The Myth of Rim Flange Grooving in Tire Cases

June 27, 2011

As hot weather leads to more tire failures in Southern states, Miami tire lawyers need to understand how to counter specious defenses raised to deflect attention away from the fact that a tire has been defectively designed or manufactured.

One of the defenses commonly encountered by tire lawyers is the defense theory of rim flange grooving.

The rim flange of a tire is the slightly recessed area at the very bottom of the sidewall of a tire which comes in contact with the wheel rim when a tire is mounted on a vehicle. For the laymen, this is the circumferential piece of rubber adjacent to the circular hole in every tire. It is a very thin area of rubber which goes around the tire next to the hole, is slightly depressed from the rest of the sidewall, and may have a pattern or sheen which is slightly different from the rest of the sidewall.

The defense theory goes something like this: If a tire has evidence of rim flange grooving, or depression marks in the rim flange area of the tire, it is evidence of under inflation. Under inflation means that at sometime during the life of the tire the tire was run with less than ideal air pressure. The theory continues that exposure by the tire to an underinflated state compromises the integrity of the tire and may lead to failure by tread separation.

The problem with this theory has been exposed by tire experts who have shown that brand new tires in use for short periods at proper inflation pressures which are then dismounted will show some evidence of rim flange grooving simply by virtue of use on the vehicle, and the forces created at the contact point between the tire and the rim by normal activities such as cornering, accelerating, and decelerating.

At Jay Halpern and Associates, we have handled tire cases throughout Florida and across the country. We believe that theories such as rim flange grooving, which rely on findings that occur through normal use of a vehicle and tire are improper barometers for what causes a tire to fail. If a tire is properly designed and manufactured, it must withstand the normal and typical use for which it was intended. If that normal and typical use renders a finding of rim flange grooving, then such a finding should not stand for the proposition that the vehicle or tire was abused by the user.

Naturally, if there are unusual deep gouge marks in the rim flange area which indicate that the tire may have been run with no air pressure whatsoever, an inquiry should be made into any such unusual markings. Nevertheless, mild to moderate rim flange grooving which occurs during the normal course of vehicle and tire use is a bogus argument used by tire manufacturers to deflect attention away from design and manufacturing defects.