The tandem bicycle or twin is a bicycle (sometimes tricycle) designed to be ridden by more than one person. The term tandem refers to the seating arrangement (forward to back, not side by side), not the number of riders. Bike with two riders side by side called friendly.
Video Tandem bicycle
Histori
Patents related to tandem bikes are from the late 1890s. In about 1898, Mikael Pedersen developed a tandem version of two riders from his 24-pound Pedersen bicycle, and four riders, or "quad," which weighed 64 pounds. They were also used in the Second Anglo-Boer War. Tandem's popularity began to decline after World War II until the revival began in the late 1960s. In the UK The Tandem Club was founded in 1971, the new tandem came to market from the French company Lejeune and Gitane, and in USA Bill McCready founded Santana Cycles in 1976. Modern technology has improved the component and frame design, and many tandems are well constructed as modern high-end roads and off-road bikes.
Maps Tandem bicycle
Performance
Compared to a conventional bike, the tandem has double paddling power, without the need to double the speed, and with just a little more friction in the drivetrain. It has the same wind resistance as a conventional bike. High performance tandem can weigh less than double the single bike, so the power-to-weight ratio may be slightly better than single motors and riders. In flat and downhill terrain, most of the power generated by cyclists is used to overcome wind resistance, so the tandem can reach higher speeds than the same rider on a single bike. They are not always slower on a climb, but are considered to be that way, partly because of the need for high-level coordination between riders, especially if the physical abilities of the two riders are very different, requiring a compromise on the rhythm.
Terminology
On a conventional tandem, the front rider directs and rides the bike and is known as captain, pilot, or driver; rear drivers only pedal and are known as stoker , navigator or rear admiral . In most tandems, two sets of cranks are mechanically connected by the time chain and rotate at the same speed. Over time, have used 'captain' and 'stoker' as a term for tandem riders. Since both are seen as riders, the use of the word 'front rider' and 'rear driver' is much more descriptive for modern tandem riders.
Usage
Tandem bikes are used in competitions like Paralympic with blind and blind bikers riding bikes as riders with a fully visible captain.
Cycling at the Summer Olympics featured a male tandem show in 1908 and from 1920 to 1972.
Variations
More than two riders
Tandem can have more than 2 riders - tandem refers to setting the rider one behind the other than the number of riders. Bicycles for three, four, or five riders are referred to as "triples" or "triplets", "quads" or "quadruplets", and "quints" or "quintuplets" respectively. One that is familiar to British TV viewers is the "trandem" driven by The Goodies. Originally a 2-person tandem with extra "doll" chairs attached, a full 3-person version was built for them by Raleigh. A marching-band in Bruges uses a six-tandem bike mounted to carry certain instruments in a way that allows them to play music while it is in progress. In the 80s or 90s, an eight-seat tandem bike was built and demonstrated in Philadelphia.
Independent stowage
Some designs such as DaVinci can allow independent pedaling through the use of multiple freewheels. In another design, the rear driver directs and pushes the rear wheels with the pedals, and the front rider pushes the front wheel with both hands and feet.
Seating settings
Tandems come with upright and recumbent seating.
Bilenky Viewpoint and Hase Pino are hybrid tandem/tandem driven by a captain sitting upright in the back, while the stoker rises in a supine position in front. Both also feature independent pedaling stockers.
"Buddy Bike" is designed to allow a child to sit in the front saddle with an adult in the rear saddle and steer with an extra long handlebar.
Double director
Both riders, in only two cases, may be able to drive. The Star Cycle Company, from Wolverhampton, England, marketed the "Combine Roadster tandem" in 1896. There is a link from the second set of handlebars to the front fork. Others include 1897 Geneva, and 1898 Stearns.
Tricycles
Tandems are also available as becak; The conventional tandem trike has small but dedicated followers in Great Britain, and is available in a one wheel drive design and two wheels. The tandem tandem wheels also gain popularity worldwide [1].
Shorter axis spacing
There is a short wheelbase model, with rear riders sitting on the rear wheels, either just in front or even behind the rear axle.
Fold
Some manufacturers offer folding tandem, whether with small wheels or not, to facilitate packing and travel.
