r.  Full of fast, built to last Caution: X-Caliber will get you hooked. It packs all of Trek's XC race hardtail experience into a light, fast bike that pairs the right wheel size with each frame size. Nothing beats the efficiency, simplicity, and straight-up fun of an X-Cal hardtail in 00er or 00.0". Great for XC racing, or simply shredding singletrack. - All-new lightweight Alpha Gold Aluminum frame delivers a phenomenal ride quality - Shorter chainstays and Boost000 hub spacing for increased agility and clearance for wider tires - Updated geometry and E0 tapered head tube for more confident handling - Sleek internal routing protects cables and accommodates dropper post upgrades  