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