Despite the widespread adoption of single-ring drivetrains in the mountain bike world, Shimano refuses to give up on double-ring setups. A 2x drivetrain offers closer steps between gears, making it easier to find your ideal cadence when you're spinning up sustained climbs with slight variations in gradient. It's also great for riders that prefer to have more top end gearing without sacrificing their low end gears. For these reasons, Shimano offers the XT FC-M8100 2x Crankset as part of their new XT 12-speed group. It uses the same Hollowtech II construction you're familiar with from previous years, but now uses direct mount chainrings, a special gear tooth profile for improved chain retention, and a narrower 172mm Q-factor for quick power and comfort in the saddle. This version features a 48. 8mm chain line that's best suited to bikes with non-Boost 12 x 142mm rear hub spacing. The crank arms are constructed using Shimano's proprietary Hollowtech II technology, balancing stiffness, strength, and weight for superior power transfer. Hollowtech uses cold-forging to create a light and hollow crank arm that doesn't compromise on strength or stiffness, enabling you to charge hard into rowdy trail sections without worries of your crankset flexing under pressure or getting damaged by rock strikes. Meanwhile the low weight keeps you from getting bogged down with extra grams when you're pushing for big mile days. Regardless of your preferred riding style and terrain, you'll appreciate the new direct-mount chainring application. The drive-side arm removes for ring placement, making chainring swaps easy to execute while your crank is still on your bike. This crankset comes equipped with a 36/26t chainset, but since the crank arms are the same for both the 1x and 2x cranks, you can easily switch back to a 1x setup by swapping the chainrings and removing your front derailleur.