Some Mountain Bikes are not made for all mountain terrain that will be encountered throughout your ride. The Giant Mountain Bikes fall under a different class of bikes because of their weight and the different components.
The Giant Mountain Bike is lighter than you might expect it to be, and it is lighter than the majority of other bikes on the market. The Giant Mountain Bikes were designed to help you keep a low center of gravity, with lower pedal feedback. These bikes have full suspension, with some great technology, all designed to help you climb and descend just a little easier.