What is Frame (vehicle)?
[[File:Land Rover Series III chassis.jpg|thumb|right|250px|{{center|A [[Land Rover]] ladder type frame}}]] A '''vehicle frame''', is the main [[structure|structural element]] of a motor vehicle. All other components are connected to the frame. Another term for this design is ''body-on-frame'' [[wikt:construction|construction]].<ref>Mark Gustavson, ''Custom Car: Modeling'' (Waukesha, WI: Kalmbach Publishing Co., 1999), p. 7</ref> A vehicle's frame is part of the [[chassis]].<ref>Tim Gilles, ''Automotive Chassis: Brakes, Suspension, and Steering'' (Clifton Park, NY: Thomson Delmar Learning, 2005), p. 317</ref> The first [[motor vehicle]]s were almost all built on a frame.<ref>Hugh Dolner, 'Considerations of Motor Car Elements', ''Cycle and Automobile Trade Journal'', Philadelphia (1 April 1906), p. 78</ref> Since then, nearly all cars have changed to unibody construction (see below). The last UK mass-produced car with a chassis was the [[Triumph Herald]], which was discontinued in 1971. By contrast, today nearly all trucks and buses still use chassis frames. == Types == === Ladder Frame === Named because it resembles a [[ladder]], the '''ladder frame''' is the simplest and oldest of all designs. It has two rails, or [[wikt:beam|beam]]s, and [[crossmember]]s connecting them. Most [[manufacturer]]s stopped using them on cars around the 1940s. They are now seen mainly on [[truck]]s. ===Unibody=== In a '''unibody''' (also '''unit body''') design, the sheet metal of the body is also the frame.<ref name=CDX971>CDX Automotive, ''Fundamentals of Automotive Technology: Principles and Practice'' (Burlington, MA: Jones & Bartlett Learning, 2014), p. 971</ref> It may use subframes in certain areas.<ref name=CDX971/> Unibody designs first appeared in the 1930s on some [[Citroën]] automobiles. Many modern vehicles use unibody construction including [[car]]s, [[minivan]]s and [[crossover SUV|crossovers]]. A few [[SUV]]s use unibody construction. An example is the [[Dodge Durango]]. == References == {{reflist}} {{transpor