Last updated
Morgan 3-Wheeler 193X.jpg
1932 Morgan Aero 2-Seater Sports
Fuldamobil NWF 200, Rare German Threewheeler.jpg
Fuldamobil three-wheeler (Postwar-era Germany)
Tricycle truck in Poland (Gorzów Wlkp)
Trihawk, a tadpole-type trike manufactured in California, United States during the 1980s

A three-wheeler is a vehicle with three wheels. Some are motorized tricycles, which may be legally classed as motorcycles, while others are tricycles without a motor, some of which are human-powered vehicles and animal-powered vehicles.



Many three-wheelers which exist in the form of motorcycle-based machines are often called trikes and often have the front single wheel and mechanics similar to that of a motorcycle and the rear axle similar to that of a car. Often such vehicles are owner-constructed using a portion of a rear-engine, rear-drive Volkswagen Beetle in combination with a motorcycle front end. Other trikes include All-terrain vehicles that are specially constructed for off-road use.

Three-wheelers can have either one wheel at the back and two at the front (2F1R), (for example: Morgan Motor Company) or one wheel at the front and two at the back (1F2R) (such as the Reliant Robin). Due to better safety when braking, an increasingly popular form is the front-steering "tadpole" or "reverse trike" sometimes with front drive but usually with rear drive. A variant on the 'one at the front' layout was the Scott Sociable, which resembled a four-wheeler with a front wheel missing. [1]

Three-wheelers, including some cyclecars, bubble cars and microcars, are built for economic and legal reasons: in the UK for tax advantages, or in the US to take advantage of lower safety regulations, being classed as motorcycles. As a result of their light construction and potential better streamlining, three-wheeled cars are usually less expensive to operate.[ citation needed ]

Some inexpensive three-wheelers have been designed specifically to improve mobility for disabled people. [2]

Three-wheeler transport vehicles known as auto rickshaws are a common means of public transportation in many countries in the world, and are an essential form of urban transport in many developing countries such as India and the Philippines.


Early automotive pioneer Karl Benz developed a number of three-wheeled models. [3] One of these, the Benz Patent Motorwagen, [4] is regarded as the first purpose-built automobile. It was made in 1885.

In 1896, John Henry Knight showed a tri-car at The Great Exhibition. [3]

In 1897, Edward Butler made the Butler Petrol Cycle, another three-wheeled car.

A Conti 6  hp Tri-car competed in (but did not complete) a 1907 Peking to Paris race sponsored by a French newspaper, Le Matin . [5]


Diagram comparing delta and tadpole layouts ThreeWheeled.svg
Diagram comparing delta and tadpole layouts

Two front

A configuration of two wheels in the front and one wheel at the back presents two advantages: it has improved aerodynamics, and that it readily enables the use of a small lightweight motorcycle powerplant and rear wheel. This approach was used by the Messerschmitt KR200 and BMW Isetta. Alternatively, a more conventional front-engine, front wheel drive layout as is common in four-wheeled cars can be used, with subsequent advantages for transversal stability (the center of mass is further to the front) and traction (two driven wheels instead of one). Some vehicles have a front engine driving the single rear wheel, similar to the rear engine driving the rear wheel. The wheel must support acceleration loads as well as lateral forces when in a turn, and loss of traction can be a challenge.

A new tadpole configuration has been proposed with a rear engine driving the front wheels. This concept (Dragonfly Three Wheeler [6] ) claims both stability and traction (two driven wheels), as well as a unique driving experience.

With two wheels in the front (the "tadpole" form or "reverse trike") the vehicle is far more stable in braking turns, but remains more prone to overturning in normal turns compared to an equivalent four-wheeled vehicle, unless the center of mass is lower and/or further forward. Motorcycle-derived designs suffer from most of the weight being toward the rear of the vehicle.[ citation needed ]

For lower wind resistance (which increases fuel efficiency), a teardrop shape is often used.[ citation needed ] A teardrop is wide and round at the front, tapering at the back. The three-wheel configuration allows the two front wheels to create the wide round surface of the vehicle. The single rear wheel allows the vehicle to taper at the back. Examples include the Aptera (solar electric vehicle) and Myers Motors NmG.

Two rear

Having one wheel in front and two in the rear for power reduces the cost of the steering mechanism but greatly decreases lateral stability when cornering while braking.

