AN ASYMMETRIC TIRE FOR SOFT SURFACES WITH LOW LEVELS OF GRIP

It is suited above all to damp, wet and at the limit muddy conditions. Usable also in dry conditions on inconsistent, loose or sandy ground. Less suited to compact and fast routes.
The tread pattern derives from the K. The reduced width of the tread and the pattern with more voids ensure the correct balance between performance and road holding on surfaces with a low grip.

The less rigid construction allows excellent adaptation of the tire to the ground and provides easier steering, above all on very winding routes, where a good level of adherence is needed also on irregular surfaces.

Available in different compounds for use in different weather conditions and with different levels of adherence to the ground.

    Km
    TECHNICAL ADVICES

    TIRE IDENTIFICATION AND MARKING
    FITMENT
    TREAD TEMPERATURES
    PRESSURE
    Tire identification and marking

    The markings that appears on the side of the tires also tells us the basic size of the tire, 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 tires.
    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: Tire’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 tires 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

    Fitment
    ​​

    Make sure that tires are fitted by experts, with specialised dedicated machinery and equipment, who follow safety procedures.
    Before mounting the tires clean the surface of the beads and the area of the rim that comes into contact with the tire.

    Use ONLY special tire lubricants for mounting tires. Do NOT use silicone or petroleum lubricants.

    Check the state of the valves to prevent air loss: Check the seals and the tightness for metal ones and check also for any tears or cracks in rubber seals. If necessary, replace them. When the tire is being used, always use the valve cover top.

    Follow the indications provided on the sidewall of the tire referring to the rolling direction and the correct positioning of the internal and external sidewalls, if specified.

    Use the safety cage when inflating tires.
    Before unseating the tire from the rim during disassembly, make sure that the tire has been fully deflated, removing the inner valve mechanism.

    Tread temperatures
    ​​Temperatures measured on the tread are an excellent indicator for deciding the best choice of final compound and for optimising corner adjustments of the vehicle, such as camber and toe.
    We recommend measuring the temperature at three different points: inner (innermost side of the vehicle), centre, outer tread.
    In particular, average temperatures must be the ones shown in the table, the difference between the values measured internally, in the centre and externally must be maximum 20°, while the difference between the front and rear axles must be no more than 25°.
    If these values are exceeded, we recommend a different final compound should be used or the vehicle’s geometry should be adjusted.
    Pressure
    ​Working pressure values depend on the size of the tire in relation to the load that it is subjected to. In other words, it will vary according to the type of car, the weight and conditions of use.

    In particular, as the weight of the vehicle, speeds and accelerations that the tire is subjected to increase, the working pressure must be increased. In any case, tires should not be used at pressures below 1.6 bar.

    Using excessively low pressures would bring about the breaking of the tire due to excess force on the sidewall or unseating from the rim. “Hot” working pressures are usually in the range of 2.2 – 2.5 bar.

    Initial inflation pressures vary in order to obtain these values, depending on whether the tires are preheated or used “cold”. Indeed, preheated tires can be inflated to slightly lower values than cold tires. 

    The difference will depend on the type of heater, the time it remains and the environmental conditions.

    Pirelli Km motorsport tire

    Km
    TECHNICAL DATA

    tire size version
    (mm)
    diameter
    (mm)
    section width
    (mm)
    D
    tread wdt
    (mm)
    CB
    rolling circumference
    (mm)
    rim
    tire size195/70R 15 TL version (mm)KM6 diameter (mm)650 section width (mm)203 tread wdt (mm)170 rolling circumference (mm)1954 rim6
    tire size205/65R 15 TL version (mm)KM4-KM6 diameter (mm)649 section width (mm)226 tread wdt (mm)170 rolling circumference (mm)1951 rim7
    SAFETY WARNING: danger may result from improper use. Follow tire manufacturer’s instructions. Refer to car manufacturer’s recommendations with respect to tire fitment for each model.

    PIRELLI OFFICIAL MOTORSPORT DEALERS