A 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. Steering is either above seat steering (ASS), which uses a handlebar that is located in front of the rider, or under seat steering (USS), which uses a handlebar located under the seat. The wheels are often smaller and/or further apart than on an upright bicycle.
The recumbent bicycle is not new, records of recumbent designs go back to the early days of cycling, but it is only recently that they have become widespread. Recumbents hold world speed records for unpaced, human-powered vehicles. Tricycles form a substantial part of the recumbent market (far more so than for upright bikes); the generic term bike tends to be applied to these as well.
Recumbent bicycles may be classified according to their wheelbase: long wheelbase (LWB) models have the pedals located between the front and rear wheel; 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 the categories there are variations and intermediate types - there is no such thing as a "standard" recumbent.
The rear wheel of a recumbent is usually behind the back of the rider and might be any size from around 20" up to the 700c of an upright racing cycle. The front wheel is commonly smaller than the rear, although there are a number of recumbents which feature dual 26" (ISO 559), ISO 571 (650c), or ISO 622 (700c) wheels. Most notable among these are "highracers" such as the Bacchetta Aero. Larger wheels generally have lower rolling resistance; the trade-off is a higher profile. Highracer aficionados also claim that they are more stable (this is correct; bicycle stability increases with the height of the centre of gravity above the ground).
The most common arrangement is probably 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 (there is a problem known as heel strike where the rider's heels catch the wheel in tight turns). Another configuration that overcomes this constraint is front wheel drive, where the pedals and front wheel turn together. Pivoting boom front wheel drive (PBFWD) bikes may have dual 26" wheels or larger.
Steering for bikes is broadly over seat (OSS) or under seat (USS), and most trikes are USS. USS is generally indirect, the bars linked to the headset through a system of rods and pivots. OSS is generally direct, the steerer acting on the front fork like a standard bicycle handlebar, but the bars themselves may be 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.
The seats themselves are either of mesh stretched tightly over a frame (as in the Gold Rush pictured) or 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 are more common in the USA.
Recumbent tricycles (trikes) are closely related to recumbent bicycles, although they have three wheels instead of two. Trikes come in two varieties, the delta, with two rear wheels, and the tadpole, with two front wheels. Most recent high-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 trikes are capable of turning sharply without leaning, producing lateral "g forces" similar to a sports car. Recumbent trikes are also often suitable for those with balance or limb disabilities.
The legendary Windcheetah, designed by Mike Burrows, is often credited with kicking off the recumbent tricycle boom, and it was certainly one of the first if not the first commercial tadpole design. As well as a long association with Giant, for whom he designed the OCR series, Burrows is a designer and builder of recumbent racing machines, two and three wheeled, and load bikes. The Windcheetah is still in production and is an iconic design much appreciated by cognoscenti. At present the trike market is led by companies such as Inspired Cycle Engineering (ICE) and Greenspeed, with touring being a strong market but sporting use also being common. ICE have produced a sub-20lb trike - all the more remarkable for being steel framed and fitted with hard shell seat, full mudguards and rack! Costs are coming down all the time and the market is expanding, the 21st Century thus far having seen the launch of the Stein range of budget recumbent trikes made in Eastern Europe and the KMX Kart stunt trike, among others.
Disabled riders have not been left out. Hand-powered recumbent trikes are a regular sight at HPV meets and are beginning to be seen on the streets. These usually follow a delta design with front wheels driven by standard derailleur gearing powered by hand cranks. Brake levers are 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.
Arms are less strong than legs but a good handcyclist can still achieve a respectable pace. Georgiev's Varna bikes have been well represented over the years (see also Records below) and in 1995 Jacob Heilveil achieved 52.47km/h (32.60mph) in the flying 200m.
Some riders fit aerodynamic devices called fairings which reduce wind drag (these are also available for upright bikes, but this is much less common). Fairings are available for the front and rear of the vehicle. Some riders also use a "sock," 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, but front fairings are less beneficial for short wheelbase bikes. A faired tailbox can increase speed on a low short wheelbase bike by around 5-10%, a worthwhile compensation for the added weight. The most exotic machines have lightweight full-body fairings, tested in wind tunnels.
For the ultimate in all weather riding a velomobile has a fully-enclosed body, is usually a three-wheeled design, and keeps the rider warm and dry in all weathers.
Advantages and disadvantages Edit
The recumbent has several advantages over the traditional upright, but also a number of disadvantages.
Recumbent riders generally consider that the braking performance, low seating position and feet-first approach to obstacles combine to give greater safety than an upright bike. Recumbents are lower down than upright bikes, leading some to conclude that they must be hard for motorists to see, but there is no evidence of this being a problem. Indeed, the opposite may well be true. Much of the problem of bike collisions is caused by drivers who see but do not notice - recumbents are nothing if not noticeable. Nonetheless many riders, especially those who ride the lowest machines, choose to fit flags and pennants when riding on roads.
Aside from the attraction of riding an unusual and eye-catching machine, there are a number of genuine advantages to the recumbent design.
