Convertible
A convertible or cabriolet is a passenger car that can be driven with or without a roof in place. The methods of retracting and storing the roof vary across eras and manufacturers.
A convertible car's design allows an open-air driving experience, with the ability to provide a roof when required. A potential drawback of convertibles is their reduced structural rigidity.
The majority of convertible roofs are of a folding construction framework with the actual top made from cloth or other fabric. Other types of convertible roofs include retractable hardtops and detachable hardtops.
Terminology
Other terms for convertibles include cabriolet, cabrio, drop top, drophead coupé, open two-seater, open top, rag top, soft top, spider, and spyder, although companies use many of these terms interchangeably. Thus, nomenclatural consistency is rare. The term cabriolet originated from a carriage cabriolet: "a light, two-wheeled, one-horse carriage with a folding top, capable of seating two persons"; however, the term is also used to describe other convertibles.In the United Kingdom, the historical term for a two-door convertible is drophead coupe, and a four-door convertible was called an all-weather tourer.
History
Most of the early automobiles were open-air vehicles without any roof or sides. As car engines became more powerful by the end of the 19th century, folding textile or leather roofs began to appear on cars. Examples of early cars with roofs include the phaeton, the brougham or a coupé de ville, having an enclosed passenger compartment at the rear, while the driver sat in front either in the open, or the landaulet, where the driver has a fixed roof and the passenger compartment has a folding roof. Less expensive cars, such as the runabouts, sporting roadsters, or sturdy touring cars, remained either completely open air or were fitted with a rudimentary folding top and detachable clear side curtains.In the 1920s, when steel bodies began to be mass-produced, closed cars became available to the average buyer, and fully open cars began to disappear from the mainstream market. By the mid 1930s, the remaining small number of convertibles sold were high-priced luxury models. In 1939, Plymouth introduced the first mechanically operated convertible roof powered by two vacuum cylinders.
Demand for convertibles increased as a result of American soldiers in France and the United Kingdom during World War II familiarizing themselves with small roadster cars, which were not available in the United States at that time. These roadsters included the MG Midget and Triumph Roadster. The convertible design was incorporated into the mass market unibody by Hudson in 1948. United States automakers manufactured a broad range of convertible models during the 1950s and 1960s – from economical compact-sized models such as the Rambler American and the Studebaker Lark, to the more expensive models, such as the Packard Caribbean, Oldsmobile 98, and Imperial by Chrysler. Automakers often included a convertible body style as an available body style in a model range.
Convertibles in the U.S. market peaked in sales around 1965, and fell in popularity over the next five years. Optional air conditioning was gradually becoming more popular, and the availability of sunroofs and T-tops limited the appeal of the open body style. Noise, leaks, and repairs associated with fabric tops also contributed to issues that many customers had. The popularity of convertibles was reduced by the increased travel speeds on roads and the emergence of more comprehensive vehicle crash safety standards in the United States.
The market share of convertibles fell to two or three percent of total sales and the U.S. automakers discontinued the body style from their lineups. American Motors stopped making convertibles after the 1968 model year, Chrysler after 1971, Ford after 1973, and most divisions of General Motors after 1975. Cadillac held out until 1976, when they made about 14,000. The last 200 had a red, white, and blue motif and a dashboard plaque. The very last was offered to the Smithsonian Institution, whose trustees turned it down as it was not at that moment a historic artifact, "Though it might well be in three generations... or at the Tricentennial." After the last Cadillac Eldorado convertible was made in 1976, the only factory convertibles sold in the United States were imported. Making convertibles on the assembly line was both expensive and time-consuming, thus not worth the problems needed to sell the limited number of cars.
