Saturday, January 30, 2010
If you'd like to see your bike as Picture of the Week, submit a picture of you and your bike along with a description of the bike.
Friday, January 29, 2010
"This hand-made motor cycle was built by John Oliver who ran a motor car and motor cycle repair business in Melbourne. Oliver was born at Talbot in central Victoria in 1872 and served an apprenticeship to a wheelwright before becoming involved in the cycle business initially in New Zealand and then in Melbourne. In the early 1900s he established the Planet Cycle Works in High Street Kew. where he built bicycles using frames he brazed together himself. By 1909 the business had transformed into a motor car repair shop situated on the corner of High and Peel Streets, Kew. Oliver had previously built a number of motor cycles under the 'Planet' and 'Planet Aero' brand-names. John Oliver often referred to this one-off machine as 'The Big Bike'. It was built between 1913 and 1916.
Oliver's plans for this motor cycle were drawn up on brown paper after "arriving home one evening a little the worse for an afternoon at the local hostelery" according to his son Monty. John Oliver made the wooden pattern for the engine mouldings and castings were obtained from Chas Ruwolt's foundry in Victoria Street, Richmond and then machined on Oliver's own workshop lathe, including turning the cooling fins. The motor cycle has a large 1497 c.c. capacity V-twin cylinder engine and a single-speed transmission with a lever operated clutch. Originally it was capable of a top speed of 85 m.p.h (140 km/h). The original carburettor was a Zenith later replaced by a Schebler. The original wheels were replaced around 1938 with a pair of conventional second-hand motorcycle wheels. John Oliver died in 1949 and the Planet was left dismantled in storage. John Oliver's sons, Allen and John (Monty) Oliver decided to reassemble the machine around 1980. One replacement magneto was purchased and a non-original S.U carburettor was fitted at this time. After Allen's death, Monty Oliver donated the Planet to the Museum in 1987.
Wednesday, January 27, 2010
On eligible units, blockage of an oil passage in the engine might restrict oil flow to the cylinder head. This could result in the engine losing power and eventually stopping which could create the risk of a crash.
The number of units has not been announced.
Check out my Motorcycle Recalls feature for more details.
Yamaha Motor (UK) Ltd have today released this image of the eagerly anticpated Yamaha FZ8, their new sport roadster.
Tuesday, January 26, 2010
The 'story within a story' at the Grande Peugeot Display at Rétromobile was the assembly of rare, historic racing machines, and a few of their equally rare riders! Bernard Salvat (where is your Wikipedia entry, monsieur?) did not bring together a typical 'old bike' hodgepodge show of Club machines from the local collectors; he curated a museum-worthy Exhibition which told the story of Peugeot from the dawn of the 20th Century to the present day, and yes, for our Yank readers, Peugeot has been in continuous production since 1898, which I believe makes it the oldest motorcycle manufacturer in the World? No?
Unfortunately for us English speakers, there is very little published information extant about the marque in our tongue; Salvat's magnum opus 'Motos Peugeot' ('1898-1998, 100 ans d'histoire', written with Didier Ganneau, EBS, 1998), remains untranslated, and the prospects are grim as Peugeot hasn't sold a car or motorbike in the US for decades. So, I muddle through with my horrible French (sad, given my surname; my Gallic pals chide me no end), but like the readers of this website, I enjoy the photos thoroughly!
These top images depict a 1914 racer with the oversize 'Peugeot' logo in white, as mentioned in my previous post; this is a rare survivor of a one-year production race machine. Whether a test example or prototype or blind alley, the little 500cc Sidevalve v-twin represented the current thinking of the world's racing fraternity; the reliability and efficiency of a Sidevalve motor was a way to win races, and 'F-head' or troublesome 'OHV' machines had technical problems in 1914 which the SV did not.
This machine was saved from oblivion by a canny collector, who recognized the very large engine pulley, special cylinders, and twin-barrel Claudel carburetor as a clues to a very rare racer. It shares the cycle gear with the famous 'Paris-Nice' model, which include the clever leading-link front forks. While this 500cc twin may have represented 'state of the art' racing technology of 1914, as compared with the rest of the world, Peugeot had far greater ambitions, and dropped this racer after only a few events, in favor of their truly astounding Double Overhead Cam, 8-Valve parallel twins! (below)
The facts on the ground in 1914. In the race for the most technically advanced motorcycle on the planet, Indian led the pack, first away with their '8-Valve' racing twin in 1912, which by 1914 had become a well-established world beater. In 1914, the Cyclone appeared with their astounding Overhead Camshaft v-twin engine, truly the stuff of legends, as was the Indian. But of course, it was Peugeot in 1914 who trumped them both, by creating the first twin-cylinder Double Overhead Camshaft engine, the '500 M' parallel twin of 500cc, a technical tour de force which placed Peugeot as creators of the Most Advanced Motorcycle in the World for many years, until the Italians doubled the formula in 1928 with their O.P.R.A. 4-cylinder DOHC design (which became the infamous Gilera 4 cyl. racers). And even this amazing machine of '28 had only two valves per cylinder!
