Tire Danger: Beware of “Flat Spots” or Localized Accelerated Wear, or Worn Localized Area on the Tread. This is Evidence of An Underlying Tread Separation and a Potential Catastrophic Crash.
According to Tire Expert Jean Claude Brico, it is not uncommon to find areas of tread more worn than other areas in radial tires. These areas of abnormal wear typically represent a separation between the two steel belts in radial tires, just below that worn area of tread, as well as other internal structural anomalies.
It has been established that the tread area situated over separation between the steel belts wears faster than the area above unseparated steel belts. The separation beneath the tread increases the mobility of that area of tread, which makes it wear at a greater rate than the rest of the tread around it. This localized wear should be distinguished from wear that extends 360 degrees around the tire.
Jean Claude Brico, a chemist, who worked for Michelin for 38 years in research and development of rubber compounds, performed extensive testing using tires that were manufactured with artificial separations between the steel belts (induced by a 0.25 mm thick film of Mylar) . The tires were run over a test track in South Carolina at speeds ranging from 28 mph to 60 mph.
Mr. Brico’s test procedures enabled him to determine the rate of wear of the tread, and increased rate of tread wear above the area where the underlying steel belts were separated. Mr. Brico is the only published tire expert that has ever conducted real world testing to actually measure the rate of treadwear in a radial tires and above separations between steel belts.
This phenomena should be contrasted with tire aging, particularly with regard to aged tires that have never been placed in service before. Aged tires that have never been used before but are more than six years old will not exhibit this localized wear pattern, but are still dangerous, because the internal components have likely degraded over time. Unused tires cannot exhibit wear patterns, as they are yet to be driven on.