Originally Posted by
PatrickGSR94
Yeah I see that now. For fat tire bikes like those from Surly, you also have to use an offset front fork which spaces the tire about an inch off-center. The rear frame triangle is made this way to prevent drivetrain interference, but if you want to be able to swap wheels the front fork also has to be off-center, or something like that.
Only the Pugsley has swappable wheels and the offset front fork, other Surly models have symmetrical forks and the front wheel has no cassette driver.