Diamondback Bicycles 2016 Overdrive Hard Tail Mountain Bike, Red (27.5-inch) Hand built 6061-T6 aluminum alloy hard tail frame is classic mountain biking Tektro Mechanical Disc Brakes help you stop in all conditions 27.5" wheels roll well over obstacles and offer quick handling SR Sun tour XCT fork delivers 100mm of suspension travel Shimano 8-speed rear derailleur and 3 chain rings give you 24 speeds to choose from