The Bontrager R4 320 Tubular Road Tyre is designed for road & crit racing. The R4 tubulars race performance gives unparalleled road feel yet is extremely durable for a racing tubular, thanks to Hard-Case Lite protection. The Hard-Case Lite sub tread material protects against punctures in the peloton & up the hardest & sketchiest road climbs. Features Excellent for road & criterium racing Supple polyamide synthetic fibre reinforcement for added casing strength Hard-Case Lite protects against punctures with superior, lightweight, sub-tread material 38 mm valve length with valve extenders available separately