Which Nokians are you talking about? My 700x35 W106 tires are a huge PITA to get on the rims (I've put them on two different wheelsets, each equally as difficult). Once they're on, they stay on until the threat of ice passes sometime in the spring. The sidewalls are so rigid, I swear I was riding on a rear flat for two blocks before I realized something was wrong (I was traversing massive icy ruts, so the normal warning signs of a flat were not noticeable). Taking the tire off, repairing the tube, and replacing the tire was a definite drag, but I was close enough to home to avoid doing it out in the cold.