Some history, as this machine didn't appear out of thin air. Ernest Henry studied engineering at the Technion in Geneva, and by 1906 was developing marine engines. Moving to Paris in 1901, he worked on both marine and aviation engines until 1911, when he joined Peugeot, to create their four-cylinder car engines 'L3' (3 liters) and 'L76' (7.6 liters), used in their successful racing cars from 1912, which totally dominated GP racing that year (winning the GP de France, Mont Ventoux, GP de l'ACF - Automobile Club de France, etc). The engines Henry designed weren't the first '4-Valves per Cylinder' design, nor were they the first 'Double Overhead Camshaft' engine, but they were the first engine in the world to have all the above. To cap it all, the 'L76' had Desmodromic valve operation! Decades ahead of the competition.
In 1913, Henry changed his camshaft drive from 'Shaft and Bevel' to 'Train of Gears', and these cars continued their winning streak at the Indianapolis 500, the GPs of France, and at Brooklands. Our M 500 racing machine is a miniature version of this type of engine, halved to produce a parallel twin, using a train of gears between the cylinders, with a mechanical oil pump driven by the camshaft. Transmission was 'chain cum belt'; chain primary drive with clutch, but a single-speed gearbox with belt drive to the rear wheel.
The M 500 was first raced at the Circuit de Rambouillet on April 5th 1914, on muddy roads, which factory rider Desvaux won, the only 500cc rider to finish the race! On June 14th, Paul Pean, a factory mechanic who raced their cars since 1907, entered the machine for a 'Records Day' organized by the A.C.F., in the forest of Fontainebleau, which had a long straightaway along the county line. Pean broke two World Records in the 500cc class that day, 122.449km/h (73.47mph) for the Kilo, and 121.205km/h for the Mile. Then, the War...and Ernest Henry left Peugeot in 1915.
Post War, the dohc 500 survived and was raced again by Desvaux, with some success. In 1920, a 3-speed gearbox was added by engineer Marcel Grémillon, but the setup proved troublesome, as did maintenance on the engine, due to the gear train between the cylinders - the engine had to be totally stripped down to do even minor running repairs. So in 1920, Grémillon drew up a revised engine, with new crankcases and the gear train up the side of the engine, keeping the DOHC and 8-Valves. This meant the end of the 'Henry' 500 M, and the original machine disappeared, and has never been seen again.
The machine in these photographs is a faithful reproduction of Henry's machine, which has been eleven years in the making, using the original blueprints.
Keep in mind also, that the very first Isle of Man TT winning Norton used a Peugeot engine! See my previous post on the subject.
Many thanks to Bernard Salvat for his research into these amazing motorcycles!
Kawasaki's 2010 updated 1400GTR and the much anticpated radical Japanese streetfighter style Z1000 will be in UK Kawasaki dealers in the next few weeks.
With a host of upgrades, the 1400GTR gets traction control, linked brakes and a special selectable fuel economy mode, heated handlebar grips and an electronically adjustable screen with a memory function.
Saturday, January 23, 2010
While Retromobile is the largest vintage automobile show in France, they have provided increasingly high profile space to a vintage motorcycle display, curated by esteemed French motorcycle historian Bernard Salvat, author of 'Les Motos Français; Cent ans d'histoire' (1999, E/P/A), 'Motos Peugeot' (1998, EBS), 'Side-Cars; Cent ans d'histoire' (1996, E/P/A), etc. For 2010, Salvat has assembled a full barrage of Peugeot motorcycle history, from 1902 - 2010, 'Toutes les Motos Peugeot' from the earliest road and race machines of the 'Noughts, 'Teens and 'Twenties, to their postwar lightweight race and roadsters. Many unique and historic machines rubbed shoulders for the first time ever in one location - quite an historic achievement, and yes, I wish I was there!
