Today, you can walk into most major motorcycle dealerships, and purchase a motorcycle that will do 200 MPH. You even have your choice of options from among multiple brands. These are not super exotic homologation specials, they are standard production machines, available to anyone. Back in the 1950s, it was difficult and expensive to find a production machine that would do half that speed. The world was recovering from WWII, and Germany in particular was just getting back into producing cars and motorcycles of higher speeds and displacements. BMW, Zundapp, and NSU were competing in the showrooms and on the racetrack for dominance. At that time, success on the track was the primary advertising material to get buyers into the showroom. And it worked. One area left dormant since before the war was the motorcycle land speed record. It was still held by a BMW from 1937. NSU siezed an opportunity and established a new record of 180.10 MPH (289.85 KPH) in 1951 with Wilhelm Herz aboard blasting down the autobahn. With 200 MPH in sight, there were several attempts by a variety of manufacturers over the next 5 years, but they all fell short.
Until 1956. The 1951 record had stood for 4 years before being eclipsed by a Vincent, and then by a Triumph in 1955. NSU decided to go all out in reclaiming it in 1956, and sent a well-equipped team of machines, spares, and mechanics to the Bonneville Salt flats that July. They brought 6 machines with engines all based on their very successful GP racing RennMax and RennFox machines. The 500cc (actually 499cc) machine was dubbed the Dolphin III as the most recent version of the original Delphin that broke the land speed record back in 1951. The 350cc and 500cc models were supercharged parallel twins, but with an interesting historical twist. The superchargers used a troichordal rotor on a fixed shaft in a figure 8 style chamber. If this sounds familiar, it is because it was the precursor of the wankel engine. The engine was an overhead cam with bevel-drive, fed by a single Amal carburetor. Soichoro Honda himself had been by the factory the prior year to take a look At what NSU was doing with production machines given their performance in the lightweight classes in GP racing.
Back to Bonneville. The Delphin (Dolphin) moniker was due to the streamlined shape of the fairing which produced a miserly 0.19 coefficient of drag. In fact, the major challenge was keeping the machine on the ground at speed, and weights were added strategically for this purpose. The seating position placed the pilot low, and was dubbed the “hammock” position. On the salt flats, it was a difficult couple of weeks. Conditions were windy, and NSU had a crash during the 250cc attempt with H.P. Mueller aboard. In fact Mueller was the pilot for all of the record-breaking runs except for the 500cc class. Several crashes or aborted runs took place in other classes as well. However, early in the morning on August 4th, 1956 with Wilhelm Herz once again in the pilot seat, and the winds finally calm, NSU was able to achieve a stunning 211.4 MPH, shattering the previous record by 26 MPH !! NSU had convincingly reclaimed dominance in the land speed arena, and returned home poised for continued success on the track and in the showroom.