One more round

| August 01, 2006

Most of the time, the first re-use of the casing will be for drive tires. The second use goes onto the trailer because trailer tires do not endure either the torque of driving the truck down the road or the twisting forces a steer tire is subjected to.

The secrets to getting good retreads include effective pre-trip maintenance and inspections, as described in the sidebar, and getting proper repairs done from the inside out. The other half of the equation is taking your casings to a large scale retreading plant like this one. A retreading plant should be equipped with the kind of precision machinery we’ve shown here and staffed by highly trained technicians who can control every step of the process in an exact manner.

Early Warning
Pretrip inspections help preserve tire casings for retreading

The most cost-effective retread program depends upon successful reuse of tire casings. The most important key to preserving casings is pretrip inspections.

Bandag, Inc. provides some suggestions on their CD called “No Detours.” It’s important to remember that, with any truck tire, air pressure actually carries the load, not the tire itself. The tire just contains the pressure.

Since the tire structure cannot support the load without sufficient air pressure, it flexes excessively when underinflated. Underinflated tires generate damaging heat, running as much as 5 degrees F. warmer than normal for each 2 psi drop from the proper rating. A tire rated to run 110 psi and holding only 90 psi because of a small leak might run more than 50 degrees F. above the proper temperature, enough to blow the tire apart. Smaller deficiencies in pressure can still reduce mileage and ruin the casing, resulting in an early trip to the scrap pile. Proper pressure also maximizes fuel economy.

“With a modern, radial tire, it’s impossible to determine if a tire is properly inflated by striking it with any kind of heavy object,” Bandag says. “You need to use a good tire gauge.” Gauges need to be checked for proper calibration and replaced occasionally.

  1. Check the pressure and bring up to the proper pressure. If any tire is found to be 20 psi below its rating, it should be considered flat and removed, inspected and, if necessary, repaired before use. This will prevent tread separation and possible destruction of the tire, along with an unsafe operating condition.

  2. Inspect the tire as well as you can for any injuries or foreign objects in the tread. If you find a foreign object that is causing leakage, make sure to have the tire removed and repaired properly from inside.
  3. Check tread depth. It must be 4/32 inch for steer tires and 2/32 inch on drive and trailer tires. Note that many fleets place more stringent limitations on tread depth. Frequently, retreading a tire with 3/32 inch or more of tread life left will improve the chances that a casing will be reusable.
  4. Inspect also for irregular wear. This can be cured by proper steering and axle alignment. Irregular wear causes the tread depth to drop below acceptable limits prematurely.
  5. Inspect the sidewalls for cracking or a rupture, which is indicated by a bulge. Get such a tire repaired because this condition frequently leads to a run flat condition and complete destruction of the casing.

For More Information:
Bandag, Inc.
(800) 523-6366 prompt 6

Tire Retread Information Bureau
(888) 473-8732

Wingfoot Commercial Tire Systems Inc.
(800) 643-7330

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