Originally Posted by PaulRivers

I ride the Marathon Winters myself and they aren't great in anything more than packed snow - they start to slide around. They've worked great for me however, as we have plowed bike paths where I live (minnesota) and I'm not a "required" bike commuter. However, if you already have a set of "real" snow tires, I would be tempted to (as you mentioned) to ride the Schwalbes the 90% of the time that you don't need more than them, and use the Nokian Extremes for everything else. The Schwalbes are great on pure ice, and when pumped up to full pressure roll *nearly* as well on pavement as my non-studded tires do.

While I have not tried it, it's also my understanding that the front tire is the most important for traction, you might only "need" to switch the front tire when conditions get bad (in other words, run a marathon winter on your back tire all the time and switch the front one depending on conditions). I haven't personally tried it yet myself, though.