Recumbent bicycle

Recumbent bicycle

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A recumbent bicycle is a bicycle
Bicycle
A bicycle, also known as a bike, pushbike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist, or bicyclist....

 that places the rider in a laid-back reclining position. Most recumbent riders choose this type of design for ergonomic reasons; the rider's weight is distributed comfortably over a larger area, supported by back and buttocks. On a traditional upright bicycle, the body weight rests entirely on a small portion of the sitting bones
Tuberosity of the ischium
-External links: - "The Female Perineum: Bones" - "Major Joints of the Lower Extremity: Hip bone "...

, the feet, and the hands.

Most recumbent models also have an aerodynamic advantage; the reclined, legs-forward position of the rider’s body presents a smaller frontal profile. A recumbent holds the world speed record for a bicycle, and they were banned from international racing in 1934.

Recumbents are available in a wide range of configurations, including: long to short wheelbase; large, small, or a mix of wheel sizes; overseat, underseat, or no-hands steering; and rear wheel or front wheel drive. A variant with three wheels is a recumbent tricycle
Tricycle
A tricycle is a three-wheeled vehicle. While tricycles are often associated with the small three-wheeled vehicles used by pre-school-age children, they are also used by adults for a variety of purposes. In the United States and Canada, adult-sized tricycles are used primarily by older persons for...

.

Description


Recumbents can be categorized by their wheelbase, wheel sizes, steering system, faired or unfaired, and front-wheel or rear-wheel drive.

Wheelbase


Long-wheelbase (LWB) models have the pedals located between the front and rear wheels; short-wheelbase (SWB) models have the pedals in front of the front wheel; compact long-wheelbase (CLWB) models have the pedals either very close to the front wheel or above it. Within these categories are variations, intermediate types, and even convertible designs (LWB to CLWB) - there is no "standard" recumbent.

Wheel sizes


The rear wheel of a recumbent is usually behind the rider and may be any size, from around 16 inches (406.4 mm) to the 700c (or 27" on some older models, as on upright road bikes of that time) of an upright racing cycle. The front wheel is commonly smaller than the rear, although a number of recumbents feature dual 26-inch (ISO 559), ISO 571 (650c), ISO 622 (700c), or even 29 x 4" oversize all-terrain tires. Larger diameter wheels generally have lower rolling resistance
Rolling resistance
Rolling resistance, sometimes called rolling friction or rolling drag, is the resistance that occurs when a round object such as a ball or tire rolls on a flat surface, in steady velocity straight line motion. It is caused mainly by the deformation of the object, the deformation of the surface, or...

 but a higher profile leading to higher air resistance. Highracer aficionados also claim that they are more stable, and although bicycle stability increases with the height of the center of gravity above the ground, the wide variety of recumbent designs makes such generalizations unreliable. Another advantage of both wheels being the same size is that the bike requires only one size of inner tube.

The most common arrangement is probably an ISO 559 (26-inch) rear wheel and an ISO 406 or ISO 451 (20-inch) front wheel. The small front wheel and large rear wheel combination is used to keep the pedals and front wheel clear of each other, avoiding the problem called "heel strike" (where the rider's heels catch the wheel in tight turns). A pivoting-boom front-wheel drive (PBFWD) configuration also overcomes heel strike since the pedals and front wheel turn together. PBFWD bikes may have dual 26 inches (660.4 mm) wheels or larger.


Steering


Steering for recumbent bikes can be generally categorized as
  • over-seat (OSS) or above seat steering (ASS);
  • under-seat (USS); or
  • center steering or pivot steering.

OSS/ASS is generally direct—the steerer acts on the front fork like a standard bicycle handlebar
Bicycle handlebar
Bicycle handlebar or often bicycle handlebars refers to the steering mechanism for bicycles; the equivalent of a steering wheel. Besides steering, handlebars also often support a portion of the rider's weight, depending on their riding position, and provide a convenient mounting place for brake...

—but the bars themselves may extend well behind the front wheel (more like a tiller
Tiller
A tiller or till is a lever attached to a rudder post or rudder stock of a boat that provides leverage for the helmsman to turn the rudder...

); alternatively the bars might have long rearward extensions (sometimes known as Superman or Kingcycle bars). Chopper-style bars are sometimes seen on LWB bikes. USS is usually indirect—the bars link to the headset through a system of rods or cables and possibly a bell crank
Bell crank
A bell crank is a type of crank that changes motion through an angle. The angle can be any angle from 0 to 360 degrees, although 90 degrees and 180 degrees are common....

.
Most tadpole trikes are USS. Center steered or pivot steered recumbents, such as Flevobikes and Pythons, may have no handlebars at all.

