Centreless wheel

Centreless wheels are toroidal in shape and have one or multiple bearings along the rim. Propulsion can be achieved in different ways, such as with gear teeth along the inner surface of the rim. They can be made lighter than solid and spoked wheels, resulting in better handling,{{Cite news |last=McCosh |first=Dan |title=Automotive Newsfront |pages=15 |work=Popular Science |date=August 1989 |url=https://books.google.com/books?id=vAAAAAAAMBAJ&pg=PA15 |volume=235 |number=2}} and less rotational inertia.{{cn|date=August 2022}} The lack of spokes or a traditional hub also allows for more space, which can be used to more easily package a hub motor.{{Cite web |date=2022-04-14 |title=If You're Considering an E-Bike, Let This Motor Guide Explain All They Have to Offer |url=https://www.bicycling.com/bikes-gear/a25836248/electric-bike-motor/ |access-date=2023-06-08 |website=Bicycling |language=en-US}}

Centerless wheels were built and patented for monowheels by at least 1869{{cite web |last1=Self |first1=Douglas |title=Monowheels |url=http://www.douglas-self.com/MUSEUM/TRANSPORT/motorwhl/motorwhl.htm |website=The Self Site |publisher=Douglas Self |access-date=12 May 2025 |ref=self-site |archive-url=https://web.archive.org/web/20250228052812/http://www.douglas-self.com/MUSEUM/TRANSPORT/motorwhl/motorwhl.htm |archive-date=28 February 2025 |language=English |url-status=live}} and were proposed to replace conventional wheels by at least 1890.{{cite web |last1=Thorp |first1=T. |title=Bicycle |url=https://ppubs.uspto.gov/api/pdf/downloadPdf/0436844?requestToken=eyJzdWIiOiJlMmU4MGQxNS0zMThmLTQ5ZmUtYjdhOS0zZTYwMTFlZDNmNzYiLCJ2ZXIiOiIzMjhiNDY5Mi0wYTJkLTRlNDEtYmE2MC0yMGE0NDI1MjI3NDYiLCJleHAiOjB9 |website=United States Patent Office |access-date=22 April 2025 |language=English |date=23 September 1890}} Prototypes for multi-wheel vehicles were built by Franco Sbarro at least by 1989, and Paul Lew had started small-volume commercial sales by 1993.{{cite web |title=Centerless/Hubless Wheels -- Black Hole |url=http://pardo.net/bike/pic/mobi/d.centerless-hubless-wheels/000.html#example:-Black-Hole |website=The Bicycle Museum Of Bad Ideas |access-date=22 April 2025 |language=English |ref=black-hole}}

The research and development of centreless wheels has not been pursued by any large company due to their complexity,{{cite web |title=Centerless/Hubless Wheels -- Problems |url=http://pardo.net/bike/pic/mobi/d.centerless-hubless-wheels/000.html#Problems |website=The Bicycle Museum Of Bad Ideas |access-date=22 April 2025 |language=English}} with their use limited to small companies and scientific analyses.{{Cite web |last1=Pinto |first1=Sheldon S.N. |last2=Amarnath |first2=Joshua M. |last3=Nair |first3=Jishnu S. |last4=Rajkumar |first4=E. |title=Design and Analysis of a Hubless Personal Vehicle |url=https://www.researchgate.net/publication/303702232 |access-date=2014-12-13 |website=ResearchGate |language=en}}{{Cite web |title=Design and Fabrication of Hubless Bike |url=https://studylib.net/doc/25317628/irjet-design-and-fabrication-of-hubless-bike |url-status=dead |access-date=2019-12-13 |website=studylib |language=en |archive-date=2021-08-19 |archive-url=https://web.archive.org/web/20210819061751/https://studylib.net/doc/25317628/irjet-design-and-fabrication-of-hubless-bike }}

The Wear and Tear Black Hole front bicycle centreless wheel and fork was designed with the goals of lighter weight and better aerodynamics than conventional wheels. It supported the rim with several small rollers, which reportedly wore out quickly - acceptable for a race-oriented product, but not practical for everyday use. The Black Hole was sold starting in 1993. Production was stopped after it was banned by the Union Cycliste Internationale, as the downsides (cost, durability, etc.) meant it was not compelling for general use. One of the designers, Paul Lew, later developed improved lightweight aerodynamic wheels using hubs. Today (2025), conventional wheel+fork assemblies are lighter than the Black Hole. It is unclear how modern aerodynamic wheels compare.

