Challenge makes Pro-only Team Edition Red cross tubulars available for very limited time - Bikerumor
Dune | Challenge Tires
Challenge Grifo H-TLR 38 Review - Slowtwitch.com
Challenge Dune PRO Cyclocross Tire
Challenge Goes Big with 38mm Cyclocross Tubulars and Tubeless Tires, Unveils Team Edition Handmade TLR - Cyclocross Magazine - Cyclocross and Gravel News, Races, Bikes, Media
Challenge Grifo PRO Tubular Cyclocross Tire
CHALLENGE Grifo Team Edition S tubular – WORLD CLASS CYCLES LLC