Remember those bright, shiny chrome bumpers on the cars of the ’50s, ’60s and ’70s? They take us back to a time when the bumpers were more of a design to make the cars more appealing than for protection. By definition, a bumper is usually a metal bar or beam, attached the vehicle’s front-most and rear-most ends, designed to absorb impact in a collision. Over the years, regulations for automobile bumpers have been implemented to allow the car to sustain a low-speed impact without damage to the vehicle’s safety systems. The main function of a bumper is to protect the car’s body in a slight collision at a very slow speed. Bumpers are installed on all vehicles, although today they are not very obvious because they blend in with the body.
Although a vehicle’s bumper systems should be designed to absorb the energy of low-speed collisions and help protect the car’s safety and other expensive components located nearby, most bumpers are designed to meet only the minimum regulatory standards. The bumper function on modern automobiles generally consists of a plastic cover over a reinforcement bar made of steel, aluminum, fiberglass composite or plastic.
In 1971, the U.S. National Highway Traffic Safety Administration issued the country’s first regulation applicable to passenger car bumpers, effective on September 1, 1972—when most automakers would begin producing their model year 1973 vehicles. The standard prohibited functional damage to specified safety-related components such as headlamps and fuel system components when the vehicle is subjected to barrier crash tests at 5 miles per hour for front and 2.5 mph for rear bumper systems. The standards were further increased for the 1974 model year passenger cars with standardized height front and rear bumpers that could take angle impacts at 5-mile-per-hour with no damage to the car’s lights, safety equipment and engine. Cars were equipped with bulky, massive, heavy, protruding bumpers to comply with the bumper standards of the ’70s and early ’80s.
By the late ’80s most bumpers were concealed by a painted thermoplastic fascia. The internal aspect of the bumper usually consists of a lightweight foam or polyurethane. This foam does not contribute to the impact absorption factor of the bumper, but serves as a filler and prevents the thermoplastic fascia from cracking upon impact.
So when you see an old classic car with those bright, shiny bumpers, remember when they contributed to the overall appearance of the car prior to the implementation of the safety standards.
- The Rock Crusher Canyon car show will be held on Saturday, Jan. 25, at the Canyon. All years and makes are invited to attend. Contact Ken for more information at 352-341-1165.
Ken McNally is the car columnist for the Chronicle. Contact him at email@example.com or 352-341-1165 for more information on any of the above events.