Para triathlon is a variant of the triathlon for athletes with a physical disability. The sport is governed by World Triathlon (TRI; formerly known as the International Triathlon Union or ITU), and was first held as a Paralympic event at the 2016 Summer Paralympics in Rio de Janeiro , Brazil.
41-463: At events sanctioned by World Triathlon, athletes compete over a para triathlon sprint distance event with a 750 m swim, 20 km cycle using handcycles , bicycles or tandem bicycles with a guide and a 5 km wheelchair or running race. Athletes compete in nine sport classes according to the nature of their physical impairments, with variations made to the traditional event structure commensurate with their disability. Paratriathlon at
82-403: A parallelogram mechanism to keep the cage properly aligned with the chain as it swings back and forth. The other end of the arm mounts to a pivot point attached to the bicycle frame . The arm pivots about this point to maintain the cage at a nearly constant distance from the different sized sprockets. There may be one or more adjustment screws that control the amount of lateral travel allowed and
123-408: A battery pack and to a small electric motor that drives the derailleur. Although expensive, an electronic system could save a racing cyclist time when changing gears. The three main manufacturers of derailleurs are Shimano (Japan), SRAM (USA), and Campagnolo (Italy). The rear derailleur has two functions: it moves the chain between rear sprockets while taking up chain slack caused by moving to
164-472: A cable-shifted derailleur. In 1949 Campagnolo introduced the Gran Sport, a more refined version of the already existing, yet less commercially successful, cable-operated parallelogram rear derailleurs. In 1964, Suntour invented the slant-parallelogram rear derailleur, which let the jockey pulley maintain a more constant distance from the different sized sprockets, resulting in easier shifting. Once
205-399: A cage that holds two pulleys that guide the chain in an S -shaped pattern. The pulleys are known as the jockey pulley or guide pulley (top) and the tension pulley (bottom). The cage rotates in its plane and is spring-loaded to take up chain slack. The cage is positioned under the desired sprocket by an arm that can swing back and forth under the sprockets. The arm is usually implemented with
246-418: A compatible system of shift levers, derailleur, sprockets, chainrings, chain, shift cable, and shift housing. The major innovations since the 1990s have been the switch from friction to indexed shifting and the gradual increase in the number of gears. With friction shifting, a lever directly controls the continuously variable position of the derailleur. To shift gears, the rider first moves the lever enough for
287-462: A longer cage length. Typical cross country mountain bikes with three front chainrings will use a long cage rear derailleur. A road bike with only two front chainrings and close ratio sprockets can operate with either a short or long cage derailleur, but will work better with a short cage. Manufacturer stated derailleur capacities are as follows: Benefits of a shorter cage length: There are at least two methods employed by rear derailleurs to maintain
328-403: A mechanism to move the chain from one sprocket to another. Modern front and rear derailleurs typically consist of a moveable chain-guide that is operated remotely by a Bowden cable attached to a shifter mounted on the down tube , handlebar stem , or handlebar . When a rider operates the lever while pedalling, the change in cable tension moves the chain-guide from side to side, "derailing"
369-550: A need to provide transportation for soldiers injured during the American Civil War , and later, the First World War . While Farffler's carriage emerged from his background as a clockmaker, mid-nineteenth century designs would be produced by mainstream bicycle manufacturers such as The Singer Cycle company of Coventry . By the end of World War I, metal tube handcycles with chain drives became more common to meet
410-422: A particular derailleur. The actuation ratio is the ratio between the amount of shifter cable length and the amount of transverse derailleur travel that it generates. Shift ratio is the reciprocal of actuation ratio and is more easily expressed for derailleurs than actuation. There are currently several standards in use, and in each the product of the derailleur's shift ratio and the length of cable pulled must equal
451-414: A rear derailleur is known as the cage length. Cage length, when combined with the pulley size, determines the capacity of a derailleur to take up chain slack. Cage length determines the total capacity of the derailleur, that is the size difference between the largest and smallest chainrings, and the size difference between the largest and smallest sprockets on the cogset added together. A larger sum requires
