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Tire Knowledge

Radial tire

AddTime:2014-07-28 Browse: 1222

  Radial tire often uses the letter “R” as its code. R is the prefix of Radial, “-” is replaced by R to connect the two group figures. Such as 9.00R20、11R22.5, showed by inch; 185R15, the former figure is metric system, and the later is inch. Groupe Michelin use “X” as its code, such as 10.00-20X, 175-14X; the Soviet Union used “P” as its code, for example 155-13P,5.90-15P; Italy uses “Cinturato” as its code.
As the variety and size of tire is increasing, the cross-section contour changes a lot. So the traditional marking method can’t get use to new demand. The marking method stipulated by the world is to use the width of tire section (mm), tire flat rate (%), structure code of tire (such as R represents radial tire) and symbol of rim diameter. For example 175/70SR14, the first group figure shows that the width of tire section is 175 mm, the second group figure represents tire flat rate is 70%, 70 tire series, the third group figure 14 expresses rim diameter in inch. SR means fast radial tire, and S means mark of speed stage.