I recently put the Surly Bud / Lou 4.8 tires on 100mm rims.
This likely requires a 190 rear spacing rather than 170. The Q-factor is insane, but ooooh baby these are huge!
I can't wait to try in the snow. I've only had this on hard-pack and quite honestly it wasn't nearly as slow as I had anticipated.
I did not have to brake at all on Town Run...rammed into each hairpin turn has hard as I could and never lost traction with 5psi (tubes).
The bike is a Mongoose Vinson. Upgraded the brakes to BB7, and put 9 speed drivetrain.
I can't find a good price on a 2x crank....tried an X5 and the Q factor was so narrow the chain was into the tire.
Even with this super wide Square Tapered 3x crank, I had to take the smallest ring off my cassette and place a spacer behind the cassette to avoid chain rub on the tire in the lowest gear since the rim isn't perfectly true.
Things I'd like to update - The aluminum fork is like a noodle and is super flexy.
straight steertube with QR - almost impossible to find replacement forks other than cheap flexy stuff.
Wheelset is kinda cheap.
135 front spacing QR
190 rear QR
Hard to find replacements on these.
Here is a pic :-D