Recumbent
A recumbent bike is a bike with a backward-sloping sitting or lying position. In contrast to a conventional bicycle, it has a mesh or bucket seat instead of a saddle . The bottom bracket and pedals are attached to the front. Most recumbents are no more difficult to ride than ordinary bicycles; Depending on the type of recumbent and the shape of the handlebars, it may take a short period to get used to it.
The rule of the International Cycling Federation (UCI), according to which only bicycles with diamond frames are allowed in competitions, excludes the use of recumbents in most competitions.
history
After the chain drive was popularized in bicycle construction in the 1880s and 1890s, various inventors implemented numerous variants of this concept. These included the first forerunners of the recumbent bike such as the French Fauteuil- Velociped with balloon tires from 1893, the chair wheel by Ferdinand Krafft from Saarbrücken, the recumbent bike by Drewitz and the chair wheel by the Swiss manufacturer Challand (1895). In the following years, today's basic types of bike design have been designed already, as the Bauchliegerad Mr. Darling (1896) and the Brown-Recumbent , the forerunner of the chopper / scooter wheel, which was developed around the turn of the century in the United States. Other concepts such as recumbents with rudder drive did not come out beyond the prototype stage. The first models were all long-lying .
In 1914, Peugeot offered the first mass-produced recumbent bike based on the Brown recumbent. In the 1920s, aviation pioneer Paul Jaray built the J-wheel , which was also mass-produced and was successful. A decade later, Charles Mochet and his son Georges developed the Velocar , the first recumbent bike that was used successfully for sport. The International Cycling Federation (UCI) allowed recumbents to take part in official competitions. In 1933 it set a world record of 45.056 kilometers. This speed was only reached five years later by a conventional (undisguised) racing bike.
On April 1, 1934, however, the UCI decided to exclude recumbents from competition operations. This marked a turning point in the development of this type of bicycle. As a result, recumbent bicycles experienced a low point in popularity between around 1950 and 1980. During this time only small series models from individual manufacturers were available.
The recumbents were developed further, however, and after the exclusion from the UCI an independent scene began to form. Mochet was already experimenting with wired vehicles in the 1930s, the modern versions of which are known as velomobiles . The Mochet vehicles were based on conventional recumbent bikes and are still the fastest human-powered vehicle type. In 1939, such a mobile exceeded the 50 km / h mark for the first time in the hourly classification. At the same time, the first short berths ( The Cycloratio , 1935) were built, which were later to become the dominant recumbent type from 1947 , mainly thanks to further development by the German engineer Paul Rinkowski .
Consumer demand for recumbents remained stable until the post-war years, as many people who couldn't afford their own car bought a recumbent instead. After that, interest flattened until the establishment of the International Human Powered Vehicle Association (IHPVA) in 1976 initiated a renaissance. Since then, the association has promoted the development of all types of muscle-powered vehicles and again organized regular competitions in which recumbent bikes were also permitted.
In the 1980s, Lui Tratter began to reproduce the Drewitz recumbent in series as part of the polytechnic lessons at the Ernst Reuter School in Frankfurt and in the youth welfare project worker self-help at the Krebsmühle . The bikes quickly gained cult status in Frankfurt am Main and can still be seen regularly in the cityscape today.
At the same time, the 200 m sprint became increasingly popular as a discipline in sports. In 1977 the 75 km / h mark was exceeded, in 1979 the 50 mph in the USA, and in 1986 the 100 km / h mark fell. At that time, fully faired tricycles dominated the competition, such as the Vector , which set numerous records in the 1970s and 1980s. At the end of the 1980s and beginning of the 1990s, single-track bicycles, especially the new low-flying aircraft ( Cutting Edge , 1990) , became popular again over tricycles because of their weight advantage.
The sporting achievements and also more modern vehicle technology studies led to a resurgence of public interest in the recumbent bike, so that large-scale models have been offered since the 1990s. Since around 2000, both velomobiles and unboarded recumbent tricycles have been slowly gaining popularity. Since 2007, more and more so-called trikes have come into fashion, which can be ridden in a similar way to a BMX bike, but which, thanks to today's technology, can also be very fast touring vehicles.
It is estimated that there are around 50 million "normal" upright wheels in Germany, many of them with diamond frames. The number of recumbent bikes in Germany is around 30,000.
Comparison with upright bikes
advantages
- Fatigue-free sitting position
- When reclining neither the results in a very relaxed posture as wrists nor the arms still shoulder girdle or back will be charged. The hands lie relaxed on the handlebars, it is not necessary to support the upper body as with a normal bicycle. The neck muscles are also relaxed, as there is no need to constantly look upwards as with a conventional bicycle. With many recumbents, the rider looks straight ahead with a natural neck posture, only with some very low recumbents with an extremely flat seat you have to put your head down to look forward. The usual seating problems caused by the saddle are also avoided.
