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Encyclopedia > Hub gear
Transmission types
Manual

Automatic In mechanics, a transmission or gearbox is the system of gears and/or the hydraulic system (called variously hydrodynamic, fluid or automatic transmission) that transmits mechanical power from a prime mover—such as an engine or electric motor—to a typically rotary output device at a lower angular momentum but... A manual transmission (also known as a stick shift, straight drive, or standard transmission) is a type of transmission used in automotive applications. ... An automatic transmission is an automobile gearbox that can change gear ratios automatically as the vehicle moves, thus freeing the driver from having to shift gears manually. ...

Semi-automatic Tiptronic is a type of discrete automatic transmission developed by Porsche and used in its vehicles and those of its licensees. ... Semi-automatic transmission, or also known as clutchless manual transmission, automated manual transmission, e-gear, or paddle shift gearbox is a system which uses electronic sensors, processors and actuators to do gear shifts on the command of the driver. ...

Continuously-variable
Multitronic
Derailleur gears
Hub gears A Twin-clutch gearbox or Dual Clutch Transmission (DCT) is a semi-automatic transmission with separate clutches for odd and even gears. ... Saxomat was a type of automatic clutch available as an option on Saab 93, Volkswagen Beetle, Borgward, DKW, BMW, Opel, NSU and Glas. ... The continuously variable transmission (CVT) is a transmission in which the ratio of the rotational speeds of two shafts, as the input shaft and output shaft of a vehicle or other machine, can be varied continuously within a given range, providing an infinite number of possible ratios. ... Audi developed a new stepless transmission named Multitronic. ... Shimano XT rear derailleur on a mountain bike Derailleur gears are a variable ratio transmission system commonly used on bicycles, consisting of a chain, multiple sprockets and a mechanism to move the chain from one sprocket to another. ...

Hub gears or internal-gear hubs are a type of gear system used on bicycles. Hub gears are used mostly on utility bikes and various types of small wheeled bicycle, such as folding bikes. Hub gears work by internal planetary or epicyclic gearing, which means that the outer case of the hub gear unit (which is attached to the spokes) is made to turn at a different speed relative to the rear wheel's sprocket depending on which gear is selected. Spur gears found on a piece of farm equipment A gear is a wheel with teeth around its circumference, the purpose of the teeth being to mesh with similar teeth on another mechanical device -- possibly another gear wheel -- so that force can be transmitted between the two devices in a... “Velo” redirects here. ... a Dutch utility bicycle A utility bicycle is one which is designed for a practical purpose, as opposed to sport bicycles which are designed for recreation and competition, such as touring bicycles, racing bicycles and mountain bicycles. ... A Brompton folding bicycle A folding bicycle or folder is a type of bicycle that incorporates a number of hinges or joints, which may be lockable, that permit it to be folded into a more compact size. ... Epicyclic gearing is used here to increase output speed. ... This article does not cite its references or sources. ...


In the United States and United Kingdom, hub gears are less common than derailleur gears which are the dominant gear system on most modern bicycles in these countries. In most of continental Europe, however, hub gear systems are dominant. Shimano XT rear derailleur on a mountain bike Derailleur gears are a variable ratio transmission system commonly used on bicycles, consisting of a chain, multiple sprockets and a mechanism to move the chain from one sprocket to another. ...

In this simple epicyclic gear mechanism, the inner gear or "sun gear" (green) provides the input rotation. The two "planet gears" (blue) rotate freely about the planet gear carrier (yellow) which is fixed. As the planet gears rotate about the sun gear, they propel the outer ring gear or "annulus" (red), which provides the output rotation
In this simple epicyclic gear mechanism, the inner gear or "sun gear" (green) provides the input rotation. The two "planet gears" (blue) rotate freely about the planet gear carrier (yellow) which is fixed. As the planet gears rotate about the sun gear, they propel the outer ring gear or "annulus" (red), which provides the output rotation

Unlike derailleur gears, where the gears and mechanism are exposed to the elements, hub gears are enclosed within the hub of the bicycle's rear wheel. Gears are changed by a cable which is tightened or loosened by a lever or twist grip on the handlebars. Wikipedia does not have an article with this exact name. ...

