I actually have 4 bikes set up for winter but that's because Denver's weather is, well, a bit goofy. Denver's snowstorms tend to hit hard and fast, then melt just as fast. While we have had a few winters where the snow hits the ground and lingers for more than a few days out of the last 30+ that I've commuted, that is rare. I've only really had it happen 3 or 4 times. Most of the time, the roads are mostly dry even a couple of days after a snowstorm and they can even be mostly dry a few hours after a snowstorm. So I have a road bike with wider tires that I use most of the time. I have a cruiser style bike (actually a mountain bike with curvy tubes) that has hard pack knobbies that I use for light snow and I have a regular mountain bike with unstudded knobbies or rides in powder snow rides. Finally, I have a softtail (not a full dually mountain bike) with studded knobbies that I use for icy rides and/or when the powder is significantly packed.

When spring comes around...about the end of May...I told you that Denver's weather is goofy...the studded knobbies come off and I switch back to regular knobbies for the softtail. I swap to slicks for the cruiser. The other two bikes just lose their fenders.