Two-wheel-drive (2WD) denotes

vehicles A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles ( trains, trams), ...

with a

drivetrain A drivetrain (also frequently spelled as drive train or sometimes drive-train) is the group of components that deliver mechanical power from the prime mover to the driven components. In automotive engineering, the drivetrain is the components ...

that allows two

wheel A wheel is a circular component that is intended to rotate on an axle bearing. The wheel is one of the key components of the wheel and axle which is one of the six simple machines. Wheels, in conjunction with axles, allow heavy objects to be ...

s to be driven, and receive power and

torque In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of t ...

from the

engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...

, simultaneously.

Four-wheeled vehicles

For four-wheeled vehicles (and by extension, vehicles with six, eight, or more wheels), this term is used to describe vehicles that are able to power at most two wheels, referred to as either

front Front may refer to: Arts, entertainment, and media Films * ''The Front'' (1943 film), a 1943 Soviet drama film * '' The Front'', 1976 film Music *The Front (band), an American rock band signed to Columbia Records and active in the 1980s and e ...

, or

rear-wheel-drive Rear-wheel drive (RWD) is a form of engine and transmission layout used in motor vehicles, in which the engine drives the rear wheels only. Until the late 20th century, rear-wheel drive was the most common configuration for cars. Most rear-wheel ...

. The term 4x2 is also used, to denote four total wheels with two being driven. Most road vehicles use a 2WD layout due to its lightweight and simplicity. Traction on the road is usually sufficient that the driving force can be reliably transmitted through only two wheels. For vehicles that have part-time

four-wheel drive Four-wheel drive, also called 4×4 ("four by four") or 4WD, refers to a two-axled vehicle drivetrain capable of providing torque to all of its wheels simultaneously. It may be full-time or on-demand, and is typically linked via a transfer ca ...

, the term refers to the mode when 4WD is deactivated and power is applied to only two wheels.

Two-wheeled vehicles

For two-wheeled vehicles such as

motorcycles A motorcycle (motorbike, bike, or trike (if three-wheeled)) is a two or three-wheeled motor vehicle steered by a handlebar. Motorcycle design varies greatly to suit a range of different purposes: long-distance travel, commuting, cruisin ...

and

bicycles A bicycle, also called a pedal cycle, bike or cycle, is a human-powered transport, human-powered or motorized bicycle, motor-powered assisted, bicycle pedal, pedal-driven, single-track vehicle, having two bicycle wheel, wheels attached to a ...

, the term is used to describe vehicles that can power the front as well as the back wheel. The term 2x2 is also used to denote two total wheels with both being driven. 2x2 vehicles are typically either mechanically driven, via a

chain A chain is a wikt:series#Noun, serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression (physics), compression but line (g ...

, belt, or

shaft Shaft may refer to: Rotating machine elements * Shaft (mechanical engineering), a rotating machine element used to transmit power * Line shaft, a power transmission system * Drive shaft, a shaft for transferring torque * Axle, a shaft around whi ...

, or are hydraulic-driven. This scheme greatly improves offroad performance, but is quite complicated and requires more power to operate, thus most 2WD machines are either "exotic" bikes for enthusiasts or created with special uses in mind. Manufacturers who have one in production include Rokon,

Jeep Jeep is an American automobile marque, now owned by multi-national corporation Stellantis. Jeep has been part of Chrysler since 1987, when Chrysler acquired the Jeep brand, along with remaining assets, from its previous owner American Motors ...

, Tarus and Christini. Manufacturers who are working or have worked on a prototype include ZID,

Suzuki is a Japan, Japanese multinational corporation headquartered in Minami-ku, Hamamatsu, Japan. Suzuki manufactures automobiles, motorcycles, All-terrain vehicle, all-terrain vehicles (ATVs), outboard motor, outboard marine engines, wheelchairs ...

, Yamaha, KTM,

Honda is a Japanese public multinational conglomerate manufacturer of automobiles, motorcycles, and power equipment, headquartered in Minato, Tokyo, Japan. Honda has been the world's largest motorcycle manufacturer since 1959, reaching a producti ...

, and Nissan.

Two-wheel-drive with sidecars

For three-wheeled vehicles such as

motorcycle A motorcycle (motorbike, bike, or trike (if three-wheeled)) is a two or three-wheeled motor vehicle steered by a handlebar. Motorcycle design varies greatly to suit a range of different purposes: long-distance travel, commuting, cruisin ...

s with

sidecar A sidecar is a one-wheeled device attached to the side of a motorcycle, scooter, or bicycle, making the whole a three-wheeled vehicle. A motorcycle with a sidecar is sometimes called a ''combination'', an ''outfit'', a ''rig'' or a ''hack''. ...

s, the term is used to describe vehicles that can power the sidecar as well as the back wheel. Sidecar-drive vehicles are typically mechanically driven via a shaft and may or may not have a differential. This scheme greatly improves offroad performance, but is more complicated and requires more power to operate, thus most 2WD machines are vehicles created with special uses in mind such as trials or military use. The first use of the sidecar drive appears in 1928 with the apparent independent invention of Baughan in the UK, and Mokharov in the

USSR The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nation ...

References

External links

A brief history of 2x2 motorcycles

KTM shows a new all-wheel-drive motorcycle under development

Christini All Wheel Drive Motorcycles

The Dryvtech 2x2x2 Experimental, a 2x2 motorcycle with two-wheel steering
{{Automobile configuration Car layouts Motorcycle transmissions

Four-wheeled vehicles

Two-wheeled vehicles

Two-wheel-drive with sidecars

See also

References

External links