Large, supported toothy side knobs and densely packed, low-centered tread. The Riddler is a fast rolling tire with great cornering abilities named after WTB athlete Nathan Riddle. XC/AM tire designed for use on dry-to-damp and hardpack-to-sand trail conditions. Tough A double layer of light casing, TCS Tough tires are composed of two full layers of casing, bead-to-bead, leaving no area unprotected on our burliest tires. FR Fast Rolling, with WTB's Dual DNA rubber compound that optimizes efficiency, traction and durability, A firm, long-wearing centerline tread with softer side knobs. TCS WTB's Tubeless Compatible System, sealant based tubeless system with improved bead shape Mountain 29x2.25 622 TBLS Bk/Blk 60 980 60 TOUGH/FR/TCS