All of these images are examples of tyres deemed scrap by other Tyre Services and will be a familiar sight to anyone footing the bill for their fleet.
Typically a Tyre Service can only carry out a repair that falls inside 40mm from the tread edge, regarded as the crown of the tyre.
Anything outside this would be a shoulder or sidewall repair and becomes the remit of a Major Repair specialist like us.
In fact, all of these examples represent very straight forward and quite minor repair work.
This page will detail some examples of significant injuries to tyres, more typical of the Truck Tyre Major Repair work we carry out to the tyres of our customers, particularly those involved in waste management and recycling.
This tyre has sustained significant damage to the sidewall and signs of rust indicate there has been some damage to the radial cords.
Our expertise in Truck Tyre Major Repair enables us to know at this stage that it is not automatically regarded as scrap but is worth a cursory look to determine how much radial cord damage is present. Radial cords are the skeleton of any radial tyre.
Removal of damaged rubber reveals that the radial cord damage is significantly less than might be guessed at when looking at the original injury.
In fact it is contained to within a 12mm diameter.
Aluminium Oxide grinding stones and diamond-cut carbide cutters are used to remove loose steel wire and rubber to ensure the injury is rounded off.
Once the injury has been cleaned and cemented it is ready for patch selection and new rubber insertion.
A look at the Radial Repair Chart shows us that for a sidewall injury larger than what we have, a 40R patch will suffice. Our decision to go to the next size up, a 42R, ensures more cord support and takes the patch's edges away from the flexing area of the tyre, eliminating the chances of patch break-out.
Patched and filled with with new rubber, the tyre is paired with another tyre with similar injuries, ready to be cured in the autoclave.
Each tyre cured receives 1.5 hours at 6 bar pressure and 120 degrees to form rubber and patch into one repair.
Once cured, the repaired area is dressed back to the original profile, pressure tested, and returned to service.