When the single wheel is in the front (the "delta" form, as in a child's pedal tricycle), the vehicle is inherently unstable in a braking turn, as the combined tipping forces at the center of mass from turning and braking can rapidly extend beyond the triangle formed by the contact patches of the wheels. This type, if not tipped, also has a greater tendency to spin out ("swap ends") when handled roughly.[ citation needed ]

Lateral stability [7]

The disadvantage of a three-wheel configuration is that lateral stability is lower than with a four-wheeled vehicle.

With any vehicle, an imaginary line can be projected from the vehicles centre of mass to the ground, representing the force exerted on the vehicle by its mass. With the vehicle stationary, the line will be vertical. As the vehicle accelerates, that imaginary line tilts backward, remaining anchored to the centre of mass the point at which the line intersects the ground moves backward. As you brake it moves forward, with cornering it moves sideward. Should the point at which this line intersects the ground move outside of the boundary formed by connecting the tyre contact patches together (a rectangle for a four-wheeled car, or a triangle for a trike) then the vehicle will tip and eventually fall over. This is true for any vehicle.

With all vehicles it is critical that the vehicle should be engineered to slide before this point of instability is reached.

This can be achieved in several ways:

In the case of a three-wheeled ATV, tipping may be avoided by the rider leaning into turns.

Tilting option

Tripendo recumbent tricycle, a tilting three-wheeler TripendoTilted.jpg
Tripendo recumbent tricycle, a tilting three-wheeler
Vandenbrink Carver Carver one 06011701.jpg
Vandenbrink Carver

To improve stability some three-wheelers are designed to tilt while cornering like a motorcyclist would do. The tilt may be controlled manually, mechanically or by computer.

A tilting three-wheeler's body or wheels, or both, tilt in the direction of the turn. Such vehicles can corner safely even with a narrow track.

Some tilting three-wheelers could be considered to be forms of feet forward motorcycles or cabin motorcycles or both.

Electric three wheelers

Battery-powered three wheelers

Toyota i-Road, a three-wheeled battery powered personal mobility vehicle I-road - Grenoble.JPG
Toyota i-Road, a three-wheeled battery powered personal mobility vehicle

Three-wheeled battery powered designs include:

Solar-powered three wheelers

Here are three notable examples of solar-powered three wheelers; two race cars, the Infinium and the Sky Ace TIGA, and a vehicle planned for production, the Aptera.

Infinium, winner of 2010 American Solar Challenge InfiniumAtAirStrip.jpg
Infinium, winner of 2010 American Solar Challenge

The Infinium, built by the University of Michigan Solar Car Team, came in 3rd place in the 2009 World Solar Challenge held in Australia, and won the 2010 American Solar Challenge.

Ashiya University's Sky Ace TIGA achieved 91.332 kilometres per hour (56.751 mph) at Shimojishima Airport, in Miyakojima, Okinawa, Japan, to win the Guinness World Record, on 20 August 2014. [8] It took the record from another three-wheeler, Sunswift IV, designed and built at the University of New South Wales in Australia, [9] by a margin of almost 3 km/h.

Solar panels on the hood, roof, dashboard and hatch of the Aptera EV APTERA2019 ASPHALT-DOORS-CLOSED crop.jpg
Solar panels on the hood, roof, dashboard and hatch of the Aptera EV

The Aptera solar electric vehicle [10] uses a tadpole layout and is being designed to have a top speed of over 100 mph. The Aptera uses 42 KW in-wheel electric motors [11] and can be ordered with two (front-wheel drive) or three (all-wheel drive) motors. The Aptera's roof and dashboard, and optionally its hood and hatch, are fitted with solar panels, with the full compliment being designed to add a range of up to 40 miles per day and 11,000 miles per year in the sunniest climates. First customer availability is planned for before the end of 2024. [12]

Steam-powered three wheelers

Cugnot's fardier a vapeur, as preserved at the Musee des Arts et Metiers, Paris, France Joseph Cugnot's 1770 Fardier a Vapeur, Musee des arts et metiers, Paris 2015.jpg
Cugnot's fardier à vapeur, as preserved at the Musée des Arts et Métiers, Paris, France

The world's first full-size self-propelled land vehicle was a three-wheeler. French Army Captain Nicolas-Joseph Cugnot's 1770 fardier à vapeur (steam dray), a steam tricycle with a top speed of around 3 km/h (2 mph), was intended for hauling artillery. [13]

Another of the earliest preserved examples is the Long steam tricycle, built by George A. Long around 1880 and patented in 1883, [14] [15] now on display at the Smithsonian Institution.