Contents

History

Hub gears were invented in 1903 by the English company Sturmey Archer, and by the 1930s they had become common on bicycles across the world. Since the 1950s their popularity has been diminished by derailleur gears which have lower price and wider gear range[citation needed], although hub gears have undergone a small revival in recent years. 1900 (MCMIII) was a common year starting on Thursday (link will display calendar) of the Gregorian calendar or a common year starting on Friday of the 13-day slower Julian calendar. ... Motto (French) God and my right Anthem God Save the King (Queen) England() – on the European continent() – in the United Kingdom() Capital (and largest city) London (de facto) Official languages English (de facto) Government Constitutional monarchy  -  Queen Queen Elizabeth II  -  Prime Minister Tony Blair MP Unification  -  by Athelstan 967  Area... Sturmey-Archer is a manufacturing company from Nottingham, England. ... The 1930s (years from 1930–1939) were described as an abrupt shift to more radical and conservative lifestyles, as countries were struggling to find a solution to the Great Depression, also known in Europe as the World Depression. ... Shimano XT rear derailleur on a mountain bike Derailleur gears are a variable ratio transmission system commonly used on bicycles, consisting of a chain, multiple sprockets and a mechanism to move the chain from one sprocket to another. ...


Though most hub gear systems use one rear sprocket, SRAM's DualDrive system combines an epicyclic hub with a multi-speed rear derailleur system to provide a wide-ranging drivetrain concentrated at the rear wheel. The system is useful for folding bicycles (where a multiple front chainset could foul the bike's folding mechanism) and in recumbent bicycles and freight bicycles (where small wheels and/or increased weight require a wider range of gears with smaller individual steps between each ratio). Hub gear systems have in the past also been used on motorcycles, although this is now rare. SRAM Corporation is a bicycle component manufacturer based in Chicago, Illinois, incorporating the former bicycle division of Fichtel and Sachs, Sachs-Huret and recently acquiring Rock Shox, Avid and Truvativ, making it much more competitive against the industry giant Shimano. ... A Brompton folding bicycle A folding bicycle or folder is a type of bicycle that incorporates a number of hinges or joints, which may be lockable, that permit it to be folded into a more compact size. ... Tandem recumbent bicycle manufactured by BikeE A recumbent bicycle is a variety of bicycle which places the rider in a seated or supine position (rarely, in a prone position). ... Old-fashioned freight bicycle Freight bicycles or Freight tricycles or cargo bikes are human powered vehicles designed and constructed specifically for transporting large loads. ... Motorcyclists take a break from the road A motorcycle or motorbike is a single-track, two-wheeled motor vehicle powered by an engine. ...

14-speed hub cutaway diagram
14-speed hub cutaway diagram

Image File history File links Download high-resolution version (1181x1146, 1760 KB) şiğüöç // Rohloff AG Schematic of a gear box Speedhub (14 Gang) Mail von Mirco Rohloff (im OTRS gespeichert) Sehr geehrte Damen und Herren, hiermit stelle ich das Bild des Speedhubschnittes von unserer Homepage (http://www. ... Image File history File links Download high-resolution version (1181x1146, 1760 KB) şiğüöç // Rohloff AG Schematic of a gear box Speedhub (14 Gang) Mail von Mirco Rohloff (im OTRS gespeichert) Sehr geehrte Damen und Herren, hiermit stelle ich das Bild des Speedhubschnittes von unserer Homepage (http://www. ...

Advantages

  • Because the mechanism is enclosed within the hub, it is not exposed to dirt or weather. Hub gears thus need less maintenance than derailleur gears and are more reliable, making them suitable for utility bicycles.
  • The gear can be shifted when the bike is stationary, which makes them suitable for riding in city traffic with many stops and starts.
  • Internal hub gears are less vulnerable to damage in shipping than derailleurs.
  • Shifting is dramatically smoother than in external rear derailleurs.
  • As the chain does not move sideways, it can be covered, protecting the rider's clothing from grease and damage, another feature useful for utility cycling.

a Dutch utility bicycle A utility bicycle is one which is designed for a practical purpose, as opposed to sport bicycles which are designed for recreation and competition, such as touring bicycles, racing bicycles and mountain bicycles. ... Ugandan bicycle taxi or bodaboda Utility cycling encompasses any cycling not done primarily for fitness, recreation such as cycle touring, or sport such as cycle racing, but simply as a means of transport. ...

Disadvantages

  • Because of the limited space available in the hub, they have a more limited range of gears than derailleurs. Traditional hub gear systems have only three or four speeds. Recently, however, seven and eight speed internal hubs have become common and models are available with as many as fourteen speeds.
  • They are less efficient than derailleurs, at least in the unusual case of both types being clean and little worn.
  • They are heavier than a derailleur system.
A bicycle with a hub gear.
A bicycle with a hub gear.