One of the most remarkable machines on display is this replica of the Peugeot Double Overhead Camshaft 494cc parallel twin racer from 1921. A tantalizing photo of this machine sits nestled in The Best Book in the World, 'The Vintage Years at Brooklands' (Dr. Joe Bayley, Goose, '68). An astounding technical tour de force from an incredibly early date, when a machine like the Duzmo, with overhead valves and an oil pump, was Advanced! What must have the Brooklands clubmen have thought when presented with a machine fully fifteen years ahead of its time, like an echo of the future? More on this machine in a later post!
Earliest of the two-wheelers on display was this 1902 'Motobicyclette', introduced at the Salon de Paris in 1901. This was Peugeot's first powered bicycle, after building Tricars and Quadricycles (see the rear of this photo) since 1898. While this machine is a true 'motorcycle', Werner's trademark on the term, filed in April 1898, had been approved just two months prior to this machine's début. While Peugeot had built all the mechanicals of their previous multi-wheelers, for their first motorcycle they chose a Swiss 'ZL' motor, made by Zürcher and Lüthi in Neuchatel. The capacity was 198cc, and used an automatic inlet valve and 'wick' carburetor. The chassis layout with the engine low and central in the frame is per the Werner patent, although soon every motorcycle maker used this solution to 'where to put the engine'. Very few survive.
Another early machine, this time a Racer, and an extremely rare machine, raced for only one year before WW1 stopped everything for four years. This machine appears in the Peugeot catalog of 1915, distinguished by the oversize white lettering adorning the petrol tank, and has a unique configuration; 500cc sidevalve, with twin Claudel carburetors. This machine may have taken part in only one race, at the Circuit de l'Eure in May 1914. The model was quickly abandoned for racing, as the 'Eight Valve', Double-Overhead Camshaft machines took its place!
This 1914 'Paris-Nice' 350cc V-Twin was the backbone of Peugeot's road trial and production before WW1. The quality of engineering and construction is impeccable - and while this motorcycle looks restored, it is in fact in original condition! How do I know? I was offered this very machine 8 years ago... and turned it down! Do I regret it? No need to answer. Almost 5000 examples of the 'Paris-Nice' were sold. Some technical details; 45 degree v-twin, sidevalve, Bosch magneto, Claudel carb, belt drive with options of a clutch and 3-speed Armstrong epicyclic rear hub, weight 45kg, with a 65km/h top speed.
Skipping ahead in time, we find this 1934 'Model 515' racer, which has a remarkable history. On Friday October 5th, at 8:36am, four riders (Marcel and Robert Pahin, Camille Naarcy, Pedro Verchére) attacked the 500cc 24-Hour World Record, established the year prior by rival Jonghe on a 350cc machine. The machine is a stripped road bike, which had first and third gears removed, and stronger forks fitted to cope with the dreaded bumps of the concrete surface of the Montlhéry speed bowl. The large tank held almost 20 liters, but began to leak after 6 hours of pounding - it was replaced by the tank of Pedro Verchére's personal road bike, also a Model 515! Unfortunately, this meant twice as many fuel stops.
At night, the track was illuminated by hurricane lamps on the banking, and the temperature dropped to 7deg C, followed by a driving rain. The rear wheel had to be replaced after so many hours of hammering, but this was the only mechanical fault of the machine. The attempt went so well, that after establishing their 24-Hour Record at an average of 118.74 km/h (71.4mph), it was decided to carry on for the 3000km record as well! This was achieved at the same speed as the 24Hr record. To put this achievement in perspective, it is the same average speed as the Bol d'Or 24-Hr. race... on a Kawasaki in 1974!
Sharing the 515 engine used for the 24-Hour machine was this lovely 1935 Art Deco-inspired roadster, the flagship model of their line and widely used Clubman's competition machine. Road-racing, Enduros, Trials, were all meat and drink to this machine, the French Gold Star of its day. And oh so elegant; by the 1930s, French motorcycle designers had mastered fluid and graceful lines, and their best machines are simply stunning.
Next: More Racers!
Friday, January 22, 2010
Today Harley-Davidson UK announced the release of the new Harley-Davidson Forty-Eight motorcycle. In Harley's words "a new factory custom in the legendary tradition of the hot rod Sportster line with the raw, elemental appeal of a Custom".
The Forty-Eight is available in Vivid Black, Brilliant Silver and Mirage Orange Pearl colours.