Wind-powered three wheelers

The Whike is a recumbent tricycle with a sail, made in the Netherlands.

All-terrain vehicles

Honda, Suzuki and Yamaha all-terrain vehicles HONDA ATC70 and SUZUKI ALT50 TRAILBUDDY and YAMAHA TRI-ZINGER YT60.jpg
Honda, Suzuki and Yamaha all-terrain vehicles

Due to the incidence of injuries and deaths related to their use, a 10-year ban, entirely voluntary for manufacturers, was placed on the sale of new three-wheeled all-terrain vehicles in the United States in January 1988.[ citation needed ] More injuries were sustained by riders by not applying a proper riding technique, and lack of wearing proper safety gear such as helmets and riding boots. In a search conducted by the Consumer Product Safety Commission, it was determined that "no inherent flaw was found in the three wheel design".[ citation needed ]


Bond Bug at Silverstone BondBugSilverstone.jpg
Bond Bug at Silverstone

In the U.S, the National Highway Traffic Safety Administration defines and regulates three-wheeled vehicles as motorcycles. [16] However, in 2015 a bill was introduced in Congress that would prevent some three wheeled vehicles from being classified as motorcycles in the United States, instead creating a new classification for "autocycles". [17] [18]

Driver's license and registration requirements vary on a state-by-state basis. Some states require drivers of three wheeled vehicles to have a motorcycle license and register the vehicle as a motorcycle. Some states, including Virginia, Kansas, and Indiana, classify some three wheeled vehicles as autocycles. Virginia defines an autocycle as "a three-wheeled motor vehicle that has a steering wheel and seating that does not require the operator to straddle or sit astride and is manufactured to comply with federal safety requirements for motorcycles." [19] Indiana defines it as "a three (3) wheeled motor vehicle in which the operator and passenger ride in a completely or partially enclosed seating area that is equipped with:(1) a rollcage or roll hoops; (2) safety belts for each occupant; and (3) antilock brakes;and is designed to be controlled with a steering wheel and pedals." [20] In other jurisdictions, such as British Columbia, Canada, and Connecticut, a three-wheeled vehicle with an enclosed passenger compartment or partially enclosed seat is considered an automobile.[ citation needed ]


