| Conditions for fitting run-flat tyres |
| Allowing cold tyres to warm up to minimum fitting temperature |
Note | This procedure also applies to ultra high performance tyres (height/width ratio 45 % or less and speed symbol V or higher). |
WARNING | The fitting temperature of a tyre must not be less than 15 °C and must not exceed 30 °C at the core. |
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| To prevent injury when fitting the tyre, the temperature of the tyre (in particular the temperature of the upper sidewall and upper bead inside the tyre) must be at least 15 °C. |
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| This internal temperature is referred to as the core temperature. |
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| Since rubber is a poor heat conductor, a cold tyre must be stored in a temperate environment until the internal rubber layers have warmed up to at least 15 °C. |
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| The surface temperature of the tyre during the warm-up phase is not indicative of the internal temperature. |
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| The quickest way for the tyres to absorb heat from the ambient air is to allow the warm air to circulate around them freely. For this purpose, they should be stored separately and NOT stacked. |
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| Never use a heater or hot air blower to warm up the tyres, as critical surface temperatures can build up extremely quickly. |
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| There is no way to heat the tyres without damaging them other than using warm water or warm ambient air (max. 50 °C). |
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| If cold tyres (below 0 °C) are brought into a warm environment (above 0 °C), a layer of frost will immediately form on the surface of the tyre. This layer of frost, which forms from the condensation of moisture in the air, is a sign that the tyre is rapidly absorbing heat from the ambient surroundings. |
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| When the layer of frost has thawed completely leaving a film of condensate, you should wipe the tyre dry with a cloth to prevent the evaporative cooling effect from slowing down the warm-up process. |
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| Assuming a minimum room temperature of 19 °C and a tyre temperature of 0 °C or higher, the tyre should be stored for at least 2 hours. |
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| Assuming a minimum room temperature of 19 °C and a tyre temperature of below 0 °C, the tyre should be stored for at least 2.5 hours. |
| Recommendations for warm-up: |
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| Make it part of your routine job preparation to store the tyres in the workshop 1 day before fitting them (if possible). |
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| Store the tyres as high up as possible on an insulated surface, such as a wood pallet or similar. |
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| Keep the tyres separate so that the warm air can circulate around them freely. |
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| Never use a heater or hot air blower to warm up the tyres. |
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