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A German test



The man, who in the old, tradition-laden organization in Frankfurt, together with a small but selected team, determines the technical lines of the development of the motorcycles, is a gifted engineer who is possessed by his task.  Even in his holidays he finds pleasure in solving mathematical equations of higher grades.  The categorical imperative to trace back every technical aspect of the task to the mathematical-physical laws and to build it up from there, to approach every problem by way of the most modern measurement technique  (continually complemented with his own brilliant ideas) - this is characteristic of his work.  This compromise-free and prejudice-free method is paired with an openness for every fruitful exchange of experience.  I owe a very deep insight into the history of development of the MB250 to this.

Whoever climbs for the first time through the labyrinthine corridors into the small research department high up in the attic, will hardly suspect that here, like in only very few other factories, the construction of motorcycles is elevated from a more or less routine craft to that of a very serious and unusually successful engineering task.  I myself have experienced how the Frankfurt engineers started from the very basics with the M100, how they systematically compared the combustion process of the known four-stroke with those of the still little known two-stroke and - with modest expenditure, but with ingenious wealth of ideas - built continuously new measurement and experimental devices, in order to be able to measure airflow, fuel flow rate vibration and silencer back pressure, fuel combustion and temperature behaviour.

Behind each measurement - or ahead of it - stood the comparative mathematics.  I shall not forget the impression which the M200 made on its first exhibition at the IFMA 1951 on my friends from the construction office and the research department. - here stood a machine, that was unmistakably built by engineers, without any leaning on any tried precursors, from the uniquely capable clockspring front-wheel suspension to the stocky motor-block, to the unusually low seat achieved by way of the 16inch wheel, from an organisation which had not built any motorcyles for the past 30 years.

This unusually careful development did not happen without serious setbacks.  The complicated block, with its deliberately thin centre-wall, could not be cast without pores, which led to lengthy delays in the manufacture.  The fuel consumption varied inexplicably, until a clever chap realised that with poor assembly, the slide spring of the initially utilised carburettor could sit on a nose of the slide instead of on the retaining clip of the jet needle, allowing the needle to dance about in the higher position .

The spur gear transfer to the gearbox, even with the most careful processing and with the smallest play through vibration between crankshaft and clutch casing did not match the exemplary mechanical smoothness of the brilliantly balanced motor.  The front-wheel suspension , convincing on the small M100 and satisfying all requirements with respect to tracking, roadholding and minimal tyre loading, was however, with the deceleration of the unusually effective 250's brakes so stiff through the rising up that the suspension was extensively nullified and a full-braking became critical. Untiring test experiments, continuing trial runs monitored with Kienzle-tachographs, and the most difficult but successful competitions have one after the other ironed out these minus-points.   But this ironing out took time and lies one reason for the fact that the current test of one of the most lovable machines that I have ever ridden has taken so long to take place, despite the implorations of the readers.