When looking at go-fast XC bikes, low weight and speed are the main factors. Trek's Superfly 9.8 SL nails it. Backed by countless wins, it boasts a superlight full-carbon frame and 100mm Fox 32 Float fork. And that's only half the story. To win, you have to ride, and the Superfly has the geometry, handing and specs to crush every section of dirt. Gary Fisher's G2 geometry is quick and confident, whether racing or just pinning your favorite loop. For gearing, you've got SRAM's excellent 1x11 X1 drivetrain with X01 rear derailleur, and you're spinning on tubeless-ready DT Swiss 29-inch wheels. Shimano Deore XT discs clamp down your speed and Bontrager controls pilot you to the win. Superfly: It's the whole package.