Editing Speed wobble (section)

{{short description|Physics phenomenon affecting two wheeled vehicles}}
{{Technical|date=March 2020}}

'''Speed wobble''' (also known as '''shimmy''', '''tank-slapper''',<ref>{{Cite book |last=Hough |year=2000 |first=David L. |author-link=David L. Hough |title=Proficient Motorcycling: The Ultimate Guide to Riding Well |edition=2nd |publisher=BowTie Press|location=USA |url=https://books.google.com/books?id=yeAIAIxS-cgC |isbn=1-889540-53-6 |page=253 |chapter=Glossary |quote='''tank slapper:''' a speed wobble so severe that the handlebars bang alternately against the sides of the fuel tank}}</ref> or '''death wobble''') is a rapid side-to-side shaking of a vehicle's wheel(s) that occurs at high speeds and can lead to loss of control. It presents as a quick (4&ndash;10&nbsp;Hz) oscillation of primarily the steerable wheel(s), and is caused by a combination of factors, including initial disturbances and insufficient [[damping]], which can create a [[resonance]] effect. Initially, the rest of the vehicle remains mostly unaffected, until translated into a vehicle [[yaw (rotation)|yaw]] [[oscillation]] of increasing [[amplitude]], producing loss of control. 

Vehicles that can experience this oscillation include [[motorcycle]]s and [[bicycle]]s, [[skateboard]]s, and, in theory, any vehicle with a single steering pivot point and a sufficient amount of freedom of the steered wheel, including that which exists on some [[light aircraft]] with [[tricycle gear]] where instability can occur at speeds of less than {{Convert|80|km/h|mph|abbr=on}}; this does not include most [[automobile]]s. The initial instability occurs mostly at high speed and is similar to that experienced by shopping cart wheels and aircraft landing gear.<ref name="Wilson">{{cite book
| title = Bicycling Science
| url = https://archive.org/details/isbn_9780262731546
| url-access = registration
| edition = Third
| last = Wilson
| first = David Gordon
|author2=Jim Papadopoulos
| year = 2004
| publisher = The MIT Press
| isbn = 0-262-73154-1
| pages = [https://archive.org/details/isbn_9780262731546/page/263 263–390]}}</ref><ref name="Cossalter">{{cite book
| title = Motorcycle Dynamics
| edition = Second
| last = Cossalter
| first = Vittore
| year = 2006
| publisher = Lulu.com
| isbn = 978-1-4303-0861-4
| pages = 241–342}}</ref>