The 650b trend is no longer confined to trail/endure long travel bikes. More and more riders are moving to this wheelsize for pure XC riding and racing, and that's what this rim is designed for. Internally called the "no holds barred" rim, this rim is the result of almost a year of R&D efforts to push the limits of weight, stiffness and durability available in a carbon rim. What our engineers came up with delivers an abundance of lateral stiffness, our trademarked asymmetric design, a generous 23mm inner width and a continued refinement of our Rockguard Hookless bead designed to provide best in the industry durability to rock strikes or other direct rim impacts. In short, if you are looking for speed on a 650b, this is the best upgrade you can make for your bike.