CUPPING OR SCALLOPING.
An unbalanced wheel assembly and faulty shock absorbers on an air-ride suspension are the leading causes of this pattern. However, mismatched dual-set inflation or a bad wheel bearing can produce similar wear.
Although not technically wear, this pattern is common enough to have its own category. Improper recapping, in methods or material, is the likely cause. If caught early enough, the problem can be remedied with another cap.
MULTIPLE FLAT SPOTTING.
This is one of the more difficult patterns to diagnose because it looks similar to diagonal and erratic depression wear. It’s usually caused by mismatched dual-set inflation pressure, faulty shock absorbers on an air-ride suspension or a bad wheel bearing. High-speed driving and consistent light loads or deadheading also contribute to the problem.
CHAFING OR OVERALL EXCESSIVE WEAR.
This pattern is the product of severe duty, from mountainous terrain, abrasive road surface, high engine torque or excessive load weight.
Hard braking is the leading cause of this pattern. However, it can also develop if drivers leave a parking area before all their brakes are fully released. Such problems are common during winter months when brake shoes freeze to drums.
RIVER (OR CHANNEL) WEAR.
Although ugly, this pattern doesn’t come from harmful forces. It typically emerges on long-wearing, free-rolling tires after they’ve racked up considerable miles.