Two front wheels

NameCountryYears manufacturedComments
Léon Bollée VoituretteFrance1895–?
TriPodCars [21] Tripod 1Australia2012–?400 kg Reverse Trike, Bandit 1250, ZX14R (200+ hp) and EV
Berkeley Cars Berkeley T60England1959
Egg Switzerland1896–99
Advance 6 hp air-cooled Tri Car and 9 hp water-cooled Tri Car [22] England1902–12
Humber Tricar [23] [24] England1904
Riley Olympia Tricar [25] England1904 [26]
Mars Carette [27] England1904–05Mars Motors Co existed in Finchley, London, White and Poppe water-cooled engine, Single-cylinder, 3.3 kW
Lagonda Tricar [28] England1904–07total production: 69 cars
Anglian England1905–07
Armadale England1906–07
Ranger Cub England1970–1980Reverse Trike/Tadpole, A-Series engine 848-1275cc
Morgan V-Twin and F-SeriesEngland1911–39, 1932–52 Morgan Super Sports 2-Seater 1937
American Tri-Car United States1912
Birmingham Small Arms Company Three WheelerEngland1929–361100cc engine [29]
Zaschka Germany1929Folding three-wheeler: Zaschka Three-wheeler 1929
Dymaxion car United States1933Concept car designed by Buckminster Fuller
Mathis VEL 333France19463 seats, flat-twin front engine, aluminium body, production less than 10 units
Fend Flitzer Germany1948 - 19511 seat, Messerschmitt kabinenroller precursor, production about 250 units
1951 Hoffmann Germany19512 seats, aluminium body, engine mounted on the rear wheel steering pivot
Velorex Oskar and other models Czechoslovakia 1951–71Originally with leather bodies
Isetta UK1957–62Three-wheeled version of the Isetta built in the UK to take advantage of tax and licensing regulations
Scootacar UK1957–64
Messerschmitt KR175 Germany1953–55
Messerschmitt KR200 Germany1955–64
Peel P50 Isle of Man 1963–64Smallest production car ever built
HM Vehicles Free-way United States1979–82
Campagna T-Rex Canada1996–present
Malone Car Company F1000|Skunk SS|TAZRUnited Kingdom1999–presentHigh-power internal combustion and pure electric versions released November 2010
Cree SAM Switzerland2001 Electric, only 80 produced
Myers Motors NmG ("No more Gas")United States2006–presentSingle-occupant all-electric plug-in
BRP Can-Am Spyder Roadster Can-Am Spyder Roadster Canada2007–presentThe Can-Am Spyder is a three-wheeled motorcycle manufactured by Bombardier Recreational Products.
Brudeli 645L Norway2008–
MoonbeamUnited States2008–present100 mpg DIY, fabric-covered car based on parts from two Honda 150cc motorscooters [30]
Triac United States2009–2011 Electric, never entered production
XR-3 Hybrid United StatesPlans–2008, Kit–2009Front 3-cylinder diesel (125 mpg), rear electric 40 mile range (220 mpg when used as a hybrid) [31]
Aptera (solar electric vehicle) United States2022 plannedSolar-powered Electric
Triton Trike United States2000–presentGas-powered, 42+ mpg, front-wheel drive, custom builds and kits available
Nobe GT100 Estonia & United States2021 planned Electric, powered at all 3 wheels
Polaris Slingshot United States2015–present
Vanderhall Laguna Roadster United States2016–2018Exotic Auto-cycle, mono-aluminum chassis, carbon fiber body, 200 HP, 1550 pounds dry weight, side-by-side seating, fwd. 1.4 liter turbo GM power plant. 6 speed Automatic with paddle shift option. Manufactured by Vanderhall Motor Works in Provo, Utah U.S.A
Vanderhall Venice United States2017–presentThe mainstay of the Vanderhall line up, the Venice brings the soul of roadster motoring while extending effortless performance in kind. [32]
Vanderhall Carmel United States2020–presentThe Vanderhall Carmel brings more luxury and convenience to the Carmel lineup. With provisions to accommodate a removable capshade, the Carmel promises additional class and comfort for your journey. [33]
Vanderhall Edison United States2020–presentThe Edison2: A fully electric roadster that combines refined and eye-catching design while maintaining classic, elegant lines. Unplug and play has been redefined [34]
Elio Motors Shreveport, LA, United StatesAwaiting fundingTwo passenger fully enclosed cockpit with car controls
Girfalco Azkarra Canada2017All-electric two-passenger three-wheeled vehicle, possibly the quickest three-wheeler
Go3WheelerUnited States2014single person three wheeler
Corbin Sparrow
Piaggio MP3
Tri-Magnum United StatesTilting 3-wheeler capable of seating two people. [35]
Volkswagen GX3
Morgan 3-Wheeler England2012–presentThe power train is a 1983cc ‘V-twin’ fuel injected engine mated to a Mazda 5 speed (and reverse) gearbox
Fuel Vapours AléCanada2005–presentPrototype. Gets 92 mpg.
Arcimoto FUVUnited States2019–presentTwo passenger all-electric, 102 mile range City
Fiberfab Scarab STM United States1976 Kit car with canopy door manufactured by Fiberfab
Bricklin 3EV United StatesPlannedTwo passenger electric vehicle from Malcolm Bricklin. [36]

