A roadster (spider or spyder) is an open two-seat car with emphasis on sporting appearance or character. Initially an American term for a two-seat car with no weather protection, usage has spread internationally and has evolved to include two-seat convertibles.
The roadster was also a style of racing car driven in United States Auto Club (USAC) Championship Racing, including the Indianapolis 500, in the 1950s and 1960s. This type of racing car was superseded by mid-engined cars.
In 1916, the U.S.'s Society of Automobile Engineers defined a roadster as: "an open car seating two or three. It may have additional seats on running boards or in rear deck." Additional seating in the rear deck was known as a rumble seat, the equivalent of a British dickey seat. The main seat for the driver and passenger was usually further back in the chassis than it would have been in a touring car. Roadsters usually had a hooded dashboard.
The term "roadster" as applied to automobiles is American in origin; before and long after World War II, the British equivalent was an "open two-seater".  The description was often used after World War II for British cars that were aimed at the North American market.
The Italian equivalent is "spider" (pronounced "speeder"). Various manufacturers have used the words "spider" or "spyder" as a name for their roadster models.
The earliest roadster automobiles had only basic bodies without doors, windshields, or other weather protection. By the 1920s they were appointed similarly to touring cars, with doors, windshields, simple folding tops, and side curtains.
Roadster bodies were offered on automobiles of all sizes and classes, from mass-produced cars like the Ford Model T and the Austin 7 to extremely expensive cars like the Cadillac V-16, the Duesenberg Model J and Bugatti Royale.
1926 Ford Model T roadster
1932 Duesenberg J Murphy-bodied roadster
1937 Delahaye 135MS roadster
1949 MG TC open two-seater marketed in USA as a roadster
1946 Triumph Roadster designed to appeal to and named for the U.S. market
By the 1970s aside from cars like Morgan "roadster" could be applied to any two-seater car of sporting appearance or character. In response to market demand they were manufactured as well-equipped as convertibles with side windows that retracted into the doors. Alfa Romeo Spider, MGB, and Triumph TR4 were all marketed in the U.S. with the description roadster.
The highest selling roadster is the Mazda MX-5, which was introduced in 1989. The older style of open two-seater remains in production by a few manufacturers and fabricators, including the windowless Roadster, the doorless Seven and the bodyless Atom.
Championship race cars
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The term roadster applies to front-engined AAA/USAC Championship cars, associated with the Indianapolis 500. The roadster engine and drive shaft are offset from the centerline of the car. This allows the driver to sit lower in the chassis and facilitates a weight offset which is beneficial on oval tracks.
One story of why this type of racing car is referred to as a "roadster" is that a team was preparing a new car for the Indianapolis 500. They had it covered in a corner of their shop. If they were asked about their car they would try and obscure its importance by saying that it was just their (hot rod) "roadster". After the Indianapolis racer was made public, the "roadster" name was still attached to it.
Frank Kurtis built the first roadster to race and entered it in the 1952 Indianapolis 500. It was driven by Bill Vukovich who led for most of the race until a steering failure eliminated him. The Howard Keck owned team with Vukovich driving went on to win the 1953 and 1954 contests with the same car. Bob Sweikert won the 1955 500 in a Kurtis after Vukovich was killed while leading. A. J. Watson, George Salih and Quinn Epperly were other notable roadster constructors. Watson-built roadsters won in 1956, 1959 - 1964 though the 1961 and 1963 winners were actually close copies built from Watson designs. The 1957 and 1958 winner was the same car built by Salih with help by Epperly built with a unique placement of the engine in a 'lay down' mounting so the cylinders were nearly horizontal instead of vertical as traditional design dictated. This gave a slightly lower center of gravity and a lower profile.
Roadsters had disappeared from competition by the end of the 1960s, after the introduction, and subsequent domination, of rear-engined machines. In 1965 Gordon Johncock brought the Wienberger Homes Watson to the finish in fifth place which was the last top-ten roadster finish and the final time that a roadster finished the full distance of the race. The last roadster to make the race was built and driven by Jim Hurtubise in the 1968 race and dropped out early. Hurtubise attempted to run the same car in 1969 but, while making his qualifying run at a very good speed, the engine failed on the last of the four laps. The car was entered many times after that but was never seriously considered fast enough to start.
