Bumper Reinforcements

Unlike the old days when bumpers were large, chrome-plated slabs of stamped-steel, bolted to the frame at each end of a car or truck, the bumpers on most modern vehicles are complex mechanisms, with most parts hidden from sight. The visible part is just a flexible plastic cover, which enshrouds energy absorbing material attached to a bumper reinforcement mounted to the frame rails. Impact absorbers and reinforcement bars damaged in collisions must be discarded when making repairs and you’ll find affordable, OE-spec replacements right here on our digital shelves that are just a phone call away.

Early bumpers were mounted away from the body on brackets where they could protect the body and safety components like lights from minor impact damage. But by the early 1970s bumpers had become integrated into the body design and were little more than trim pieces, providing very little protection. In 1973 the Federal government stepped in and enacted standards to improve bumper protection. In response to the new 5-mph regulations manufacturers once again made bumpers larger and positioned them further from the body, often mounted on telescoping shock absorbers that compressed on impact.

Unfortunately, 5-mph bumpers resulted in vehicles with ungainly styling that was not well-liked by car buyers. To improve appearances, car makers installed filler panels to bridge the gap between body and bumper, and over the years these plastic panels gradually evolved into the full bumper covers that are so prevalent today. While specific designs will vary according to vehicle manufacturer and model, the first line of defense under the cover is typically a foam or plastic honeycomb mesh energy absorber. These are designed to crush or collapse upon impact, thereby absorbing the energy applied during a minor collision, and protecting the vehicle structure behind them. Due to this design, energy absorbers are considered one-time use components and must be replaced during collision repair.

The energy absorbing material is attached to an UHSS (Ultra High Strength Steel) or aluminum bumper reinforcement bar. Like the energy absorbers, a reinforcement bar must be replaced if damaged. When inspecting a crash-damaged vehicle, the reinforcement should be carefully checked for signs of cracking or deformation and replaced if any defects are evident. Bumper reinforcements are often mounted on crush tubes or crush boxes that attach to the frame rails, and some reinforcements are supplied with these components. As their names imply, crush tubes and boxes are designed to collapse and absorb impacts that would otherwise damage the frame. Like the energy absorbers, they are considered sacrificial components that must be replaced if there is any evidence of damage.

Consumers benefit from modern bumper design because it allows vehicle stylists to create sleek, sculpted, attractive cars. But more importantly, this modern design is a product of more enlightened thinking that has increased passenger safety. At one time manufacturers thought making vehicles as rigid as possible was best, but this was found to only transfer collision energy directly to the vehicle occupants and cause injury. The development of crush zones that absorbed and deflected collision energy reduced injury. This type of design, using sacrificial components that collapse and absorb energy from minor impact, is employed on modern bumpers to prevent damage to the more expensive and critical parts of the vehicle structure.