An exoskeleton car has a visible external frame, being made of steel, aluminum or

carbon fiber Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...

tubes. Body styles are open wheel sports cars, with their wheels outside of the main body and each wheel covered by its own lightweight mudguard, usually carried as

unsprung weight The unsprung mass (colloquially unsprung weight) of a vehicle is the mass of the suspension, wheels or tracks (as applicable), and other components directly connected to them. This contrasts with the sprung mass (or weight) supported by th ...

supported on the hub carrier. The chassis has four large longitudinal tubes, two on each side of the car body, inboard of the wheels. These main chassis tubes are spaced apart by smaller diagonal or vertical tubes. Structurally, an exoskeleton chassis is midway between a

ladder chassis A ladder is a vertical or inclined set of rungs or steps used for climbing or descending. There are two types: rigid ladders that are self-supporting or that may be leaned against a vertical surface such as a wall, and rollable ladders, such a ...

and a

spaceframe chassis In architecture and structural engineering, a space frame or space structure ( 3D truss) is a rigid, lightweight, truss-like structure constructed from interlocking struts in a geometric pattern. Space frames can be used to span large areas with ...

. At its simplest, it consists of two ladder chassis, one above the other. The classic ladder chassis is stiff against sideways forces, but weak against vertical bending forces. Using paired tubes, separated vertically, makes the chassis much stiffer in this direction. Unlike a spaceframe though, the main forces act as bending loads upon these tubes, rather than the pure tension or compression forces of the true spaceframe. A drawback to the exoskeleton is that there is no chance to cut doors through the upper suspension tubes. The car style is thus restricted to low-slung cars, for agile drivers prepared to climb out over their high sills. The simplistic construction of the vehicle follows

Colin Chapman Anthony Colin Bruce Chapman (19 May 1928 – 16 December 1982) was an English design engineer, inventor, and builder in the automotive industry, and founder of Lotus Cars. In 1952 he founded the sports car company Lotus Cars. Chapman ...

's philosophy of maximizing the power-to-weight ratio by minimising weight rather than simply adding power. Early

monocoque Monocoque ( ), also called structural skin, is a structural system in which loads are supported by an object's external skin, in a manner similar to an egg shell. The word ''monocoque'' is a French term for "single shell". First used for boats, ...

racing cars such as the

Lotus 25 The Lotus 25 was a racing car designed by Colin Chapman for the 1962 Formula One season. It was a revolutionary design, the first fully stressed monocoque chassis to appear in Formula One. In the hands of Jim Clark it took 14 World Championship ...

had their chassis exposed but the term exoskeletal is more usually reserved for vehicles with an exposed space frame, such as

sandrail A sandrail, also called a sand rail, rail, or sand car, is a lightweight off-road motor vehicle specifically built for traveling in sandy terrain. Similar in some respects and often mistakenly referred to as a dune buggy or sand car, a sandrail ...

s, dune buggies or specialized light weight track cars.

Examples of exoskeleton cars

Ariel Atom The Ariel Atom is a road-legal high performance open-wheel car made by the British Ariel Motor Company based in Crewkerne, Somerset, England, and under license in North America by TMI Autotech, Inc. at Virginia International Raceway in Alton, ...

Deronda Type F The Deronda Type F is an extreme performance, road going, track day car. It has been designed and developed by professional motorsport engineers and utilises racing car technology. When former airline executive, Andy Round, wanted to create the ...

* KTM X-Bow *

MEV Rocket, Atomic, tR1ke, Missile, Eco-Exo and Exocet Mills Extreme Vehicles (MEV) is a kit car design and manufacturing company based in Gloucestershire, England, founded in 2003. As of January, 2016 they exclusively manufacture the Exocet, an exoskeletal design which uses donor parts from the Maz ...

References

Automotive chassis types Sports cars {{Auto-stub

Examples of exoskeleton cars

See also

References