Drive


As with upright bicycles, most recumbents are rear wheel drive. However, due to the proximity of the crank to the front wheel, front wheel drive (FWD) can be an option, and it allows for a much shorter chain. One style requires the chain to twist slightly to allow for steering. Another style, Pivoting-boom FWD (PBFWD), has the crankset connected to and moving with the front fork.
In addition to the much shorter chain, the advantages to PBFWD are use of a larger front wheel for lower rolling resistance without heel strike (you can pedal while turning) and use of the upper body when sprinting or climbing. The main disadvantage to all FWD designs is "wheelspin" when climbing steep hills covered with loose gravel, wet grass, etc. This mainly affects off-road riders, and can be ameliorated by shifting the weight forward, applying steady pressure to the pedals, and using tires
Bicycle tire
A bicycle tire is a tire that fits on the wheel of a bicycle, unicycle, tricycle, quadracycle, bicycle trailer, or trailer bike. They may also be used on wheelchairs and handcycles, especially for racing...

 with more aggressive tread. Another disadvantage of PBFWD for some riders is a slightly longer "learning curve" due to adaptation to the pedal-steer effect (forces applied to the pedal can actually steer the bike). Beginner riders tend to swerve along a serpentine path until they adapt a balanced pedal motion. After adaptation, a PBFWD recumbent can be ridden in as straight a line as any other bike, and can even be steered accurately with the feet only. Examples of PBFWD recumbents include Cruzbike, Flevo Bike, and Python Lowracer. Another drive-train variation is on rowing cycles where the rider rows using arms and legs.

Fully suspended bikes


Modern recumbent bikes are increasingly being fitted with front and rear suspension systems for increased comfort and traction on rough surfaces. Coil, elastomer, and air-sprung suspension systems have all been used on recumbent bikes, with oil or air-damping in the forks and rear shock absorbers. The maturation of fully suspended conventional mountain bikes has aided the development of these designs, which often use many of the same parts, suitably modified for recumbent use.

Fairings


Some riders fit their bikes with aerodynamic devices called fairings. These can reduce aerodynamic drag and help keep the rider warmer and drier in cold and wet weather. Fairings are also available for upright bikes, but are much less common.

Seats


The seats
Bicycle seat
A bicycle seat, unlike a bicycle saddle, is designed to support the rider's buttocks and back, usually in a semi-reclined position. Arthur Garford is credited with inventing the padded bicycle seat in 1892, and they are now usually found on recumbent bicycles.Bicycle seats come in three main...

 themselves are either of mesh stretched tightly over a frame (as in the Gold Rush pictured) or foam cushions over hard shells like the Stinger pictured, which might be moulded (as here) or assembled from sheet materials. Hard-shell seats predominate in Europe, mesh seats in the USA.

Variations



Mountain bike recumbents


With the right equipment and design, recumbent bikes can be used for riding unpaved roads and offroad, just as with conventional mountain bikes. Because of their longer wheelbase and the manner in which the rider is confined to the seat, recumbents are not as easy to use on tight, curving unpaved singletrack. Large-diameter wheels, mountain gearing and off-road specific design have been used since 1999. Crank-forward
Crank forward
Crank Forward is a category term for a type of bicycle distinct from the road bike, hybrid bike, and mountain bike.The term 'Crank Forward' was created by RANS, Inc., a manufacturer of bicycles based in Hays, Kansas, USA...

 designs that facilitate climbing out of the saddle, such as the RANS Dynamik, also can be used off-road.

Lowracers


Lowracers are a type of recumbent more common in Europe among racing enthusiasts. These typically have two 20" wheels or a 26" wheel at the rear and 20" wheel at the front. The seat is positioned between the wheels rather than above them. The extreme reclined position, and the fact that the rider is sitting in line with the wheels rather than atop them, makes this type the most aerodynamic of unfaired recumbents.

Highracers


Highracers are distinguished by using two large wheels (usually two ISO 559 or 26"). This necessitates a higher bottom bracket than on a lowracer so that the rider's legs are above the front wheel, and this in turn requires a higher seat. The seating position may be otherwise identical to that on a lowracer allowing similar aerodynamics. "Racer" in the name implies that this will often be the case, since these bikes strive for speed.

Highracers are generally more maneuverable than lowracers since their higher center of gravity allows stability at lower speeds (see Bicycle and motorcycle dynamics
Bicycle and motorcycle dynamics
Bicycle and motorcycle dynamics is the science of the motion of bicycles and motorcycles and their components, due to the forces acting on them. Dynamics is a branch of classical mechanics, which in turn is a branch of physics. Bike motions of interest include balancing, steering, braking,...

). Given the same seating position they may be faster than lowracers, since it is widely believed that rolling resistance is inversely proportional to wheel diameter, although good data on this subject is scarce. However, lowracer proponents reply that their design is faster due to aerodynamics. The reasoning is that the riders body is in line with the wheels, reducing drag.

Hip and elbow injuries are more common on highracers than on lowracers due to the greater height from which the rider can fall. However, the injuries are very rare and seldom serious.

Semi-recumbent and crank forward bicycles


Bicycles that use positions intermediate between a conventional upright and a recumbent are called semi-recumbent or crank forward
Crank forward
Crank Forward is a category term for a type of bicycle distinct from the road bike, hybrid bike, and mountain bike.The term 'Crank Forward' was created by RANS, Inc., a manufacturer of bicycles based in Hays, Kansas, USA...

 designs. These generally are intended for casual use and have comfort and ease of use as primary objectives, with aerodynamics sacrificed for this purpose.

Tandem recumbents


Just as with upright bicycle
Bicycle
A bicycle, also known as a bike, pushbike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist, or bicyclist....

s, recumbents are built and marketed with more than one seat, thus combining the advantages of recumbents with those of tandem bicycle
Tandem bicycle
The tandem bicycle or twin is a form of bicycle designed to be ridden by more than one person. The term tandem refers to the seating arrangement , not the number of riders. A bike with two riders side-by-side is called a sociable.-History:Patents related to tandem bicycles date from the late 19th...

s. In order to keep the wheelbase from being any longer than absolutely necessary, tandem recumbents often place the stoker's crankset
Crankset
The crankset or chainset , is the component of a bicycle drivetrain that converts the reciprocating motion of the rider's legs into rotational motion used to drive the chain, which in turn drives the rear wheel...

 under the captain's seat
Bicycle seat
A bicycle seat, unlike a bicycle saddle, is designed to support the rider's buttocks and back, usually in a semi-reclined position. Arthur Garford is credited with inventing the padded bicycle seat in 1892, and they are now usually found on recumbent bicycles.Bicycle seats come in three main...