- health
- When cycling recumbent, the spine is in a relaxed position. Doctors have shown that in the best case scenario , the intervertebral discs regenerate. In addition, there is no pressure from the saddle, so that there are no pressure or chafing points in the buttocks and crotch area , and important nerves are not pinched in this area. Men with prostate problems can have problems on normal bicycles that can be avoided with the recumbent bike. The irritation of the finger nerves such as annoying tingling and even numbness , which is common on longer journeys, is also excluded .
- Air resistance
- In principle, around 20 to 30% of the air resistance is lost compared to normal bikes thanks to the high legs. In addition, the stretched seating position and the smaller frontal area result in less braking air vortices , which results in less suction behind the driver. In particular, a rear panel, often in the form of a suitcase, can again significantly reduce the air resistance. On the flat and downhill, this enables much higher speeds than with a conventional racing bike. This does not apply to inclines because the air resistance is negligible at low speeds.
- Safety and the consequences of accidents
- The center of gravity of most recumbent bicycles is significantly lower than that of conventional bicycles, and at the same time the wheelbase is often considerably longer. Both of these together are very effective in preventing rollover due to a blocked front wheel. Even if you hit an obstacle, the consequences for recumbent cyclists are less severe. In both cases, with conventional bikes, severe head and spinal injuries can result if the rider hits an obstacle head first. The stretched position with the feet first causes the recumbent cyclist not to hit with the head, but with the feet. The lower height of fall also reduces the risk of injury at low speeds.
- Power transmission
- In general, recumbent bicycles make it possible to apply considerable forces to the crank by supporting the pelvis and the upper body on the backrest, without the arms and upper body having to actively build up a corresponding counterforce. This and the fatigue-free sitting position avoid any muscle work that is not directly used for propulsion. However, a far higher torque can be built up on the diamond frame for a short time by kicking the saddle in a standing position, which is impossible on the recumbent bike due to the design.
disadvantage
- price
- The prices for recumbent bikes are considerably higher than for conventional bikes. This is due to small numbers and the use of some special parts, such as the seat, power transmission and the luggage rack . On the other hand, because of the higher driving speed, very high-quality gears and brakes are often used. Recumbents without full suspension are uncomfortable given the lack of suspension options for the seat. The price range for recumbents is between 1,100 euros and 10,000 euros.
- Weather protection
- Uncovered recumbent cyclists are more exposed to rain than those who ride a conventional bike. Precipitation hits the body in full length and the high wind pushes the water up the clothing from below, depending on the angle of the seat. On the other hand, due to the design, fully faired recumbents provide good rain protection - usually three-wheeled velomobiles. However, front protection (streamer, front fairing) can usually be fitted to uncovered recumbent bikes without any problems, to which a special rain cape can also be attached, making very good weather protection possible. Recumbent tricycles are particularly suitable for this because they are less susceptible to cross winds.
- Weight of the frame
- Many recumbents have a heavier weight due to their often large frame tube and full suspension. However, this cannot be generalized: unsprung racing recumbents with spartan equipment are available with system weights from 7.5 kg, sporty recumbent tricycles from around 10 kg (unsprung, full carbon) or 12 kg (full-suspension, suitable for everyday use).
- Balance and handling
- Recumbent two-wheelers are more difficult to balance due to the immobility of the upper body. In addition, the lower center of gravity forces the handlebars to swing quickly at slow speed, so that the recumbent two-wheelers are a little more wobbly at walking pace. The longer wheelbase and the limited steering angle generally make recumbent bikes less manoeuvrable when driving slowly, when maneuvering, taking sharp bends and when passing diagonal locks.
- Driving in traffic
- How well recumbent bicycles are visible in road traffic is controversial. Some motorized road users say that recumbents are easy to overlook behind parked vehicles because they do not protrude far above the vehicle roof like normal wheels. On the other hand, car accidents with conventional cyclists usually occur because the car driver in question did not pay any attention to the bicycle traffic. In contrast, recumbent riders report an above-average level of attention from their vehicle. Looking backwards, for example when changing lanes, is uncomfortable or difficult due to the semi-recumbent sitting position; A rearview mirror can help.
- Driving over curbs
- Driving up curbs is, depending on the construction of the recumbent bike, only possible when driving very slowly or not at all, as the front wheel cannot be pulled up while driving.
