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. Light Lighter weight compound conforms to trail objects while still providing a happy balance between low rotational weight and reliability. 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 Tires Wtb Riddler 700X37 Bk/Tan Tcs Light Fr Fold