Diamondback Bicycles Overdrive Sport Hard Tail Compete Mountain Bike with 27.5" Wheels Hand built 6061-T6 aluminum alloy hard tail frame with custom formed and butted tubing balance stiffness and weight savings SR Suntour 100mm fork gives just the right amount of suspension Shimano 27-speed drivetrain offers gears for any terrain Tektro Auriga Hydraulic Disc Brake, 180/160mm Rotor 27.5" wheels roll well over obstacles and offer quick handling