. A common configuration for two riders in the recumbent position is the "sociable tandem", wherein the two riders ride side by side.

Recumbent tricycles


Recumbent tricycle
Tricycle
A tricycle is a three-wheeled vehicle. While tricycles are often associated with the small three-wheeled vehicles used by pre-school-age children, they are also used by adults for a variety of purposes. In the United States and Canada, adult-sized tricycles are used primarily by older persons for...

s (trikes) are closely related to recumbent bicycles, but have three wheels instead of two. Trikes come in two varieties, the delta, with two rear wheels, and the tadpole, with two front wheels.

Characteristics of recumbent trikes include:
  • 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.
  • Trikes are capable of turning sharply without leaning, producing lateral "g forces" similar to sports car
    Čar
    Čar is a village in the municipality of Bujanovac, Serbia. According to the 2002 census, the town has a population of 296 people.-References:...

    s.
  • Recumbent trikes may also be more suitable for people with balance or limb disabilities.


The popularity of trikes has grown significantly over the years as aging baby boomers discover the benefit of continued riding without the issues of balance and pain mostly associated with traditional upright bikes.


Handcycles



In order to accommodate paraplegics and other individuals with little or no use of their legs, many manufacturers have designed and released hand-powered recumbent trikes, or handcycles. Handcycles are a regular sight at HPV
Human-powered transport
Human-powered transport is the transport of person and/or goods using human muscle power. Like animal-powered transport, human-powered transport has existed since time immemorial in the form of walking, running and swimming...

 meetings and are beginning to be seen on the streets. They usually follow a delta design with front wheels driven by standard dérailleur gearing powered by hand cranks. Brake levers are usually mounted on the hand holds, which are usually set with no offset rather than the 180° of pedal cranks. The entire crank assembly and the front wheel turn together, allowing the rider to steer and crank simultaneously.

Although arms are weaker than legs, many hand cyclists are able to make use of the power of the whole upper body. A good hand cyclist can still achieve a respectable pace in competitions. Handcycles have also been used for touring, though few designers incorporate mudguards or luggage racks. Also, the gear ratios of standard handcycles tend to be less useful for long steep climbs.


Hand-and-foot recumbent tricycles


Recumbent cycles offer the possibility of combined hand and foot power inputs, and thus the potential for a full-body workout, and the option for persons with a weak or missing leg(s) to power a cycle. In one recumbent tricycle design the user makes the two front wheels change direction by shifting his center of weight, and moves forward by rotating the rear wheel. There are also hybrids between a handcycle, a recumbent bike and a tricycle; these bikes enable cycling by use of legs, despite a spinal cord injury

Recumbent quadracycles



Recumbent four wheel cycles have the same general advantages of tricycles. For quadracycles with only one seat the stability improvements of the fourth wheel offer only a marginal advantage over a tadpole recumbent tricycle. More wheels introduce more weight and more complexity. The fourth wheel is only of the most benefit to the single seat rider when going off-road. When two and sometimes four riders want to ride together in a sociable configuration the four-wheel recumbent cycle is a viable option.

Homebuilts



As with upright bikes, there is a subculture of recumbent builders who design and build home-built recumbents. Often these are assembled of parts from other bikes, particularly mountain bikes. The frame designs may be as simple as a long steel tube bent into the appropriate shape, or as elaborate as hand-built carbon fiber frames. For many builders, the engineering and construction of the bikes is as much of a challenge as riding them.

Folding


Several manufacturers offer folding
Folding bicycle
A folding bicycle is a bicycle designed to fold into a compact form, facilitating transport and storage. When folded, the bikes can be more easily carried into buildings and workplaces or onto public transportation or more easily stored in compact living quarters or aboard a car, boat or plane...

 recumbents to facilitate packing and travelling.

Couplers


It is possible to add couplers
Bicycle Torque Coupling
An S and S Coupling also known as a Bicycle Torque Coupling or BTC is a coupling which enables bicycle frames to be separated into smaller pieces, usually to facilitate packing and transporting. They can be built into the frame by the frame manufacturer when the frame is originally assembled or...

 either during manufacturing or as a retrofit so that the frame can be disassembled into smaller pieces to facilitate packing and travel.

Compared to uprights


The striking difference in appearance between recumbents and upright bikes begs comparison. Since recumbents vary widely, the advantages and disadvantages listed below may apply to different types to different degrees or not at all. (For example, balance is not an issue on tricycles.)




Advantages


Advocates cite a number of advantages over traditional upright bicycles.
  • Safety. Particularly with the lower designs, the recumbent bicycle's low center of mass and short distance from the ground significantly reduce the consequences of a fall for the rider. In particular, the recumbent cyclist's head is roughly half a meter (and in some cases, as much as 1 meter) lower than that of a conventional cyclist. The worries of head injuries (including both standard compression-type concussions and axial-rotational-type brain damage) are therefore reduced. A direction-of-travel fall from a recumbent will be less harmful than from an upright bike due to the feet-first orientation, which ensures that the rider cannot be pitched headfirst over the handlebars.

