Sometimes it helps to take a fresh approach to a familiar situation, and tires are no exception. Consider looking at tires as a portfolio of assets and think about ways to improve your tire investment through smart asset management.
Current conditions make this approach especially attractive. We're in the middle of a heavy new truck build period, and one result of this new equipment influx is that older vehicles will be idled, traded or sold. Second, new tires have been improving in original treadlife and casing durability. And the retread industry has improved materials, processing, and quality measures. As a result, tires are lasting longer in both their original tread and retread stages.
One inescapable fact, however, is that tires, just like all of us, eventually do age and grow less able to work as hard as they did in their prime. There are at least three effects that conspire to “age” tires. First, there is fatigue cycling. Each time a tire rotates under load and deflects where its load is transferred to the road, rubber and other structural reinforcements in the tire are deformed and stressed. Excessive deflection due to overloading and/or underinflation accelerates this type of aging.
Second, time tends to age tires since they are complex chemical composites of different rubber types and reinforcements, with many interfaces that can be weakened over time — especially when exposed to fuel, lubricants, or other harsh chemical solvents. If tires are not used regularly, this chemical degradation is accelerated.
Third, torque transfer can age tires over time. This primarily affects drive axle tires, but remember that all the forces necessary to steer, accelerate and brake the truck are transferred through the tires.
So it seems reasonable that in addition to choosing new tires carefully and maintaining and retreading them properly, you should also determine how to exit them from your fleet most gracefully.
Your objective should be to keep the most productive, least aged tires in service and use those that are near the end of their useful service life in less demanding applications, as well as in sidelined vehicles.
Here are some pointers for giving your tire portfolio a tune-up:
Recognize that some drive tires age faster than others. Single drive axles and higher torque drivetrains, for example, tend to be more demanding. Consider switching them to free-rolling service during their second or third treadlife.
Free-rolling tires, e.g., steer and trailer, should be considered prime candidates for drive tire service on their first retread. Purchase high quality new tires for free-rolling positions and take care to assure casing compatibility for retreading.
Review shop and yard cleanliness procedures, taking special care to prevent tires from coming into contact with fuels, lubricants or other solvents.
Maintain proper inflation pressures to avoid over deflection and resulting high heat buildup. This is especially important for inside dual position tires.
Tires should be exercised periodically to help resist the harmful effects of ozone and oxidation from exposure to sunlight and normal atmospheric chemicals.
If casing purchases are required, choose casings from fleets with good tire maintenance practices.
Establish a hierarchy or preference listing of tires to be placed on sale, trade or scrap vehicles that will exit the most aged tires first.
Just like your financial portfolio, your tires should be managed to keep those with the most quality and get rid of those with the least The resulting dividends will be worthwhile.