Atomette
In 1921 Mr. Allan Thomas, who had a garage at 25 Cleveland Street, Wolverhampton, designed and built several prototype three-wheeled, single seater cars, using the name Atomette. The following year he introduced a two seater cyclecar. The machine, powered by a 2.5hp. two-stroke, air-cooled Villiers engine, mounted behind the seat, was fitted with a three speed Burman gearbox. The engine was fitted immediately in front of the rear wheel and even though it was behind the seat, cooling was adequate. There was a primary chain drive and a single rubber belt for the final drive, which ran onto a 'V' shaped pulley on the rear wheel. The pulley also accommodated two shoe type brakes.


A single-seater 'Atomette'  cyclecar from 1921. From the 'Light Car & Cyclecar' magazine.

The frame was built from two cross-braced tubes which were strengthened by tie rods. The back wheel was unsprung to reduce the possibility of skidding, and quarter-elliptic springs were attached to the front axle. There was direct steering with a moveable steering column to facilitate the driver's entrance. The other controls were similar to those found on motorcycles of the day, and the body was made from three-ply wood. Only a few were built, and production lasted for about a year.

The following article appeared in the "Light Car and Cyclecar" on 4th March, 1922:

The Atomette cyclecar, made by Mr. Allan Thomas, of Cleveland Street, Wolverhampton, has undergone several changes since it was first described in these pages, and it was on the new two-seater that we recently had the pleasure of a trial run.    

The specification is generally the same as that of the single-seater, with an air-cooled 2hp. Villiers engine, three-speed Burman gearbox, and chain-cum-belt transmission to the rear wheel. The rear wheel is rigid, but the body itself is mounted on transverse leaf springs, quarter-elliptic springs being supplied in front. The engine is situated behind the seat, and is cooled by an aluminium fan.

Handle starting has been replaced by a kick starter on the Burman gearbox. Owing to the cold weather, both driver and passenger were heavily clothed, and the seating accommodation was, therefore somewhat cramped. We understand, however, that the body is an experimental one and that those supplied to the public will be two or three inches wider and longer. This, in conjunction with the movable steering column, should provide ample room for average-sized persons.
Exemplifying the simplicity of the whole design. The front quarter-elliptic springs are anchored direct to the tubular chassis member. The sketch also shows the simple-type steering pivot.

Capable of 30 m.p.h.

The Atomette is not claimed to be a "go-anywhere" cyclecar. It is a simple and economical runabout, which, at 90 guineas, will take two persons in warmth and comfort over any ordinary roads. We were surprised, however, to find that a speed of 25-30m.p.h. could be reached. The springing was not by any means perfect, but it was reasonably good, and the rough roads of Wolverhampton were traversed with very little discomfort. Tettenhall Rock Hill, an ascent which necessitates a change down on many cars, was climbed by the Atomette, two up, in top gear, and Old Hill, in the same district, which has a gradient of about 1 in 6, was negotiated in bottom gear without difficulty.

The ingenious method of altering the rake of the steering wheel. It is fixed in the desired position by means of the wing nut.

The Atomette weighs, approximately, 2½cwt. which is about the weight of a medium-powered solo motorcycle. A reverse gear is therefore, altogether unnecessary, for the machine can easily he pushed with a hand on the steering wheel. Another advantage of its lightness is that it can be tipped up either way, thus making it simple for the transmission, etc. to be attended to should this become advisable. When it is wished to get at the carburettor or sparking plug, the expanded metal door above the engine can be raised. Should this not give sufficient room for the job, the back portion of the body, which contains the petrol tank, can be removed complete by undoing the petrol pipe union and  taking off four winged nuts.

A Sturdy Two-stroke Engine.

After a run of several miles, we found the engine quite cool and developing its full power. Also, as it was always running under load, there was a total absence of four-stroking. There is a pleasure in driving this sturdy, but featherweight, cyclecar, which has to be experienced to be appreciated.

Even at full speeds, it is remarkably steady on the road due, no doubt, to the rigidity of the back wheel, and its narrow track and good accelerating power proved great assets in traffic. It can he stored in any shed which has a door of sufficient width, and can easily be lifted up a step should this shed be on higher ground than the road. Over ordinary roads an average speed of about 17 or 18m.p.h. can be maintained without difficulty.

An ingenious feature is the manner in which the rake of the steering column can be altered. This column, as can be seen, is anchored at its base to a cross tube, the angle of the column being governed by a diminutive radius rod secured to the floor of the car. By slacking off a single wing nut the steering wheel can be pushed away from or pulled towards the driver until the most comfortable angle is found, and the steering column can then be locked.
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