At just 1255g, Cosmic Ultimate UST Disc is the ultimate balance of lightweight, stiffness and aerodynamics: the pinnacle of tubeless carbon wheels Ultimate is not just a name, it’s the word we reserve for pinnacle performance. And it’s now finally compatible with tubeless and clincher tyres and for disc brake bikes. At just 1255g, this wheelset is the ultimate balance of lightweight, stiffness and aerodynamics. The rim is engineered with a NACA-inspired, full-carbon profile that’s 45mm deep and 27mm wide. It’s made from a complex lay up that optimizes the stiffness to weight ratio. Its external layer takes our distinctive UD² finish. The rim is not drilled, so it doesn't require the use of a rim tape to become airtight: a guarantee for a hassle free tubeless use. The 20 elliptical carbon fiber spokes and high, thin carbon hub flanges offer a proven aero advantage. The spokes are made with unidirectional carbon fibers, so they don’t stretch. The spokes run continuously from one edge of the rim to the other, through the hubs (R2R technology), creating one single spoke instead of two. This adds wheel stiffness and eliminates the need to mechanically attach the spokes to the hub. Inside the carbon hub shells, the axles are paired with automatically adjusted sealed cartridge bearings for perfect preload. At the back, the ID360 freewheel system provides instant engagement (40 points of engagement = 9°) and low friction. The hubs are thru-axle compatible (12x100 up front and 12x142 at the back) and made for Center Lock brake rotors. These wheels are designed, engineered and patented by Mavic in Annecy, France, and are 100% handmade in France. They benefit from a lifetime warranty and from a generous crash replacement policy (upon on-line registration at Mavic.com/care) . Main features Ultralight and aero help you climb, sprint and accelerate faster​ Monobloc full carbon construction 45mm NACA rim profile seamlessly laced with elliptical spokes on high thin hub flanges Stiffest wheel system in its class​ with super low rolling resistance for high reactivity Carbon spokes with high tensile resistance Rim to rim (R2R) lacing system Tapeless tubeless UST rim Handmade in France Manual molding and assembling process Developed and manufactured in the Mavic carbon workshop in Annecy, France Delivered with exclusive wheelbag