When it comes to carbon fiber rims, stiffer is not always better. This has been proven over the years by the considerable number of professional mountain bikers and enthusiasts alike that choose to stick to aluminum, due to the plethora of carbon rims that have a bit of a harsh ride quality. While aluminum rims certainly offer additional compliance, they're also more susceptible to dents and flat spots that can eventually render the rim unrideable, and their lateral stiffness and steering precision is generally inferior to carbon. When developing the 3ZERO MOTO 27. 5in Carbon Rim, Zipp did away with conventional design all together, opting instead for a single-walled rim that they feel better utilizes the potential of carbon fiber. It's a design inspired by the motocross industry, and is intended to alleviate the stiffness problems of conventional box-section carbon rims while providing a level of traction unlike anything else currently on the market. Furthermore, Zipp claims the wheel can sustain impacts that would destroy competitor's alloy wheels, and that the risk of pinch flats is decreased--all good things for discerning riders and racers. Zipp calls their single-walled approach Moto Technology. The single-walled rim allows for more radial compression, resulting in a more compliant and comfortable ride that Zipp feels makes you faster on the trail. Additionally, like motocross wheels, the 3ZERO MOTO rim can pivot from either side of the spoke bed while traversing rough terrain. Zipp calls it "ankle compliance" because the rim behaves like a human ankle, allowing a bit of local flex so the rim can stay more parallel to the ground in corners to improve traction, and also deflect in the right direction during single-bead impacts to prevent the rider from getting bounced off line. On the trail, Moto Technology feels a bit like extra suspension travel, making it easier to hold a line over chundery rocks and roots while improving your overall traction. As for ...