i was just about dead when i arrived, and it was pretty warm by your standards (around 30f) I have also found that the more the temp drops the slower you ride i wonder if theres a point where they jsut even out?