Looking to lighten up your FatBike? Well swapping out your current frame for a titanium one won't hurt.
We brought this titanium one in for a customer but we could just as easily bring one in for you. Our quick weigh in indicates it saves over a pound on the equivalent steel or aluminum FatBike frame AND it has a slider rear dropout so you can easily set the bike up geared or single speed.
Note that this bike has 170mm rear spacing so to swap over the parts from your Surly you'll need to buy a new rear hub and rebuild the wheel (and a Large Marge offset only rim obviously won't work).