How to choose correct bicycle inner tube

Bicycle inner tube common sense and purchase precautions

1, bicycle inner tube size specifications

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Size specifications to match the outer tire, the wall of the outer tire will indicate the size, such as 26×1.95 (26 refers to the diameter of the wheel, mountain bikes are generally 26 inches, children's mountain bikes are generally 24 inches, 1.95 refers to the width of the section), 700×23c such words, according to the size of the outer tire to choose the inner tube.

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Generally, the size of the inner tube has a suitable range, such as an inner tube labeled 26×1.95 ~ 2.1, which means that the inner tube can be used with a 26-inch outer tube with a width in the range of 1.95 ~ 2.1.

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2. Type and specification of bicycle inner tube nozzle

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The air nozzle should be selected with the rim, the size of the air nozzle hole on the rim determines whether you use the American mouth or the French mouth, the thickness of the rim determines the choice of the length of the air nozzle, and the knife ring we say needs to use the inner tube with the extended air nozzle.

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The common air nozzle types in China are British mouth, American mouth and French mouth.

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The 26 inch and 28 inch bikes we used to ride daily are all British nozzle (E/V), which need to use valve core rubber tubes. When I was a child, most of the elastic materials used to make slingshots are made of valve core rubber tubes with British nozzle:) Because the rubber tubes are easy to age, resulting in poor air tightness and need to be replaced frequently. At present, sports bikes rarely use British nozzle.

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French nozzle (F/V) manual locking valve, high pressure resistance, smooth linear leakage, thin base of the air nozzle, light weight, small diameter of the air nozzle, less impact on the strength of the ring, can be used in 19C size inner tube or narrow ring, high price! It is the best air tightness when the pressure is high in several inner tubes, and the road tires need high air pressure, so most of them use French mouth. The French mouth is very small, the hole on the rim is also very small, which is conducive to the strength of the rim, and the road car uses the French mouth for many, which may also be related to this. But it's also fragile. I broke a couple of them when I was pumping.

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The motorcycle inner tube we see is basically using the American mouth (A/V), so the American mouth is also commonly known as the motorcycle mouth. Mainly by internal pressure jacking, high pressure resistance, the linear leakage is steeper, that is to say, the air leakage is faster when the air pressure is not enough, the air nozzle base is large, the diameter of the air nozzle is also large, but the inflation flow is large, the air tightness of the American mouth is better, the air is much more convenient than the French mouth, so the most common use, most of the mountain bikes are the use of American mouth, many low-end road vehicles are also configured with American mouth. At present, the American mouth is very convenient in the country, the vast majority of portable pumps can play the American mouth, outside the repair stall and motorcycle maintenance can also pump, the most suitable for bicycle travel and outing.

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Nozzle length:

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The length of the standard American mouth is 2.8cm, the length of the French mouth is 3.2mm, (the number above is not clear, look back if it is wrong and then modify) we have to choose the right length of the air nozzle according to the thickness of the rim, and the air nozzle protruding from the rim to the part of the length is convenient to pump.

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3. Thickness of bicycle inner tube

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Different thickness of the inner tube is suitable for different situations, to build a large example, the general thickness of the inner tube 0.87 mm, on this basis there are 0.73, 0.6, 0.45 mm thickness of the lightweight inner tube, there are 1.2, 2.25, 4.3 mm thickness of the reinforced inner tube.

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Lightweight inner tubes are mainly used in bicycle speed competitions, and lightweight inner tubes can reduce the weight of wheel rotation. Because the thickness is reduced but the strength is not small, the price is more expensive than the ordinary thickness inner tube.

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The reinforced inner tube is used for high-strength use, such as high-strength mountain cross-country, DH, BMX, etc., 4.3mm ultra-thick inner tube is thin and thick, extremely thick and heavy, looking very confident not to burst a tire, Master Hai at that time looked at it and said it was simply an outside tire. It was sold by cyclists, and it must have been bought by cyclists who were extremely tired of repairing tires, and bought for bicycle travel.

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General riding, we use ordinary thickness or slightly thick inner tube can be, many riders do not understand, think that the expensive must know durable, when doing travel use also buy lightweight inner tube is not right.

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4. Bicycle inner tube material

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Generally, natural rubber and butyl rubber are common, and butyl rubber is better than natural rubber in high temperature resistance and anti-aging, and has a long service life. At the same time, the air tightness is much better, so the middle and high-end inner tubes are basically using butyl rubber as a material. Generally, a few dollars on the repair stall are natural rubber inner tubes, and the current sales in the riders are butyl rubber inner tubes.