![Challenge Shows New Grifo Clincher and Gravel Grinder Tire at NAHBS 2014 - Cyclocross Magazine - Cyclocross and Gravel News, Races, Bikes, Media Challenge Shows New Grifo Clincher and Gravel Grinder Tire at NAHBS 2014 - Cyclocross Magazine - Cyclocross and Gravel News, Races, Bikes, Media](https://www.cxmagazine.com/wp-content/uploads/2014/03/challenge0.jpg)
Challenge Shows New Grifo Clincher and Gravel Grinder Tire at NAHBS 2014 - Cyclocross Magazine - Cyclocross and Gravel News, Races, Bikes, Media
![Amazon.com : Challenge Grifo Cross Open Tubular Tire (Clincher) (Black/Brown, 33-mm) : Bike Tires : Sports & Outdoors Amazon.com : Challenge Grifo Cross Open Tubular Tire (Clincher) (Black/Brown, 33-mm) : Bike Tires : Sports & Outdoors](https://m.media-amazon.com/images/I/71ZMB3c-GIL._AC_SX425_.jpg)
Amazon.com : Challenge Grifo Cross Open Tubular Tire (Clincher) (Black/Brown, 33-mm) : Bike Tires : Sports & Outdoors
![Challenge Shows New Grifo Clincher and Gravel Grinder Tire at NAHBS 2014 - Cyclocross Magazine - Cyclocross and Gravel News, Races, Bikes, Media Challenge Shows New Grifo Clincher and Gravel Grinder Tire at NAHBS 2014 - Cyclocross Magazine - Cyclocross and Gravel News, Races, Bikes, Media](https://www.cxmagazine.com/wp-content/uploads/2014/03/0challengegravel.jpg)
Challenge Shows New Grifo Clincher and Gravel Grinder Tire at NAHBS 2014 - Cyclocross Magazine - Cyclocross and Gravel News, Races, Bikes, Media
![Challenge Tires had the Grifo Pro clincher, but now offers the G - Cyclocross Magazine - Cyclocross and Gravel News, Races, Bikes, Media Challenge Tires had the Grifo Pro clincher, but now offers the G - Cyclocross Magazine - Cyclocross and Gravel News, Races, Bikes, Media](https://www.cxmagazine.com/wp-content/uploads/2014/03/challenge-cyclocross-gravel-tires-cxmagazine-img_9882-e_1.jpg)
Challenge Tires had the Grifo Pro clincher, but now offers the G - Cyclocross Magazine - Cyclocross and Gravel News, Races, Bikes, Media
![Challenge Unveils Grifo Race Clincher, Hints at New Gravel and Fat Bike Tires, Colors - Cyclocross Magazine - Cyclocross and Gravel News, Races, Bikes, Media Challenge Unveils Grifo Race Clincher, Hints at New Gravel and Fat Bike Tires, Colors - Cyclocross Magazine - Cyclocross and Gravel News, Races, Bikes, Media](https://www.cxmagazine.com/wp-content/uploads/2014/03/challenge-cyclocross-gravel-tires-cxmagazine-img_9870-e_1.jpg)