View source for Dicycle

{{Short description|Vehicle with two parallel wheels}}
[[File:FlorenceSegwayTour.jpg|thumb|upright|Two tourists on a Segway tour in [[Florence]], Italy]]
A '''dicycle''' ({{IPAc-en|ˈ|d|aɪ|s|ɪ|k|əl}}<ref>{{Cite web|url=https://www.lexico.com/definition/dicycle|archive-url=https://web.archive.org/web/20191216180921/https://www.lexico.com/definition/dicycle|url-status=dead|archive-date=December 16, 2019|title=DICYCLE &#124; Meaning & Definition for UK English &#124; Lexico.com|website=Lexico Dictionaries &#124; English}}</ref>) (also known as a '''diwheel''') is a [[vehicle]] with two parallel [[wheel]]s, side by side, unlike [[single-track vehicle]]s such as [[motorcycle]]s and [[bicycle]]s, which have two wheels inline. Originally used to refer to devices with large wheels and pedals, the term is now used in relation to powered [[Personal transporter#Self-balancing_scooter|self-balancing scooters]] with smaller wheels and no pedals such as the [[Segway PT]] and the [[self-balancing scooter|self-balancing hoverboard]].

==Etymology==
In more recent usage, "dicycle" has been used for both pedaled and motorised vehicles with wheels of varying sizes, as long as they share a common [[Rotation around a fixed axis|axis]], though not necessarily a common [[axle]].<ref>{{Cite web|url=http://mashable.com/2013/05/01/electric-dicycles/#GrMUfZgBuZqI|title=Dicycles: The Scooter Gets a Hip Upgrade|work=Mashable|date=1 May 2013}}</ref><ref>{{cite web|url=http://inhabitat.com/crazy-marshall-dicycle-is-an-electric-motorcycle-and-mobile-disco-in-one/|title=Crazy Marshall Dicycle is an Electric Motorcycle and Mobile Disco in One|work=Inhabit|access-date=2017-07-03|archive-date=2017-05-09|archive-url=https://web.archive.org/web/20170509150406/http://inhabitat.com/crazy-marshall-dicycle-is-an-electric-motorcycle-and-mobile-disco-in-one/|url-status=dead}}</ref><ref>{{cite web|url=http://www.eaken.net/dicycle.html|title=Jack Mbatu on the dicycle|work=Eaken|quote=The dicycles cleared a grove of acacia trees, dodged termite mounds, and darted into a brushy thicket. They were not fast, but could cross rough and complicated landscape with ease}}</ref> In 2017, the [[Merriam-Webster]]'s dictionary, limited usage to '[[velocipede]]s with two parallel wheels,'<ref name=MW>{{Cite web|url=https://www.merriam-webster.com/dictionary/dicycle|title=Dicycle|work=Merriam-Webster|access-date=2 July 2017|quote=A velocipede having the two wheels parallel instead of in the same line}}</ref> and the [[Oxford English Dictionary]] limited it to 'pedal-powered vehicles with large wheels placed parallel to each other'.<ref name=OED>{{Cite web|url=https://en.oxforddictionaries.com/definition/dicycle|title=Dicycle|work=Oxford English Dictionary|access-date=2 July 2017|quote=A pedal-powered vehicle with two large wheels placed parallel to one another, instead of being in line as in a bicycle; especially a vehicle of the design devised by E. C. F. Otto}}{{dead link|date=September 2022|bot=medic}}{{cbignore|bot=medic}}</ref>

==Examples==
===Segway PT===
The [[Segway PT]] is a two-wheeled self-balancing [[personal transporter]] which uses computers, sensors, and electric motors to keep the device upright. The rider commands the PT to go forward or backward by shifting their weight forward or backward on the platform. The maximum speed of the Segway PT is {{convert|12.5|mph|kph}} with a range of {{convert|24|mi|abbr=on}} on a fully charged [[lithium-ion battery]], depending on terrain, riding style, and the condition of the batteries.<ref>{{cite web |url=http://www.segway.com/products/consumer-lifestyle/segway-i2-se |title=i2 SE Personal Transporter |accessdate=May 24, 2016 |url-status=dead |archiveurl=https://web.archive.org/web/20160527111842/http://www.segway.com/products/consumer-lifestyle/segway-i2-se |archivedate=May 27, 2016 }}</ref> Invented by [[Dean Kamen]], it is produced by [[Segway Inc.]]

===Self-balancing scooter===
The [[Personal transporter#Self-balancing scooter|self-balancing scooter]] is a category of personal transporter which includes all self-balancing powered portable devices with two parallel wheels that includes the [[Segway PT]], the Segway miniPRO and the [[Self-balancing scooter|self-balancing hoverboard]].

