Four common tire specifications

There are generally four common systems in the market, the British system, the German system, the metric system and the American system. We will briefly explain the following four systems. The imperial specification was adopted by the British vassal countries in the past, and the unit was in inches. For example, 4.00 H 18 4PR means 4 inches wide, suitable for speeds below 210KM/H, tire rim diameter is 18 inches, and 4 wire layer strength. In the metric system, the description of the characteristics of the tire is more complete. It is similar to the German system, but cancels the "-" low-pressure tire mark, and replaces it with the word "R" to indicate radial tires, such as FZR400 The rear wheel is 140/60R18 64H, where the R of R18 means that the tire is a radial tire. The specifications of the German system are similar to the "metric system." In addition to the width of the tire expressed in millimeters, the aspect ratio of the tire is also increased. The inner diameter of the tire is still in inches, and there are load index and speed signs behind the inner diameter. Such as: 140 (tyre width 140MM) \ 70 (flat ratio 70%)-(low tire pressure) 18 (inner diameter 18 inches) 66 (load index 66) H (speed sign 210KM/H or less).