The Fastest Way to the Podium 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.