"Clearly outshine series shock absorbers"
Whereas the market analyses of the booming leisure market delivered a clear message, the Bilstein marketers also noted that driving behavior (still) plays a subordinate role for camper drivers in many cases. Knopik: "They are clearly and primarily focused on the interior, and less on the suspension. That's precisely why the new shock absorbers had to be good enough to clearly outshine series shock absorbers and make an immediate impression."
Noticeably better driving behavior was therefore the key requirement during development. The engineers initially concentrated on the Fiat Ducato, a commercial vehicle on which most campers and motorhomes are based. Two aspects favored this approach: "For one thing, our market analysis showed that nearly a quarter of a million Fiat Ducatos are registered as camper vans in Europe alone," Knopik said. "On the other hand, we already had a number of B4 applications in the range for the Ducato, which we developed further during extensive testing specifically for use in camper vans and motorhomes."
Demanding program of tests
Hundreds of hours were spent on driving tests alone, most specifically on the "Automotive Testing Papenburg" site, where automotive manufacturers such as Mercedes-Benz also perform their testing behind hermetically sealed gates. For this purpose, the engineers developed various shock absorber prototypes adapted to the high weight of the various Ducato camper models from panel vans to semi-integrated motorhomes. On the demanding test tracks, the shock absorbers were tested down to the last detail and tuned until the Bilstein developers were completely satisfied.
Knopik: "In multiple iterative loops, engineers from our Road Test department are checking the performance of the prototypes: How do the rebound and compression stages of the shock absorbers behave, and how does the vehicle respond? Based on subjective and objective test data, working pistons and valves are adjusted until the driving behavior is perfect."