Sram: OVERVIEWThe workhorse of X-Range gearing. The SRAM RED XG-1290 cassette progresses fluidly and quickly through a wider range of gears. It's specifically designed for wireless electronic shifting and the one-piece design offers you the best in weight savings.FEATURESDesigned for smooth and fast shiftingGradual gear progression between cogs—at least five one-tooth jumps—while still offering a wider range10-tooth start helps provide a wider gearing rangeDesigned to work with an XDR driver bodyOne-piece machined steel X-DOME design for weight savingsAll Zipp wheels starting from 2012 are XDR ready SPECIFICATIONSSpeed (CS) 12sGearing 10-26t, 10-28t, 10-33tCog finish (Cassette) Rainbow, SilverTechnology (Cassette) XGCog sizes 10-26t;10,11,12,13,14,15,16,17,19,21,23,26 / 10-28t;10,11,12,13,14,15,16,17,19,21,24,28 / 10-33t;10,11,12,13,14,15,17,19,21,24,28,33