A dicycle () (also known as a diwheel) is a

vehicle A vehicle () is a machine designed for self-propulsion, usually to transport people, cargo, or both. The term "vehicle" typically refers to land vehicles such as human-powered land vehicle, human-powered vehicles (e.g. bicycles, tricycles, velo ...

with two parallel

wheel A wheel is a rotating component (typically circular in shape) that is intended to turn on an axle Bearing (mechanical), bearing. The wheel is one of the key components of the wheel and axle which is one of the Simple machine, six simple machin ...

s, side by side, unlike single-track vehicles such as

motorcycle A motorcycle (motorbike, bike; uni (if one-wheeled); trike (if three-wheeled); quad (if four-wheeled)) is a lightweight private 1-to-2 passenger personal motor vehicle Steering, steered by a Motorcycle handlebar, handlebar from a saddle-style ...

s and

bicycle A bicycle, also called a pedal cycle, bike, push-bike or cycle, is a human-powered transport, human-powered or motorized bicycle, motor-assisted, bicycle pedal, pedal-driven, single-track vehicle, with two bicycle wheel, wheels attached to a ...

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 self-balancing scooters with smaller wheels and no pedals such as the Segway PT and the 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

axis An axis (: axes) may refer to: Mathematics *A specific line (often a directed line) that plays an important role in some contexts. In particular: ** Coordinate axis of a coordinate system *** ''x''-axis, ''y''-axis, ''z''-axis, common names ...

, though not necessarily a common

axle An axle or axletree is a central shaft for a rotation, rotating wheel and axle, wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In ...

. In 2017, the

Merriam-Webster Merriam-Webster, Incorporated is an list of companies of the United States by state, American company that publishes reference work, reference books and is mostly known for Webster's Dictionary, its dictionaries. It is the oldest dictionary pub ...

's dictionary, limited usage to '

velocipede A velocipede () is a human-powered land vehicle with one or more wheels. The most common type of velocipede today is the bicycle. The term was probably first coined by Karl von Drais in French as ''vélocipède'' for the French translation ...

s with two parallel wheels,' and the

Oxford English Dictionary The ''Oxford English Dictionary'' (''OED'') is the principal historical dictionary of the English language, published by Oxford University Press (OUP), a University of Oxford publishing house. The dictionary, which published its first editio ...

limited it to 'pedal-powered vehicles with large wheels placed parallel to each other'.

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 with a range of on a fully charged

lithium-ion battery A lithium-ion or Li-ion battery is a type of rechargeable battery that uses the reversible intercalation of Li+ ions into electronically conducting solids to store energy. Li-ion batteries are characterized by higher specific energy, energ ...

, depending on terrain, riding style, and the condition of the batteries. Invented by Dean Kamen, it is produced by Segway Inc.

Self-balancing scooter

The 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 hoverboard.

Diwheel design

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 Oscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulu ...

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 between the wheel and the frame, to minimise power consumption during locomotion. 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. The equations of motion for the diwheel have been published.

Gallery

References

External links

US Patent Class 180/240
(lists all the vehicles coming under powered dicycles).

EDWARD, an electric dicycle by University of Adelaide studentsDi-Cycle: A Bike That Travels Over Land and Water
{{Webarchive, url=https://web.archive.org/web/20160828040907/http://gizmodo.com/5048066/di-cycle-a-bike-that-travels-over-land-and-water , date=2016-08-28 Land vehicles