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#1732780860181492-436: A smaller sprocket at the rear or a smaller chainring by the front derailleur. In order to accomplish this second task, it is positioned in the path of the bottom, slack portion of chain. Sometimes the rear derailleurs are re-purposed as chain tensioners for single-speed bicycles that cannot adjust chain tension by a different method. Although variations exist, most rear derailleurs have several components in common. They have
533-755: A tighter curve with the automatic rear wheels steering system. The off-road is different from other handcycles in that there are two wheels in front and one behind, and it has a lower gear ratio range. This gives the cycle the ability to tackle steep slopes and permits handcycle mountain biking . The addition of a wider tire with suitable tread makes some mountain biking possible on standard road bikes. Handcycles have also been used for touring , and to better accommodate this interest, some manufacturers incorporate mudguards and pannier cargo racks. As handcycles have evolved they have become progressively lighter, and they have better gearing for long climbs and long-distance touring. Racing handcycles tend to be extremely low to
574-511: A variety of gearing, wheel and tire configurations depending on intended use: racing, recreation, or touring. Manufacturers of this type of handcycle include Invacare (Top End), Intrepid Equipment, Varna, Schmicking and Sunrise Medical (Quickie). Riders turn lean steer handcycles by leaning into the turn. There is a longer learning curve with lean steer handcycles and they are significantly less stable at high speed. The lean steer system feels similar to mono skiing: using your whole body to steer
615-502: Is not a wheelchair ; a handcycle has a crank and gears, while a wheelchair has push-rims directly on the main wheels. Handcycles come in a variety of styles, making them accessible to people with a wide variety of disabilities . There are also hybrids between a handcycle, a recumbent bike and a tricycle. Fork steer handcycles represent the majority of handcycles sold. They work well for both low and high-level spinal injuries, and most have adjustable footrests, seat angle, and come with
656-483: The chain stay : this is called chain slap and can damage the chain stay. Clutches are also helpful in preventing the chain from derailing from the chain ring on systems without a front derailleur. The front derailleur only has to move the chain side to side between the front chainrings, but it has to do this with the top, taut portion of the chain. It also needs to accommodate large differences in chainring size: from as many as 53 teeth to as few as 20 teeth. As with
697-404: The freewheel in the crankset so that the chain moves even when the rider is not pedalling. The Shimano FFS (Front Freewheel System) circa 1980 was the most widespread such system. Chain-drive systems such as the derailleur systems work best if the chain is aligned with the sprocket plane, especially avoiding the biggest drive sprocket running with the biggest driven sprocket (or the smallest with
738-515: The Summer Paralympics is a sprint race consisting of 750 m swimming, 20 km cycling and 5 km running stages. At the 2018 Commonwealth Games , para triathlon was staged with athletes across multiple categories, with staggered starts introduced to ensure fair competition between categories. Until the 2014 season, there were seven categories: The ITU revised the para triathlon classification system in preparation for
779-429: The appropriate gap between the upper jockey wheel and the rear sprockets as the derailleur moves between the large sprockets and the small sprockets. One method, used by Shimano, is to use chain tension to pivot the cage. This has the advantage of working with most sets of sprockets, if the chain has the proper length. A disadvantage is that rapid shifts from small sprockets to large over multiple sprockets at once can cause
820-433: The cage to strike the sprockets before the chain moves onto the larger sprockets and pivots the cage as necessary. Another method, used by SRAM, is to design the spacing into the parallelogram mechanism of the derailleur itself. The advantage is that no amount of rapid, multi-sprocket shifting can cause the cage to strike the sprockets. The disadvantage is that there are limited options for sprocket sizes that can be used with
861-586: The chain onto different sprockets. Dérailleur ( [ d e ʁ a j œ ʁ ] ) is a French word, derived from the derailment of a train from its tracks. Its first recorded use was 1930. Various derailleur systems were designed and built in the late 19th century. One example is the Protean two-speed derailleur available on the Whippet safety bicycle. The French bicycle tourist, writer and cycling promoter Paul de Vivie (1853–1930), who wrote under
