you think I can ignore the studs when factoring a wheel size? I know the best method is to measure a roll-out but I'm in bed and wanna set the computer close enough. meaning ...

- current wheel/tire = 700c x 35 w/studs (at MAX pressure)
- wheel factor setting for 700c x 32 of 2155

- think this is close enough for a ballpark until I do a roll-out?
- also how would using a factor that is smaller than the exactly correct one affect my speed and distance readings?

When I calibrated my computer the first time, I just tossed my hiking GPS onto the bike and ride to work. Then I see how much they disagreed by, then added that. For instance, if the GPS said 10.5 miles, and the bike said 10.1 miles, and the computer was set to 2150mm, I'd change the setting to 2150 * (10.5/10.1) = 2235

Since my route is entirely consistent, I know that when I get to work every day I should have really close to 10.47 miles on the trip odometer. When I put on new tires, I just check that. So far I haven't noticed any significant difference between different 700c tires, including both Nokian and Schwalbe studs.