The role of the bumper can be inferred easily from the name.
Originally they were mere metal bars attached to the front of the car, and were visually separate from the wings and grille they were intended to protect. Let’s take a quick look at how they changed over time from a piece of steel to complex plastic assemblies merged seamlessly to the rest of the car.
The Altima (above) shows how far bumpers have come from being horizontal iron bars. The bumper has grown to be a part of the unified form of the car and at the moment is extending upward around and past the lamps, and rearward to take surface space from the pressed-steel elements of the cars. The wing is becoming a smaller proportion of the area of the car, leading to the need for unusually placed shutlines. Where did this all start?
Our first example is a 1930 Austin 7. Notice how the bumper is separated from the other parts, connected to the body by two steel rods. There is a lot of space between the bumper and the wing and grille. The bumper itself is only very slightly decorated, with ribs for additional strength. The small curls at the end are there to provide a simple finish and to reduce the chance of the car hooking onto something during parking manoeuvres. The stylist was not very involved in this, one could say.
Our second example, a 1950 Humber Snipe, shows the bumper becoming a chromed item, made of pressed steel. It is now closer to the body but still visually distinct. It features over-riders which offer some capacity to vertically extend the protection offered against bumpers of a slightly greater height. In the US a 1954 Buick Century shows the American approach, flamboyant, dangerous and integrated with the grille.
Moving to 1965 the Rolls-Royce Silver shadow shows little advance on the 1950 concept. Around this time in the United States bumpers were far more advanced in terms of integration but of rather less use, as shown on this 1964 Lincoln Continental.
In 1971 the US government decided that bumper design was unsatisfactory. For one thing they were incapable of withstanding damage and had become very costly to repair. The result of legislative changes was that bumpers now had to withstand a 5 mph impact. This requirement vexed the designers whose first response was to separate the bumpers from
the body and to make them stand further forward. Adapting the regulations to existing vehicles was thus something of a challenge as this 1976 AMC Matador coupe. The indicators and tail lamps migrated from the bumper to the body, reducing the cost of small collisions.
In Europe it was mostly business as usual, as shown by this 1972 Opel Rekord which is conceptually the same as a 1960s US vehicle. However, Renault’s 1971 Five showed the way forward, in being the first car with plastic bumpers. Note also how it is beginning to show integration of the bumper and the body. For the next twenty-five years, bumpers were generally a variation on this theme.
Some manufacturers managed the transition from bumper to combined bumper-spoiler more effectively than others. Half-way houses involved adding an apron to the underside of the bumper though the metal-work was still there underneath. This is the beginning of the trend to reduce the extent of the car’s body-in-white to only those areas where it was needed structurally.
The 1990 Honda Civic shows the same concept as the Renualt 5 but paint has been added and the construction is more complex. The bumper is now formally a part of the
overall shape of the car’s body and the addition of paint means that the aerodynamic requirement of a smoother body plus the need to protect the car is being carried by one assembly. From then on it was a matter of time before the visually distinct bumper vanished into the car’s overall form, with small black strips added at crucial points: bumperettes or bumpers on the bumper.
The possibility of extending the now nominal bumper is being pushed by various manufacturers. The game is to see how far back and how far upward the area made of plastic can be extended. The advantage is that these parts can be more cheaply restyled, potentialy changing much of the car’s character without altering the expensive sheet metal. The trick is to avoid having feature lines cut across the metal-plastic border so that when the front and rear bumper changes the centre section can remain the same.
PSA have been quite aggressive about this on the 508 and C6 cars. Here is the 508’s rear end. The bumper is quite huge, making this a very complex piece of injection moulding indeed. The trade off is that it can be very hard to manage the continuity of highlights from the metal areas to the plastic. The 508 is an especially egregious example as the flow of reflections is quite poor owing to problems reliably aligning the parts during construction and also the different properties of plastic and metal during forming.