Editing Anti-roll bar (section)

{{Distinguish|Rollover protection structure}}{{short description|Device that reduces the body roll of a vehicle}}
[[Image:Stabilisator (Porsche).jpg|thumb|An anti-roll bar (in black) on the rear of a [[Porsche]], which traverses the underside of the car. Flexible bushings attach it to the chassis. Also visible on the right is one of the links that connect the bar to the suspension (drop link). These twist the anti-roll bar when the vehicle is cornering, resisting body roll.]]

An '''anti-roll bar''' ('''roll bar''', '''anti-sway bar''', '''sway bar''', '''stabilizer bar''') is an [[automobile]] [[suspension (vehicle)|suspension]] part that helps reduce the [[body roll]] of a vehicle during fast cornering or over road irregularities. It links opposite front or rear wheels to a [[torsion spring]] using short [[lever]] arms for anchors. This increases the suspension's [[body roll|roll]] stiffness—its resistance to roll in turns.

The first stabilizer bar patent was awarded to Canadian inventor Stephen Coleman of [[Fredericton, New Brunswick]] on April 22, 1919.<ref>{{Cite book |last=Theriault |first=Mario |title=Great Maritime Inventions, 1833-1950 |date=2001 |publisher=Goose Lane Editions |isbn=978-0-86492-324-0 |pages=69 |language=en}}</ref><ref name=patent>{{Cite web
| url = http://brevets-patents.ic.gc.ca/opic-cipo/cpd/eng/patent/189894/summary.html
| title = Patent Summary: CA 189894 Spring suspension
| access-date = 2014-08-21
| last = Coleman
| first = Stephen L. Chancey
| date = 1919-04-22
| publisher = [[Canadian Intellectual Property Office]]
| archive-date = 2017-10-23
| archive-url = https://web.archive.org/web/20171023205451/http://brevets-patents.ic.gc.ca/opic-cipo/cpd/eng/patent/189894/summary.html
| url-status = live
}}</ref>

Anti-roll bars were unusual on pre-WW2 cars due to the generally much stiffer suspension and acceptance of body roll. From the 1950s on, however, production cars were more commonly fitted with anti-roll bars, especially those vehicles with softer coil spring suspension.