BMI ca. 1935 80 cc aiv with “Burgers” bicycle frame# 63271 engine # 2321
During his years at the well-known Dutch Stork machine factory engineer Beyerman designed an auxiliary bicycle engine.
The company saw not much commercial success in the design so Beyerman decided to quit his job and market the little engine himself.
The 80 cc four stroke engine had bore and stroke dimensions of 45×50 mm.
It had an automatic inlet valve and a side exhaust valve. Cylinder, head and crankcase were cast as a single unit and an outside flywheel was fitted.
A V-belt drove the rear wheel; this drive belt could be taken off in a moment to transform the BMI to a pedal-driven vehicle if necessary.
Production started in 1934 at the “Bilthovense Metaal Industrie”, a small company in the village of Bilthoven.
Most parts of the engine were manufactured by other Dutch companies in the Bilthoven region, the only foreign parts being the Amal carburetor and the Bosch flywheel ignition. Assembly and testing took place at the BMI facility at 22, Rembrandtlaan Bilthoven.
Customers could order a loose power unit or a complete motorized bicycle: the bicycles were produced by the Sengers bicycle factory, conveniently located in the same street in Bilthoven.
Sales were not very encouraging because the very popular and more powerful DKW RT 98 cc and its rivals were not much more expensive than the BMI.
The little engine proved to be useful in various applications, though: it was used to power rail inspection vehicles, mobile grinding wheels, small boats, washing machines, invalid carriages, tandems and transport bicycles to name a few.
By the end of 1936 an updated model with front suspension was brought out and in 1937 a prototype proper motorcycle with 175cc four stroke engine was constructed which didn’t make it to the production stage.
In the course of 1937 production was stopped.
Allegedly some 3,500 units have been produced between 1934 and 1937. (source: Piet Cornet, “ De Nederlandse Motorhistorie”.)
This interesting little machine is in good condition.