I'm planning on mounting my Nokians this weekend. I also just purchased Freddy Fenders. How much clearance is going to be required? Or are fenders a bad idea for riding in the snow? I commute and want the fenders for rainy days like today. But I won't get any warning when the rain will turn to snow, so taking the fenders off just in time doesn't seem practical. Also It would be nice to have fenders for the road slop associated with melting snow.