The good folks at Stan"s NoTubes make it easy to convert your rear wheel to the new SRAM XX1 11-speed group with the Stans XD Driver for a fraction of the cost of a new wheelset. Just pop off your 10-speed freehub body and install the XD Driver. Stan"s even included the drive side end cap for your particular axle. The Stan"s NoTubes XD Driver is available in four sizes-135/10mm, 135/12mm, 135/9mm, and 142/12mm.