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#1732780860181902-642: The chain to jump to the next sprocket, and then adjusts the lever a slight amount to center the chain on that sprocket. An indexed shifter has a detent or ratchet mechanism which stops the gear lever, and hence the cable and the derailleur, after moving a specific distance with each press or pull. Indexed shifters require re-calibration when cables stretch and parts get damaged or swapped. On racing bicycles , 10-gear rear cassettes appeared in 2000, and 11-gear cassettes appeared in 2009. Most current mountain bicycles have either. Many modern, high-end mountain bikes have begun using entirely one chain ring drivetrains, with
943-534: The downtube. However, these systems, along with the rod-operated Campagnolo Cambio Corsa were eventually superseded by parallelogram derailleurs . In 1937, the derailleur system was introduced to the Tour de France , allowing riders to change gears without having to remove wheels. Previously, riders would have to dismount in order to change their wheel from downhill to uphill mode. Derailleurs did not become common road racing equipment until 1938 when Simplex introduced
984-497: The easier change to smaller sprockets. In road racing, the swiftest gear changes are required on the sprints to the finish line. Therefore high-normal types, which allow a quick change to a higher gear, remain the preference. Low normal or rapid rise rear derailleurs return the chain to the largest sprocket on the cassette when no cable tension is applied. While this was once a common design for rear derailleurs, it has become relatively uncommon. In mountain biking and off-road cycling,
1025-454: The ground to minimize air drag and maximize the lateral acceleration that can be generated in a turn without rolling over to the outside. An attachment, consisting of a steerable front wheel and crank, can convert a wheelchair into a handcycle. Derailleur gears A derailleur ( French pronunciation: [deʁajœʁ] ) is a variable-ratio bicycle gearing system consisting of a chain , multiple sprockets of different sizes, and
1066-531: The handcycle. Lean steer handcycles can work well for lower-level injuries; although, some athletes with high-level disability use them as well. Manufacturers of this type of handcycle include Lighting Handcycles and Brike International Ltd. (Freedom Ryder). Another type of lean steer hand trike has two steering rear wheels and one non-steerable, powered front wheel with handholds offset at 180°, similar to pedal cranks, that can be operated with only one hand, thus making it easy to ride uphill, and it can be ridden in
1107-417: The handholds which are usually mounted in phase , unlike pedal cranks, which are usually 180° out of phase. This allows the rider to more easily use their torso to help propel the cycle. The entire crank assembly and the front wheel turn together, allowing the rider to steer and crank simultaneously. Some designs use two front wheels and a single rear wheel, while others use lean-steer designs. A handcycle
1148-420: The industry constantly pushing the number of rear cogs up and up, as shown by SRAM's Eagle groupsets (1 by 12) and Rotor's recent 1 by 13 drive-train. Most road bicycles have two chainrings, and touring bicycles commonly have three. An electronic gear-shifting system enables riders to shift with electronic switches instead of using conventional control levers. The switches are connected by wire or wirelessly to
1189-405: The limits of lateral travel allowed. The components may be constructed of aluminium alloy, steel, plastic, or carbon fibre composite. The pivot points are usually bushings, and these will require lubrication. Because of the possibility of the chain shifting past the smallest inner chainring, especially when the inner chainring is very small, even on bikes adjusted by professional race mechanics, and
1230-410: The most critical gear changes occur on uphill sections, where riders must cope with obstacles and difficult turns while pedalling under heavy load. This derailleur type provides an advantage over high normal derailleurs because gear changes to lower gears occur in the direction of the loaded spring, making these shifts easier during high load pedalling. The distance between the upper and lower pulleys of