- Driving on ice, snow and slippery surfaces
- The risk of falling with a recumbent two-wheeler is slightly higher than with a normal bike, because if a tire slips away, it is more difficult to regain balance over the upper body. However, the height of the fall is lower, which reduces the consequences of injury. Tricycle recumbents, on the other hand, have almost always an advantage on difficult terrain.
- Driving when the sun is low and in the dark
- Due to the leaning back posture, like in a car, one is more dazzled by the evening sun from the front. In the dark, on the other hand, recumbent cyclists are at the height of the driver's headlight cone and can therefore be seen more easily - with normal bikes, a driver can only see their legs. Backlight, however, blinds the recumbent cyclist more accordingly.
- Contents of trouser and jacket pockets
- If the trouser and jacket pockets are not cut properly, the contents, e.g. B. wallet or keys, are more easily lost, especially if they are not secured by locks.
Design-related features
- Transport of loads
- Because of their low center of gravity, recumbent touring bikes are much better suited to transporting luggage than conventional bikes. Up to four large panniers can be attached to brackets under and behind the seat without shifting the center of gravity of the bike. In contrast to conventional touring bikes, the handling of the recumbent bike does not change when it is loaded. However, it is not possible to carry a backpack or use a handlebar bag . Also Lowrider are unsuitable by the often small wheel diameter. Furthermore , depending on the suspension of the rear wheel, towing a trailer is not always possible.
- Repairs
- The usual wear and attachment parts correspond to those of ordinary bicycles. A few typical recumbent components (e.g. pulleys and seats) are not standardized, so that they usually cannot be exchanged between different models. Such spare parts are therefore difficult to obtain and must be obtained from the shipper or the manufacturer.
- Smaller wheel diameter
- As a rule, very small front tires measuring 20 inches are used on recumbent bikes. With such small tires, the rolling resistance increases for physical reasons. Higher air pressure or a structurally lower load on the front wheel can partially compensate for this. However, driving out of ruts remains more difficult, as the small tires cannot anticipate the slope that far.
- Longer chain
- A long chain is required for all rear-wheel drive recumbents. Appropriate chain guidance devices do not result in any significant problems for the drive. Even if the chain is completely covered with a Teflon hose, recumbent bikes are not suitable for rock because of the Monroe effect . The enormous chain length (3.5 m for a short-stay model) also increases the total weight.
- Change of posture
- A change between flat-sporty-fast and upright-casual-relaxed posture is not possible with the recumbent bike. However, it is also unnecessary, because it usually serves to avoid overloading or cramping, which in any case does not occur with a recumbent bike.
- To adjust
- The adjustment of the bike to the body size of the rider, which is done with conventional bikes by pulling out the seat and handlebar supports, is also possible with the recumbent bike. In contrast to conventional bicycles, this usually changes the length of the chain , which means that it cannot be quickly converted for shared use by several riders of different sizes. An exception to this are chair wheels (e.g. the Spirit from HP Velotechnik), as the distance to the crank can be changed with an adjustable seat (often without tools with quick releases), thus enabling riders of different sizes to use a bike.
Recumbent types
There are numerous variants of recumbent bikes. For example, with front or rear wheel drive , with and without crankcase elevation , directly or indirectly steered, with handlebars in front of the body or under the seat.
Frame constructions
Recumbent bikes can be structurally divided into the following categories, whereby many models fall into more than one category and an exact classification is often impossible.
-
Short layovers have a short wheelbase. They are suitable for everyday use as well as for traveling and are by far the most common design.
- Low-flyers are short-stay vehicles for racing or a decidedly sporty driving style.
- Articulated vehicles are short-stay vehicles with front-wheel drive. Instead of a handlebar, they have a hinge in the frame and are steered by shifting your weight.
-
Long-lying vehicles offer a high level of comfort thanks to their long wheelbase, but they are bulky and not very agile.
- Armchair bikes or scooters are long-lying people with a high seating position. They are suitable for both the city and travel.
-
Recumbent tricycles usually have two front wheels and convey a go-kart driving experience .
- Velomobiles are fully covered, heavy recumbent tricycles with good weather protection and good aerodynamics.
- Liege tandems are for two drivers. They are available with both two and three (and rarely four) wheels.
- Rowing bikes are recumbent bikes that are driven by the force of the arms. They are available with two and three wheels.
- Lying on the stomach have a low air resistance, but at the expense of comfort, overview and safety.
steering
There are different types of steering. One distinguishes between:
- Top handlebar with the handles above the seat and in front of the driver's chest. Forms of the top link that are widespread in short-term and low-flying aircraft are:
- Tiller, a mostly T-shaped handlebar with the handles relatively close to the chest while driving. Tiller is available in a rigid version and as a folding tiller, in which the entire handlebar can be folded forward using a joint on the steering head to make getting on and off easier.