  • Additionally, the low center of gravity greatly increases braking and stopping capabilities, since the recumbent design avoids the concern of vigorous front-wheel braking resulting in the rider flying over the handlebars. This may, however, increase the risk of a front wheel skid. Likewise, losing a front wheel or fracturing a front fork will also be far less injurious than in a conventional bike. Furthermore, the recumbent design makes it possible to cycle very close to the curb without risking a pedal-curb collision. However, while riding close to the curb can be a useful safety maneuver, habitually riding this close to the curb is considered dangerous, since the rider's objectives should be to be as visible as possible, to maintain some maneuverability, and to prevent cars from passing when there is not enough room to do so safely.

  • Comfort. The recumbent riding position reduces strain on the body, making it particularly suitable for long rides and touring. Depending on the angle of the seat, it can be very easy on the neck, wrists, hands, arms, shoulders, lower back, and ischial tuberosities ("sit bones"). Riders who suffer back pain or genito-urinary trouble often find that recumbents allow them to make significant rides without pain. Urogenital trouble is less because the pedals are not under the seat, thus the seat can be larger so weight can be distributed to a larger area and to the seat back. Shorts made for recumbent riders do not have padding or any need for it.

  • View angle. The recumbent riding position, if not too aggressively reclined, can enable the rider to face straight ahead comfortably and view the passing scenery. Many upright bikes, particularly those used in competition
    Bicycle racing
    Bicycle racing is a competition sport in which various types of bicycles are used. There are several categories of bicycle racing including road bicycle racing, cyclo-cross, mountain bike racing, track cycling, BMX, bike trials, and cycle speedway. Bicycle racing is recognised as an Olympic sport...

    , on the other hand, have a riding position in which the natural position is to face more downwards towards the pavement; in order to face straight ahead, the neck must be craned upward.

  • Health. Many riders switch to recumbents to alleviate the chronic back or neck pain from riding upright bikes. On tricycles, the inherent stability of three wheels allows very low gearing to be used, so hills can be climbed without strain on joints. Also, on some recumbents, the rider's legs are nearly at the same height as the heart. This reduces the rider's hydrostatic pressure, thus allowing venous blood
    Blood
    Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

     to more easily return to the heart
    Heart
    The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

    . This physiological effect of improved circulation
    Circulatory system
    The circulatory system is an organ system that passes nutrients , gases, hormones, blood cells, etc...

     suggests an increase in rider endurance and/or increased power output on long rides. Recumbent riders are not bent over as are conventional bike riders, and this makes breathing easier. Additionally, studies indicate that upright bicycle riding may be a cause of male impotence due to pressure placed on the perineal nerve by the seat; recumbent seats do not present the same issue.

  • Speed. On declines, on the flat, or on shallow inclines, the more horizontal recumbent bicycle designs are generally faster than upright bicycles for the same level of effort because the aerodynamic profile of the rider reduces wind resistance. It is this feature which led to the Union Cycliste Internationale (UCI)
    Union Cycliste Internationale
    Union Cycliste Internationale is the world governing body for sports cycling and oversees international competitive cycling events. The UCI is based in Aigle, Switzerland....

     banning them in the 1930s (see History). The world speed record for human-powered vehicles was set by Sam Whittingham
    Sam Whittingham
    Sam Whittingham is a Canadian cyclist who has held several world records on recumbent bicycles., he holds the following world records under the sanction of the International Human Powered Vehicle Association:...

     on a fully faired recumbent bicycle on September 18, 2008 with a speed of 132.5 km/h (82.33 mph).

  • Turns. Although long-wheelbase recumbents have larger turning circles than most conventional bicycles, one advantage on designs with high bottom brackets is that the rider can continue pedaling even during tight turns without the pedals striking the ground.

Disadvantages


Critics of the recumbent design counter the claimed advantages with a number of disadvantages:
  • Balance. Balance is generally more difficult on a recumbent bicycle due to the lower center of gravity
    Center of gravity
    In physics, a center of gravity of a material body is a point that may be used for a summary description of gravitational interactions. In a uniform gravitational field, the center of mass serves as the center of gravity...

    . It is easier to balance with a higher center of gravity because of the "pendulum effect" (it is easier to minutely change the angle at which upright bicycles lean). In addition, compared with riders of conventional bikes, two-wheeled recumbent riders have less scope for shifting their weight to steer or help balance the bicycle. As a consequence, riding at low speed and tight maneuvers can be more challenging on a recumbent. Of course, recumbent tricycles are a special case that are ideal for riders who cannot balance a two-wheeled bike.

  • Starting and stopping. Because of the supine position, most recumbents do not allow the rider to push forward with the feet on the ground. This makes for slow starts and requires balance at low speed for a longer time. The recommended way to start an upright bicycle is by pushing off with one foot on the ground, and one foot on a high pedal. This is particularly advantageous if the upright bicycle is next to a curb or similar object. Recumbents cannot be started with this recommended upright bicycle technique. Starting a recumbent does not require great strength; it is a matter of balance and a skill which must be learned. It is best to learn from an experienced rider, who can help with a little push at first. Several rides may suffice to become confident enough of one's starting and stopping skills before becoming ready to ride in traffic or perform uphill starts. Recumbent tricycles do not require balancing and hence do not require any special skill in this regard. With many recumbent seats quite low it is often easier to get a foot down onto the ground on stopping than is the case from a conventional bike with the saddle set high for optimum pedaling.