Other classes of racing cars were built with the offset drive train and were referred to as roadsters. Some pavement midgets roadsters were built and raced into the early 1970s but never were dominant.
- Barchetta, a related two-seater body style designed primarily for racing
- Convertible, the general term to describe vehicles with retractable roofs and retractable side windows
- Roadster utility
- Tonneau cover, a protective cover for the seats in an open car
- Webster, Goodrich & Porter 1861, p. 959.
- Haajanen 2003, p. 113.
- Porter 1898, p. 1246.
- Society of Automobile Engineers 1916.
- Clough 1913, p. 258.
- Culshaw & Horrobin 2013, pp. 480-481.
- Clough 1913, p. 257.
- "The Used Car Problem". Garage Organization and Management. Taylor & Francis. pp. 259–260. Retrieved 2012-10-26.
(for the purposes of this British publication) "In order to avoid confusion, however, the universally understood terms 'Tourer', 'Coupé', 'Saloon', 'Limousine', etc., have been adopted, adding the American term 'Roadster' as the two-seater edition of the tourer."
- "Short History of the MGA & Magnette". www.namgar.com. Retrieved 20 June 2018.
- Georgano 1971, p. 216.
- Culshaw & Horrobin 2013, p. 482.
- Boeriu 2011.
- "Mazda Produces 900,000th MX-5, Recognized as World's Best-Selling Sports Car". www.motortrend.com. Retrieved 23 June 2018.
- "History of the Mazda MX-5 - picture special". www.autocar.co.uk. Retrieved 23 June 2018.
- "25 Snapshots of the Mazda Miata Through History". www.cheatsheet.com. Retrieved 23 June 2018.
- Anderson, Sandra; Crozier, Justin; Gilmour, Lorna; Grandison, Alice; McKeown, Cormac; Stibbs, Anne; Summers, Elspeth, eds. (2006). Collins Concise Dictionary & Thesaurus. Glasgow, UK: HarperCollins Publishers. p. 740. 978-0-00-722971-0.
- Boeriu, Horatiu (2011-02-09), Video: BMW Roadster History
- Clough, Albert L. (1913). A dictionary of automobile terms. The Horseless Age Company. LCCN 13003001. Retrieved 1 September 2014.
- Haajanen, Lennart W. (2003). Illustrated Dictionary of Automobile Body Styles. Illustrations by Bertil Nydén; foreword by Karl Ludvigsen. Jefferson, NC USA: McFarland. ISBN 0-7864-1276-3. LCCN 2002014546.
- Culshaw, David; Horrobin, Peter (2013) . "Appendix 5 - Coachwork styles". The complete catalogue of British Cars 1895 - 1975 (e-book ed.). Poundbury, Dorchester, UK: Veloce Publishing. pp. 480–484. ISBN 978-1-845845-83-4.
- Pollard, Elaine, ed. (1994). "R". The Oxford Paperback Dictionary (fourth ed.). Oxford, UK: Oxford University Press. p. 692. ISBN 0-19-280012-4.
roadster noun an open car without rear seats.
- Georgano, G. N., ed. (1971). "Glossary". Encyclopedia of American Automobiles. New York, NY USA: E. P. Dutton. pp. 215–217. ISBN 0-525-097929. LCCN 79147885.
Roadster. A two-passenger open car of sporting appearance.
- Porter, Noah, ed. (1898). "Roadster". Webster's International Dictionary of the English Language. Springfield, MA US: G. and C. Merriam. LCCN 98001281.
- Society of Automobile Engineers, Nomenclature Division (August 20, 1916). "What's What in Automobile Bodies Officially Determined" (pdf). The New York Times. New York, NY USA. Nomenclature Division, Society of Automobile Engineers. ISSN 0362-4331. OCLC 1645522. Retrieved 2012-05-31.
Here it is, with other body types and distinctions, officially determined recently by the Nomenclature Division of the Society of Automobile Engineers:
- Webster, Noah; Goodrich, Chauncey A.; Porter, Noah (1861). "Roadster". An American Dictionary of the English Language. Springfield, MA US: G. and C. Merriam.
- Media related to Roadsters at Wikimedia Commons