Just about everyone in our circle of pedal turners has ridden Mavic's Ksyrium wheels before, but few have ridden them like this. The Ksyrium Pro Exalith SL Clincher Wheelset represents the top of the French brand's do it all wheel family, elevating the Ksyrium almost to the R Sys SLR's level. In fact, except for the branding and bearings, which are slightly heavier in the Ksyrium, the two wheels are the same. This includes sharing the Tracomp carbon fiber spoke technology, and the two are the only wheelsets in the world that can make that claim. If the Pro Exalith SL is the king of the Ksyrium line and it most certainly is then the path to the throne was paved with carbon fiber Tracomp spokes. The Tracomp spokes feature on the front wheel and the rear non drive side, stiffening the wheelset by reducing spoke stretch and compression. This drastically reduces rim deflection during the lateral load of hard efforts and fast cornering, so the rims respond more like super stiff carbon. But the rims aren't carbon, they're alloy, so Mavic can treat them with the Exalith II process and increase stopping power in dry and wet conditions by a claimed 18%. A new padbrake track interface reduces engagement noise compared to the previous generation of Exalith, but we actually like Exalith's jet engine hum especially compared to squealing, unresponsive carbon brake tracks. Thought the wheels substitute Tracomp spokes for the Ksyrium line's usual Isopulse design, it still adopts many other qualities that have made the wheels Mavic's go to. The hubs house Mavic's QRM bearings and FTS L freehub in a carbon body front a departure from most other Ksyriums and an aluminum body rear, and the bearings are adjustable with an Allen key and Mavic's included wrench. The Pro Exalith SL maintains the Ksyrium line's traditional internal rim width of 15mm. Along with Mavic's latest generation of milling, Inner Spoke Milling 4 Dimensions, the narrow footprint gives the wheels a ..