When it comes to medium- and heavy-duty trucks, small increases in cost-per-mile can have a major effect on the bottom line. After all, you can’t shrink the distance between two points, and driving and maintenance improvements can only improve the lifespan of a single tread by so much. To get better returns beyond that, you have to get more retreads from the casing. In order to do that, you have to put your detective hat on and take a closer look at the causes of casing failure.
Some failures are environmental and come from how the tire is used or maintained. Bob Eck, vice president of the TA Truck Service Commercial Tire Network, says that it’s important to understand the different causes of failure and to understand whether they are a result of usage or construction issues.
Eck mentions stone drilling, casing separation and some large injuries to the casing can prevent retreading. In the case of injuries, the casing may be technically salvageable, but it may not be worth the expense, rather than simply replacing it with a new tire.
In some cases, the source of a failure can be easily identified by external inspection, Eck says. Other times, there is no way to really know what went wrong without using modern diagnostic tools.
Once you’ve assessed the source of a casing failure, it’s important to look at the full picture painted by the data points. Understanding which tires are failing is a good start, but if you want to have a good idea where you are getting value, you have to understand why a tire fails.
“Comparing the percentage of tires rejected of each brand tells you very little about the quality of that brand of casing,” says Jerry Southergill, manager of the technical department at Marangoni Tread North America. “In our most recent study, which included 145,582 casings, 27% of the tires rejected were rejected due to maximum repair limits exceeded; 15% of the tires rejected were rejected due to road damage; 11% of the tires rejected were rejected due to excessive age.”
Eck says that failures due to ply gap, thin inner liner or pulled loose cords are likely related more to the construction quality of the casing than the usage. Southergill adds belt package separations, liner separations, bead separations and rust migration to that list.
Once you learn to recognize some of the tell-tale signs of failure, it’s still important to document what you find. Once you account for damage and maintenance failures, you can start to factor in miles traveled and upfront cost to determine a total cost of operation. More importantly, you can don the deerstalker hat and wooden pipe, because you are a retread detective. And you are on the case.
