 | This articleneeds additional citations forverification. Please helpimprove this article byadding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Two-wheel drive" – news ·newspapers ·books ·scholar ·JSTOR(December 2010) (Learn how and when to remove this message) |
Two-wheel drive (2WD) denotesvehicles with apowertrain that allows twowheels to be driven, and receivepower andtorque from theengine, simultaneously.[1] Also calledall-wheel drive for motorcycles without sidecars.
For four-wheeled vehicles (and by extension vehicles with more wheels) are referred to as eitherfront-, orrear-wheel drive. The term4×2 is also used, to denote four total wheels with two being driven. Most road vehicles use 2WD layout due to its lower cost and weight, highergas mileage and simplicity, and its traction on roads under normal conditions being sufficient with only two wheels.
For vehicles that havefour-wheel drive (4×4) the term 4×2 refers to the mode when 4×4 is deactivated and power is applied to only two wheels.
For two-wheeled vehicles such asmotorcycles andbicycles, the term is used to describe vehicles that can power the front as well as the back wheel. The term2×2 is also used to denote two total wheels with both being driven. 2×2 vehicles are typically either mechanically driven, via achain,belt, orshaft, or arehydraulic-driven. This scheme greatly improves off-road performance, but isquite 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 includeRokon,Jeep,Tarus and Christini. Manufacturers who are working or have worked on a prototype includeZID,Suzuki,Yamaha,KTM,Honda, andNissan.
For three-wheeled vehicles such asmotorcycles withsidecars, 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 off-road 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 ofBaughan in the UK, and Mokharov in theUSSR.[citation needed]