Image File history File links Download high-resolution version (800x781, 64 KB) 14 speed Hub gear by Rohloff 14-Gang Nabe der Firma Rohloff Source: German Wikipedia (first upload 16:31, 28. ... Image File history File links Download high-resolution version (800x781, 64 KB) 14 speed Hub gear by Rohloff 14-Gang Nabe der Firma Rohloff Source: German Wikipedia (first upload 16:31, 28. ...

See also

Internal Schematic of a Rohloff Speedhub 500/14 Internal picture of a Rohloff Speedhub 500/14 The Rohloff SPEEDHUB 500/14 is a 14 speed epicyclic internal hub gear for bicycles. ... Spur gears found on a piece of farm equipment. ... The cycloidal gear profile is used in mechanical clocks. ... Epicyclic gearing is used here to increase output speed. ... Epicyclic gearing is used here to increase output speed. ... Worm and worm gear A worm gear, or worm wheel, is a type of gear that engages with a worm to greatly reduce rotational speed, or to allow higher torque to be transmitted. ... Non-circular gear example A non-circular gear (NCG) is a special gear design with special characteristics and purpose. ... The involute gear profile is the most commonly used system for gearing today. ... This article does not cite its references or sources. ... A hypoid is the name given to a type of helical (spiral) gear. ... Illustration of a Gear train with a pinion shown. ... Rack and pinion animation A rack and pinion is a pair of gears which convert rotational motion into linear motion. ... On a bicycle, the cassette or the freewheel is the set of rear sprockets that attaches to a hub on the rear wheel. ... Download high resolution version (500x680, 39 KB)Description: Photograph of spur gears on a piece of farm equipment. ... In an automobile and other four-wheeled vehicles, a differential is a device, usually consisting of gears, for allowing each of the driving wheels to rotate at different speeds, while supplying equal torque to each of them. ... A gear coupling is a mechanical device for transmitting torque between two shafts that are not coaxial. ... A gear train is a set or system of gears arranged to transfer rotational torque from one part of a mechanical sytem to another. ... There are very few or no other articles that link to this one. ... A hobbing machine is a special form of milling machine that mills gears. ... The Antikythera mechanism (main fragment) The Antikythera mechanism (Greek: O μηχανισμός των Αντικυθήρων transliterated as O mēchanismós tōn Antikythērōn) is an ancient mechanical analog computer (as opposed to most computers today which are digital computers) designed to calculate astronomical positions. ... Photo showing two ball screws. ... Jackscrew ( animation) A jackscrew mechanism uses a long threaded rod used to position a matching nut at any position along its length. ... South Pointing Chariot (replica) Supposedly invented sometime around 2600BC in China by the Yellow Emperor Huang Di, the South Pointing Chariot (Zhi Nan Ju 指南車) is widely regarded as the most complex geared mechanism of the ancient Chinese civilization. ... The Falkirk Wheel The Falkirk Wheel, named after the nearby town of Falkirk in central Scotland, is a rotating boat lift connecting the Forth and Clyde Canal with the Union Canal, which at this point differ by 24 metres, roughly equivalent to the height of an eight storey building. ... A leadscrew is a threaded shaft that is used in machines to create linear motion. ... Bicycle gearing is concerned with the connection between the pedals and the rear wheel of a bicycle, and with the effect this connection has on how easy or hard it is to turn the pedals. ...

External links

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Hub gear

  Results from FactBites:
 
Hub gear - Wikipedia, the free encyclopedia (635 words)
Hub gears are used mostly on utility bikes and various types of small wheeled bicycle, such as folding bikes.
Hub gears work by internal planetary or epicyclic gearing, which means that the outer case of the hub gear unit (which is attached to the spokes) is made to turn at a different speed relative to the rear wheel's sprocket depending on which gear is selected.
Unlike derailleur gears, where the gears and mechanism are exposed to the elements, hub gears are enclosed within the hub of the bicycle's rear wheel.
Hub gears (355 words)
Hub gears are less common than derailleur gears which are the dominant gear system on most modern bicycles.
Hub gears work by internal planetary or epicyclic gearing, which means that the outer case of the hub gear unit (which is attached to the spokes) is made to turn at a different speed to the rear wheel's axle depending on which gear is selected.
Hub gears were invented in 1903 by an English company called Sturmey Archer[?], and by the 1930s they had become common on bikes across the world.
  More results at FactBites »

 
 

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