Two rear wheels

NameCountryYears manufacturedComments
Apino Brazilunknown Mini Truck
Benz Patent Motorwagen Germany1886–93
Eco-Fueler USA2009–20112 seater built in Oregon. [37]
La Va Bon Train France1904–1050–100 believed built
Davis D-2 Divan United States1947–48about 13–17 built, including the 494, a Jeep-like military vehicle [38]
Scammell Scarab England1948–67
Autoette United States1948–70
Daihatsu Bee Japan1951–1952
Daihatsu Midget Japan1957–72
Mazda T-2000 Japan1957–74
Mazda K360 Japan1959–69
Mazda T600 Japan1959–71
Kia K-360 South Korea1962–1973Kia's first truck (OEM Mazda K-360)
Kia T-1500 South Korea1963–?1484 cc, 60 hp, four cylinder and a maximum load of 1.5 tons. (OEM Mazda T-1500)
Kia T-600 South Korea1969–1974577cc, 20 HP and 500 kg load. Top speed of 75 km/h. 7726 produced (OEM Mazda T-600)
Kia T-2000 South Korea1967–19811985 cc, 81 hp, four cylinder and a maximum load of 2 tons. 15952 produced (OEM Mazda T-2000)
Piaggio Ape Italy1948–present
Electra-King United States1964?–1980s?Two-seater electric car [39]
Bond 875 England1965–70
Bond Bug England1970–74
Reliant Robin England1973–81, 1989–2002
Reliant Regal England1953–1973An example of this vehicle is the iconic van belonging to Del Boy and Rodney Trotter in the long-running BBC sitcom Only Fools and Horses, though it is often incorrectly referred to as a Reliant Robin.
GM Lean Machine [40] [41] United States1980sTilt, concept car [42]
TriVette United States1974–1976
Twike Germany1995–presentElectric-human-power hybrid, developed in Switzerland
ZAP Xebra United States2006–2009electric power
eTukUnited States2014–re-designed tuk tuk for the US Market, including an all-electric motor [43]
Snyder ST600-c United States2011–2012Imported by Snyder Technologies / Wildfire Motors, this is a rebrand of the Fulu Motors 富路金骏马, Fulu Jinjunma in English. Referred to as the 09 golden horse internally.
Carver Netherlands2007–2009Tilt
CityEl DenmarkMini-El, City-El
United States1932-1973 [44]
Tri Glide
United Statessince 2009

See also

Related Research Articles

<span class="mw-page-title-main">Anti-lock braking system</span> Safety anti-skid braking system used on aerospace and land vehicles

An anti-lock braking system (ABS) is a safety anti-skid braking system used on aircraft and on land vehicles, such as cars, motorcycles, trucks, and buses. ABS operates by preventing the wheels from locking up during braking, thereby maintaining tractive contact with the road surface and allowing the driver to maintain more control over the vehicle.

<span class="mw-page-title-main">Recumbent bicycle</span> Type of bicycle

A recumbent bicycle is a bicycle that places the rider in a laid-back reclining position. Some recumbent riders may choose this type of design for ergonomic reasons: the rider's weight is distributed comfortably over a larger area, supported by back and buttocks. On a traditional upright bicycle, the body weight rests entirely on a small portion of the sitting bones, the feet, and the hands.

<span class="mw-page-title-main">Tricycle</span> Three-wheeled self-powered vehicle

A tricycle, sometimes abbreviated to trike, is a human-powered three-wheeled vehicle.

<span class="mw-page-title-main">Cargo bike</span> Human powered vehicle to carry goods

There have been many human powered vehicles designed and constructed specifically for transporting loads since their earliest appearance in the 20th century. They are referred to variously depending on the number of wheels — typically two, three, or four — and by their specific use. Adjectives used to describe the tasks to which the bicycles, dicycles, tricycles, or quadracycles are put include cargo cycles, freight cycles, box cycles, carrier cycles, and so on. Sometimes they are also called cycletrucks, which uses a sense of the word 'truck' predating the automobile.

<span class="mw-page-title-main">Trailer (vehicle)</span> Towed cargo vehicle

A trailer is an unpowered vehicle towed by a powered vehicle. It is commonly used for the transport of goods and materials.

<span class="mw-page-title-main">Tilting three-wheeler</span> Tilting three-wheeled vehicle

A tilting three-wheeler, tilting trike, leaning trike, or even just tilter, is a three-wheeled vehicle and usually a narrow-track vehicle whose body and or wheels tilt in the direction of a turn. Such vehicles can corner without rolling over despite having a narrow axle track because they can balance some or all of the roll moment caused by centripetal acceleration with an opposite roll moment caused by gravity, as bicycles and motorcycles do. This also reduces the lateral acceleration experienced by the rider, which some find more comfortable than the alternative. The narrow profile can result in reduced aerodynamic drag and increased fuel efficiency. These types of vehicles have also been described as "man-wide vehicles" (MWV).

