Although we don't have definitive figures on hand, we can say without a doubt that the XX1 Eagle DUB FAT Crankset is the lightest fat bike crankset ever developed by SRAM. We can make this bold statement, as this crankset's using the newly introduced 28. 99-millimeter spindle diameter that lessens its overall weight (especially when paired with SRAM's DUB bottom bracket) while maintaining bearing durability and sealing out moisture ingress in snowy environments. It's designed exclusively for running SRAM's Eagle 12-speed drivetrain, which provides a massive 500 percent gear range across its 10 to 50-tooth cassette, so you can enjoy the simplified shifting of a 1x set-up--all without reducing your gear range needed for steep climbs and swift descents. SRAM calls this new spindle diameter DUB, which stands for Durable Unified Bottom Bracket, seeing it's compatible with virtually any major bottom bracket standard on the market, regardless if your frame boasts a threaded, Press Fit, BB30, or PF30 bottom bracket. Upon introducing this 28. 99-millimeter spindle diameter, SRAM aimed to improve bearing life and seal out moisture, then designed the spindle to meet these needs, meaning it's ready for fat biking in the deepest snow and grittiest springtime melt-off alike. Ultimately, SRAM claims this new DUB crankset is every bit as stiff and light as those with 30-millimeter spindles, but one that provides the increased bearing life of 24-millimeter spindles. This particular XX1 Eagle DUB Fat Crankset is available in Fat 4 and Fat 5 versions. The Fat 4 accommodates 66. 5-millimeter chainlines for riding a fat bike with 170-millimeter rear hub spacing and the Fat 5 accommodates 76. 5-millimeter chainlines on those fat bikes with massive 190-millimeter rear hub spacing. Both feature Carbon Tuned arms for superior stiffness and lightweight pedaling efficiency, as well as SRAM's X-Sync 2 chainring for optimal chain retention and muck-shedding abilities in the snow and dirt.