Roll bar redirects here. For the suspension component called a roll bar or anti-roll bar, see sway bar

Sway bar

A sway bar or anti-roll bar or stabilizer bar is a part of an automobile suspension that helps reduce the roll of a vehicle that is induced by cornering or road irregularities. It connects opposite wheels together through short lever arms linked by a torsion spring...

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A roll cage is a specially constructed frame built in (or sometimes around) the cab of a vehicle to protect its occupants from being injured in an accident, particularly in the event of a roll-over. Roll cages are used in nearly all purpose-built racecars, and in most cars modified for racing. There are many different roll cage designs depending on the application, hence different racing organizations have differing specifications and regulations. They also help to stiffen the chassis, which is desirable in racing applications.

A roll bar is a single bar behind the driver that provides moderate roll-over protection. Due to the lack of a protective top, some modern convertibles utilize a strong windscreen frame acting as a roll bar. Also, a roll hoop may be placed behind both headrests (usually one on older cars), which is essentially a roll bar spanning the width of a passenger's shoulders.

A newer form of rollover protection, pioneered on the Mercedes-Benz R129

Mercedes-Benz R129

The Mercedes-Benz R129 automobiles were produced from 1989 through 2002. They were sold under the SL-Class model names. The R129 replaced the R107 SL-Class in 1989 and was in its turn replaced by the R230 in 2003 .-Models:-Model history:...

 in 1989, is deployable roll hoops that are normally hidden within the body of a car. When sensors detect an imminent rollover, the roll hoops quickly extend and lock in place. Cars that have a deployable rollover protection system include the Peugeot 307

Peugeot 307

The Peugeot 307 is a small family car produced by the French Peugeot manufacturer since 2001. It was awarded the European Car of the Year title for 2002, and continues to be offered in China and certain South American markets through 2009 despite the French launch of the 308 in September...

 CC , Volvo C70

Volvo C70

The Volvo C70 is a luxury automobile manufactured by Volvo Cars in two generations: the first from model years 1997-2002 as coupé and from 1999 to 2006 as a softtop convertible...

, Mercedes-Benz SL 500, and Jaguar XK

Jaguar XK

The Jaguar XK series is a series of grand tourer cars produced by British car maker Jaguar since 1996. The series was introduced at the Geneva Motor Show on 5 March 1996. The first generation of the series, the XK8, replaced the XJS, and was available as a coupé and convertible...

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Roll bars are also used historically on row crop tractors, and roll cages are common as part of the cab on modern tractors.