  • Maneuverability. Most recumbents have a larger turning radius and combined with the greater difficulties of balance, tight and low-speed maneuvers can be difficult. It is also very hard to jerk the front wheel onto curbs. Since the front wheel is often small, driving up unlowered curbs is very risky even with suspension.

  • Uphills. A perceived and much debated disadvantage of the recumbent position is that it is more difficult to ride up hills. This is most noticeable during the initial period of riding a recumbent when the legs are not yet trained for the different muscle requirements. On a traditional bicycle, the rider can stand on the pedals and pull against the handlebars, although on a recumbent the rider can push against the seat. On either style, higher cadence
    Cadence (cycling)
    In cycling, cadence is the number of revolutions of the crank per minute; roughly speaking, this is the rate at which a cyclist is pedalling/turning the pedals...

     reduces leg strain and fatigue when climbing. Recumbent tricycles are a special case, as riders can climb almost any gradient of hill (subject to tire traction) with appropriate gearing since balance (and hence speed) is not a consideration.

  • A few designers have attempted to build bikes which convert from recumbent to upright for climbs. In practice the biggest difference is probably the additional weight of the recumbent layout combined with the difficulty of balancing a bike with a low center of gravity at speeds below about 5 mi/h.

  • Length of the frame. Some recumbent bicycle designs use longer frames than conventional bicycles. This generally results in a weight penalty and in more flexing of the frame that causes a loss of power . The chain is two to three times as long as an upright and usually requires one or more idler pulleys. There is a small amount of friction in such pulleys which also reduces power slightly. Longer frame designs are more difficult to transport if the bikes are shipped, or put on racks on automobiles. Some manufacturers offer folding or break-apart designs, but these tend to be expensive. The longer distance from the handlebars to the wheels can be problematic for speedometers and cyclocomputers, including both wireless and hard-wired models. The distance from the handlebars to the crankset is likewise longer than a conventional bike and can give problems for cadence sensors.

  • Constant position. While the riding position is comfortable and removes stress from the arms, it cannot easily be varied during a ride (as upright riders might stand for a hill), and some find that bottom brackets at or near hip level produces problems with cold or numb feet. Some riders suffer "recumbent butt," a pain in the gluteal muscles caused by their increased effort while being compressed. This can usually be addressed by adjusting the seat angle and pedal position. In a more reclined position, the weight is spread evenly between the back and buttocks. The rider of a conventional bike can stand up on the pedals to allow his legs to take up the shock of a severe bump in the road. The recumbent rider cannot (although many designs include suspension to alleviate this).

  • Visibility of the road. The distance from the eyes to the front end is somewhat larger than an upright, and also the rider cannot lean forward. This leads to a bad insight angle at sharp corners. (Car drivers have the same problem, though less acute, since they are closer to the middle of the street.) In some designs - notably low-racers - the rider is also significantly lower than on a conventional bicycle and so visibility can often be obscured by fences, parked cars, etc. It is also a bit more difficult to glance back, which can be addressed by adding helmet or handlebar mirrors.

  • Visibility of the bicycle. In urban traffic, many recumbent bikes are below the eye level of many automobile drivers, although proponents suggest that the relative novelty of the design helps make drivers more conscious of them. Recumbent commuters often add flags, lighting, and reflective material to their bikes and gear to enhance visibility, and many refer to being able to see eye-to-eye with the automobile drivers as an advantage.

  • Price. Recumbents are generally 10 - 15% more expensive than upright bikes of equivalent quality. Most are hand-built in comparatively small runs by independent manufacturers, usually with high specification components. At the low end, the vast majority of upright bikes sell for less than the cost of the cheapest new recumbent.

  • Nonstandard design. Recumbents often have radically different shapes from diamond-frame bikes, so conventional bike racks, automobile carriers, accessories, and locks do not fit in the usual ways. Additionally the designs are difficult to mount in traditional bicycle work stands and often require a second person during derailleur adjustments to spin cranks that are too far from the shift controls and derailleur locations. Some bicycle mechanics may be reluctant to work on "nonstandard" bicycle designs.

  • Safety. Although recumbent bicycles are generally considered safer than upright bicycles (as noted above), they do have some specific safety issues. A type of injury characteristic of recumbents called "leg suck" occurs when a foot touches the ground and the bike runs forward over the contact point, causing ligament damage and, in some cases, ankle fractures. The use of clipless pedals reduces this possibility by preventing the foot from slipping off the pedal. But with clipless pedals, remaining clipped in during a front tire or wheel failure at high speeds can result in the recumbent rolling over the rider and taking a clipped in leg or legs with it. This scenario, although very rare, can create severe spiral fractures of the femur
    Femur
    The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...

     rarely seen with upright bicycles.

  • Overlap of heels with the front wheel during tight turns with some short-wheelbase (SWB) and some compact long-wheelbase (CLWB) design is known as "heel strike." This is only evident during tight turns and can be avoided by lifting the heel or pausing pedaling. It is similar in many respects to "toe strike" in upright designs, which is similarly dependent upon design, implementation, size of feet and their position on the pedal and the presence or otherwise of fenders/mudguards.

History


Recumbent bicycle designs date back to the middle of the 19th century. A couple were patented around 1900 but the early designs were unsuccessful.

