Built at Neuilly-sur-Seine by Ets Ballot (established by Ernest Ballot), the engines were fitted to motorcycles which they produced under the Labor marque. They were also sold to Armor, among others.
The firm also manufactured engines for aircraft and automobiles.
Ballot by Cabart and Sen runs to over 900 pages. Review at Velocetoday.com
A Two-stroke Engine Unit with no Exposed Working Parts.
A VERY neat type of unit constructed engine and gear box for motor cycle use has been produced by the Ballot Cie., of Paris. This firm has specialised for a number of years in engines for car use, and supplies these for a large number of manufacturers both in France and abroad. The adoption of a power plant for motor cycles is, however, of recent date. It is understood that the whole of the present production has been secured by one of the leading French firms for their new types of machines; other firms, however, will adopt the Ballot engine as soon as production increases.
The engine is a single-cylinder air-cooled two-stroke, mounted on an aluminium crank case. A valve is mounted in the cylinder head, but this is only used to relieve the compression, and allows the machine to be ridden without interfering with the carburetter and ignition controls. Crank case compression is employed, and the aluminium piston is fitted with a deflector. Ball bearings are fitted for both the crankshaft and the connecting rod big end. The crankshaft is of the built-up type, consisting of two full discs united by the crank pin, which is conical ends fitting into the discs. One of the features of this engine is the enclosed magneto, only the distributor of which is outside. Magneto drive is by means of a roller chain, naturally enclosed. A metal disc clutch, working in oil, is used, and there are two speeds operated by lever with forked arms, so as to encircle the tank and horizontal tube of the machine. With the exception of the pulley or sprocket for the final drive,, there is not a single exposed working part on the Ballot engine. Even the kick starter is enclosed, and is operated by means of the right-hand footboard.
This engine was exhibited at the 1919 Paris Salon in an earlier form. Since then, however, it has undergone detail modifications only. It is interesting to note that the majority of French motor cycles are fitted with engine and gears constructed on the unit system, and the Ballot product adds another example to the list. The Bleriot and Louis Clement machines may be cited as excellent examples of unit construction, especially the latter, in which case a clutch and three-speed gear box are combined with an original design of twin-cylinder V type engine, having shaft operated over-head valve gear. Many capable engineers consider that unit construction will be adopted eventually in this country, though at the present moment British examples could easily be counted on the fingers of one hand.
The Motor Cycle December 9th, 1920. Page 705