The Nokians work. On ice. But on gravel, they're only marginally better than slicks. Not enough of a difference to make them worth it unless I needed them to combat the ice.

Because that's another problem with the bike paths. They aren't cleared of snow and ice like regular streets. Oh, they get their little machines out and scrape the worst snow off, but they leave a layer that quickly turns into ice, and since no cars drive there, the ice stays until it thaws. And that's not the worst!

The worst part is the extremely poor surface of the bike paths. They're so bumpy and full of depressions that trap water, that huge sections are completely covered with inch-thick layers of pure ice. Again, this doesn't happen on the real streets, because of the cars. They salt the streets, which removes the snow and ice, leaving a much safer road surface.