Screws
It is possible to add couplers either during manufacturing or as a retrofit so that frames can be dismantled into smaller pieces for easy packing and travel. Santana produces a "triplet" (or quad) that can be transformed into a tandem simply by removing the center of the frame. "
Tandem specific components
Tandems are subjected to unique pressure caused by additional and heavy riders who need a special solution for tandem construction. The phrase "Tandem Specific" was popularized by its use in the Santana tandem catalog during the 1990s.
Drive train
To transfer power from all the pedals to the rear wheel requires a drive train. Typically, the forward crankset is connected by a left-side timing chain to the rear crankset, which in turn is connected by a right-side chain to the rear wheels. This configuration is called crossover rear drive , and requires both rear cranks to have a chain chain. To work reliably, both left-side cranks must be tandem- or special left-drive to receive the left-hand threading used on the left pedal.
The second most popular solution, since it does not require a special tandem crank is called one side of the rear drive . The forward crankset is connected by a right-side timing chain to the rear crankset, which in turn is connected by a right-side chain to the rear wheels. This requires that one of the back chains be devoted to the time chain and limit the shifting options.
The most unpopular solution is to run the drive chain from the forward crankset to the rear wheels, and also run the timing chain from the front crankset to the rear crankset. It's less popular because it requires a lot more chains than the first two settings. Such an arrangement is called crossover front drive .
A rare solution for coordinated paddling needs is the use of jackshafts plus two freehubs, allowing one rider to shore while the other continues to pedal. It also allows the rider to choose different crank positions, such as inphase (IP), or Out-Of-Phase (OOP), while pedaling together. Davinci Tandems uses a unique "Independent Drive" in which the intermediate shaft transfers power from the stoker and captain to a converter allowing up to four chains. This variant also allows stoker and crank captain to freewheel (beach) independently.
Crankset
The front crankset usually has only one chain. The rear crankset usually has many chains, sometimes on both sides. At the tandem where the paddling is designed for sync, both cranks will use chains for timing chains of the same size. Chainrings of chain drives can be single gear or use derailleur.
To maintain the necessary strain on the timing chain, many tandem use eccentrics placed in the skin of the bracket under the front rider. An alternative solution is to implement a pulley, or idler, at the bottom of the timing chain to pick up slack. Idler adds friction and potential failure points to drive train.
Fork
Tandem has a very different weight and load distribution on wheels, brakes, and forks. Tandem special forks are designed to handle this. Special tandem makers such as Co-Motion make special fork for tandem, triple, and quad-bikes. Brake force can be very large. On each bike, front brakes (and forks) are essential for safe and efficient braking. On tandem brake discs, it is important that heat transfer and dissipation have been engineered correctly. In particular, carbon tandem forks can provide all the benefits of comfort and control, but are also designed to handle the increased heat load.
Handle bar and revoke
The stocker handlebar is usually connected to a stocker rod clamped around the captain's seatpost. Handlebar handlebar is usually a bull horn or a very wide drop bar with "stoker pegs" in lieu of brake lever.
Wheel
Due to the extra weight and pressure, tandem wheels can use higher talk rates, stronger rims, higher pressure tires, stronger freewheels, imperfect speech configuration, or asymmetrical wheels. Tandem wear out the rear wheels faster than the front wheels; therefore, they can use non-symmetrical wheel settings, such as more radius or a stronger rim on the rear wheels.
The wheel plate measures the amount of asymmetry between the rim and the center flange. To accommodate large tapes, more space on the shaft drive is required; this increases the complexity of manufacturing and down the wheel. Tandem rear wheels tend to run wider hubs to allow the right-sided flank hub to be farther to the right of the center of the wheel and thereby reduce the total wheel of the wheel. Some modern tandem use a 160mm wide axle that allows the wheel to be completely "unclean" (ie symmetrical). The disadvantage is that it can increase the Q-factor of the buffer crank and can also cause "heels-strike" of the buffer on the fixed chain. Others use a shorter axle (often 145mm wide) thereby reducing the power of the wheel for the same decrease in the bending axis bending moment. The rear hub can also be threaded on the left side to allow the use of drum brakes.
Special wheels such as Aerospoke or Shimano "Sweet-16" can make racing wheels "tandem certified". The Aerospoke tandem wheelset is built over their roadset with a special tandem hub that can be removed and that facilitates stacking flat rims into the travel case.
