D-Rad 1924 3 PS type “ M 24 ” 374 cc IOE flat twin frame # 6041 engine # 4573
D-Rad motorcycles were produced between 1921 and 1933 by the Berlin-based Deutsche Industriewerke and designed by engineer Christiansen.
The machines were nicknamed “Springboks from Spandau” and constitute the archetype of 1920s German motorcycle design: sturdy, strong and well-built.
This “M24” is one of the more elegant designs of D-Rad and technically very interesting: at first sight the engine could be mistaken for a Douglas clone, but a more close look will reveal an overhead inlet valve configuration. Bore x stroke are 61 x 67 mm, engine speed is 1500 rpm, cruising speed amounts to a leisurely 65 kilometres per hour, with a petrol consumption of about 3 litres per 100 kilometres.
This elegant and splendid M 24 weighs 85 kilograms and has automatic engine lubrication and a three speed gearbox with foot operated clutch.
There are two independent brakes on the rear wheel, an internal expanding device with foot control and an external contracting band brake with hand control. Ignition is provided by a Siemens magneto and the electric lighting comes from a Bosch dynamo which is spring-driven from a pulley behind the flywheel.
The mixture is provided by a Pallas instrument and the speed can be checked via a