Our Lightest and Fastest Hardpack XC Tire For ultimate XC speed on hardpack, Air Trak delivers. Its fast-rolling tread cluster and high-speed center T5 compound ensure unmatched straight-line velocity, while grippier T7 compound on the sides delivers traction to maintain cornering speed. Our lightest Flex Lite casing keeps the tire at just 575 grams, offering lightning-fast acceleration and top climbing performance. When sheer speed matters, Air Trak is the perfect choice. At a Glance Use XC Racing Tread Fast-rolling center knobs, Block-In-Block outer knobs Compound GRIPTON Dual T5/T7 compound for speed on straights and corners Casing 60TPI Flex Lite for speed Type Tubeless Approximate Weight 29x2.2, 575g29x2.35, 585g