The Borealis Yampa XX1 ($5549) is the new standard bearer for fat bikes. It features a carbon fiber frame that is extremely light. Weighing just 1270 grams (2.8 pounds) and extremely durable this frame will be able to easily handle anything you can dish out. Additional features include 190mm centered rear spacing and clearance for the largest fat tire and rim setup available, a 2×10 drivetrain, and a seat stay designed to flex just enough to provide an extremely comfortable ride. If you like to build your own setups, you can buy the Borealis Yampa XX1 frame for $2249 or get a completely built bike for $5549.