Maintaining the proper levels of inflation in a truck’s tires is a crucial aspect of keeping drivers safe and the truck fuel-efficient. But there’s another, often overlooked reason to make pre- and post-trip tire inflation inspections part of a driver’s daily routine: protecting the tire bead.
The tire bead is an integral component of any tire, and it can be found at the tire’s inner circle where it connects to the wheel rim. The bead is made of heavy-duty rubber, fabrics and high-tensile wound steel cables called bead bundles. Two bead bundles can be found in every tire—one on the inner side and one on the outer side.
Phil Mosier, Cooper Tire’s manager of commercial tire development, says while traditional passenger and commercial tires are all designed with beads, they are manufactured to be especially tough in truck tires.
“[The tire bead] helps securely fit the tire to the rim and seals in the inflation pressure so it doesn’t leak from the tire/rim interface,” Mosier says. “Commercial tire beads are designed to withstand high loads since the durability of the bead area is critical to trouble-free operation. The bead area of commercial truck tires contains lots of steel reinforcement, which enables the tires to withstand the higher loads and heat that the equipment experiences.”
Because the bead serves as the foundation for the tire’s lower sidewall, Mosier warns that running tires at a lower inflation pressure than is recommended can be detrimental to the lifespan of the tire bead, and in turn, the tire itself.
“With low tire pressure comes the flexing of the lower sidewall, and that increases when inflation pressures decrease. This flexing may lead to separations or cracks in the bead area,” he says. “Most truck drivers don’t forget about the tires, but the way they go about checking inflation pressure could be improved. The old-school method of kicking tires, or ‘tire thumping’ with a small bat, just doesn’t work. Tires need to be properly and routinely checked with a calibrated tire pressure gauge and inflated accordingly.”
Kyle Harris, an account manager for Hennessy, an aftermarket manufacturer of wheel-servicing equipment, says it’s good to remember that any routine tire service that’s good for the tire is also good for the bead. This includes regularly rotating, balancing, aligning and, most importantly, maintaining proper pressure.
To fleets that have their own hydraulic-powered tire changers in-house, Harris says the best thing a technician can do is to be patient throughout the tire-changing process.
“One of the most important safety tips regarding beads is to always verify correct tire and wheel sizing, and never try to mount a tire on an incorrect or damaged wheel. Most commonly, technicians might not have the bead in the proper position during demounting or mounting of the top bead. This can stress or break the cables that make up the bead,” Harris says. “And, most importantly, always wear proper safety gear and utilize an inflation cage when [inflating the tires].”
