The tandem bicycle or twin is a form of bicycle (occasionally, a tricycle) designed to be ridden by more than one person. The termtandem refers to the seating arrangement (fore to aft, not side by side), not the number of riders. A bike with two riders side by side is called a sociable. Tandem Bike26" 26 Inch Tandem Bike, Two People Leisure Bike, Steel Frame Tandem Bike, Leisure Tandem Bike Hangzhou Datasports Equipment Co.,Ltd(Oembicycle) , http://www.oembicycle.com
1. Percussion sound: A heavier impact sound of an iron hammer, it is likely that the engine mount will wear out for a long time, and the impact will occur when the engine speed changes. However, it is also possible that the front and rear suspensions of the sprinkler are damaged.
2. Tap: The sound is similar to a double tap, but the sound is small. When this kind of sound appears, the sprinkler driver must think about whether or not to use inferior gasoline. If a poor quality oil is used, a popping sound can also occur.
3. Tick: It may be that the gimbal of the drive shaft is damaged, or it may be caused by small stones in the tire hitting the tire or the fan blade bending loose.
4. Buzz: Like a balloon leak, most of the cooling system is defective. If the cooling system fails, liquid can be seen at the bottom of the car. In addition, this sound may also occur with large tire air leaks or engine vacuum chamber leaks.
5. Re-tap: Like a dull knock. Most of the internal causes of the sprinkler engine are likely to be due to the aging of the sprinkler, and bearing or engine valve damage can also be caused.
6. Whistling sounds: Mostly present when the sprinkler turns, it may be that the fan belt is loose or worn. Sometimes there is not enough gas in the tire and this sound also occurs.
7. Howl: This kind of sound is like the sound of a bee. Its appearance is likely to be caused by loose parts. The plastic or metal parts at the bottom of the engine of the sprinkler and loosening of the fixing brackets of air conditioners or compressors are the most common.
8. Roar: A call from the sprinkler with a squeak. It is very likely that the ball bearings in the wheels, in the compressor or in the pump are broken, and it is very likely that the sprinkler air conditioner or compressor has malfunctioned.
Patents related to tandem bicycles date from the late 1890s.In approximately 1898, Mikael Pedersen developed a two-rider tandem version of his Pedersen bicycle that weighed 24 pounds, and a four-rider, or "quad", that weighed 64 pounds. They were also used in the Second Anglo-Boer War. Tandem popularity began to decline after WWII until a revival started in the late sixties. In the UK The Tandem Club was founded in 1971, new tandems came on to the market from the French companies Lejeune and Gitane, and in the USA Bill McReady founded Santana Cycles in 1976. Modern technology has improved component and frame designs, and many tandems are as well-built as modern high-end road and off-road bikes.
Tandems can have more than 2 riders - tandem refers to the arrangement of the riders one behind the other rather 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 such familiar to UK TV viewers was the "trandem" ridden by The Goodies. Originally a 2-man tandem with an extra "dummy" seat attached, a full 3-man version was built for them by Raleigh.
Some designs such as the DaVinci can allow independent pedaling through the use of multiple freewheels.  In another design, the rear rider steers and propels the rear wheel with pedals, and the front rider propels the front wheel with both hands and feet.
The tandem bicycle or twin is a form of bicycle (occasionally, a tricycle) designed to be ridden by more than one person. The termtandem refers to the seating arrangement (fore to aft, not side by side), not the number of riders. A bike with two riders side by side is called a sociable.
26 Inch Tandem Bike, Two People Leisure Bike, Steel Frame Tandem Bike, Leisure Tandem Bike
Hangzhou Datasports Equipment Co.,Ltd(Oembicycle) , http://www.oembicycle.com