Why do tyres crack?

Cracking, sometimes called dry rot or weather cracking, happens when the rubber compounds dry out, losing their flexibility.

There are several reasons for cracking:

• Age - Rubber dries out naturally with time, even if the tyres are not in use
• UV exposure - Direct sunlight accelerates rubber breakdown
• Ozone and heat - Environmental exposure makes rubber more brittle so it cracks easily
• Underinflation - Tyre pressure below the recommended value increases flex and stress on the rubber, promoting cracking
• Chemical exposure - Direct contact with fuels, solvents, or cleaning chemicals can cause cracking

Older tyres with small surface cracks do not always require immediate replacement. Sidewall cracks weaken tyre structure and the tyre should be replaced immediately.