- The exceptional profile and OneStar rubber compound make the Schwalbe X-One one of the fastest cross tires ever. - To make it the absolute high-flyer, mount it without a tube on a tubeless-compatible wheel. - In combination with the right wheel you can run tubeless tires for cyclo-cross with extremely low air pressures without fear of "Burping" (unwanted air leakage). - For instance, it works extremely well with the Iron Cross from No Tubes.