Early recumbents



Recumbent designs of both prone and supine varieties can be traced back to the earliest days of the bicycle. Before the shape of the bicycle settled down following Starley
John Kemp Starley
John Kemp Starley was an English inventor and industrialist who is widely considered the inventor of the modern bicycle, and also originator of the name Rover....

's safety bicycle
Safety bicycle
A safety bicycle is a type of bicycle that became very popular beginning in the late 1880s as an alternative to the penny-farthing or ordinary and is now the most common type of bicycle. Early bicycles of this style were known as safety bicycles because they were noted for, and marketed as, being...

, there was a good deal of experimentation with various arrangements, and this included designs which might be considered recumbent. Although these dated back to the 1860s the first recorded illustration of a recumbent considered as a separate class of bicycle is considered to be in the magazine Fliegende Blätter of September 10, 1893. This year also saw what is considered the first genuine recumbent, the Fautenil Vélociped. Patent applications for a number of recumbent designs exist in the late years of the 19th century, and there were discussions in the cycling press of the relative merits of different layouts. The Challand designs of 1897 and the American Brown of 1901 are both recognisable as forerunners of today's recumbents.

Mochet's Velocar



A four-wheeled pedal-propelled car called the 'Velocar
Velocar
Velocar was the name given to velomobiles made in the 1930s and 40s by Mochet et Cie of Puteaux, France....

' (or 'Vélo couché') was built in the early 1930s by French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 inventor and light car builder Charles Mochet. Velocars sold well to French buyers who could not afford a motor car, possibly because of a poor economy
Economy
An economy consists of the economic system of a country or other area; the labor, capital and land resources; and the manufacturing, trade, distribution, and consumption of goods and services of that area...

 during the Great Depression
Great Depression
The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...

. The four-wheeled Velocars were fast but didn't corner well at high speed. Mochet then experimented with a three-wheel design and finally settled on a two-wheel design.

To demonstrate the speed of his recumbent bicycle, Mochet convinced cyclist Francis Faure, a Category 2 racer, to ride it in races. Faure was highly successful, defeating many of Europe's top cyclists both on the track and in road races, and setting new world records at short distances. Another cyclist, Paul Morand, won the Paris-Limoges race in 1933 on one of Mochet's recumbents.

On 7 July 1933, at a Paris velodrome
Velodrome
A velodrome is an arena for track cycling. Modern velodromes feature steeply banked oval tracks, consisting of two 180-degree circular bends connected by two straights...

, Faure rode a Velocar 45.055 km (28 mi) in one hour, beating an almost 20-year-old hour record
Hour record
The hour record for bicycles is the record for the longest distance cycled in one hour on a bicycle. There are several records. The most famous is for upright bicycles meeting the requirements of the Union Cycliste Internationale . It is one of the most prestigious in cycling...

 held by Oscar Egg
Oscar Egg
Oscar Egg was a Swiss track and road bicycle racer. He captured the world hour record three times before the First World War...

, and attracting a great deal of attention.

When the Union Cycliste Internationale
Union Cycliste Internationale
Union Cycliste Internationale is the world governing body for sports cycling and oversees international competitive cycling events. The UCI is based in Aigle, Switzerland....

 (UCI) met in February, 1934, manufacturers of upright bicycles lobbied to have Faure's one-hour record declared invalid. On 1 April 1934, the UCI published a new definition of a racing bicycle that specified how high the bottom bracket could be above the ground, how far it could be in front of the seat and how close it could be to the front wheel. The new definition effectively banned recumbents from UCI events for a combination of tradition, safety, and economic reasons.

After the decision, Faure continued to race, and consistently beat upright bicycles with the Velocar. In 1938, Faure and Mochet's son, Georges, began adding fairings to the Velocar in hopes of bettering the world record of one hour for a bicycle with aerodynamic components. On 5 March 1938, Faure rode a faired Velocar 50.537 kilometers in an hour and became the first cyclist to travel more than 50 kilometers in an hour without the aid of a pace vehicle
Derny
A Derny is a motorized bicycle for motor-paced cycling events such as during six-day and Keirin racing, or motor-paced road races. It is driven by a 98cc Zurcher two-stroke engine and by being pedalled through a fixed gear, typically of 70 teeth on the front chainring and 11 on the sprocket on the...

.

The UCI ban on recumbent bicycles and other aerodynamic improvements virtually stopped development of recumbents for four decades. Although recumbent designs continued to crop up over the years they were mainly the work of lone enthusiasts and numbers remained insignificant until the 1970s.

1970s resurgence and the IHPVA


While developments had been made in this fallow period by Paul Rinkowski and others, the modern recumbent movement was given a boost by the work of Chester Kyle and particularly David Gordon Wilson
David Gordon Wilson
David Gordon Wilson is emeritus professor of engineering at Massachusetts Institute of Technology .Born in Warwickshire, England, Wilson came to the U.S. on a post-doctoral fellowship in 1955. He returned to Britain in 1957 to work in the gas-turbine industry. He taught engineering in Nigeria from...

 of MIT
Massachusetts Institute of Technology
The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...

, two Americans who opposed the UCI restrictions and continued to work on fairings and recumbents. In 1974, they also nucleated the International Human Power speed Championship in Long Beach, California
Long Beach, California
Long Beach is a city situated in Los Angeles County in Southern California, on the Pacific coast of the United States. The city is the 36th-largest city in the nation and the seventh-largest in California. As of 2010, its population was 462,257...

