Originally Posted by
jsohn
but as to the original question...I think the biggest factor for me is not the snow so much as it is the different equipment. Going from a road bike on 25mm tires to a winter bike with heavier frame, heavier wheels, and most importantly studded tires makes the biggest difference snow or no snow. I feel like I am climbing up a decent incline at all times on my winter bike. If I were to put a number on it, I would say 25% harder. On the other hand, I haven't fallen since I got my studded tires. I'll take the 12mph commute over a cracked skull any day.
Same here, except it's the same bike year-round, just different tires in the winter. My 28mm three-seasons tires are 250 grams, compared to my studded tires at 865 grams. It's a noticeable difference, even before you factor in rolling resistance and snow. It's part of the reason I also switch my my three-seasons 12-23 cassette to my winter 12-27.
I can't put a number on how much harder it is because a lot of it for me is psychological. What I can say is that in 2011 my average speed of all rides in January was 3 MPH slower than the average speed of all rides in July, dropping from 16.75 to 13.75. Interestingly, my top speed for both months was the same, 28 and change.
Much as I try to put a happy face on it (You'll fly in April!) by the end of February, I dread even getting on the bike and begin to wonder if I should buy a car. Fortunately, March comes along and wipes that silliness out of my head.