Recumbent bicycle

From Wikipedia, the free encyclopedia

Jump to: navigation, search
Lightning P38 (a short wheelbase recumbent) and rider rest during a long tour.
Cruzbike Sofrider (a PBFWD recumbent) and woman at end of the 500-mile (800 km) "Ride Across North Carolina" 2007
The Gold Rush, a classic American long wheelbase bike

A recumbent bicycle is a bicycle that places the rider in a reclined position. For most enthusiasts the advantage is ergonomic; the rider’s weight is comfortably distributed over several square feet of the back and buttocks.

On a conventional upright bicycle, the body weight rests on a few square inches of the sit bones and the hands. Most recumbent models also have an aerodynamic advantage; the reclined, legs-forward position of the rider’s body presents a smaller front profile.

Recumbents hold the world speed record for a bicycle and were banned from international racing in 1934.[1]


[edit] Description

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

[edit] Wheelbase

Bacchetta Corsa, a short wheelbase high racer

Recumbent bicycles may be classified according to their 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.

[edit] Wheel sizes

The rear wheel of a recumbent is usually behind the rider and may be any size, from around 16 inches (410 mm) to the 700c 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), or ISO 622 (700c) wheels. Notable among these are "highracers", such as the Bacchetta Corsa and Strada or Volae Team, or the "LWB-style" RANS Stratus XP. Larger wheels generally have lower rolling resistance 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 pivoting-boom front-wheel drive Flevobike racer with 700c wheels (NL)

The most common arrangement is probably an ISO 559 rear wheel and an ISO 406 (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-inch (660 mm) wheels or larger.

Handlebar setup for under-seat steering (USS)

[edit] Steering

Steering for bikes can be generally categorized as over-seat (OSS) or above seat steering (ASS) and under-seat (USS). Most tadpole trikes are USS. USS is usually indirect -- the bars link to the headset through a system of rods and bell cranks. OSS/ASS is generally direct -- the steerer acts on the front fork like a standard bicycle handlebar -- but the bars themselves may extend well behind the wheel (more like a tiller); alternatively the bars might have long rearward extensions (sometimes known as Superman or Kingcycle bars). Chopper-style bars are sometimes seen on LWB bikes.

[edit] 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.[2]Another style, Pivoting-boom FWD (PBFWD), has the crankset connected to and moving with the front fork.[3] 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 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.

A RANS V2 Formula long wheelbase recumbent bike fitted with a front fairing

[edit] 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 utilized on recumbent bikes, using oil or air-damping in forks and rear shock absorbers. The maturation of fully-suspended conventional mountain bikes has aided the development of these designs, which often utilize many of the same parts, suitably modified for recumbent use.

[edit] Fairings

Some riders fit their bikes with aerodynamic devices called fairings. These have two main benefits: they reduce wind-drag (typically increasing average speeds by around 2mph), and they keep the rider warmer and drier in cold and wet weather. Fairings are also available for upright bikes, but are much less common.

[edit] Seats

The seats 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.

[edit] Variations

This Barcroft Columbia is an example of how a tandem recumbent can be fitted within a compact layout for easy transport.

[edit] 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 on the Lightfoot Ranger. Crank-forward designs that facilitate climbing out of the saddle, such as the RANS Dynamik, also can be used off-road.[4]

[edit] 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 the fastest type of bicycle that can be used on roads.

[edit] 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 manoeuverable than lowracers since their higher center of gravity allows stability at lower speeds (see Bicycle and motorcycle dynamics). Given the same seating position they may be faster than lowracers, since it is widely believed that larger tires have lower rolling resistance, although good data on this subject are scarce.

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.

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

[edit] Tandem recumbents

Just as with upright bicycles, recumbents are built and marketed with more than one seat, thus combining the advantages of recumbents with those of tandem bicycles. In order to keep the wheelbase from being any longer than absolutely necessary, tandem recumbents often place the stoker's crankset under the captain's seat.

[edit] Recumbent tricycles

Recumbent tricycles (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.

A tadpole recumbent tricycle made by Inspired Cycle Engineering with a transparent front fairing

Three remarkable characteristics of recumbent trikes include: (1) the rider does not need to disengage from the pedals when stopped; (2) the trike can be geared very low to enable mountain climbing while heavily loaded and at a slow speed, without losing stability; and (3) trikes are capable of turning sharply without leaning, producing lateral "g forces" similar to sports cars. Recumbent trikes may also be more suitable for people with balance or limb disabilities.

The Windcheetah, designed by Mike Burrows and one of the first commercial tadpole designs, is often credited with kicking off the recumbent tadpole tricycle boom.

At present, the tadpole trike market is represented by companies such as Inspired Cycle Engineering (ICE), Greenspeed and HP Velotechnik, with touring being a strong market but sporting use also being common. ICE has produced a sub-20 lb trike - all the more remarkable for being steel framed and fitted with a hard-shell seat, full mudguards, and luggage rack. As the market expands, costs continue to drop. Stein has launched a range of budget recumbent trikes made in Eastern Europe, the KMX Kart stunt trike, and others.

