Trade it Now, or Trade it Later
Retread plants grind off tread rubber so the new tread will fit properly around the casing. All the rubber removed in that process is lost miles-per-thirty-second to the fleet. Bridgestone suggests tires be run down to about 6/32 before retreading in order to get maximum safe mileage from the tread.
Time for a bit of simple math. If you were to take a $400 tire out of service and sell the casing to a retreader for $100, the net cost of the tire is $300, using round numbers. If the casing is retread twice, or perhaps three time, the net cost of the original tire can be reduced to as little as $100.
Now compare the cost of two retreads versus two new tires, even at a trailer position, and you'll see how you're saving money twice each time a tire is retreaded.
We assume here that you're treating your tires well, repairing them properly, and not abusing the casing. Depending on your location and a few other factor, like the market for retreadable casings, you might get $100 for a casing in tip-top shape -- an A-grade casing. If you beat the thing up, it could be only a B- or a C-grade casing. Here again, if you're maintenance program isn't up to par, you're throwing money away in casing value.
"Currently, in most of the U.S., 22.5 low-profile casings (295/75R22.5 and 275/80R22.5) are in very short supply," says Bowman. "They'll fetch the highest casing value, but you may get $95 per casing in one part of the country and only $65 in another, depending on the local market."
The number 1 killer of tire casings is heat, and that's directly attributable to underinflation.
Each revolution of the tire causes the steel wire in the casing to flex. A tire will go around about 500 times per mile, times 100,000-plus miles a year for a couple of years. Try flexing a paperclip like that and see how long it lasts.
"It's critical that proper pressure and loading be maintained so the casing will function as designed through the millions of flexing cycles a tire undergoes in its service life," says Bridgestone's director of engineering for commercial products and technologies, Guy Walenga. "That keeps the casing strong and makes it a good candidate for retreading."
Improper repairs and rusted belts are the next most likely killers of casing value. Each is manageable. Eliminating them will preserve casing value. Tire repairs aren't a problem for retreaders, even section repairs, provided they are done to accepted industry standards, but improper repairs will render the casing non-retreadable.
"There could be any number of nail hole repairs, so long as the repair units do not overlap, which would be considered an improper repair,” says Kevin Rohlwing, senior vice president of training for the Tire Industry Association. "Rust in the tires' steel cords is bad news for retreading. Punctures should be repaired as soon as possible after detecting the wound to prevent moisture from wicking its way into the belts and ruining the casing."
Retreads Keep You Honest
While that may sound like a silly statement, consider the tire maintenance program as whole. If you treat tires as disposable commodities, then retreading probably isn't for you – though it should be. If you invest heavily in tire management and maintenance, a retread program could very beneficial.
Several of the major tire makers offer cost-effective, cradle-to-grave tire management programs that can provide the labor and the oversight needed to make such programs successful. Depending on the need and the volume, they can provide regular yard surveys, pressure checks, reports and recommendations, mounting and dismounting service as well as on-road repairs, casing management through dealer networks, and monthly billing.
Each time you turn a casing into a retreaded tire, you extend its life and lower its life cycle cost. You also get a good-as-new tire for half to two-thirds the cost of a new one, and that's harder to ignore than your tire pressure.