A mountain bike (MTB) or mountain bicycle is a bicycle designed for off-road cycling. Mountain bikes share some similarities with other bicycles, but incorporate features designed to enhance durability and performance in rough terrain. These typically include a suspension fork, large knobby tires, more durable wheels, more powerful brakes, straight handlebars, lower gear-ratios for climbing steep grades and sometimes rear suspension to really smooth out the trail.
Mountain bikes are generally specialized for use on mountain trails, single track, fire roads, and other unpaved surfaces, although perhaps[original research?] the majority of them are never used off-pavement, and it is common to find hybrid road bikes based on “mountain-bike” frames for sale. Mountain biking terrain commonly has rocks, roots, loose dirt, and steep grades. Many trails have additional TTFs (Technical Trail Features) such as log piles, log rides, rock gardens, skinnies, gap jumps, and wall-rides. Mountain bikes are built to handle these types of terrain and features. The heavy-duty construction combined with stronger rims and wider tires has also made this style of bicycle popular with urban riders and couriers who must navigate through potholes and over curbs.