Forty-Eight features and highlights:
Blacked and polished rubber-mounted Evolution 1200 cc V-Twin engine with chrome accents
Electronic Sequential Port Fuel Injection (ESPFI)
Steel 2.1-gallon (7.95 litre) peanut fuel tank with lightening hole mounting bracket
One-piece, solo Sportster classic seat
710mm seat height
Fat balloon tyres
16-inch Black Steel Laced wheels
Low profile custom handlebar
Under-bar mounted mirrors
New front forks with wide triple clamps
Chopped front fender mounted on fork brace with lightening holes
Fork brace mounted chopped front fender
Blacked components including air cleaner cover, clutch and brake levers and turn signals
Chopped rear fender
Two-year factory warranty
Harley-Davidson Smart Security System
All we know is it looks darn hot!!!
Around 1958, he insinuated himself into a totally different 'scene' of young rebels and bikers, who squirmed under the thumb of Conformity, and grasped at the crack in the universe which was Elvis Presley, James Dean, rock music, and motorcycles... just like kids in the rest of the world! These youngsters (dubbed 'Halbstark' - half-strong - by Swiss media) grew a flamboyant style, which veered away from an already hardening 'rebel' dress code of blue jeans, t-shirts, and boots. They wore belt buckles the size of hubcaps, with crudely chased images of skulls, Elvis, or just studs, and favored oversize artillery shells, animal skins, and horseshoes as necklaces. They wore cowboy boots with heels rather than engineer's boots. Better still, they tore out the zippers of their blue jeans and replaced them with bolts, chains, or barbed wire!
They shaped a fiercely independent identity and close-knit culture in relative isolation, away from the prying eyes of the international press...after all, how many Swiss rock bands 'broke out' in 1958? The members of these Zurich gangs were 'Nowhere', they knew it, and they made their own life raft.
By the mid-1960s, the Swiss media began to take note of this homegrown oddity, and Karlheinz Weinberger's photographs of the gangs were published for the first time. He carried on, embedded with his friends, documenting their dissolution as the 60s wore into the 70s, and the period's corrosive elements began to take their toll.
In the last 7 years of his life, Weinberger became the subject of much attention and acclaim, and in 1999 a book was published about his work - 'Karlheinz Weinberger' (Andrea Zust Verlag, Binder/Meyer/Jaegi authors); it's now a collector's item, selling for nearly a thousand dollars per copy. He had numerous exhibitions around the world, and his photographs adorn the walls of major museums. Born in 1921, living in obscurity, he died in 2006, a famous artist.
During the 1950s and early 60s, other pioneering artists working with motorcycle gangs as subject matter (Danny Lyon, Kenneth Anger - see my earlier post, etc) knew nothing about each other, but they each produced rich and fascinating bodies of work with very similar themes. Let's call it the Zeitgeist of the 50s, which led these photographers and filmmakers into some interesting territory. A branch of Motorcycling was evolving rapidly, which was self-consciously 'antisocial', and celebrated imagery which was highly charged, threatening, or just plain offensive, mining subterranean or anxiously avoided cultural turf (homoeroticism, fascist symbols, sadomasochistic hardware, blasphemous language). Motorcycles, symbolizing independence, fearlessness, and fun, became the perfect accessory for individuals who just didn't jibe with how they were 'supposed to be', as the rest of society (mostly, their parents!) desperately grasped for a period of normalcy after the horrors of global War and the threat of nuclear annihilation.
While the numbers of 'rebels on motorcycles' were relatively small in the US, Britain, and Europe, their powerful imagery stained the public's perception of Motorcycling for decades. Films about motorcycles during the 50s through 70s almost always featured violent gangs of ignorant thugs, with a few bright exceptions like 'On Any Sunday'. It took the concerted efforts of Soichiro Honda and his advertising team to shine a light back on Motorcycling as a fun pastime, allowing just regular folks to approach 'two wheels' without stigma for the first time since the 1930s.
But damn, those thugs looked cool.
Thursday, January 21, 2010
At the tender age of 14, P.J. 'John' Wallace had an epiphany at a motorcycle exhibition, and decided to build a motorcycle. He bought a set un-machined engine castings for £2 10s, and proceeded to equip a workshop in his father’s garden, teaching himself to use a few simple machine tools. He soon realized the finish work required of the castings was beyond his equipment and his ability. So he bought a frame and wheels from a local cycle maker, plus a secondhand engine, and built his motorcycle, which he promptly sold.
In 1912 (age 16), John landed an apprenticeship with Collier & Sons, of Matchless fame. After an accident at the factory, John’s father put a stop to his employment with the Collier’s. The pill was sweetened by his father buying him and his brother a pair of T.T. Rudges (see below). They both swiftly joined the British Motor Cycle Racing Club (B.M.C.R.C., or 'Bemsee') and took to racing at Brooklands. However, things did not go as planned (ah, racing!) and soon John's crashed his Rudge, which was damaged beyond repair.