<span class="mw-page-title-main">Motorized bicycle</span> Bicycle with an attached motor or engine and transmission

A motorized bicycle is a bicycle with an attached motor or engine and transmission used either to power the vehicle unassisted, or to assist with pedalling. Since it sometimes retains both pedals and a discrete connected drive for rider-powered propulsion, the motorized bicycle is in technical terms a true bicycle, albeit a power-assisted one. Typically they are incapable of speeds above 52 km/h (32 mph), however in recent years larger motors have been built, allowing bikes to reach speeds of upwards of 72 km/h.

The powertrain layout of a motorised vehicle such as a car is often defined by the location of the engine or motors and the drive wheels.

<span class="mw-page-title-main">Cargo tricycle</span>

A cargo tricycle or transport tricycle is a type of cargo bike that has historically been used for the transport of goods, and more recently also for transport of children. It can stand on its own when parked and is stable at low speeds. However, they often have poor stability at high speed as most simple models are not able to lean into the turn to shift the center of gravity. However, there are some cargo tricycles with advanced suspension that allows for some roll which alleviates some of the stability problems at high speed.

<span class="mw-page-title-main">Can-Am Spyder</span> Three-wheeled motorcycle

The Can-Am Spyder ("Spyder") is a three-wheeled motorcycle manufactured by Can-Am motorcycles, a division of Bombardier Recreational Products. The vehicle has a single rear drive wheel and two wheels in front for steering, similar in layout to a modern snowmobile. The Spyder uses an ATV-like chassis. The manufacturer refers to it as a "roadster," but in technical terms, it is more of what has been traditionally called a trike.

<span class="mw-page-title-main">Electric trike</span>

An electric trike is a three-wheeled vehicle powered by an electric motor.

<span class="mw-page-title-main">Motorized tricycle</span> Resembling a bicycle with two rear wheels and an engine

A motorized tricycle, motor trike, or motortrycle is a three-wheeled vehicle based on the same technology as a bicycle or motorcycle, and powered by an electric motor, motorcycle, scooter or car engine.

<span class="mw-page-title-main">Elio Motors</span> American automotive company

Elio Motors is a company founded by Paul Elio in 2009, to design and manufacture a three-wheeled, enclosed autocycle.

<span class="mw-page-title-main">Polaris Slingshot</span> Three-wheeled car

The Polaris Slingshot is a three-wheeler. The first edition of the model was introduced in 2014 as a 2015 model.

<span class="mw-page-title-main">Vanderhall Motor Works</span> American vehicle manufacturer

Vanderhall Motor Works is an American vehicle manufacturer based in Provo, Utah. It manufactures hand-made three-wheeled autocycles designed for sports driving, touring, commuting and city driving.

<span class="mw-page-title-main">Yamaha Niken</span> Three-wheeler motorcycle by Yamaha

The Yamaha Niken is a 845 cc tilting three-wheeler motorcycle, manufactured since 2018 by Yamaha Motor and sold worldwide.

<span class="mw-page-title-main">Vanderhall Venice</span> Motor vehicle

The Vanderhall Venice is a three-wheeled roadster produced by the American vehicle manufacturer Vanderhall Motor Works. Competitive models include the Morgan 3-Wheeler and the Polaris Slingshot.

<span class="mw-page-title-main">Vanderhall Laguna</span> Motor vehicle

The Vanderhall Laguna is a three-wheeled roadster produced by the American vehicle manufacturer Vanderhall Motor Works from 2016 to 2018.


