"Go all out off road with the Mongoose Grafton Mountain Bike. Great for ripping down rugged mountain trails, this hardtail aluminum bike features a suspension fork, internal headset, and 21-speed trigger shifters for excellent performance every time you ride. Mechanical disc brakes deliver all-weather stopping power and speed control, while 27.5"" wheels with 2.3""W knobby tires provide extra grip and stability. Plus, this Mongoose mountain bike boasts aluminum double-wall rims for added strength without weighing you down. Lightweight, durable aluminum frame Suspension fork soaks up shock on the trail 21-speed drivetrain with reliable trigger shifters Front and rear mechanical disc brakes Double-wall alloy rims 27.5"" wheels"