Delta trikes also offer the possibility of expanded cargo capacity; the Lightfoot Cycles line includes several delta recumbent trike models which provide cargo capacity from 6,000 cubic inches (100 L, for errands or touring) to as much as 35,000 cubic inches (575 L, for cargo delivery).

A competition handcycle

[edit] 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 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 less strong 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. Georgiev's Varna bikes have been well represented over the years (see also Records below) and in 1995 Jacob Heilveil achieved 52.47 km/h (32.60 mph) in the flying 200 m.

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 & Foot recumbent tricycle

[edit] 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. Lightfoot Cycles offers this hand-and-foot option on many of their recumbent trike models. 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[1].

[edit] Homebuilts

As with upright bikes, there is a subculture of recumbent builders who design and build home-built recumbents.[citation needed] 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 to 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.

[edit] Couplers

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

[edit] 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.)

The Optima Stinger short-wheelbase bike with disc brakes, rear suspension and over seat (tiller) steering; ETRTO 406 wheels front and rear
Shop for recumbents in Nijmegen, Netherlands
2008 Nazca Fuego short wheelbase recumbent with 20" front wheel and 26" rear wheel.

[edit] Riding position

A study by Bussolari and Nadel (1989) led them to pick a recumbent riding position for the Daedalus flight even though the English Channel crossing was accomplished in the Gossamer Albatross with an upright position. Drela in 1998 confirmed "that there was no significant difference in power output between recumbent and conventional bicycling."[5]

[edit] Advantages

Recumbents have several advantages over traditional upright bicycles.

Variety. A specific recumbent can be purchased that best meets the physical needs and aesthetic preferences of the rider. Models can range from semi-upright to a full reclined position, short wheelbase to long wheelbase, fairings for rain/wind protection, suspension, and many others.
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 metre (and in some cases, as much as 1 metre) 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.[6] 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. 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 manoeuver, 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 manoeuverability, and to prevent cars from passing when there is not enough room to do so safely.[7]
Comfort. The recumbent riding position reduces strain on the body, making it particularly suitable for long rides and touring. [8] It is 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 enables the rider to face forward, at a comfortable angle, and view the passing scenery. A recumbent rider can even look straight upward. An upright bike, particularly a road bike, on the other hand, has a riding position in which the natural angle is to stare down at the pavement below. In order to see the scenery, 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 to more easily return to the heart. This physiological effect of improved circulation 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. [8]
Speed. On declines, on the flat, or on shallow inclines, recumbent bicycles are generally faster than upright bicycles for the same level of effort because the aerodynamic profile of the rider reduces wind resistance[6]. It is this feature which led to the Union Cycliste Internationale (UCI) banning them in the 1930s (see History). The world speed record for human powered vehicles was set by Sam Whittingham on a fully-faired recumbent bicycle on September 18, 2008 with a speed of 132.5 km/h (82.33 mph). [9]
Turns. Although recumbents have larger turning circles than conventional bicycles, one advantage on many designs is that the rider can continue pedaling even during tight turns without fear of the pedals striking the ground.

[edit] Disadvantages

Balance. Balance is generally more difficult on a recumbent bicycle due to the lower 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).[10] 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 traditional 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 excellent balance. However, since starting a bicycle by pushing the feet against the ground is probably a poor way to start[11], this criticism may invalidate itself. 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 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 an issue.
A few designers have attempted to build bikes which convert from recumbent to upright for climbs [12]. 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 mph (8 km/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 .[citation needed] 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 - noteably 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. [13]
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.
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.[citation needed] The use of clipless pedals reduces this possibility by preventing the foot from slipping off of 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 rarely seen with upright bicycles.[citation needed]
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 pedalling. 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.

[edit] 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.

[edit] Early recumbents

Recumbents from the 1920s in the Velorama

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's safety bicycle, 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.

[edit] Mochet's Velocar

A crucial story in the history of recumbent cycling began with the design of a four-wheeled pedal-propelled car called the 'Velocar' (or 'Vélo couché') built in the early 1930s by French 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 during the Great Depression. 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.

Then on 7 July 1933 at a Paris velodrome, Faure rode a Velocar 45.055 km (27.9 miles) in one hour, smashing an almost 20-year-old hour record held by Oscar Egg. Since the one-hour record was one of the most important in all of cycling, that accomplishment attracted a great deal of attention. Less than two months later, on 29 August 1933, Maurice Richard, riding an upright bicycle, also bettered Egg's one-hour record.

When the Union Cycliste Internationale (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 and guaranteed that upright bicycles would not have to compete against recumbents[14]. For all intents and purposes, the ban is still in effect.

After the decision, Faure continued to race, and consistently beat, upright bicycles with the 'illegal' (according to the UCI) 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.

The UCI ban on recumbent bicycles and other aerodynamic improvements virtually stopped development of recumbents for four decades[14]. 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.

