Following on from my previous e mail concerning further investigations into your 2 tyres returned under warranty.
Firstly, the tyres were returned under description of complaint and ‘Cuts on Tread Shoulder’ was stated for the reason of return.
The report issued was based on the visual examination of the tyres and concluded that the tyres had sustained accidental damage by numerous cuts confined to the outer facing shoulder, on each of the tyre- hence the report findings issued to you.
Second
What has actually caused this cutting cannot be determined, sometimes a trapped object between the vehicle bodywork or suspension bounce would manifest itself into, part stuttered scoring or entire circumferential scoring to parts of the tyre as it rotated, but this is unlikely.
Equally driving through or over something to cause this type of damage that confines itself to a particular area of the tyre only, without damaging other areas or indeed, the other 2 tyres fitted to a vehicle is difficult to find the exact reasons for what has caused the damage.
Third
From our part, we have carried out rubber density checking using calibrated shore meters, this has found that the rubber consistency is well within tolerances across all areas of the tread rubber, also the examination was carried out using magnification equipment ( I doubt very much that tyre suppliers or fitters would have done this or have equipment to do so)
During manufacture, the tyre rubber is extruded and is cut to precise length, any deficiencies from the compounds and materials used, would show up in other areas of the tread and not be confined to one part of the tyre, due to the volume of manufacture any deficiencies in compound would result in high numbers of tyres being affected.
Fourth
To date we have received no other tyres in the same size or pattern or from the same factory of manufacturer with the same type of symptoms found on your tyres.
Fifth
Because of the unusual nature of the symptoms, it is understandable that because it has not been observed before, the wrong conclusions could be made.
The conclusions are that the tread rubber has sustained damage, there seems to be only one common factor on this, is that the tyres were originally fitted on the front and may have been driven on or over something to cause this type of damage to the front tyres only and I would be confident from our findings, that the tyre could be submitted for independent professional investigations, would not find any fault with manufacturer or materials used.
However I note the points that you have raised concerning your loyalty to our products and it is quite understandable that you are disappointed if you think that our products are not up to their usual high standard of manufacturer and not have performed as expected, I would like to thank you for taking the time to write in to us and providing us with more details concerning your tyres returned under warranty.
As a valued customer in the past, I would like to think that you will be a satisfied customer for the future, therefore in this instance as a gesture of goodwill we will give an allowance of 2 x 100% to restore your faith in our products.
I think that this is a fair outcome and it also gives us the opportunity to continue further investigations on this as I have notified the factory quality control about this and have supplied photos and other information to them, they are just as curious over this issue.
For my part, if there are any developments on this, I will keep you informed incase my findings are incorrect.
I hope that this has been concluded to your satisfaction and it goes towards preserving your future custom.
Thank you for contacting Hankook Tyre UK Ltd
Regards