, from which the IHPVA grew. Kyle and his students had been experimenting with fairings for upright bicycles, also banned by the UCI.

In 1978, the "Vélérique" is the very first commercialized recumbent bicycle (fully faired), by the Belgian Erik Abergen.

The Avatar 2000, a LWB bike very much like the current Easy Racers products, arrived in 1979, and is often considered the first modern production recumbent. It was featured in the 1983 film Brainstorm, ridden by Christopher Walken, and in the popular cycling reference Richard's Bicycle Book by Richard Ballantine
Richard Ballantine
Richard Ballantine is a cycling writer, journalist and cycling advocate. Born in America the son of Ian and Betty Ballantine of Ballantine Books fame, he now principally resides in London, England. He is most famous for his 1972 book titled Richard's Bicycle Book and its subsequent editions...

. A faired Avatar 2000 was the first two wheeler to beat the European Vector three wheeler in the streamliner races. For about ten years afterward, speed records were exchanged between Easy Racers with Freddy Markham in the cockpit and the Lightning Team. So America's strength became the flying 200 meter sprint in the streamliner division. The oil crises of the 1970s sparked a resurgence in cycling coincident with the arrival of these "new" designs.

A parallel but somewhat separate scene grew up in Europe, with the first European human power championships being held in 1983. The European scene was more dominated by competition than was the US, with the result that European bikes are more likely to be low SWB machines, while LWB are much more popular in the US (although there have been some notable European LWB bikes, such as the Peer Gynt).

In the 1980s


In 1984, Linear Recumbents of Iowa began producing bicycles. In 2002, Linear Manufacturing's assets were bought by Bicycle Man LLC and moved to New York. Since then owner Peter Stull has been working with senior engineering students at Alfred University
Alfred University
Alfred University is a small, comprehensive university in the Village of Alfred in Western New York, USA, an hour and a half south of Rochester and two hours southeast of Buffalo. Alfred has an undergraduate population of around 2,000, and approximately 300 graduate students...

, local engineers and machinists utilizing available technology including computer FEA testing to improve their recumbent bikes.


In the UK in the 1980s, the most publicised recumbent cycle in the UK was the delta configuration, sometime electrically powered Sinclair C5
Sinclair C5
The Sinclair Research C5 is a battery electric vehicle invented by Sir Clive Sinclair and launched by Sinclair Research in the United Kingdom on 10 January 1985. The vehicle is a battery-assisted tricycle steered by a handlebar beneath the driver's knees. Powered operation is possible making it...

. Although sold as an "electric car", the C5 could be characterised as a recumbent tricycle with electrical assistance.

A study by Bussolari and Nadel (1989) led them to pick a recumbent riding position for the Daedalus
MIT Daedalus
The MIT Aeronautics and Astronautics Department's Daedalus was a human-powered aircraft that, on 23 April 1988, flew a distance of 71.5 mi in 3 hours, 54 minutes, from Iraklion on the island of Crete to the island of Santorini...

 flight even though the English Channel crossing was accomplished in the Gossamer Albatross
Gossamer Albatross
-See also:-Further reading:*Allen, Bryan. Winged Victory of "Gossamer Albatross". National Geographic, November 1979, vol. 156, n. 5, p. 640-651...

 with an upright position. Drela in 1998 confirmed "that there was no significant difference in power output between recumbent and conventional bicycling."

In the 2000s


A number of recumbent manufacturers went out of business after the 1990s, including BikeE (August 2002) and Vision.

Performance



Over distances recumbent bicycles outperform upright bicycles as evidenced by their dominance in ultra-distance events like 24 hours at Sebring. Official speed records for recumbents are governed by the rules of the International Human Powered Vehicle Association
International Human Powered Vehicle Association
The International Human Powered Vehicle Association is dedicated to promoting the design and development of human powered vehicles.- History :...

. A number of records are recognised, the fastest of which is the "flying 200 m", a distance of 200 m on level ground from a flying start with a maximum allowable tailwind
Tailwind
A tailwind is a wind that blows in the direction of travel of an object, while a headwind blows against the direction of travel. A tailwind increases the object's speed and reduces the time required to reach its destination, while a headwind has the opposite effect...

 of 1.66 m/s. The current record is 133.284 km/h (82.819 mph), set by Sam Whittingham
Sam Whittingham
Sam Whittingham is a Canadian cyclist who has held several world records on recumbent bicycles., he holds the following world records under the sanction of the International Human Powered Vehicle Association:...

 of Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 in a fully faired Varna Diablo front-wheel-drive recumbent lowracer bicycle designed by George Georgiev. The official record for an upright bicycle under IHPVA-legal conditions (but at sea level, not high altitude) is 82.53 km/h (51.29 mph) set by Jim Glover in 1986 with an English-made Moulton bicycle with a USA-made hardshell fairing around him and the bike.

