Challenge Gravine XP H-TLR 700 x 40 BlackDesigned for improved performance and traction across muddy sections and on more rugged, rocky terrains, the Gravine is designed to deliver. Featuring a more aggressive tread pattern, this tire pushes the boundaries of gravel further, allowing for totally new adventures. With the growing demand for more robust Gravel tires, Challenge has developed a new technology applied to the handmade construction, adding Xtra Protection (XP) for more endurance