By Tim Walker & Paul d’Orléans

At the tender age of 14, P.J. ‘John’ Wallace had an epiphany at a motorcycle exhibition, and knew he would build his own motorcycle. He bought a set of unmachined engine castings for £2 10s, and proceeded to build a workshop in his father’s garden, teaching himself to use a few simple machine tools. He soon realized the finishing work required of the castings was beyond both his equipment and his ability. So he bought a frame and wheels from a local cycle maker, plus a secondhand engine, and built his first motorcycle, which he promptly sold.


John Wallace racing his own Duzmo at the 1920 Kop Hill Climb. Dr. A.M. Low, another motorcycle designer, officiates. [Vintagent Archive]
In 1912 (age 16), John landed an apprenticeship with Collier & Sons, makers of Matchless motorcycles, at the time the most successful British manufacturer in racing, having won the single-cylinder class of the very first Isle of Man TT, and many races at Brooklands after that.  Unfortunately John had an industrial accident at the Matchless factory,  and his father put a stop to his employment with the Colliers.  The pill was sweetened by his father buying both John and his brother a T.T. model Rudge, which was a single-speed belt drive machine, stripped for speed. The brothers both joined the British Motor Cycle Racing Club (B.M.C.R.C., or ‘Bemsee’) and took to racing at Brooklands as typical ‘clubmen’. However, things did not go as planned (ah, racing!) and in short order John crashed his Rudge, which was damaged beyond repair.

Herbert LeVack, who would later gain fame working for J.A.P. in engine development, both raced for and developed John Wallace’s engine for Duzmo in 1920, including at the Isle of Man TT. [Vintagent Archive]
With this meager Brooklands experience under his belt, in 1913 he secured a job as a test rider for the J.A. Prestwich (J.A.P) experimental department, where testing motorcycles at Brooklands was part of the job description. When the Prestwich family became aware of his age they promptly sacked him! Wallace spent the the next year studying engineering and training to become a draughtsman. With the onset of WW1, Wallace felt there would be little demand for motorcycles, so took a job at Scottish car makers Arrol-Johnston, as an aero-engine designer. This employment too was short-lived; it was over by mid-1915. However, his lengthening resumé was enough to land him a job with the design team at Westland Aircraft Company (Petters Ltd), which was to last until the end of the war.

One of Wallace’s engine designs, this for a DOHC racing single-cylinder of very advanced specification. [Vintagent Archive]
Late in 1918 Wallace returned to his first love, and laid out a design for an advanced high-performance motorcycle engine. When drawings were finished, he cleverly advertised his design in The Aeroplane, knowing aircraft builders would need to diversify after their war contracts had ended. One such company was the Portable Tool & Engineering Co. of Enfield, who were impressed enough to employ Wallace as Chief Designer. Their plan was to sell ‘loose’ engines to motorcycle manufacturers, and by September 1919 the prototype was ready for trials. Clearly, Wallace had learned a few tricks from cutting-edge aircraft technology, as his engine used Overhead-Valves and was ‘oversquare’ at 88.9mm bore x 76.2 stroke, giving a capacity of 475cc, using a fully-recirculating oil system with two oil pumps on the timing cover; all very advanced for 1919.

After Herbert LeVack left Duzmo, John Wallace hired Harold L. Biggs as his development engineer, and this is the original ‘Duzmo Biggs Special’ of 1921, using a single-speed chassis. [Vintagent Archive]
Herbert LeVack had been employed during the war assembling and testing aero engines, and his services were secured by P.J. Wallace to build his new motorcycle engines. LeVack proved a valuable asset, with an uncanny ability to produce wonderful results from ill-fitting components. He built the prototype engine and got it running satisfactorily; a second engine was then fitted into a motorcycle chassis, and used by Le Vack in demonstrations to the trade and the public, and in competitions. LeVack’s development and riding skills produced excellent results from Wallace’s design. The motorcycle was first christened the ‘Ace’, then the ‘Buzmo’, before ending up as the ‘Duzmo’ in 1920.

Harold L. Biggs and John Wallace outside the Duzmo premises, 1921. [Vintagent Archive]
LeVack won many speed events on his tuned single-speed belt-drive Duzmo, winning over 100 awards. Racing success created demand from the public, but the business plan with Portable Tool called for engine manufacture, not motorcycle manufacture, and Duzmo was barely a company! There was no chance of fulfilling orders for whole motorcycles with the small workshop that P.J. Wallace ran near the Enfield highway. Wallace suggested to the Board of Portable Tool that they take Duzmo ‘public’ and sell stock to raise capital for proper motorcycle manufacturing facilities, but they balked, and wound down production. A silver lining emerged when a kindly Board member loaned Wallace enough money to create his own company (John Wallace Ltd) to build his Duzmos.