The IHPVA hour record
Hour record
The hour record for bicycles is the record for the longest distance cycled in one hour on a bicycle. There are several records. The most famous is for upright bicycles meeting the requirements of the Union Cycliste Internationale . It is one of the most prestigious in cycling...

 is 90.6 km (56.3 mi), set by Sam Whittingham on July 1, 2009. The equivalent record for an upright bicycle is 49.7 km (30.9 mi), set by Ondřej Sosenka
Ondrej Sosenka
Ondřej Sosenka is a Czech professional cyclist and rides for the UCI Professional Continental team PSK Whirlpool-Author. He won the Peace Race in 2002. He broke the nine-year old UCI hour record on July 19, 2005 in Moscow, Russia, riding in one hour.Sosenka was known as one of the largest...

 in 2005. The UCI no longer considers the bike Chris Boardman
Chris Boardman
Christopher "Chris" Boardman MBE is a former English racing cyclist who won an individual pursuit gold medal at the 1992 Summer Olympics and broke the world hour record three times, as well as winning three stages and wearing the yellow jersey on three separate occasions at the Tour de France...

 rode for his 1996 record to be in compliance with its definition of an upright bicycle. Boardman's Monocoque
Monocoque
Monocoque is a construction technique that supports structural load by using an object's external skin, as opposed to using an internal frame or truss that is then covered with a non-load-bearing skin or coachwork...

 bike was designed by Mike Burrows, whose Windcheetah recumbent trike (see above) also holds the record from Land's End to John o' Groats
Land's End to John o' Groats
Land's End to John o' Groats is the traversal of the whole length of the island of Great Britain between two extremities; in the southwest and northeast. The traditional distance by road is and takes most cyclists ten to fourteen days; the record for running the route is nine days. Off-road...

, 861 miles (1,386 km) in 41 h 4 min 22 s with Andy Wilkinson riding.

In 2003, Rob English took on and beat the UK 4-man pursuit champions VC St Raphael in a 4000 m challenge race at Reading, beating them by a margin of 4 min 55.5 s to 5 min 6.87 s - and dropping one of the St Raphael riders along the way.

In 2009 Team RANS won the Race Across America
Race Across America
The Race Across America, or RAAM, is an ultra marathon bicycle race across the United States that started in 1982 as the Great American Bike Race....

 (RAAM) on recumbents.

Stationary recumbents


As well as road-going recumbent bicycles with wheels, stationary versions also exist. These are often found in gyms but are also available for home use. Like a regular stationary exercise bike, these stay in one place and the user pedals against some kind of resistance mechanism such as a fan or alternator but in a recumbent position. These have the same comfort advantages as road-going recumbents. Stationary recumbents almost always have a fairly upright seat and the pedal crank is lower than the level of the seat. The seat is normally adjustable and is adjusted by sliding it along a rail.

See also

  • Bicycle and motorcycle dynamics
    Bicycle and motorcycle dynamics
    Bicycle and motorcycle dynamics is the science of the motion of bicycles and motorcycles and their components, due to the forces acting on them. Dynamics is a branch of classical mechanics, which in turn is a branch of physics. Bike motions of interest include balancing, steering, braking,...

  • Bicycle and motorcycle geometry
    Bicycle and motorcycle geometry
    Bicycle and motorcycle geometry is the collection of key measurements that define a particular bike configuration. Primary among these are wheelbase, steering axis angle, fork offset, and trail...

  • Bicycle performance
    Bicycle performance
    A bicycle's performance, in both biological and mechanical terms, is extraordinarily efficient. In terms of the amount of energy a person must expend to travel a given distance, investigators have calculated it to be the most efficient self-powered means of transportation...

  • Bicycle seat
    Bicycle seat
    A bicycle seat, unlike a bicycle saddle, is designed to support the rider's buttocks and back, usually in a semi-reclined position. Arthur Garford is credited with inventing the padded bicycle seat in 1892, and they are now usually found on recumbent bicycles.Bicycle seats come in three main...

  • Bicycle suspension
    Bicycle suspension
    A bicycle suspension is the system or systems used to suspend the rider and all or part of the bicycle in order to protect them from the roughness of the terrain over which they travel...

  • Handcycles
    Handcycles
    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.Many...

  • International Human Powered Vehicle Association
    International Human Powered Vehicle Association
    The International Human Powered Vehicle Association is dedicated to promoting the design and development of human powered vehicles.- History :...

  • Prone bicycle
  • Quadracycle (human-powered vehicle)
  • Tricycle
    Tricycle
    A tricycle is a three-wheeled vehicle. While tricycles are often associated with the small three-wheeled vehicles used by pre-school-age children, they are also used by adults for a variety of purposes. In the United States and Canada, adult-sized tricycles are used primarily by older persons for...

  • Unicycle
    Unicycle
    A unicycle is a human-powered, single-track vehicle with one wheel. Unicycles resemble bicycles, but are less complex.-History:One theory of the advent of the unicycle stems from the popularity of the penny-farthing during the late 19th century...

  • Velomobile
    Velomobile
    A velomobile or bicycle car is a human-powered vehicle, enclosed for aerodynamic advantage and protection from weather and collisions. They are virtually always single-passenger vehicles. They are derived from recumbent bicycles and tricycles, with the addition of a full fairing . There are few...

  • Whike
    Whike
    The Whike is a recumbent tricycle with a sail, made in the Netherlands.The Whike 1.0 was released on 5 June 2008. It has a standard 1.6 m2 sail and can reach speeds up to 50 km/h with wind speeds of 4-5 bft . It can be legally used on both bike lanes and streets in the Netherlands and UK...

    , a recumbent bicycle with a sail
  • Feet forwards motorcycle
    Feet forwards motorcycle
    A Feet First Motorcycle is a class of motorcycle design that seeks to look at the two-wheeled concept afresh, and create a new form of practical personal transport...

     recumbent motobike equivalent.
  • Fastest speed on a bicycle

External links