cracked and perished tyres (modern content)

Hi, I don't think it's as much to do where on the planet we are rather than the Ultra Violet from the nearest star (The Sun). Also the composition of modern rubber being more vulnerable to ageing, look how long track rod end boots last and they don't see direct sunlight.

Colin

I changed a 2yr old Skoda Karoq last April 16k on the clock, it had Bridgestones on which has started to crack in the tread base. I have recently bought a Vauxhall Victor with 02 dated Firestones, only done 5k, no cracks, they look great. They are getting changed, I think 21yrs old is pushing my luck.

Pretty normal for tyres not to last past 4-5 years. How many miles are on the car?

I was cleaning up the wheels on the mx5 today and noticed one of the valve stems fitted around 4 years ago has massive cracks in it, does make you wonder what's going on with rubber nowadays.

The cracking could have come from ramming it up kerbs when parking (on kerbs).

The Michelin’s on the rear of my Mini are the same. They’re the original tyres from 2018 but still have loads of tread 🙄

My Mustang was a 2018 that I bought in 2020 with 11k on, the front tyres were Pirelli's & were starting to crack, seems modern tyres are just garbage.

thanks everyone for the useful comments - I phoned Bridgestone and their customer service bod said speak to technical 01926 488580 if you ever need it - who were very friendly, said send us some pictures.

Here is their reply:

Thank you for the photographs of the Bridgestone tyres fitted to your car.

Concerning the ‘cracking’ in the tyre shoulder grooves; this we have seen many times in the past (across many products, and most brands) where the top layer of surface rubber begins to oxidise and appears perished. We refer to this as ‘crazing’, as ‘cracking’ generally relates to splitting after force or trauma during operation.

The visible surface rubber crazing on your tyres is very minor and will pose no detriment to the vehicles safety of tyres performance.

It is worth noting that as part of tyre manufacturers’ compliance to environmental responsibility legislation, there are increased restrictions on the materials used in tyre construction.

‘Crazing’ can also be caused by other factors:
• Extended exposure to sunlight. (UV light dries out the anti-aging oils in the rubber which give a tyre it’s tackiness and elasticity).
• The application of ‘Tyre Dressing’. - Used by dealer forecourts and carwash companies mainly to make the sidewalls/shoulders of the tyres look ‘more black’. These can be quite strong and some are even mildly corrosive if used consistently over time.
• Poor pressure maintenance during the tyre’s life. This causes over flexing in the tyre casing eventually causing tyres to prematurely age.
• Exposure to contaminates. - Petrol, anti-freeze, motor oil, tyre ‘dressing’ (used on the sidewalls to appear more “black”).
• Regular, but short frequent trips in the vehicle (lack of use), where the tyres are heating up, then cooling down over a short period of time. (essentially preventing the aforementioned oils from percolating/migrating throughout the tyre fully). We add anti-aging oils into the rubber compound, however for these oils to be released the tyres need to get to an operating temperature. If the tyres are not used regularly then the releasing agents in the anti-aging oils are unable to percolate through the casing and ensure the tyre stays subtle.

The upside to this phenomenon is that ‘crazing’ only affects the top cap layer of rubber, so is only cosmetic in nature. This type of appearance does not have any effect on the tyres handling or performance, and based on the appearance in the image provided we would advise that these tyres are ok to continue running. However as with any appearance-based condition reported in the market, we always advise to monitor the tyres regularly.

Please note that we take safety very seriously and we would never recommend you to continue using tyres that we thought were unsafe to use.
In their current conditions the tyres will not cause any detriment to the tyres serviceability or affect the cars dynamic performance abilities. If the tyres are well serviced and the correct tyre pressure is maintained the tyres will continue to provide an excellent service life.

We hope this info has helped, please let us know if there is any more info you require on this subject to assist with your enquiry.

which in today's world of litigation is pleasingly unequivocal, and not what I was expecting (which was - buy a new tyre!)

thanks again

Cortinaman

Having been in the tyre world for too many years i can go on about this for hours...

Low mileage and sitting seems to be the biggest contributor with more pressure applied to the sidewalls of the tyre in one area, along with UV exposure it really does a number on the surface of the tyres.

Avon are particularly bad and really do suffer if the car isn't in regular use.

Additives in tyres have changed over the past few years to reduce microplastics and noise whilst still offering high levels of fuel efficiency without detrimentally impacting grip levels.

All in all, its normal, it shouldn't be but it is.

5 years is getting on for any tyre anyway and I would be looking to change them. Caravans/ trailers always have issues with tyres outside this window.