Post
by Zippy99 » Sat May 08, 2021 7:30 am
Yes Stinky it’s definitely a G01and Leslie, in my ownership the tyres have always been at the right pressures. I’ve had it since December ‘18. The car was originally registered end of March ‘18, but wasn’t actually put on the road until end of August, so I have no knowledge of its storage and on road condition during the first ‘official’ part of its life.
Here’s the relevant body of the letter I received back from Bridgestone, as you will see there are many reasons given for why the tyres could develop these cracks and whilst not directly saying so ‘lack of use i.e. lock down is an obvious contributory candidate.
‘ Based on the images you have provided the concern seems to be surface rubber cracking in the main grooves. The cracking on the tyre is due to oxidation of the rubber, which causes the rubber to become more brittle, and crack under stress. Ageing of the rubber is accelerated by exposure to certain factors, such as sunlight, sea air, contaminants (including tyre blacking agents), and ozone (which can come from motor exhaust and electrical motors). The effects of ageing are particularly noted when the vehicle is parked up for periods of time, and the anti-ageing oils and agents on the surface of the tyre are broken down or washed off, and not replenished from within the tyre by the tyre’s movement. Also, oxidation of the tyre is possible when the rubber is under stress, the more stress the tyre is under, the more likely the tyre will suffer from oxidation. Tyres which are run with insufficient pressure are more likely to crack in this manner.
Tyre manufacturers add ingredients to rubber compounds to slow down the rate at which tyres age. However, conditions of storage and use (including tyre maintenance) have a larger influence over the tyre aging process. Tyres that are used infrequently (low mileage) and/or in coastal areas will age more quickly. Low usage prevents the anti-ageing oils from migrating to the tread surface (oil replenishment at the tread surface is diminished), so causing the tyres to display surface rubber cracking.
From the images you have provided, I can confirm that in their current state we would recommend that you continue using the tyres, as the surface rubber cracking is not compromising tyre safety or the tyres dynamic characteristics. Apart from the visual appearance of surface cracking the tyres are totally fine for continued use. However, you should check tyres regularly for any signs of damage or further deterioration. A change in the dynamic properties of the tyre and/or vibrations could be an indicator of the effects of tyre ageing. If any such symptoms appear, replace the tyres immediately.’