Originally Posted by
Yellowbeard
This is my second Ottawa winter on a bike, and I find it's surprising how LITTLE difference there is between something like a 1.75" with studs and a 27" x 1 1/4 in the snow. Last year I was riding 700 x 25s late in the season, but there were no more snowstorms to get a real test. Nonetheless, they cut through the road snot pretty well.
Right now I'm using both a fixed gear with 26" Marathon Winters and a 5 speed with 27" x 32 (smooth, no tread at all) and I'm actually choosing the 32c Ultrasports over the studs. The Marathon Winters are great when it's -25 Celsius and everything is hard and frozen, but when the snow is thick and slippery I'm doing some sliding no matter what. You've just gotta know how to handle it.
Supposedly(assuming your 1.75 was a 26"), the functional differences in width are narrowed by the longer contact patch of the larger diameter wheel. As a result you end up having a tire control-patch that is closer to the same area provided by the slightly wider 26" wheel.
OP, I think the largest difference in the road snot comes from running taller knobbies. Same reason you wouldn't try to walk in snow wearing dress shoes even if they had little studs on them.