[edit] 1970s resurgence

While developments had been made in this fallow period by Paul Rinkowski and others, the fathers of the modern recumbent movement are usually said to be Chester Kyle and particularly David Gordon Wilson of MIT, two engineers working in the USA. Kyle and his students had been experimenting with fairings for upright bicycles, also banned by the UCI, leading in 1974 to the International Human Power speed Championship, from which the IHPVA grew.

The Avatar 2000, an 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. The oil crises of the 1970s sparked a resurgence in cycling coincident with the arrival of these "new" designs. Since competition was not a driving force, the UCI ruling did not hinder the commercial development of recumbent designs. The influence of Kyle and Wilson and their students probably also had a lot to do with the strength of this renaissance.

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).

[edit] In the 1980s

In 1984 Linear recumbents (of Iowa) began producing what was at the time arguably one of the most comfortable and relaxing bicycles available. Their stability, handling, comfortable seat and natural arm position made them a relaxing form of transportation, recreation and exercise. One rider, returning from their first test ride said, "If my butt had wheels this is what it would be like!"

Linear ownership has changed hands since the 80's. 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, local engineers and machinists utilizing available technology including computer FEA testing to improve their recumbent bikes and bring an old favorite into the new century.

BikeE still running
Two short-wheelbase recumbents in an amateur HPV race
HPV's racing in Wonthaggi, Victoria. Many of these cycles are fully faired

In the UK in the 1980s the most publicised recumbent cycle in the UK was the delta configuration, sometime electrically powered Sinclair C5. Although sold as an "electric car", the C5 would be more accurately characterised as a recumbent tricycle with electrical assistance, with all the associated advantages and disadvantages.

[edit] In the 2000s

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

[edit] Performance

Over distances recumbent bicycles outperform upright bicycles as evidenced by their dominance in ultra-distance events like 24 hours at Sebring.[15] Official speed records for recumbents are governed by the rules of the International Human Powered Vehicle Association. 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 of 1.66 m/s. The current record is 132.47 km/h (82.33 mph), set by Sam Whittingham of Canada in a fully faired Varna Diablo front-wheel-drive recumbent lowracer bicycle designed by George Georgiev.[9] 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 is 87.123 km (54.136 miles), set by Damjan Zabovnik on July 12, 2008. The equivalent record for an upright bicycle is 49.700 km (30.882 miles), set by Ondřej Sosenka in 2005. The UCI no longer considers the bike Chris Boardman rode for his 1996 record to be in compliance with its definition of an upright bicycle. Boardman's Monocoque bike was designed by Mike Burrows, whose Windcheetah recumbent trike (see above) also holds the record from Land's End to John o' Groats, 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.

[edit] Stationary recumbents

As well as road-going recumbents 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. The heads-up position also makes it easier to watch TV.

[edit] See also

[edit] Notes

  1. ^ "The History of the Recumbent Bicycle: Winning Forbidden". Retrieved on 2008-08-28. 
  2. ^ "Toxy ZR Race Recumbent". Retrieved on 2007-02-03. 
  3. ^ "Front Wheel Drive - Is it practical?". Retrieved on 2006-10-22. 
  4. ^ Recumbent News: November 2007 Archives
  5. ^ Wilson, David Gordon (2004). Bicycling Science (Third ed.). Massachusetts Institute of Technology. pp. 72,86. ISBN 0-262-73154-1. 
  6. ^ a b Landis, Bruce; Petritsch, Theodore; Huang, Herman (2004), Characteristics of emerging road users and their safety, US Department of Transportation, Publication No. FHWA-HRT-04-103, 
  7. ^ Oswald, Fred. [ "Bicycle Commuter's Guide, Tips & Techniques: Do you know how to ride a bicycle?"]. 
  8. ^ a b Nolan, M.D., Paul. "Medical Benefits of Recumbent Bicycles". Retrieved on 2008-07-05. 
  9. ^ a b "World's Fastest Cyclist Hits 82.3 MPH". Retrieved on 2008-09-26. 
  10. ^ Fajans, Joel. "Email Questions and Answers: Robot Bicycles". Retrieved on 2006-08-07. 
  11. ^ Brown, Sheldon. "Bicycling Technique: Starting and Stopping". 
  12. ^ van Pelt, James L, "Convertible bicycle", US ... a bicycle that can be quickly and easily configured in an upright position, a recumbent position, and a tandem position. 6497426, issued 2002-12-24
  13. ^ "Upright vs Recumbent Comparison Table". Retrieved on 2007-04-21. 
  14. ^ a b Recumbents share this historical profile with Catamarans, which were also banned for unfair performance reasons and their unconventional design.
  15. ^ "An Epic Race at Sebring 2006! Recumbents Rule! Tandems Triumph! Females Forceful!". Retrieved on 2008-12-08. 

[edit] Further reading

  • Fehlau, Gunnar (2003). The Recumbent Bicycle (2nd ed.). Out Your Backdoor Press. ISBN 1-892590-58-1. 
  • Fehlau, Gunnar (2006). The Recumbent Bicycle (3rd ed.). Out Your Backdoor Press. ISBN 1-892590-59-X. 

[edit] External links

Personal tools