Challenge's Pista 320 Tubulars rule the velodrome. The casings are crafted with their CoreSpun, a 320tpi top-quality woven cotton. It makes for a supple, strong, and light tire. With the high thread count, the 320 holds your line at any speed. You also get a latex tube. Latex tubes are lighter, thinner and more flexible than butyl tubes, increasing your comfort, lowering rolling resistance, and helping to prevent flats, too.