Specialized coachbuilders were contracted to make dealer-available cars such as the Targa top versions of the AMC Concord and Eagle "Sundancer" as well as the Toyota Celica "Sunchaser" as specialty models. American Sunroof Company, which was responsible for popularizing the sunroof option for regular body styles, converted a Buick Riviera into a full convertible that compelled General Motors to market it as part of the 1982 Buick models. Chrysler Corporation also introduced a convertible body style in its 1982 lines that was based on the K-Car. These models were the LeBaron, produced under Chrysler, and the 400, manufactured under Dodge. Ford reintroduced a convertible Mustang for 1983, while American Motors Corporation added a convertible version of the Renault Alliance in 1984.
In 1989, Mazda released the first generation Mazda MX-5, which has become the best-selling convertible with over 1 million cars sold. Also in 1989, Toyota released the Toyota Soarer Aerocabin, which uses an electrically operated retractable hardtop roof. A total of 500 were produced.
Models dedicated to the convertible body style include the Mazda MX-5, Porsche Boxster, and Opel Cascada.
Roof types
Textile
A "soft top" is made from a flexible textile material:- Early convertibles used cotton canvas woven so tightly that it was waterproof. Automakers had problems in securing raw materials to fulfill orders after World War II, including canvas in various shades for convertible tops, therefore limiting their manufacture.
- A cloth-based material has become more common in recent years.
The collapsible textile roof section over an articulated folding frame may include linings such as a sound-deadening layer and/or an interior cosmetic lining, to hide the frame.
The folded convertible mechanism with the top is called the stack. Designs that fold down to a lower stack height offer a smoother silhouette for the car with the top down while concealed side rails allow room for three passengers in the back seat such as on the 1967 Rambler Rebel convertible.
Detachable hardtop
Rigid removable hardtops, many of which can be stored in a car's trunk/boot, have been available at least since the 1950s. These usually provide greater weatherproofing, soundproofing, and durability compared to fabric-based tops; some are available with integrated rear-window defrosters and windscreens. Examples include the Ford Thunderbird, Mercedes SL, Porsche Boxster, Jeep Wrangler, Ford Mustang Cobra, and Mazda MX-5.During the 1950s and 1960s, detachable hard-material roofs were offered for various convertible sports cars and roadsters, including the 1955–1957 Ford Thunderbird and Chevrolet Corvette, as well as the 1963–1971 Mercedes-Benz W113 series of two-seaters. Because the convertible top mechanism is itself expensive, the hard roof was customarily offered as an additional, extra-cost option. On early Thunderbirds, buyers could choose between a detachable hardtop and a folding canvas top at no additional cost, but paid extra for both.
The metal-framed "Carson top" was a popular addition for the 1930s Ford convertibles or roadsters because it turned these models into an almost instant hardtop. The design mimicked a convertible top, but lacking the bulky folding mechanisms enabled the removable hardtop to have a much lower and more rakish profile.
Improvements in canvas tops have rendered the detachable hard roof less common in part because the top cannot be stored inside the vehicle when not in use, requiring a garage or other storage facility. Some open cars continue to offer it as an option. For example, the Mazda MX-5 has an accessory hardtop, which is compulsory for some auto racing series.
Retractable hardtop
A retractable hardtop – also known as "coupé convertible" or "coupé cabriolet" – is a car with an automatically operated, self-storing hardtop.The benefits of improved climate control and security are traded off against increased mechanical complexity, cost, weight, and often reduced luggage capacity.
Other design features
Tonneau cover
Folding textile convertible tops often fail to completely hide their internal mechanism or can expose their vulnerable underside to sun exposure and fading. A tonneau cover provides a solution.Rear window
Rear windows are often part of the roof assembly. Traditionally, the rear window in a soft-top was made from plastic; however, more recently some convertibles have used glass for the rear window.Windblocker
A windblocker or wind deflector minimizes noise and rushing air reaching the occupants. According to the engineer responsible for the 2008 Chrysler Sebring, its windblocker reduces wind noise by approximately 11 to 12 dB.Several convertibles are available with a heating duct to the neck area of the seat, which is often called an "Air Scarf". Examples of cars with this feature include Mercedes-Benz SLK-Class, Mercedes-Benz SL-Class, and Audi A5/S5.