The Trek X-Caliber 8 Hardtail Mountain bike is a cross-country mountain bike made for fast laps and long days on the trail. It's built with special attention to value and the parts that make the biggest difference in performance. A 1x SRAM drivetrain, RockShox fork, and hydraulic disc brakes make it a great choice for new mountain bikers and XC racers searching for fast, fun, singletrack adventure.   It has the price of a more basic hardtail, but the parts and performance of a more expensive one     The RockShox air fork has a rebound adjust and can be tuned to the rider’s weight, and it’s way higher quality than what you’d normally get on an MTB at this price   The frame is fully compatible with higher-end parts, like race wheels and a dropper post, if you ever find the need to upgrade   Smart Wheel Sizing means you'll get the fastest wheel that fits (29? wheels on larger frames, 27.5? wheels on smaller frames)   The 1x drive train delivers a wide range of gearing with the simplicity of a single shifter   Trek X-Caliber 8 Hardtail Mountain bike 2021 Features Frame Alpha Gold Aluminum, tapered head tube, internal derailleur & dropper post routing, rack & kickstand mount, Boost141, 5mm QR  Fork RockShox Judy Silver, Solo Air spring, rebound adjust, TurnKey hydraulic lockout, tapered steerer, Boost110, 15mm Maxle, 100mm travel   Rear derailleur SRAM SX Eagle   Brakeset Shimano MT200 hydraulic disc