Overdrive Magazine | Trucking Business News & Owner Operator Info
Issue link: http://read.dmtmag.com/i/675322
32 | Overdrive | May 2016 LONG LIVE YOUR TIRES for Michelin Truck Tires. "Compounds, casing design and tread sculpture work synergistically and provide a complete package toward achieving performance gains," Crehan says. Today's compounds generate less heat buildup in over-the-road tires, which in- herently leads to less severe heat history in the tire and more retreadability. "This is also directly related to the push for more fuel efficiency in com- mercial truck tires," says Dr. Prosser Carnegie, head of Commercial Vehicle Tires brand management for Continen- tal Tire the Americas. Proper maintenance Once you've chosen the most appropri- ate tires for your application, the poten- tial for cost savings lies in maintenance. Improper inflation and poor rotation are the two primary causes of irregular tire wear. They're also among the easi- est to avoid. "Tire rotation should be part of your maintenance program," says Homer Hogg, manager of technical develop- ment for TA/Petro. "But understanding how and when to rotate will depend on your specific operation." A rotation schedule should ensure that tires on the same axle have a simi- lar tread depth. "The mismatching of dual tire diameters will result in one tire carry- ing more individual tire load than the other," Buckham says. "This also can occur when one tire is operated at a dif- ferent air pressure than the other." The life of both tires will be reduced substantially if dual tires are not within a quarter-inch diameter of each other, Hogg says. When one dual tire is larger in diameter than the other – but still within the quarter-inch requirement – he recommends the larger tire always be placed on the outside position. Underinflated tires build up exces- sive heat, which can damage the tire and shorten its life. Inflation also af- fects performance, fuel economy and maintenance costs, says Jon Intagliata, who manages tire pressure monitoring systems for Bendix Commercial Vehicle Systems. A Michelin study shows that a 15 percent over- or underinflation can reduce a tire's lifespan by 10 percent. Research from the American Trucking Associations' Technology & Mainte- nance Council has shown underinfla- tion by just 10 percent – less than 11 psi on a 105-psi tire – can result in a fuel economy drop of 1.5 percent. "Nearly half of all emergency service road calls are tire-related, and under- inflation and excessive heat are respon- sible for 90 percent of tire failures," Intagliata says. Retreading Just as improper tire maintenance can prematurely erode tread, it also can destroy retread capabilities. The way a truck is driven "can have a significant effect on the casings – this cannon be understated," Crehan says. These driving habits include curb im- pacts, braking, emergency stops, speed, route choice, road maneuvers and obstacle avoidance, he says. "The main reason a tire casing is rejected during the retread process is due to the tire being underinflated or overloaded at some point during its lifecycle," says Terry Smouter, business development manager for Continental CVT. Ben Rosenblum, director of Bandag marketing for Bridgestone Commercial, says the company's studies have shown that high-quality casings retread just as well on the second and third retread as they do on the first. "Casings today are built to last many years and multiple retread cycles," he says. "If you maintain the appropri- ate pressure – and hopefully avoid too many curbs – you'll get the most out of your casings." Trailer owners have more potential for retreading because of options for One aspect of extending tire life often goes undetected until the damage is done. That's a worn wheel end, which causes the wheel to shimmy. Even a slight irregular- ity there can strip tire tread. The problem is often disguised as something more familiar. "Irregular wear is sometimes misdi- agnosed as an alignment issue," says Rick Martin, Meritor's senior aftermarket training manager. "If they see tire wear on a trailer axle or steer axle, they'll usually just take it and have it aligned." No amount of alignment is going to fix a problem caused by a worn wheel end, he says. "You're going to end up with some feathering," says Jim LeClaire, national original equipment sales manager for Webb Wheel Products. "The tire is going to end up squirming." DON'T OVERLOOK THIS WEAR POINT Improper inflation and poor rotation are the two primary causes of irregular tire wear.