1271-591: The most impaired and PT4 for the least impaired. PT5 was for visually impaired athletes. The ITU revised the para triathlon classification system post- 2016 Summer Paralympics . There are nine sport classes that compete in six medal events: Handcycle A handcycle is a type of human-powered land vehicle powered by the arms rather than the legs , as on a bicycle . Most handcycles are tricycle in form, with two coasting rear wheels and one steerable powered front wheel. Despite usually having three wheels, they are also known as handbikes . Stephan Farffler
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1312-553: The name Vélocio , invented a two speed rear derailleur in 1905 which he used on forays into the Alps . Some early designs used rods to move the chain onto various gears. 1928 saw the introduction of the "Super Champion Gear" (or "Osgear") from the company founded by champion cyclist Oscar Egg , as well as the Vittoria Margherita* both employed chainstay mounted 'paddles' and single lever chain tensioners mounted near or on
1353-490: The needs of a specific group of disabled cyclists. High-end racing handcycles are also produced to fit the needs of para-cycling competitors . Many manufacturers have designed and released hand-powered recumbent trikes, or handcycles. Handcycles are a regular sight at HPV meets and are beginning to be seen on the streets. They commonly follow a delta design with front wheels driven by standard derailleur gearing powered by hand cranks . Brake levers are usually mounted on
1394-462: The needs of soldiers who lost their legs. As handcycles have grown in popularity and availability, the needs of a wide array of users have led to handcycle manufacturers innovating on earlier designs. Specialist manufacturers such as Freedom Concepts (whose STRAE Sport handcycle caters to teens and adults with spinal cord injuries ) and Theraplay Mobility Cycles (who design cycles for children with spina bifida ) build handcycles designed to meet
1435-412: The patents expired, other manufacturers adopted this design, at least for their better models, and the "slant parallelogram" remains the current rear derailleur pattern. Before the 1990s many manufacturers made derailleurs, including Simplex , Huret , Galli, Mavic , Gipiemme, Zeus, Suntour, and Shimano . However, the successful introduction and promotion of indexed shifting by Shimano in 1985 required
1476-405: The pitch of the rear sprockets. The following standards exist. Shifters employing one convention are generally not compatible with derailleurs employing another, although exceptions exist, and adaptors are available. Some rear derailleurs, especially for mountain bikes, incorporate a clutch to keep the lower length of chain in sufficient tension to prevent the chain from striking the bottom of
1517-466: The problems such misshifts can cause, a small after-market of add-on products, called chain deflectors, exists to help prevent them from occurring. Some clamp around the seat tube, below the front derailleur, and at least one attaches to the front derailleur mount. Derailleurs require the chain to be in movement in order to shift from one ring or sprocket to another. This usually requires the rider to be pedalling, but some systems have been developed with
1558-403: The rear derailleur, the front derailleur has a cage through which the chain passes. On a properly adjusted derailleur, the chain will only touch the cage while shifting. The cage is held in place by a movable arm which is usually implemented with a parallelogram mechanism to keep the cage properly aligned with the chain as it swings back and forth. There are usually two adjustment screws controlling
1599-455: The sport's debut at the 2016 Summer Paralympics . The ITU formed a Paratriathlon Classification Research Group to develop an evidence-based and sport-specific classification system, drawing on work in swimming , cycling and athletics . The result of the research is a new classification system which has been implemented during the 2014 season. There were five classes; PT1 to PT4 was for athletes with various mobility impairments , with PT1 for
1640-527: The spring tension. The components may be constructed of aluminium alloy , steel , plastic , or carbon fibre composite. The pivot points may be bushings or ball bearings . These will require moderate lubrication. High normal or top normal rear derailleurs return the chain to the smallest sprocket on the cassette when no cable tension is applied. This is the regular pattern used on most Shimano mountain, all Shimano road, and all SRAM and Campagnolo derailleurs. In this condition, spring pressure takes care of
1681-410: Was a Nuremberg watchmaker of the seventeenth century whose invention of a manumotive carriage in 1655 is widely considered to have been the first self-propelled bicycle. He is believed to have been either a paraplegic or an amputee . The three-wheeled device is believed to have been a precursor to the modern-day tricycle and bicycle . Later innovations in handcycle design would be driven by