Brake
The tandem bike has about twice as much kinetic energy as a bike that runs at the same forward speed. This may be more than that can be handled by the same brake, especially the rim brake, as a single bike. Two alternatives have been used to solve this problem: drum brakes and disc brakes.
Arai drum brakes are used during long downhill derivatives where the rim brake may overheat the tire and may cause it to fail. Drill the brake screw to the left side of the tandem hub, which must be threaded for the drum. The shoe platter slips over the axle and the small reaction arm of the shoe plate moves with the bicycle frame to prevent the plate from turning. The drum brakes are usually controlled by friction levers such as BARCON or similar. The brakes are designed to keep moving while down to keep the speed fixed. Standard brakes can be used as necessary additions.
Some modern tandem use disc brakes, with all the advantages and disadvantages incurred.
Equestrian techniques
The rear driver starts to truncate when the front rider holds an upright tandem . For those who can get used to the rear driver who is always cut off, the distinct advantages for this technique will become apparent when trying to start at the foot of the bridge or on the hill. If tandem teams do not practice this, they often order these early types when they are faced with bridges or hills. This technique allows the rear driver to use sustained power when the front rider drives a tandem during the initial take-off. This reduces the risk of tandem being toppled because it starts on a slope. The rear driver will continue to pedal as the front rider tries to get the legs used to tighten the tandem cut off the pedal.
Phase crank
Riders can choose to sync their pedals through in-phase (IP) or out-of-phase (OOP) braking. At stages in phase, each crank has the same or opposite clock position at each point of time. In out-of-phase pedaling, both riders have their cranks in a different non-opposite position. It has the potential for variety. Some tandem riders regulate their cranks so they exit 90 Â ° from phase to produce so-called "4 guard settings". In practice, OOP settings range from a two-gear phase difference between the cranks with a full 90 Â ° phase difference. Generally, OOP provides the greatest benefit for tandem teams that have different leg strengths. When a tandem pedal IP is possible, and often happens, that a more powerful rider literally drops the pedal out from under the leg of a weaker rider and causes the latter can not contribute significantly. Using OOP makes a significant difference in the choice of movers because each rider has a full tandem mass in their power stes, so a lower gear is preferred. However, using OOP can help develop leg strength for the same reason. Some argue that this produces a smoother power stroke, or that it reduces stress on the drive train because the maximum power point is reduced to about half and distributed over the chainring.
Manufacturer
Since the tandem bike market is significantly smaller than the market for single bikes, there are much fewer tandem bike manufacturers than a single bike manufacturer. There are several builders who specialize in tandems, as well as a single bike maker that offers a tandem model. Leading tandem bike manufacturers currently include:
- Bilenky Cycle Works
- Bohemian Bikes
- Burley Design (now out of production)
- Calfee Design
- Cannondale Bicycle Corporation
- Co-Motion Circle
- Cyfac International
- Dawes Cycle
- Gazelle
- Hase SpezialrÃÆ'¤der (Hase Bikes)
- KHS bicycle
- ÃÆ' â € Å"bbb bicycle
- The Santana Cycle
- Schwinn Bicycle Company
- Torker
- Bicycle Tracks
See also
- Sociable
References
External links
- Designing a tandem in BikeCAD - BikeCAD bike design software can be used to model a tandem bike
- Tandem Experience - original experiment before you buy and train company
- The Tandem Club - the original tandem club, based in England with the Netherlands, other European and international members
- American Tandem Club - US-based club
- The Bishops Castle Tandem Triathlon
- Tandem Bike News and Info - an interactive community for tandem bike enthusiasts. Includes information about road tandems, mountain tandems, and tandem specific routes. Centric AS
- daVinci Designs - Tandem producers offer independent shipping systems
- Totally-Bikes.com - Tandem hires in the UK
- Bikeforums.net Tandem-Cycling - Discussions on tandems (purchase, travel, service, all other aspects)
- TandemMag.com - An amazing site to get started together, though many parts have not been updated recently. The Secret section is still alive.
- Tandemclub.nl - Tandem Club in The Netherlands
- Tandem Maniac - French tandem club
- Tandem VTT - French tandem club for mountain bikes
- TheTandemLink Learning Center - A collection of links for beginners
Source of the article : Wikipedia
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