I can't really understand the logistics of having two bikes or two sets of wheels for different riding conditions. What if the weather during the evening commute is very different from the morning commute? Or what if the conditions change in the middle of your 19 mile ride? Are you going home to change your bike and then continue? Are you going to stop and change your tires everytime something changes?

Winter tires are much slower than summer tires. My objective is to get to my destination safely, not necessarily quickly. That's why after the first major snowfall of the season there are so many auto collisions all over the city. Those motorists are still trying to get to work quickly - until the bad drivers take themselves (and others) out.

I ride with studded tires on the winter- street and trail.