Sacrificial Rubber?
If you spec a tire with extra rubber on the sidewall, don't forget to rotate your tires on rim.
Mark Putz
Associate Editor
Tires take a real beating in the city and some fleet managers figure there's not a whole lot you can do about it. You maintain proper inflation, tell your drivers to go slow around corners and over curbs and you hope for the best. But there are ways to stretch tire longevity and avoid early replacement due to failure.
In many congested areas, drivers find themselves scraping or bouncing over the curb during turns. They get close to the edge of the road to keep four-wheelers from squeezing into their blindspot, or maybe they confront unavoidable tight spots. For these high-scrub applications, you can spec tires with a beefy sidewall strip designed to take on curbs. Michael Burroughes, market segment manager for Michelin regional/urban truck tires, says Michelin's urban tire offerings feature "sacrificial rubber" on the sidewall. These tires are proven survivors on city buses, so truck drivers shouldn't damage them during "normal" curb strikes or when backing into docks.
Drivers will tell you that backing into a customer's location from the road is stressful enough without having to worry about damaging tires. Yet driveways and loading docks are minefields for sidewalls. When the driver and/or spotter gets out of the cab to check the backing path, he should also check curbs and docksides for steel strips. These heavy gauge strips often edge storm-drain openings and can do serious damage. Drivers can't do much about them when cornering, but there's no excuse for a speared tire in the more controlled arena of warehouse parking lot.
All of the above assumes your driver will be conscientious about the rubber he rolls on. How do you encourage conscientious driving habits? A typical city driver wants to drive the same equipment on a daily basis. Let him. Driving the same tractor every day allows the employee the opportunity to feel ownership and keep a hand in the maintenance of the truck. And, he's more likely to concern himself with the bedrock of tire maintenance: proper inflation.
We all know low psi equals heat, which can lead to failure and a wasted tire. But overinflation is a serious problem in the city. While a linehaul truck may get away with a few extra psi, a city driver who runs over-inflated is subjecting tires to unnecessary shocks and injuries. Overinflation increases the risk of tread injury from puncture. And, remind drivers that wet days offer an increased risk of tire injury from puncture. Tell them that water acts as a lubricant and they'll get the picture.
Over-the-road drivers entering the urban environment must remember that their tires are spec'd to perform best at higher speeds and with limited turns. So they must avoid high-lock turns and the lateral forces of aggressive urban driving and curb-bouncing.
And, if your equipment features a high wheel cut, then it is especially important to slow down in the city.
Spec'ing & Maintenance
Spec a tire with "urban compounding." Most manufacturers tout a special rubber that's well-suited for city driving, and it's not all hype. Years of research shows the proper compound for a city tire will make a difference in longevity and retreadability. The rough pavement, uneven surfaces and potholes of the city can lead to early replacement and casing damage. Tires don't hit potholes square, so a sidewall that's never seen a curb still suffers in the city.
If you spec a tire with extra rubber on the sidewall, don't forget to rotate your tires on rim: That extra strip appears on both sides, so take advantage of it.
Of course, a tire can be babied every time out and still be wasted due to underflation. As a result, many city fleets are moving toward automated inflation systems solutions such as the recent market entrant, Airgo, which makes a constant tire inflation system (CTIS) that monitors tire pressure and automatically maintains proper psi using the trailer's air supply. An automatic inflation system eliminates any driver-error issues, unless the driver slaps a piece of tape over the low-psi warning light.
