A twistgrip is a handle that can be twisted to operate a control. It is commonly found as a

motorcycle A motorcycle (motorbike, bike, or trike (if three-wheeled)) is a two or three-wheeled motor vehicle steered by a handlebar. Motorcycle design varies greatly to suit a range of different purposes: long-distance travel, commuting, cruising ...

's right handlebar grip to control the

throttle A throttle is the mechanism by which fluid flow is managed by constriction or obstruction. An engine's power can be increased or decreased by the restriction of inlet gases (by the use of a throttle), but usually decreased. The term ''throttle'' ...

, but is sometimes found elsewhere, such as on a bicycle as a

gearshift A gear stick (rarely spelled ''gearstick''), gear lever (both UK English), gearshift or shifter (both U.S. English), more formally known as a transmission lever, is a metal lever attached to the transmission of an automobile. The term ''gear sti ...

, and in

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...

History

Roper steam velocipede 1868 The Standard Reference Work

Daimler Reitwagen color drawing 1885 DE patent 36423

The first use of the twist grip throttle control was on the

Roper steam velocipede The Roper steam velocipede was a steam-powered velocipede built by inventor Sylvester H. Roper of Roxbury, Boston, Massachusetts, United States sometime from 1867–1869. It is one of three machines which have been called the first motorcycle, a ...

of 1867-69. Rather than a sleeve that rotated around the handlebar, Sylvester H. Roper's steam motorcycle's entire handlebar rotated, with a dual mode operation. When rotated forward it opened the throttle, and when rotated backwards it applied the

spoon brake A bicycle brake reduces the speed of a bicycle or prevents it from moving. The three main types are: rim brakes, disc brakes, and drum brakes. Most bicycle brake systems consist of three main components: a mechanism for the rider to apply the ...

. ''

Motorcycle Consumer News ''Motorcycle Consumer News'' (MCN) was a monthly motorcycling magazine that reviewed motorcycles and accessories, and covered motorcycle safety, training and industry news. Unlike most publications, it was wholly subscriber-supported and did not ...

'' design columnist

Glynn Kerr Glynn Kerr is a British-born motorcycle designer residing in California, who has specialised in motorcycle design for over thirty years. He has written for ''Bike India'', ''Kicxstart'' (Netherlands), ''Motorcycle Consumer News'' (USA), ''Solo M ...

said that pioneering this technology was a point in favor of the Roper's precedence as the first motorcycle, in response to '' Cycle World'' Technical Editor Kevin Cameron's position that the 1885 Daimler ''Reitwagen'' was more deserving because it used the more successful technology,

internal combustion An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combust ...

rather than steam. The design drawings of the ''Reitwagen'' depicted a twist grip speed control, also applying the brake when turned one way, but when turned the other way, it would have tensioned the belt drive's

idler pulley {{refimprove, date=June 2015 An idler-wheel is a wheel which serves only to transmit rotation from one shaft to another, in applications where it is undesirable to connect them directly. For example, connecting a motor to the platter of a phonog ...

, applying power to the rear wheel in the manner of a clutch. The actual working model, however, did not have the twist grip, belt drive, or brakes.

Glenn Curtiss Glenn Hammond Curtiss (May 21, 1878 – July 23, 1930) was an American aviation and motorcycling pioneer, and a founder of the U.S. aircraft industry. He began his career as a bicycle racer and builder before moving on to motorcycles. As early a ...

, unlikely to have been aware of the prior uses of the twist grip, used it in his 1904

motorcycle land-speed record The motorcycle land-speed record is the fastest speed achieved by a motorcycle on land. It is standardized as the speed over a course of fixed length, averaged over two runs in opposite directions. AMA National Land Speed Records requires 2 passes ...

machine, and is sometimes credited as the inventor of the device.

Indian Indian or Indians may refer to: Peoples South Asia * Indian people, people of Indian nationality, or people who have an Indian ancestor ** Non-resident Indian, a citizen of India who has temporarily emigrated to another country * South Asia ...

claimed in their advertisements, also for their 1904 models, to have invented the twist grip. Whether Curtiss,

Gottlieb Daimler Gottlieb Wilhelm Daimler (; 17 March 1834 – 6 March 1900) was a German engineer, industrial designer and industrialist born in Schorndorf ( Kingdom of Württemberg, a federal state of the German Confederation), in what is now Germany. He w ...

, or Roper were the true inventors, the 1904 Indian would be the earliest use of the device on a production motorcycle. Motorcycle throttles are spring-loaded to cut the engine power back to idling when the twistgrip is released. Formerly some motorcycle throttle twistgrips had a screw that could be screwed in to make the twistgrip stay still when released (e.g. for the rider to signal right turn), but a ruling from

Brussels Brussels (french: Bruxelles or ; nl, Brussel ), officially the Brussels-Capital Region (All text and all but one graphic show the English name as Brussels-Capital Region.) (french: link=no, Région de Bruxelles-Capitale; nl, link=no, Bruss ...

forbad that on safety grounds.

References

{{reflist, 30em, refs= {{Citation , last= Girdler , first= Allan , title=First Fired, First Forgotten , magazine= Cycle World , publisher=

Hachette Filipacchi Media U.S. Hachette Filipacchi Media U.S., Inc. (HFM U.S.), originally known as CBS Publications, was a subsidiary of Hachette Filipacchi Médias (one of the world's largest magazine publishers), and was based in New York City. History It was formed in 19 ...

, issn=0011-4286 , location=Newport Beach, California , date= February 1998 , volume= 37 , issue= 2 , pages= 62–70 {{Citation , author-link=Glynn Kerr , last= Kerr , first= Glynn , date = August 2008 , title=Design; The Conspiracy Theory , magazine=

, location=Irvine, California , publisher=Aviation News Corp , volume=39 , issue=8 , issn=1073-9408 , page=36–37 , postscript=
Roper year 1869. {{Citation, last= Setright , first=L.J.K. , author-link=L. J. K. Setright , year= 1979 , title=The Guinness book of motorcycling facts and feats , publisher=Guinness Superlatives , isbn=0-85112-200-0 , pages= 12–18 {{Citation, url= https://books.google.com/books?id=ZdXaa3a2rtEC&pg=PA44 , title= Standard Catalog of American Motorcycles 1898-1981 , first= Jerry , last= Hatfield , publisher= Krause Publications , year= 2006 , ISBN= 978-0-87349-949-1 , page= 44 Motorcycle technology