700c 35. The conditions of snow that I have trouble with is fresh, unplowed but very wet snow. It's miserable stuff and we invariably have several days of it per year. Also I have 4 miles of gravel road on my route that sometimes doesn't get plowed for as long as a day after the snow stops. And they can't use salt on gravel roads, so once it's plowed, it's a solid layer of ice all winter. That's where they're really nice.