It seems paradoxical to pursue low weight gear when you're riding a fat bike, but just because the tires and wheels are big and heavy doesn't mean everything else on the bike needs to weigh more. In fact, those jolly fat tires mean that the other components should try even harder to lose weight. The Next SL Cranks Arms for Fat Bikes, which Race Face claims constitute the lightest production carbon crankset in the industry, do just that. The Next SL Crank Arms omit a spider, so you can customize it to your tastes with a spider for multiple gears or a direct bolt, one by chain ring. This modularity speaks to the ever changing standards of the industry, which routinely make top end equipment obsolete after only a few seasons of use. Race Face makes aluminum spiders for all manner of setups, so the Next SL Crank Arms are currently compatible with anything from a direct mount one by to a triple with the optional aluminum spider. This virtually limitless compatibility also all but guarantees them to be future proof. This is an investment that'll stay with you for years and years of use. The arms themselves are made from hollow carbon with no aluminum spine or filler material for the lowest weight possible. While the arms are pretty cool, the real star here is arguably the redesigned spindle. It's been beefed up from 24 to 30 millimeters, which lets Race Face use what it's calling a super aluminum that is 20% stronger than the usual 7050 alloy. That means less material for equal stiffness, which the increased diameter also helps with.