One real-life example of hubless wheels are those used in the replica Tron: Legacy Light Cycle. The street-legal motorcycle was modelled after the vehicle from the film and sold through Hammacher Schlemmer. Its hubless wheels are made from former truck tires, and a chain-driven friction drum provides power and brake force.{{Cite web |last=Chitwood |first=Adam |date=2012-02-27 |title=Geek Gifts: $55,000 Street-Legal TRON: LEGACY Light Cycle Replica |url=https://collider.com/tron-legacy-light-cycle-replica/ |access-date=2022-08-09 |website=Collider |language=en-US}}

Designed "for casual cruising and slow ride-bys at shows", it consists of a {{convert|996|cc|cuin|abbr=on}} fuel-injected Suzuki 4-stroke engine{{Cite news |last=Welsh |first=Jonathan |date=2011-02-16 |title=For 'Tron' Fans: Your Very Own Light Cycle |language=en-US |work=Wall Street Journal |url=https://www.wsj.com/articles/BL-DSB-6887 |access-date=2022-08-09 |issn=0099-9660}} in a steel frame covered by a fiberglass body with electroluminescent wire lighting.{{Cite web |last=Edelstein |first=Stephen |title=Functional 'Tron: Legacy' Light Cycle Replica Sells For $77,000 At Auction |url=https://www.motorauthority.com/news/1098355_functional-tron-legacy-light-cycle-replica-sells-for-77000-at-auction |access-date=2022-08-09 |website=Motor Authority |language=en}}

The Skatecycle is a device similar to a caster board, but with hubless wheels and a 2-axis twisting axle replacing the function of the casters. The central axle connects two standing platforms surrounded by 9" polyurethane hubless wheels, giving said wheels the appearance of stirrups. In order to move the unit, the rider rotates their feet inwards and outwards, creating a wave-like motion in the hinged frame and providing propulsion. In recognition of its novel design, the Skatecycle received the Bronze International Design Excellence Award in the transportation category in 2010.{{Cite web|url=https://www.core77.com//posts/18110/Alon-Karpmans-TRON-Inspired-Skatecycle|title=Alon Karpman's TRON Inspired Skatecycle|website=Core77|language=en|access-date=2019-04-13}}

Another example of a vehicle with centreless wheels is the Zero Bike, a lightweight hubless bicycle whose non-functional prototype won an Industrial Design Excellence Award in 1991.{{Cite news |last=Louie |first=Elaine |date=1991-08-29 |title=CURRENTS; A Bicycle Far Ahead Of the Pack (On Paper) |language=en-US |work=The New York Times |url=https://www.nytimes.com/1991/08/29/garden/currents-a-bicycle-far-ahead-of-the-pack-on-paper.html |access-date=2022-08-09 |issn=0362-4331}} Designed by then-ArtCenter College of Design students Makota Makita and Hiroshi Tsuzaki, it is based on the principle of magnetic superconductivity, also used in high-speed maglev trains.

The Ujet One electric scooter, produced in Luxembourg since 2019,{{Cite web |title=Case Study — Ujet One |url=https://www.ujet.com/case-study/ujet-one |access-date=2022-08-09 |website=www.ujet.com |language=en}} features front and rear centreless wheels connected to its frame with torsion-sprung suspension, as well as an electric hub motor. Such a setup is communicated to benefit from minimal energy loss in transmission. In 2019, the One won both the iF Gold{{Cite web |title=iF - UJet - Electric Mobility Solutions |url=https://ifdesign.com/en/winner-ranking/project/ujet-electric-mobility-solutions/259245 |website=iF WORLD DESIGN GUIDE}} and Red Dot{{Cite web|url=https://menafn.com/1098305315/Ujet-electric-scooter-wins-Red-Dot-Award-2019|title=Ujet electric scooter wins Red Dot Award 2019|website=menafn.com}} awards for its design.

A working prototype of a centreless wheel, using ball bearings, was shown at India Bike Week 2014 in Goa. Attached to a customized Royal Enfield motorcycle, the prototype rear wheel was designed by a team by the name of Freedom Sprints, which included Abhishek Sharma, Ankur Tiwari, Sarvesh Khemka, Yashodeep Yadav, and Mohammed Ansar.{{cite news |last=Choudhary |first=Neha |date=13 January 2014 |title=En Route to Goa: Having Modified the Royal Enfield 535cc, Bike Enthusiasts from Pink City Are Optimistic about Their Success in the Upcoming India Bike Week |newspaper=DNA : Daily News & Analysis |agency=Highbeam |url=http://www.highbeam.com/doc/1P3-3179247261.html |url-status=dead |url-access=subscription |accessdate=21 March 2014 |archive-url=https://web.archive.org/web/20140611094743/http://www.highbeam.com/doc/1P3-3179247261.html |archive-date=11 June 2014}} During testing, the bike was ridden from Ajmer to Jaipur.{{cite news |last=Singh |first=Ajay |date=12 January 2014 |title=Now, a 'spooky' bike without spokes |newspaper=The Times of India |location=Jaipur |url=http://timesofindia.indiatimes.com/city/jaipur/Now-a-spooky-bike-without-spokes/articleshow/28695709.cms?referral=PM |accessdate=21 March 2014}}

• Hub-center steering
• Motorcycle wheel

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Category:Wheels