I've been told that riding a fixie will prevent you from slipping, but I think i'll take that notion with a grain of salt. I think that if your back wheel slips there is nothing you can do on a fixed that you can't do on any other bike to prevent yourself from falling. I think the best defense against ice in the winter is fatter tires. I rode 23c's through this past winter, and I was wishing the whole time I had some wider tires.