=== Diwheel design ===
[[File:USPatent 6752231.png|Drawing from 2002 patent application<ref name=Patent6752231>{{US patent|6752231|US patent 6,752,231, personal transportation system (2002)}}</ref>|thumb]]
The diwheel design has the two large outer wheels completely encompassing an inner frame. The inner frame is free to rotate within the wheels, and is typically supported by a common axle or idlers which roll on the wheels (see figure). Diwheels, like their more popular cousins the [[monowheel]], have been around for almost one and a half centuries. All of these platforms suffer from two common issues affecting driver comfort; [[slosh]] and tumbling (also known as gerbilling). Sloshing is when the inner frame [[oscillate]]s, and it occurs in all monowheels and diwheels where the centre of gravity of the inner frame is offset from the centre line of the wheels. It is very prevalent as these platforms typically have low [[Damping ratio|damping]] between the wheel and the frame, to minimise power consumption during locomotion.{{cn|date=July 2017}} In addition, during severe braking or acceleration the inner frame will tumble relative to the earth centred frame, which affects the ability of the driver to control the platform.  Both the sloshing and tumbling issue can be controlled through feedback control, and has been demonstrated successfully.<ref name=Patent6752231/><ref>{{cite web
| url = http://sites.mecheng.adelaide.edu.au/robotics/robotics_projects.php?wpage_id=44&title=60&browsebytitle=1
| title = EDWARD - Electric Diwheel With Active Rotation Damping
| publisher = University of Adelaid School of Mechanical Engineering
| accessdate = 2015-02-05
| archive-url = https://web.archive.org/web/20130519095151/http://sites.mecheng.adelaide.edu.au/robotics/robotics_projects.php?wpage_id=44&title=60&browsebytitle=1
| archive-date = 2013-05-19
| url-status = dead
}}</ref> The equations of motion for the diwheel have been published.<ref>{{cite web
| url = http://data.mecheng.adelaide.edu.au/robotics/projects/2009/EDWARD/DiwheelPaper_v3.pdf
| title = Control of an electric diwheel
|author1=B. Cazzolato |author2=J. Harvey |author3=C. Dyer |author4=K. Fulton |author5=E. Schumann |author6=C. Zhu |author7=Z. Prime | date = 2009}}</ref>

== Gallery ==

{{gallery
|File:Otto Dicycle.jpg|Otto dicycle (1870s)<ref>{{cite web |title=Dicycles and Diwheels - The Otto Dicycle |url=http://douglas-self.com/MUSEUM/TRANSPORT/diwheel/diwheel.htm#otto |website=Museum of Retro Tech |publisher=Douglas Self |access-date=24 February 2022 |date = January 2002 |quote="Left: The Otto Dicycle: 1870s. Designed by a Mr Otto and manufactured in the 1870s by the BSA company of Britain.  Note the little wheel on a stalk at the rear to stop you falling over backwards. Presumably falling forwards was your own responsibility."}}</ref>
|File:Dicycle.jpg|Dicycle at [[Delft University of Technology]] (photo 2011)
|File:Red self-balancing two-wheeled board with a person standing on it.png|A [[Self-balancing scooter]]
||[[Uno dicycle]] electric motorbike, with two wheels close together
|File:Airwheel-Q5.jpg| [[Airwheel Holding Limited|Airwheel]] Q5
}}

== See also ==
{{Portal|Transport}}
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*{{annotated link|Cart}}
*{{annotated link|Uno (dicycle)}}
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==References==
{{Reflist}}

==External links==
* [http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=0&p=1&f=S&l=50&Query=ccl%2F180%2F218&d=PTXT US Patent Class 180/240] {{Webarchive|url=https://web.archive.org/web/20210224034508/http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=0&p=1&f=S&l=50&Query=ccl%2F180%2F218&d=PTXT |date=2021-02-24 }} (lists all the vehicles coming under powered dicycles).
* [http://www.aqpl43.dsl.pipex.com/MUSEUM/TRANSPORT/diwheel/diwheel.htm Dicycles and Diwheels throughout history]
* [https://web.archive.org/web/20110404052943/http://www.fabels.org/fred.html Dicyclet - pedal driven Dicycle by Dutch artist Fred Abels]
* [https://laughingsquid.com/edward-an-electric-dicycle-by-university-of-adelaide-students/ EDWARD, an electric dicycle by University of Adelaide students]
*[https://gizmodo.com/5048066/di-cycle-a-bike-that-travels-over-land-and-water Di-Cycle: A Bike That Travels Over Land and Water]

[[Category:Land vehicles]]