Dave Paulk, manager of field technical services for BKT USA Inc., discusses the average lifespan of a large ag tire and what steps tire dealers can take to prolong it.
“The lifespan of an ag tire is dependent on how it is used and for what purposes,” says Paulk. “If an ag tire is used only in the field, it will last much longer before it wears out. Unfortunately, with farms scattered and tractors traveling on the road, the life of ag tires is diminished because of the road wear.
“On mechanical four-wheel drive tractors, the fronts are drive tires, but wear out about 2:1 to the rears, especially where traveling on the road is required. The reason is that fronts usually turn 1.3 to 1.5 times faster than the rears.
“The crown of the road also plays a part in how the tires wear. The right front tire will often wear out faster than the left front. The right rear tires will exhibit signs of road wear, but are larger and don’t turn as many times as the front. The road wear doesn’t show up as quickly.
“Rotating the fronts from right to left will prolong the life for a while longer. Using correct, recommended wheels is important in several ways,” explains Paulk.
“Generally, there is a recommended wheel with alternates. The recommended wheel will give the tire a better footprint on soil and on the road. Where compaction is important, the tire is spread out over a large area – longer and wider.
“Recommended alternate wheels will work without damaging the tire, but sometimes don’t give the optimum footprint. If wheels are too narrow, it pulls the sidewall of the tires in and puts more pressure in the middle of the tire’s tread. If wheels are too wide, the beads are pushed out, which creates undue pressure in the bead area and lower sidewall.
“Very high-flexion (VF) tires play prominently into this, as they can be run at lower pressures and give a wider and longer footprint with the correct wheels,” he says.
“The use of steel belts in ag tires can serve a dual purpose. Tires can be made with a steel belt in the tread area or made with an all-steel casing. A steel belt strengthens the casing and offers a measure of resistance to punctures in the tread area. It doesn’t make tires bullet-proof, but the steel belt does help.
“They also help the integrity and form of the casing stay intact. Some tires are made with all-steel casings. These tires have steel running from bead to bead in a radial design. This helps minimize damage to the sidewalls and tread area of the tire.”
