“Road” studs can be fitted, which protrude about 1/1.5 mm, which can therefore also cover long asphalted stretches without damaging the road surface.
The compounds and the tread have been developed to perform best both in the case of the application of studs for heavy snow conditions, and also - without studs - to guarantee adequate grip also on slippery surfaces and at very low temperatures.
The markings that appears on the side of the tyres also tells us the basic size of the tyre, the rim diameter and the width of the rim.
We will illustrate how to read two different types of branding that may appear on the side of the rally tyres.
C: Nominal section width expressed in mm - 225
D: Nominal external diameter expressed in mm - 600
d: Nominal rim diameter of the rim, expressed in inches - 16
C: Nominal section width expressed in mm - 205
h/C: Tyre’s technical series. This expresses the ration between the section height (in mm) and the nominal section width (in mm) - 65
Radial construction - R
d: Nominal rim diameter of the rim, expressed in inches - 15
The treads of the various versions of rally tyres are described by one or two letters followed by a number. The letters identify the type of tread.
The number after the letter indicates the type of use, for example: RX 7
|tyre size||version||diameter(mm)D||section width(mm)C||tread wdt(mm)Cb||rolling circumference(mm)||rimE|
|tyre size235/40ZR18||versionSottozero 'SNOW' RALLY WRC||diameter(mm)D649||section width(mm)C222||tread wdt(mm)Cb175||rolling circumference(mm)1976||rim