- UDK ("Um die Knie") or aero handlebars, in which the handlebar is arranged in an arc around the knees. The handles are usually at knee height.
- Lower handlebar, a handlebar usually attached under the seat, with the handles usually located on the side and slightly above the seat surface.
- Armored steering, usually only found in velomobiles or trikes, describes a handlebar shape in which the two steered front wheels are each linked directly by a steering lever with a handle. The handles are located here, similar to the lower link, on the side and a little above the seat.
DIY
Especially in the 1980s, when commercial recumbent bicycles were even less common than they are today, self-made bikes were common on the scene. Often, "bicycle corpses" were recycled when building recumbents, sometimes with adventurous constructions. Many construction plans from this period are still available today, for example in the booklet “Chopper Bicycles” from the series “Ideas instead of waste” by Christian Kuhtz, ISBN 3-924038-66-X . The Hobbythek recumbent bike is based on a similar concept , and parts of old bicycles were also used.
Since recumbent bikes have to be designed and manufactured with particular precision if they are to have good handling characteristics, self-made bikes are almost always inferior to professional bikes. The same applies to cheap imported bicycles from the Far East, which were manufactured according to the quality standards of normal bicycles.
Sports
in Saint Helier , Jersey
Bicycles were used early on in athletic competition. In the year of the World's Fair in 1867 , the first documentary race on bicycles was held on December 8, 1867 in Paris , in which the riders mainly competed against each other on Pierre Michaux's “ Boneshaker ” . With the advent of recumbent bicycles, like other types of bicycles, they were also used in sport. Due to their aerodynamic potential, recumbent bikes set records that racing bikes could not. Basically, a distinction is made between speed records and distance records. Controlling bodies outside the UCI are the WHPVA and the IHPVA .
Speed records
| Racing discipline | date | Time in s | Speed in km / h | Driver | gender | vehicle | Manufacturer | venue |
|---|---|---|---|---|---|---|---|---|
| 200 m (flying start) | 09/18/2008 | 5.434 | 132.50 |
Sam Whittingham
|
Men | Varna Diablo III | Georgi Georgiev (Varna Innovation and Research Corporation) | Battle Mountain , Lander County , Nevada , USA |
| 200 m (flying start) | 09/15/2010 | 5.911 | 121.81 |
Barbara Buatois
|
Women | Varna Tempest | Georgi Georgiev (Varna Innovation and Research Corporation) | Battle Mountain , Lander County , Nevada , USA |
| 1000 m (flying start) | 09/14/2013 | 26,909 | 133.78 |
Sebastiaan Bowier
|
Men | VeloX3 | Students from the TU Delft and the Free University of Amsterdam | Battle Mountain , Lander County , Nevada , USA |
| 1000 m (flying start) | 07/10/2005 | 33,900 | 106.98 | Lisa Vetterlein
|
Women | Varna II | Georgi Georgiev (Varna Innovation and Research Corporation) | Battle Mountain , Lander County , Nevada , USA |
Varna Diablo (longitudinal section)
The VeloX3 is being prepared by the Dutch Human Powered Team Delft / Amsterdam on September 9, 2013 for a race run by Sebastiaan Bowier during the "World Human Powered Speed Challenge" on the street southwest of Battle Mountain, Nevada, USA.
Sebastiaan Bowier in the third race of the “World Human Powered Speed Challenge” with the VeloX3 of the Dutch Human Powered Team Delft / Amsterdam on September 10, 2013 on the flat road “State Route 305” southwest of Battle Mountain, Nevada, USA.
Course records
Hourly world records : see table.
| Racing discipline | date | Distance in km | Average speed in km / h | Driver | gender | vehicle | Manufacturer | venue |
|---|---|---|---|---|---|---|---|---|
| 1 hour (standing start) | 08/02/2011 | 91.556 | 91.556 | Francesco Russo
|
Men | Egg stretto | - | Dekra Oval test track in Germany |
| 1 hour (standing start) | 07/19/2009 | 84.020 | 84.020 |
Barbara Buatois
|
Women | - | - | Romeo |
| 6 hours (standing start) | 10/09/2010 | 426.917 | 71.153 | Axel Fehlau
|
Men | Speedhawk 2 | - | Opel circular track in Frankfurt am Main, Germany |
| 6 hours (standing start) | 10/09/2010 | 338.689 | 56.448 | Ellen van Vugt
|
Women | Speedhawk 2 | - | Dudenhofen, Germany |
| 24 hours (standing start) | 07/11/2006 | 1045.920 | 43,580 | Greg Kolodziejzyk
|
Men | Critical Power | - | Eureka, California, USA |
| 24 hours (standing start) | 08/02/2009 | 1069,000 | 44,542 | Christian von Ascheberg
|
Men | - | - | - |
| 24 hours (standing start) | 04/02/2010 | 1109,000 | 46.208 | Jeff Nielsen
|
Men | - | - | - |
| 24 hours (standing start) | 08/01/2010 | 1219,000 | 50.792 | Christian von Ascheberg
|
Men | Milan SL | - | Lausitzring, Germany |
With the exception of the driver Christian von Ascheberg on his Bülk and Milan SL recumbent bikes , all of the records listed were achieved with vehicles that were fully faired and not approved for road use.
