A mountain bike which is also called as MTB or ATB ( or all terrain bicycle) is a bicycle created and made for off-road cycling, including jumps, and traversing of rocks and , and steep declines, on dirt trails, logging roads,  usually called mountain biking.

mountain bikes usually have only a small amount of front and rear suspension  and are relatively light, which is achieved via the use of lightweight materials and construction in both frame and components. As a consequence,  XC bikes are often less durable than other types of mountain bikes when used outside of their intended purpose.

The gear ratio chosen depends on the terrain being ridden, the strength and skill of the rider, and the size of the bike . Often single-speeds are fully rigid, steel-framed bikes. These are typically ridden by very fit individuals on mild to moderate cross country terrain.

Enduro/all-mountain (AM) bikes bridge the gap between cross-country and freeride bikes, typically weighing between  14 to 16 kg.