I try not to. In cold weather, washing your bike can give you much larger problems than a dirty bike! At least if you normally store your bike outdoors or in a unheated space. The point is that it HAS to dry properly afterwards, or you risk water freezing in places where it can be dangerous, like inside brake cables. If I feel I have to wash my bike, for example if I'm been riding a lot on salted roads, I wash it quickly with quite hot water and take my bike indoors afterwards to dry overnight, which means clogging up our entarnceway... ![Roll Eyes (Sarcastic)](images/smilies/rolleyes.gif)
I usually get by with "dry-cleaning" my chain - rag, thin oil, rag again, more oil, let sit, wipe off lightly before riding. I like to use rags a lot to clean the gunk off my bike otherwise too, no water.
Winter riding is much less about badassery and much more about bundle-uppery. - malkin
1995 Kona Cinder Cone commuterFrankenbike/Selle Italia SLR Lady Gel Flow
2008 white Nakamura Summit Custom mtb/Terry Falcon X
2000 Schwinn Fastback Comp road bike/Specialized Jett