  1. "Scott Sociable" . Retrieved 2015-10-05.
  2. Stańko-Pająk, K; Bursa, B; Seńko, J; Detka, T; Korczak, S; Nowak, R; Popiołek, K; Lisiecki, J; Paczkowski, A (2022-07-01). "A three-wheeled vehicle for the disabled people". IOP Conference Series: Materials Science and Engineering. 1247 (1): 012039. Bibcode:2022MS&E.1247a2039S. doi: 10.1088/1757-899X/1247/1/012039 . ISSN   1757-8981. S2CID   250504234.
  3. 1 2 Elvis Payne (2012). "The History of the 3-Wheeled Vehicle". Retrieved 2012-01-03.
  4. Chris Chong (July 2, 2006). "History in its magnificence". Archived from the original on 2007-10-24. Retrieved 2008-01-20.
  5. "History". Archived from the original on 2007-08-26. Retrieved 2008-01-20.
  6. Design. "Dragonfly three wheeler". Retrieved 2021-06-09.
  7. Riley, Robert Q. "The Dynamic Stability of Three-Wheeled Vehicles in Automotive-Type Applications". Robert Q. Riley Enterprises. Archived from the original on 2020-09-22.
  8. "Fastest solar-powered vehicle". Guinness World Records.
  9. "Aussie car breaks a world speed record". AAP. 7 January 2011. Retrieved 2011-01-07.
  10. Voelcker, John (2019-08-28). "Exclusive: 3-Wheeled Aptera Reboots as World's Most Efficient Electric Car". IEEE Spectrum. IEEE. Retrieved 2020-01-20.
  11. "Aptera solar EV Launch Edition: 400-mile range, no Supercharging yet". Green Car Reports. 2023-01-22. Retrieved 2023-03-18.
  12. Chris (2023-01-27). "Aptera Announces Accelerator Program to Kick Off Production Plan". Aptera. Retrieved 2023-02-24.
  13. "Fardier de Cugnot". Archived from the original on July 16, 2013.
  14. "1880 Long Steam Tricycle - Pictures". 2009-06-17. Retrieved 2010-07-29.[ dead link ]
  15. "America on the Move | Long steam tricycle". 2008-10-24. Retrieved 2014-06-17.
  16. "Highway Safety - Title 23, United States Code, Chapter 4 and Related Highway Safety Provisions" (PDF). December 2008. Retrieved 2015-10-05.
  17. "Newly Introduced Federal Legislation Would Ensure That Three-Wheeled Automobiles Are Not Classified As Motorcycles". Motorcycle Law Group. Retrieved 26 April 2017.
  18. "S.685 - Autocycle Safety Act". Congress. 10 March 2015. Retrieved 26 April 2017.
  19. Va. Code Ann. § 46.2-100 (West)
  20. Ind. Code Ann. § 9-13-2-6.1 (West)
  21. "Tri Pod Cars".
  22. "Advance Fore-Cars and Tri-Cars". Archived from the original on 2008-01-12. Retrieved 2008-01-23.
  23. "British Motor Manufacturers (1894-1960) Humber". Archived from the original on February 21, 2009. Retrieved 2008-01-20.
  24. "Humber History". Archived from the original on June 8, 2007. Retrieved 2008-01-20.
  25. "Rileys 1896 - 1939 The Pre-Nuffield Years". Rob's Riley Pages ( Archived from the original on March 21, 2005. Retrieved 2008-01-20.
  26. illustration Archived December 29, 2010, at the Wayback Machine
  27. "1904 Mars Carette - Franschhoek Motor Museum". 20 October 2017. Retrieved 2020-11-24.
  28. "The History of Classic Cars: 1905 Lagonda Tricar". Retrieved 2008-01-20.
  29. Peter Bowler, president The BSAFWD Club. "image and description". Archived from the original on 2012-02-05. Retrieved 2012-04-09.
  30. Wilson, Mark (2006-09-24). "Moonbeam: 100mpg Homemade Car". Retrieved 2015-10-05.
  31. "XR3 Hybrid Personal Transit Vehicle: A 125 mpg Plug-In Hybrid Three Wheeler You Build From Plans". Retrieved 2012-04-09.
  32. "Venice". Vanderhall Motor Works. Retrieved 2020-09-18.
  33. "Carmel". Vanderhall Motor Works. Retrieved 2020-09-18.
  34. "Edison 2". Vanderhall Motor Works. Retrieved 2020-09-18.
  35. "Project 32: A High-Performance Tilting Three-Wheel Vehicle". Archived from the original on 15 January 2006. Retrieved 19 April 2022.
  36. "Meet The Bricklin 3EV".
  37. "Eco-Fueler". Archived from the original on 7 February 2011. Retrieved 19 April 2022.
  38. Patton, Phil (September 24, 2009). "A Dreamer's Machine, More Promise Than Reality". The New York Times via
  39. Rob & Sharon McLellan. "advertising brochure". Retrieved 2012-04-09.
  40. "General Motors Three Wheeled Cars". GM's Lean Machine ( Retrieved 2008-04-08.
  41. "Lean Machines: Preliminary Investigation" (PDF). Institute of Transportation Studies, University of California at Berkeley ( Retrieved 2008-04-08.
  42. "illustration" . Retrieved 2012-04-09.
  43. "eTuk USA" . Retrieved 2014-07-01.
  44. "Remembering the 1937 Harley-Davidson Servi-Car GE". March 2022.