On my 2017 Citigo all 4 tyres have developed cracks around the entire circumference of them as shown below

 

I opted to replace the front 2 immediately and before replacing the rear I'd write to Bridgestone to see if there was a manufacturing defect or if were deemed beyond what you'd normally expect given their age/mileage.  They're the tyres from the factory and date code on the tyre is 4516 so less than 4 years old and the car has done 18,000 miles.  They wrote back to me a copy and paste response to say that it was entirely normal...  needless to say I opted to fit a different manufacturer of tyre

 

 

 

 

"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 condition the tyres very minor crazing 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.

 

Regard"

 

 

ooh - thanks - I have those on the Swift so will take a closer look as they will be of similar age

I've had a similar issue with Dunlop SportMaxx tyres. I had a response from their customer services team which suggested it was cosmetic and not a structural thing. Long story short, I'm changing the tyres this next week or so. Funnily enough I was going to Bridgestone. 

 

I found an article on another forum which suggested some modern tyres are prone to cracking. Not sure of that is correct.  

17 hours ago, LLCC1975 said:

I found an article on another forum which suggested some modern tyres are prone to cracking. Not sure of that is correct.  

"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."

 

Seemingly the suggestion here is that eco friendly legislation has increased the propensity of "crazing" in modern tyres.  I've personally never experienced it before but then these 2016 tyres are the newest I've had to date.  I really wouldn't have expected it on these tyres which are around £80 each.

 

Certainly none of their explanations as to why it may have occurred seem to be the cause in my case, and definitely not the suggestion of too much exposure to sunlight in the UK ! 

Edited 10 September, 20205 yr by maxychat

FWIW my Citigo has the same tyres and one of them has exactly the same 'crazing' as shown. Its due an MOT so will see if it affects that. 11K miles on a 2016 Citigo, so four years old.

13 minutes ago, Luckypants said:

FWIW my Citigo has the same tyres and one of them has exactly the same 'crazing' as shown. Its due an MOT so will see if it affects that. 11K miles on a 2016 Citigo, so four years old.

 

My car had "crazing" on all 4 tyres when it went for it's first MOT in March and it didn't even register as an advisory.  This was at the main dealership too so perhaps they are aware of this occurring and also consider it cosmetic/superficial etc

Is this a Brigestone thing? Our 3.5/4 year old ER300 on our 66 plate Fabia mk3 have cracked on the edge too. Not sure if we should replace them as have plenty of tread left. They were on rear until earlier this year.

I had this with the EP150 on my last Suzuki Swift. I actually lost a tread block on one of the rears. I pinged another couple off with my fingers when the tyres went in for replacements. The tyres where well in date and on a car used for lots pf miles 6 days a week. Dunlop Sportmaxx RT on the Jag are showing signs of a single line of cracking around the join between sidewall and tread shoulder. They'll be going shortly too.

Edited 28 October, 20205 yr by Chris GB