This quiz is about a Berlin built oddball. We were glad that the hints were enough to get nearly 10 competitors on the right track. The explanation comes from Thomas Ulrich, car historian from Berlin. The photo shows the winning Bob 5HP racing-car at the Stadium Rennen of 1923 in Berlin. This car with driver Fettkenheuer won the class V race at the Grunewald Radrennbahn in front of a Koco and a Peter Moritz. The last car in this race was an Omikron. The class V was for cars with 5 'Steuer PS' (Tax rated horsepower) Carraciola won the race for 4 PS cars. As it was a bicycle racetrack, only 4 cars competed together in one race.
The firm Bob was founded in early 1919 and they built cars until 1925 under three different owners. They built mostly cyclecars with 4 HP, but also some 5 HP. They also built a sportscar with a 5 HP engine, Siemens & Halske like most of the other engines. It had an underslung chassis and only two were built. One of them was bought by Zora Arkus Duntov of later Chevrolet fame. Over the years the total production of Bob was around 350 in total.
The racing car from the photo had an engine built by Bob themselves. The four cylinder engine had a bore of 63 mm and a stroke of 102mm. Of nine competitors Anders Svenfelt, Robert Hafner, Fedor, Graeme Jarrett, Heinzgerd Schott and Leon Mitchell plus one competitor Mr. S were all correct on Bob. In the end it was decided that this last competitor was best, even in view of the fact that the car was not 5 but 4 PS as in his answer: "The Bob Automobilgesellschaft AG built cars in Berlin between 1919 and 1925, mostly using Siemens & Halske engines. The most powerful 4 cylinder engine (5/25hp) had a bore and stoke at 63mm and 102mm respectively with 1298ccm, pressurized lubrication, thermo-syphon cooling and chassis weight of app. 690kg. Bob Cyclecars made appearances in various races in the 1920s and did especially well at the Stadionrennen in Berlin on 28/29 April 1923. The Fettkenheuer piloted Bob car came first within the 5hp class. In the 4hp class an EGO car came first piloted by ... Rudolf Caracciola!"
Congratulations Mr. S. (name known with the editors), please send us your shirt size and mail address.
(Text Thomas Ulrich, photo from his collection; Thomas is member of the Society of Automotive Historians)