See also
|
Construction types |
Manufacturer |
Bicycle museums |
|
literature
- Gunnar Fehlau: The recumbent bike. 3rd, completely revised edition. Delius Klasing, Bielefeld 1996, ISBN 3-89595-025-4 .
- Christian Kuhtz: Chopper bikes. Very simple construction plans, made from garbage, without welding. Also as a tandem! As well as plans, measurements & tests for the construction of the finest professional recumbent bikes (= ideas instead of waste / bike. Issue 5). 3rd, expanded edition. Kuhtz (self-published), Kiel 2005, ISBN 3-924038-66-X .
- Andreas Pooch: Recumbents. Part: 1. Liegerad-Daten -Verlag, Troisdorf 1999, ISBN 3-9806385-1-0 .
- Andreas Pooch: The science of fast cycling. Part: 2nd 2nd, revised edition. Recumbent file publisher, Troisdorf 2008, ISBN 978-3-9806385-5-5 .
- Werner Stiffel: Notes on the design and construction of recumbent bikes. Self-published. Karlsruhe 1994.
Web links
- History of the recumbent bike
- Recumbent history & typology
- Link catalog on recumbent bikes at curlie.org (formerly DMOZ )
- About the invention of the recumbent bike
Individual evidence
- ^ Gunnar Fehlau: The recumbent bike. 3rd, completely revised edition. Delius Klasing, Bielefeld 1996, ISBN 3-89595-025-4 , p. 11.
- ↑ a b c d e f Gunnar Fehlau : The recumbent bike. 2nd Edition. Moby Dick Verlag, Kiel 1994, ISBN 3-922843-86-7 , p. 10ff.
- ^ History of the recumbent bike. In: Human Powered Vehicles eV HPV Deutschland eV accessed on February 6, 2017.
- ^ Gunnar Fehlau: The recumbent bike. 2nd Edition. Moby Dick Verlag, Kiel 1994, ISBN 3-922843-86-7 , p. 58ff.
- ^ Gunnar Fehlau: The recumbent bike. 2nd Edition. Moby Dick Verlag, Kiel 1994, ISBN 3-922843-86-7 , p. 92.
- ^ Gunnar Fehlau: The recumbent bike. 2nd Edition. Moby Dick Verlag, Kiel 1994, ISBN 3-922843-86-7 , p. 41.
- ^ Gunnar Fehlau: The recumbent bike. 2nd Edition. Moby Dick Verlag, Kiel 1994, ISBN 3-922843-86-7 , p. 61.
- ↑ Pryor Dodge: The fascination of bicycles. History - technology - development. With a foreword by Hans-Erhard Lessing. Translation from English by Renate Bauer ‑ Lessing. Delius Klasing Verlag, Bielefeld 2007, ISBN 978-3-7688-5253-1 , p. 46.
- ↑ a b c d International Human Powered Vehicle Association: LAND - MEN'S 200 METER FLYING START SPEED TRIAL (Single Rider) ( Memento from August 14, 2012 in the Internet Archive ) - List of records.
- ↑ Tobias Ochsenbein: I always wanted to be the fastest in school. In: Berner Zeitung . (online), Tamedia AG , August 9, 2011, accessed February 6, 2017.
- ↑ IHPVA Official Speed Records - LAND. International Human Powered Vehicle Association, April 4, 2017, accessed July 31, 2017 .
- ↑ a b Report of the record run ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ^ Greg Kolodziejzyk: Human Powered Vehicle 24 Hour Record. How far can a man travel under his own power in one day? , adventuresofgreg.blog , 2009, accessed February 6, 2017.
- ↑ velomobilforum.de
- ↑ Report of the record drive ( Memento from May 11, 2013 in the Internet Archive )
- ↑ Three new world records on Continental Grand Prix tires , (press release from Continental AG ), quoted after world records in August 2010: Sensation: The Milan is one of the world's best in series trim. Fahrradwerk GmbH , August 2010, accessed on February 7, 2017.
