An intricate component in the redesign of SRAM's Red eTap AXS group is that of its Red XG-1290 12-Speed Cassette. To go 12-speed, you need well, 12 cogs, but it's so much more than just that. Because of its 10-tooth starting cog afforded by its XDR driver body, it opens up a whole new, wider gearing range that makes us all rethink the current gear ratios. SRAM claims that the Red XG-1290 cassette was specifically designed for wireless electronic derailleurs offering smoother and faster shifting. Its one-piece X-Dome design is machined from steel for strength, precision, weight savings, and offers a longer lifespan when compared to titanium. Of course, this means you will have to have the new XDR freehub driver to install it on your wheelset but many companies already offer the driver and more and more are coming out all the time. Perhaps the most significant change with the Red XG-1290 12-Speed Cassette is its ability to offer a more gradual gear progression between the cogs. All 3-gearing options have the smallest possible jumps with the 10-33t offering 1-tooth jumps between the 6 largest gears while the 10-26 and 10-28 options have 1-tooth jumps between the 8 largest gears. When mated to the close ratio 2x chainrings or a single ring setup, it makes it easy to find just the right gear.