A centreless wheel or hubless wheel is a wheel that lacks a centre or hub, instead being supported and driven at the rim.
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, [1] and less rotational inertia.[ citation needed ] The lack of spokes or a traditional hub also allows for more space, which can be used to more easily package a hub motor. [2]
While Franco Sbarro was the first to replace vehicles' conventional wheels with hubless wheels in 1989, [1] monowheels, which are similar in practice, predate Sbarro's hubless-wheel vehicles by more than 100 years. [3] The research and development of centreless wheels has not been pursued by any large company due to their complexity, with their use limited to small companies and scientific analyses. [4] [5]
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. [6]
Designed "for casual cruising and slow ride-bys at shows", it consists of a 996 cc (60.8 cu in) fuel-injected Suzuki 4-stroke engine [7] in a steel frame covered by a fiberglass body with electroluminescent wire lighting. [8]
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. [9]
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. [10] 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, [11] 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 [12] and Red Dot [13] 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. [14] During testing, the bike was ridden from Ajmer to Jaipur. [15]
A bicycle, also called a pedal cycle, bike, push-bike or cycle, is a human-powered or motor-assisted, pedal-driven, single-track vehicle, with two wheels attached to a frame, one behind the other. A bicycle rider is called a cyclist, or bicyclist.
A bicycle wheel is a wheel, most commonly a wire wheel, designed for a bicycle. A pair is often called a wheelset, especially in the context of ready built "off the shelf" performance-oriented wheels.
A sidecar is a one-wheeled device attached to the side of a motorcycle, scooter, or bicycle, making the whole a three-wheeled vehicle. A motorcycle with a sidecar is sometimes called a combination, an outfit, a rig or a hack.
A feet first (FF) motorcycle is a class of motorcycle design which positions the rider with their feet ahead, like a car, rather than below and astride, as with conventional bikes. As there are other types of motorcycle that have a 'feet forward' position, an alternative term sometimes used is advanced single track vehicle. The name "feet first" was first used by Royce Creasey
Vehicles that have two wheels and require balancing by the rider date back to the early 19th century. The first means of transport making use of two wheels arranged consecutively, and thus the archetype of the bicycle, was the German draisine dating back to 1817. The term bicycle was coined in France in the 1860s, and the descriptive title "penny farthing", used to describe an "ordinary bicycle", is a 19th-century term.
29ers or two-niners are mountain bikes and hybrid bikes that are built to use 700c or 622 mm ISO wheels, commonly called 29″ wheels. Most mountain bikes once used ISO 559 mm wheels, commonly called 26″ wheels. The ISO 622 mm wheel is typically also used for road-racing, trekking, cyclo-cross, touring and hybrid bicycles. In some countries, mainly in Continental Europe, ISO 622 mm wheels are commonly called 28″ wheels or "28 Incher".
The six main types of motorcycles are generally recognized as standard, cruiser, touring, sports, off-road, and dual-purpose. Sport touring is sometimes recognized as a seventh category or integrated with the touring category.
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.
An electric bicycle is a motorized bicycle with an integrated electric motor used to assist propulsion. Many kinds of e-bikes are available worldwide, but they generally fall into two broad categories: bikes that assist the rider's pedal-power and bikes that add a throttle, integrating moped-style functionality. Both retain the ability to be pedaled by the rider and are therefore not electric motorcycles. E-bikes use rechargeable batteries and typically are motor-powered up to 25 to 32 km/h. High-powered varieties can often travel more than 45 km/h (28 mph).
A kick scooter is a human-powered street vehicle with a handlebar, deck, and wheels propelled by a rider pushing off the ground with their leg. Today the most common scooters are made of aluminum, titanium, and steel. Some kick scooters made for younger children have 3 to 4 wheels and are made of plastic and do not fold. High-performance kickbikes are also made. A company that had once made the Razor Scooters revitalized the design in the mid-nineties and early two-thousands. Three-wheel models where the frame forks into two decks are known as Y scooters or trikkes.
Many countries have enacted electric vehicle laws to regulate the use of electric bicycles, also termed e-bikes. Some jurisdictions have regulations governing safety requirements and standards of manufacture. The members of the European Union and other regions have wider-ranging legislation covering use and safety.
The rim is the "outer edge of a wheel, holding the tire". It makes up the outer circular design of the wheel on which the inside edge of the tire is mounted on vehicles such as automobiles. For example, on a bicycle wheel the rim is a large hoop attached to the outer ends of the spokes of the wheel that holds the tire and tube. In cross-section, the rim is deep in the center and shallow at the outer edges, thus forming a "U" shape that supports the bead of the tire casing.
Wire wheels, wire-spoked wheels, tension-spoked wheels, or "suspension" wheels are wheels whose rims connect to their hubs by wire spokes. Although these wires are considerably stiffer than a similar diameter wire rope, they function mechanically the same as tensioned flexible wires, keeping the rim true while supporting applied loads. The term suspension wheel should not be confused with vehicle suspension.
A motorized scooter is a stand-up scooter powered by either a small internal combustion engine or electric hub motor in its front and/or rear wheel. Classified as a form of micro-mobility, they are generally designed with a large center deck on which the rider stands. The first motorized scooter was manufactured by Autoped in 1915.
Rudge Whitworth Cycles was a British bicycle, bicycle saddle, motorcycle and sports car wheel manufacturer that resulted from the merger of two bicycle manufacturers in 1894, Whitworth Cycle Co. of Birmingham, founded by Charles Henry Pugh and his two sons Charles Vernon and John, and Rudge Cycle Co. of Coventry.
The history of the motorcycle begins in the second half of the 19th century. Motorcycles are descended from the "safety bicycle," a bicycle with front and rear wheels of the same size and a pedal crank mechanism to drive the rear wheel. Despite some early landmarks in its development, the motorcycle lacks a rigid pedigree that can be traced back to a single idea or machine. Instead, the idea seems to have occurred to numerous engineers and inventors around Europe at around the same time.
Motorcyclewheels are made to cope with radial and axial forces. They also provide a way of mounting other critical components such as the brakes, final drive and suspension. Wheels, and anything directly connected to them, are considered to be unsprung mass. Traditionally motorcycles used wire-spoked wheels with inner tubes and pneumatic tyres. Although cast wheels were first used on a motorcycle in 1927, it would not be until the 1970s that mainstream manufacturers would start to introduce cast wheels on their roadgoing motorcycles. Spoked wheels are usually made using steel spokes with steel or aluminium rims. Cast wheels are predominantly made from an aluminium-alloy, but can also be made from more-exotic materials, such as magnesium content alloy or carbon fibre.