The problems I have are with break pads wearing much more quickly, and the rest is probably more to do with road grime and salt. Salt water gets in the rear derailleur housing and causes the cable and housing to rust, preventing good shifts. Also hard to keep chains clean. It probably becomes more crucial to keep things lubed well (silicond spray is good, just have to use it more frequently). When the temp drops that low, my legs don't work as well either. Maybe it's just me, but it takes more effort than in the summer. I'm thinking about a mountain bike for wet and snow, the kind with the cable routed down the back instead of along the bottom.