First and foremost the recumbent riding position reduces strain on the hands, arms, shoulders, genital area and ischeal tuberosities ("sit bones"), making it particularly suitable for very long rides and touring. Panniers can be mounted low down, under the rider, which gives good handling and stability when loaded. Recumbents usually have better aerodynamics, safer braking with very little chance of an "endo" (rear wheel lifting) and - with trikes - greater stability. Some trike riders exploit this stability by mounting 80 or more gears, with bottom gears giving speeds as low as 2mph for 90rpm cadence - sufficient to climb the steepest hills in comfort.
Riders who suffer back pain or genito-urinary trouble will often find that a recumbent allows them to ride for longer without pain. Trikes are particularly suited to those with limited mobility or balance problems. The inherent stability of three wheels allows very low gearing to be used, so that hills can be climbed without strain on joints.
On the flat, recumbent bicycles are generally faster than upright bicycles for the same level of effort because the aerodynamic profile of the rider reduces wind resistance - wind resistance rises with speed squared and at a typical brisk riding pace of 20mph, over 80% of rider effort is overcoming air resistance. It is this feature which led to the Union Cycliste International (UCI) banning them in the 1930s (see History).
Forward visibility is very good, the neck is better adapted to the supine recumbent position than the normal riding position on an upright bike, so the dangerous temptation to watch the front wheel is lost.
Lastly, recumbent riding is huge fun. A lower seating position gives a greater impression of speed, and top speeds on descents in particular can be screamingly fast. The KMX Kart capitalises on this as a primary selling point. Low wind resistance means the fastest racers are often hard-pressed to keep up.
The need to support the rider's back requires a much more substantial (read: heavier) seat, most noticeable when climbing. Long chainlines are common, and idlers and chain tubes are often employed to route the chain, which introduces mechanical losses. Small wheels generally have higher rolling resistance, and a less comprehensive choice of tires is available. The riding position, while comfortable, 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. Forward visibility in traffic is less good than on an upright and rearward visibility generally requires a mirror. There is a risk of heel strike on many models, and a phenomenon known as "leg suck", where a foot touches the ground and the bike runs forward over the contact point, causing ligament damage, makes the use of clipless pedals strongly advisable. Finally some riders suffer "recumbent butt", a pain in the gluteal muscles caused by their working harder and also being sat on. This can usually be tuned out by adjustment to seat angle and pedal position.
Recumbents are also expensive. Almost all are craft-built in comparatively small runs by small independent manufacturers who have not the buying power of the large bike firms. A typical recumbent will also be built with high specification components, so it's important to compare like with like, but even so a recumbent will typically cost between 10% and 25% more than an equivalently specified upright bike.
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 on an upright, would 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.
Bicycle designs that put the rider in a reclined position date back to the middle of the 19th century. A couple of recumbent designs were patented around 1900 but the early designs were unsuccessful.
Early recumbents Edit
Recumbent designs of both prone and supine varieties can be traced back to the very 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 differnet layouts. The Challand designs of 1897 and the American Brown of 1901 are both recognisable as forerunners of today's recumbents.
The Mochet Velocar Edit
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 due to a poor economy just after World War I. The four-wheeled Velocars were fast but they didn't corner well at high speed, so Mochet experimented with a three-wheel design and then finally settled on a two wheel design, a bicycle.
Looking for a way demonstrate the speed of his recumbent bicycle, Mochet convinced cyclist Francis Faure, who was not one of the top cyclists, to ride the two-wheeled Velocar 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. 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 Charles Mochet's son, Georges, began adding fairings to the Velocar in hopes of bettering the world record for 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 recumbent bicycles 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.
Modern recumbents Edit
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 particuarly 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, a LWB bike very much like the current Easy Racers products, arrived in 1979, and is often considered the first production modern recumbent. It 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 70s sparked a resurgence in cycling coincident with the arrival of these "new" designs, and this time competition was not the driving force, so the UCI ruling did not prevent 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, with LWB much more popular in the US (although there have been some notable European LWB bikes, such as the Peer Gynt).
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 200m", a distance of 200m on level ground from a flying start with a maximum allowable tailwind of 1.66 m/s. The current record is 130.36 km/h (81.00 mph), set by Sam Whittingham of Canada on a fully-faired Varna Diablo front wheel drive recumbent lowracer bicycle designed by George Georgiev. The official record for an upright bicycle under somewhat similar conditions is 72.98 km/h (45.36 mph) set by Curt Harnett in 1995.
The IHPVA hour record is 84.215 km (52.32 miles), set by Sam Whittingham on July 31, 2004. 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 in 41h 4m 22s with Andy Wilkinson riding.
In 2003, Rob English took on and beat the UK 4-man pursuit champions VC St Raphael in a 4000m challenge race at Reading, beating them by a margin of 4m 55.5s to 5m 6.87s - and dropping one of the St Raphael riders along the way.
Recumbent culture Edit
Recumbent riders tend to be strongly individualistic. Bikes may be highly customised either to reduce weight, cut drag, increase comfort, or maybe just to say "Hey! Look at me!". There is a thriving amateur racing culture and home-built bikes are also common. Seemingly, no two bikes are the same, even if they were when they left the factory.
Further Reading Edit
The Recumbent Bicycle, Gunnar Fehlau, Out Your Backdoor ISBN: 1892590581
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