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. (Also employed thus was one Herbert LeVack, about whom more later.) When J.A.P. 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.
Late in 1918 Wallace returned to his first love, and laid out 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.
Herbert LeVack (above) 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 & 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.
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.
Ever looking forward, in 1920 Wallace (on the right, above) 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. ... he was no stranger to the T.T., having raced there in 1914 (the last T.T. before WW1) finishing in 15th place at 45 MPH on a Motosacoche, winning a gold medal. Road conditions in the race were atrocious, more resembling motocross than road racing to modern eyes, on machines with almost no suspension, narrow high-pressure tires, and virtually no brakes.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 race (more on this shortly). Le Vack had some fierce competition from his Sprint and Brooklands rivals such as George Dance (number 65, Sunbeam), Tommy de la Haye (also SV Sunbeam) and F.W. 'Freddie' Dixon (number 52) on an Indian.
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 the lack of spare parts. Reading between the lines on these reports, it is possible Sclater’s Duzmo was sacrificed to keep Le Vacks machine alive, and might be why Sclater ultimately rode a Norton (below) in the T.T. that year.
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 side valve Sunbeam.
Herbert LeVack had greater ambitions, and by early August the press announced that he had severed his connection with Duzmo, joining Freddy Dixon in the Indian camp, and his track career blossomed at Brooklands where he so regularly broke speed records, he became known as 'The Wizard'.
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, a new 992cc ohv v-twin was built for racing at Brooklands in 1922, by adding another cylinder to his original design. He also penned a new single-cylinder chassis design in 1922, with a unique sloping petrol tank, and while an attractive machine, sales were poor, and the Duzmo was finished by 1923.
Tim Walker bought his Duzmo from a friend who had saved it from the scrap yard in the late 1960s; it came with an early Triumph; the friend bought the pair not knowing what the Duzmo was - above is the Duzmo on the trailer just after he got it home. The crankcases were smashed around the timing gears, as a broken cam follower pivot had wreaked havoc. There were 2 tax discs in the holder, last dated 1928, both issued in Cornwall. It looked to have had a hard life but was basically intact, sadly missing the 2 external mechanical oil pumps that feed and return the oil to a tank beneath the saddle. Clearly, the bike had been ridden using only the hand auxiliary oil pump fitted on the side of the oil tank. Both bronze-bodied external pumps had been sawn off, the plunger holes plugged and soldered up. Tim was lucky, as the remains of the pumps indicated the diameters of the original plungers, so he was able to reproduce them.
The forks are Druid MK 2s, which move up and down normally, but include a limited movement backwards and forwards through a complicated link, which alter the wheel base slightly. Gearbox is a close-ratio Sturmey-Archer 'CS' type with a Sturmey single-spring clutch. Carburetor is large bore Amac, and the magneto is an ML. The front brake is a Bowden scissor action lever on a dummy rim, which actually works, but only in the dry. The rear brake uses a V band attached to the spokes. The frame still has a casting to mount a second rear brake, to press the other side of the dummy rim. LeVack raced his Duzmo with both rear brakes fitted, but no front brake of any type. The back hub is an early Enfield type with a cush drive fitted. Only the saddle was missing from my bike.
The prior owner did a cosmetic restoration but never ran the Duzmo due to the crankcase damage. Tim Walker repaired the crankcases for him, but advised his friend not to ride the Duzmo until new crankcases were made. He did some research, but never found another Duzmo, only old Motorcycling reports and drawings of the new oil system from 1919 reports. The engine is the same over-square OHV with 88.9mm bore x 79mm stroke, with fully re-circling oil system - just as LeVack used.
With today's eyes, the Duzmo has quite a few design faults; weak valve gear and pivots , very soft valve springs which allow valve float at around 3500 rpm, although there are loads of power below this range. With the over-square engine, it would seem Wallace designed it to rev higher than 3500 rpm, but the design fault is in the timing chest; stronger valve springs would enable it to rev more but would load up the cam gear and lead to disaster, which must have happened to Tim's bike in 1928.
Still, the Duzmo was technically far ahead of the competition in 1919/20, and it is no surprise to find such a modest enterprise as the Duzmo had teething troubles which were never addressed, as the baby never got old enough to have teeth!
Many thanks to Nick Harrison at Duzmo.co.uk for his research and photographs!