As SRAM brings more 11 speed and 1x simplicity to more of their mountain groups, the balance of price versus new design and material selection is a factor. Some of the key components in the drivetrains are intricate and expensive to produce. As the company developed the X1 level cassette for the XD Driver freehub system, it wasn't willing to sacrifice too much weight, and had to keep the 10-42 gearing option. The engineers came up with the the MINI CLUSTER design, a hybrid that is both light and durable, but as cost effective as possible. The larger eight cogs are machined independently, then pinned together for integration and stiffness. These are steel, except for the 42, which is alloy. The botttom three cogs are CNC machined out of a single block of billet steel, ensuring incredible accuracy and strength further away from the center of the hub. All of the cogs have been finished with SRAM's JEtT process, which has a high level of corrosion and wear resistance, and is all-black, a cool look for a cassette.

The XG-1180 MINI CLUSTER Cassette weighs in at just 315 grams, which is clearly more than the 268 gram X-DOME design which lists well over $100 more than the XG=1180, but still pretty darn light for such a huge range cassette. The steps between gears have been optimized for 1x use, with tight shifts in the bottom half, getting gradually wider as you go up to the 42. The clean, open design sheds mud very well, and can easily be cleaned with light water pressure during or after your ride (one good reason to carry a water bottle even when you have wear a hydration pack). Of course you also get the stiff, stable, and easy to use benefits of the XD Driver system as well. Don't take it for granted, SRAM's patented design delivers more than 11 speeds with a 10t small cog. It also functions exceptionally well and transfers power as effectively as any other system. This driver and cassette design is what makes 1x11 drivetrains feasible for nearly all terrain. With X1 getting the treatment, and the XG-1180 being more cost effective, you know you have to have it.