The term road bicycle is used to describe bicycles built for traveling at speed on paved roads. Some sources use the term to mean racing bicycle. Other sources specifically exclude racing bicycles from the definition, using the term to mean a bicycle of a similar style but built more for endurance and less the fast bursts of speed desired in a racing bicycle; as such, they usually have more gear combinations and fewer hi-tech racing features. Certain of these bicycles have been referred to as 'sportive' bicycles to distinguish them from racing bicycles.
A mountain bike or mountain bicycle (abbreviated Mtn Bike, MTB; or ATB, for all-terrain bicycle) is a bicycle designed for off-road cycling. Mountain bikes share similarities with other bikes, but incorporate features designed to enhance durability and performance in rough terrain. These typically include suspension on the frame and fork, large knobby tires, more durable heavy duty wheels, more powerful brakes, and lower gear ratios needed for steep grades with poor traction.
A single-speed bicycle is a type of bicycle with a single gear ratio. These bicycles are without derailleur gears, hub gearing or other methods for varying the gear ratio of the bicycle.