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Recumbent BicycleA recumbent bicycle is a variety of bicycle which places the rider in a seated or supine position (rarely, in a prone position). The back of the rider is supported, and the rider's legs are extended forward to pedals that are about the same height as the seat. The handlebars may be placed under the seat or in the more conventional position with arms in front of the rider's chest to form more normal handlebars. The wheels may be smaller and/or further apart than on an ordinary bicycle. The advantages are a more comfortable seating position without pressure on the genital area and without neck and back strain, sometimes better aerodynamics, safer braking and particularly with trikes, greater stability (see Recumbent Types (german)). Recumbent trikes are very suitable for anyone with a balance or limb disability. There are four general classifications of recumbent bicycles: under seat steering (USS), above seat steering (ASS), short wheelbase (SWB), and long wheelbase (LWB). These general classifications can be mixed and matched at the builder's whim to create a multitude of variations. The short wheelbase has the rider's pedals in front of the front wheel and the long wheelbase has the front wheel in front of the pedals. The rear wheel is usually behind the back of the rider and is the size of a normal bicycle wheel or smaller. The front wheel is usually smaller than conventional bicycle wheel size. A new trend for performance recumbents is the hi-racer which has dual 26" (ISO 559), ISO 650, or ISO 622 (700c) wheels. Many feel that the larger wheels are faster. Most recumbents have an ISO 559 rear wheel and an ISO 406 (20") front wheel. The small front and large rear wheel combination comes about because the pedals and front wheel must be kept clear of each other. A further configuration that overcomes this constraint is a front wheel drive arrangement where the pedals and front wheel move together. The moving bottom bracket front wheel drive usually has dual 26" wheels or larger. On the flat, recumbent bicycles are often substantially faster than upright bicycles for the same level of effort because the aerodynamic profile of the rider reduces wind resistance. Many owners prefer a "'bent" because it reduces the strain on the hands, arms, shoulders, and buttocks. A perceived disadvantage of the recumbent cycling position is that the rider is unable to stand on ascents and so tends to be slower going uphill than on an upright bicycle. This is most noticeable during the initial period of riding a recumbent when the muscles are not yet trained for the different exertion. Some riders who switch styles find that they are slower in hilly terrain but they are able to keep riding longer because they experience much less discomfort. Others (especially those who would otherwise NOT stand up to climb a hill) find that the ability to brace against the seat-back gives them the perception of being faster uphill than they were on an upright bike. Experienced recumbent riders learn to pedal at a higher cadence than they would on an upright, or "diamond-frame" bicycle. This reduces leg strain and fatigue in strenuous situations. Some recumbent bicycles and tricycles utilize aerodynamic devices called fairings which reduce wind drag. Fairings are available for the front as well as the rear of the vehicle. Some recumbents also use a "sock" which is a fabric covering which connects the front fairing and the rear fairing, enclosing the rider for even more aero benefit. Front and rear fairings have been shown to be beneficial for long wheelbase bikes whereas front fairings are not beneficial for short wheelbase bikes. Recumbent tricycles, "trikes", come in two varieties, the delta, with two rear wheels, and the tadpole, with two front wheels. Most recent hi-performance trikes are of the tadpole variety. There are three remarkable characteristics of recumbent trikes: The rider does not need to disengage from the pedals when stopped; the trike can be geared very low to enable mountain climbing while heavily loaded and at a slow speed without losing stability and becoming wobbly; and trikes are capable of turning sharply without leaning, producing lateral "g forces" similar to a sports car. Some riders of very low recumbent bikes (low-racers or trikes) attach a flag to the rear of the bicycle to give themselves greater visibility in traffic. However, the unusual appearance of a recumbent often means it is readily spotted anyway. In 1933, riding a "Velocar" recumbent bicycle made by Charles Mochet, Francis Faure set a record of 45.055 km for the hour, one of cycling's most prestigious events. In response, the Union Cycliste Internationale (UCI) banned all recumbents from mainstream bicycle racing in 1938. Racing and record-breaking on recumbent bicycles is now governed by the International Human Powered Vehicle Association. As of 2004, the hour record on a recumbent bicycle is 84.215 km (52.32 miles), set by Sam Whittingham on July 31, 2004. For comparison, the equivalent record for an upright bicycle is 49.441 km (30.723 miles), set by Chris Boardman in October 2000. (The UCI no longer considers the bike Boardman rode for his 1996 record to be in compliance with its definition of an upright bicycle.) External links
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