The 1922 version of the Duzmo racing special at Brooklands, now using Wallace’s engine and chassis design, developed by Harold L. Biggs (left). [Vintagent Archive]
Ever looking forward, in 1920 Wallace and Le Vack altered their single-speed frame to fit a 3-speed Sturmey-Archer gearbox, for all-chain-drive. This machine completed the 1920 London to Edinburgh trial, and was then shipped to the Isle of Man for LeVack to ride in the 1920 Senior T.T.   LeVack was no stranger to the T.T., having raced there in 1914 (the last T.T. before WW1) finishing in 15th place averaging 45mph on a Motosacoche, and winning a gold medal. Road conditions on the Isle of Man were atrocious, more resembling motocross than road racing to modern eyes, as the roads were mostly unpaved farm tracks, and the racing machines had almost no suspension, used narrow high-pressure tires, and had virtually no brakes.

After leaving Duzmo, Herbert LeVack made a real name for himself as one of a rare breed: designer/tuner/racer, who actually won. Here he is in 1921 being carried aloft at Brooklands after winning the 500-mile race on an Indian. [The Motor Cycle]
At the 1920 T.T., our man LeVack took number 69 on his Duzmo, while a second Duzmo was entered by N.C. Sclater (number 67), who actually rode a Norton in the race (more on this shortly). Le Vack had some fierce competition from his Sprint and Brooklands rivals such as George Dance (number 65, on a sidevalve Sunbeam), Tommy de la Haye (also on a SV Sunbeam) and F.W. ‘Freddie’ Dixon (number 52) on an Indian.

John Wallace on the second-generation Duzmo circa 1920, before he was quite ready to manufacture motorcycles. [Mortons Archive]
Press reports state Le Vack’s Duzmo arrived on the island via the Saturday morning boat, leaving little time to practice. Another report mentions Le Vack laboring over his machine since its arrival, working almost night and day, being rather handicapped by a lack of spare parts. Reading between the lines on these reports, it is possible Sclater’s Duzmo was sacrificed to keep LeVack’s machine alive, and might be why Sclater ultimately rode a Norton in the TT that year.

The 990cc V-twin Duzmo, made by doubling up the single-cylinder model. [Vintagent Archive]
The Senior race was held on Thursday, June 17th, in favorable conditions. Le Vack on the Duzmo had an excellent start, but on the second lap he had a bad skid at Governor’s Bridge and fell, bending his rear stand enough to rub the tyre; he was delayed eight minutes while he removed it and left it behind. He was reported passing through the grandstand on his third lap at speed, with his engine emitting a healthy bark. The fifth lap saw 16 competitors still in the race. Le Vack tried to overtake another rider near the Bungalow, when his quarry suddenly shot across his racing line, and Le Vack was brought off, damaging the Duzmo and forcing him to retire. The name of the fellow who supposedly cut off LeVack was never mentioned – was he forced into a ditch or did the Duzmo simply blow up? It was common practice for manufacturers to disguise mechanical calamity by blaming chains or magnetos or a spill. The race was won by Tommy de la Haye on a sidevalve Sunbeam.

The Duzmo decal used on the fuel tank and in advertising. [Vintagent Archive]
Herbert LeVack could see the writing on the wall at Duzmo, and had greater ambitions, so by early August the press announced that he had severed his connection with Duzmo, joining Freddy Dixon in the Indian camp. LeVack’s track career blossomed at Brooklands where he so regularly broke speed records, he became known as ‘The Wizard’, and by 1921 he had joined J.A.P. developing their racing engines for all customers.

The last-generation Duzmo single, with their own loop frame and curved gas tank. [Vintagent Archive]
Wallace soldiered on racing with himself as tuner/rider, with much less success than LeVack. In a move which foreshadowed the legendary Vincent tale of ‘doubling up’ his single cylinder machine, in 1922 Wallace created a new 992cc OHV V-twin for racing at Brooklands by adding another cylinder to his original OHV design. He also designed a new single-cylinder chassis that year, with a unique sloping petrol tank, and while it was an attractive machine, sales were poor, and Duzmo was finished by 1923.