A gravel road that turns into a rutted, grassy double track halfway through a ride asks a lot of one set of tires, and the Challenge Gravel Grinder Pro Tubeless Tire is a handmade gravel tire made for that change. Its diamond center tread clears dirt and mud, while wide-spaced side knobs hook soft ground and steer the tire through ruts. A supple Super Polyester casing carries that tread, and the mixed pattern keeps rolling resistance solid on firmer stretches while adding cornering grip. What Our Gearhead(R) Experts Are Saying:"Compliant hookless rims take this tire without a workaround, and a tight fit is what holds air and keeps it seated. Challenge Smart Tubeless Sealant is what I pair with it for setup."