2PCS CST Bike Inner Tubes 20inch For 451 Wheelset Bike Camera Tyre Butyl Rubber 20X1 1/8 -1 3/8 Presta Schrader Inner Tubes

FAQ:

Q1. How to select the inner tube size?

A: First, check the outer tube. The identification size of the outer tube is 26 * 1.95. You can choose the inner tube of 26 * 1.95 / 2.125 (the inner tube is elastic and can be compatible with the range of 1.95-2.125)

Q2: how to select the inner tube valve?

A:The air nozzle needs to be selected with the rim. The size of the air nozzle hole on the rim determines whether you use American air nozzle or French air nozzle. The thickness of the rim determines the length of the air nozzle. Generally speaking, the inner tube with extended air nozzle needs to be used for the knife ring. In order to facilitate pumping, the air nozzle larger than 2cm of rim thickness is generally selected.

Air nozzle.

-【Schrader Valve (S/V)】

American valve is the abbreviation of American valve. American valve (English: Schrader Valve or American valve) is usually referred to as American valve. It is an inflation device widely used in the tires of all power vehicles today. After opening the valve cover, the American valve will expose a copper pipe with external thread, which is called the air channel called the core cavity, which is called the valve body. An air core is locked in the core cavity in the middle of the body, and there is a core rod supported by a coil spring. Press the core rod to charge or vent; The air core can be rotated and taken out with special tools.

-【Presta Valve (F/V)】

French valve (English: Presta valve, sclaverand valve or French valve) is usually referred to as French valve, which is mostly used on road bicycles. This type of valve is composed of copper pipe body with external thread, air valve screw held, valve cover and a nut fixing the valve on the rim.

The biggest feature of the French nozzle is just opposite to the American nozzle, and its air core cannot be removed. However, the air core of some French nozzles can be used to inject inner tube repair agent, but the number of such rare French nozzles is quite rare. For different applications, the length of the copper tube body will change; Its 6mm aperture is also smaller than that of the American nozzle (the body aperture of the American nozzle is 8mm). Because the bottom of the French valve and the rim are fixed with nuts, it is helpful to strengthen the narrow bicycle rim, because the most vulnerable part of the rim is often in the valve hole.

Another advantage of the French mouth is its light weight, and it can fine tune its speed and accurately control the air pressure when discouraged. Before inflation, the air valve screw at the top must be loosened before inflation. The air pump of the French nozzle is different from the American nozzle, but the adapter can be locked at the front end of the French nozzle to use the air pump of the American nozzle.

NOTE：When installing the inner tube, please carefully check whether there are sand particles or other adverse factors on the inner wall of the outer tube. After the inner tube is installed, please use the tire prying rod carefully to avoid scratching the inner tube. When inflating, please pay attention to whether the inner tube is clamped by the outer tube. Once the tube is clamped, re inflation will lead to tire burst. When installing the outer tire, do not pry it hard, so as not to pry the steel wire edge of the outer tire.