A smart upgrade for your road bike is now even smarter. Lighter, and smoother riding, the Ksyrium UST Disc delivers proven performance and new Road Tubeless technology. Roll faster and smoother with a reduced risk of punctures. No tube means no friction, so less rolling resistance and higher speeds. Ride with lower tire pressure for smoother ride and a reduced risk of punctures. UST system offers a perfect union between tire and wheel, so installation, removal and maintenance are easy. Lightweight rims for easier climbing and faster acceleration. ISM machined, welded rims. 19mm internal rim width for low rolling resistance and extra comfort with 28mm tires. Lateral stiffness boosts agility and efficiency. Optimized bearing placement. Straight-pull bladed double butted spokes deliver optimal stiffness.