Here we also point uit that the later production versions of the 300 SL were further worked out by Friedrich Geiger, faithfully following Uhlenhauts concepts. Geiger had become after the second World War chief of styling, and he was together with Karl Wilfert responsible for the shape and styling of Mercedes production cars, right up to 1972. Geiger was not a very outspoken man, and his work merits more attention in the history of Mercedes cars, but it can be said that Uhlenhaut is and remains the « initiator » of the 300 SL, its concept, aura and unique shape.

Suspension genius…

Uhlenhauts profound instinct on how a car should handle made him transform as a young engineer the ill-handling 1936 W25 Grand Prix car, which performed so dismally that Neubauer decided to retire the cars even in the midst of the 1936 racing season.

Soon Uhlenhaut found what was wrong on the suspension of the W25. The steering geometry caused too large toe-in changes and the suspension travel was designed as far too short. This caused the springs to bottom frequently under heavy lateral and vertical loads and inevitably during heavy braking, which caused also the whole weak chassis to bend…

To fight these problems, both hydraulic and friction dampers were used in the W 25 and the springs were set up excessively hard. This stiff suspension setup then caused the wheels to lose contact with the road, resulting in the cars darting all over the Nurburgring tarmac and many other circuits with rough road surfaces.

Rudolf ‘s answer of was simple: make a stiffer chassis, increase the allowed suspension travel, weaken the springs, adjust the damping accordingly to prevent bottoming out of the suspension under heavy loads. He convinced the drivers that friction dampers were not needed at all…

The W125, which was the fruit of his findings, was the star of the 1937 Grand Prix season, and Rudolf Caracciola became European champion. Its successor, the W 154, dominated the 1938 and 1939 seasons.

On test runs at the Nürburgring, Uhlenhaut proved to be 3 seconds faster than Fangio in the W 196...  

…and gifted driver

Rudolf Uhlenhaut had found out about the W25 handling problems because he was able to drive the monoposto himself at racing speeds. Indeed, he would have made a good racing driver himself. The story goes that in 1955 after a test session on the Nürburgring, world champion Juan Manuel Fangio strolled to Uhlenhaut’s lunch table and said quietly in his typical manner that the car needed some further setting up. So Uhlenhaut wiped his lips clean after a substantial lunch, and still dressed in suit and tie he climbed into the car, and lapped the Ring three seconds faster than the world champion. When Uhlenhaut got out of the car and walked back to Fangio he told him it was nothing a little practice wouldn’t put right…. It is a story, which will have an endless life, showing Uhlenhauts’ unique talent, but also making him the pioneer of the era where racing drivers also become test drivers.

He was actually the very first of its kind…but then also maybe he was the last man who engineered and designed and created the whole car, from how it looked and felt to the way it drove, « aus einem Guss ».

The « early » 300 SL

Uhlenhaut’s post-war cars are well known, and personally I find the his personal « street » racing car, the 300 SLR, one of the most beautiful Mercedes cars ever built. But then again, the « early » 300 SL Grand Touring Racing car is almost as beautiful in its purity. I could not resist to show You some pictures of its magnificent dashboard and instruments, bearing the unmistakeable styling elements which we find back in the later Grand Prix and 300 SLR racing cars… 

Hans Knol ten Bensel

De nederlandse tekst verschijnt binnenkort in de geschreven autopers, met nog bijkomend beeldmateriaal.