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Welcome To Cleaning and Servicing NEMAG and Governor Speedometers



The Smiths Mechanical Governor Speedometer was produced earlier than the Nemag perhaps in the late 1920. As the name implies, the operation of the speedometer is controlled by a mechanical governor. Gradually they were phased out in favour of the much less complicated and perhaps cheaper NEMAG type.

The Smiths Jaeger ‘Nemag’ make of speedometers were fitted in very many British cars light vans and motorcycles of the 1930-1960 and even beyond. They work on a simple principle of magnetic eddy currents. In most cases they are reliable and generally give trouble free operation. Smiths Jaeger referred to them as the NEMAG instruments.


The part that indicates the speed is correctly called a Speedometer. The part that indicates the miles travelled is correctly called a Odometer.


We can clean and service your damaged or faulty speedometer. We hold a dedicated range of parts but also have the specialist facilities to make any part that is required; from having new bespoke dials made in the traditional fashion or new central arbors, shafts, gears, we can re pivot worn shafts and re-bush where required. We can calibrate your speedometer after a service, using a specially made state of the art calibration machine. Most of the speedometers we work on are well over fifty years old and calibration is carried out setting the speedometer to run as close as possible at an indicated 30mph.