The lists below highlight a number of reasons which should lead you to replace your tyres.
1. The first instance in which you would replace your tyres is if they are visibly below the legal limit of 1.6mm or below 1mm if you ride a motorcycle.
2. If there are visible signs of damage to your tyre, e.g. bulges on the sidewall
3. If you can see signs of ageing such as cracks in the tread and / or on the sidewall
4. If you notice that parts of the tyre are wearing unevenly, maybe with bald spots in the middle compared with the edges of the tyre.
5. If you are noticing issues with handling and stability, i.e the tyres are not suitable for your vehicle, maybe you have run flats on a car not set up to handle these.
6. While some punctures can be repaired, this is an instance when often you should replace your tyre. Please also note, that whilst the legal tread limit is only 1.6mm most manufacturers and industry bodies recommended replacing your tyres when your tread falls below 3mm.