This “Fruin Dartella” motorcycle raced in the Isle Of Man 50cc TT of 1962 and at many other UK circuits throughout the UK and Europe. The 49cc 6-speed (converted by Bert) foot change, highly modified DEMM Dick Dick engine also achieved a speed of 89mph when put through a speed trap. Bert also built 4 cylinder engines using the Demm barrels and heads (see Bert Fruin's page). The third image below shows Bert's Dartella before the three speed to 6 speed conversion.
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This is the Fruin Dartela two-stroke DEMM engine with a separate foot change gear box mounted behind the engine crankcase. This gave the engine a 6 speed capability and was used in conjunction with the twist grip change on the handlebar. You will notice that Bert fitted a rubber mounted head-steady to minimise vibration.
A watery wonder, the Pope Special, was one of the fastest machines in 1962. It was built by the Pope brothers but for some reason did not bring its rider, A. E. Dawson, the deserved renown though he put up some excellent performances.
The Pope Special was based on a Demm engine of the late 50s early 60s and similar to those previously mentioned. It was raced on many of the UK circuits and was a podium finisher. It also competed in the Isle of Man 50cc TTs with its rider A . E. Dawson. Due to the fragility of the DEMM the engine was changed through its life to the water-cooled ITOM unit that is now in the bike. The cooling works on the Thermo-Syphon approach as there is no pump fitted to the engine.
1960 DEMM 50cc Lusso Sports Special
This is a close replica of the DEMM Competizione Speciale produced in the 1950's. Air cooled, two stroke single cylinder, 49cc Capacity, 18mm Dell 'Orto carburettor fitted with vertical float bowl, 6v electronic ignition. 4 speed gearbox, telescopic front forks, 30mm stanchions.
These were built using both two and four-stroke engines mounted in both tubular and pressed metal frames. This model utilised the tubular frame.
The swinging arm is a twin shock with springs and dampers at 11" centres. Front wheel is made by Borrani and is a flanged alloy 200 x 18 x 36 hole. The rear wheel is a unit - 185 x 18 but manufactured by DID of Japan and is a alloy, non flanged 30 hole to fit the available hub. Front brake, single leading shoe drum - ventilated. Rear brake, single leading shoe drum. An interesting feature of the exhaust system is an expansion chamber with twin tail pipes. One would have to consider the dynamics of this design as to weather the interference of flow is detrimental to the performance of the engine.
The Wilier 48cc Sport / Super Sport 1962 - 1966
Wilier Triestina began in 1906 in Trieste, Italy as Ciclomeccanica Dal Molin. The shopkeeper and craftsman Pietro Dal Molin from Bassano was fascinated by bicycles and the speed with which they were gaining popularity in daily life. Newspapers focused on the sporting achievements of the first moustached cyclists in England, France and Italy, and Dal Molin decided to get involved in this adventure and opened a small workshop to manufacture bicycles.
He purchased an almost unknown English brand, Wilier, and established his first modest workshop in San Fortunato. Owning a Wilier became fashionable, requests started coming in from far and wide and the modest workshop was expanded and enhanced. Mass production made possible with an industrial facility, kept the costs of the bicycles down and in turn encouraged their progressive distribution. The picture on the left is of a Wilier pre. 1950 The model was called The TONI BEVILACQUA after one of their riders. | |
In 1948 Wilier Triestina was able to launch a broad range of bicycles on the market. Touring bikes for men, women and children as well as road and track models left the factory in via Colomba. Due to the more skilled and profuse production, coupled with the quality, Wilier found an important market in South America. Having found business premises in Buenos Aires, Dal Molin started advertising his products in Argentina, a nation with many inhabitants of Italian origin and where cycling seemed to be catching on much more quickly than in other countries of the American continent. | |
At the beginning of the 50’s, Wilier Triestina produced a scooter, to their own design, as that was the craze moving through Italy. It was well received but it did not join the cult of the "Scooter Boys" "Mods" of the late 50s-60s. The Lambretta and Vespa held these places. The Lambretta held the number 1 in the world. The rich Italian heritage gave birth to the two competing scooter brands that soon conquered the world with their classic designs, their quality, and their ability to attract young people. Wilier also manufactured motorcycles for other marques and assembled some models for the Parilla company. | |
Cargo to Argentina | The decline of Wilier Triestina came quickly. The episode mainly linked with the collapse of the company was an unexpected event that Dal Molin was not able to react to: the non-payment of a significant number of bicycles. A vast cargo of cases, of the Wilier bicycle, had been crammed on a merchant vessel heading for Argentina, similar to the ones that were building their reputation for speed and durability and also featured on the adverts and panels that Wilier showed off in fairs and on the company walls. However, all of the bicycles were never paid for and Wilier Triestina, already staggering, ended up on its knees |
In 1952 the Dal Molin family sold their ownership to MMM (Meccanica Moderna Milano), which decided to dedicate some departments of the factory in Bassano to assembling Parilla sports motorbikes. A bicycle production line was maintained at the same time.
The new Wilier was a company founded by Motocicli Wilier based in Trieste in the sixties, that produced a motorcycle model with a 48 cc engine. It is an Italian brand that from 1961 /62 made small two-stroke motorbikes/ Mopeds that were popular in Italy at the time. Production was ceased in about 1970. It used a badged DEMM two-stroke engine that had proved itself over a number of years and had an improved head and barrel from the earlier 3M model shown in the pictures below, this was the Wilier 48cc Sport.
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The frame, for both models was of a Wilier design. A change was made away from the DEMM engine and use was made of the Italian Franco Morini 50cc engine, a more up-to-date technology and eminently suitable for faster speeds. The group of three pictures below are of the Wilier 48cc Super Sport. You will note that the petrol tank design is based on the Parilla models that the company worked on previously.
1962 DEMM DICK DICK 49cc ITALIAN SPORTS ROADSTER
Again from the Italy factory this Lovely 1962 Moto DEMM (Milano) Dick Dick 49cc Sports Roadster A very rare model to see in the UK. You can see it's in lovely all round condition having been fully restored in the Silver/ Blue livery. The owner has kept the bike as near to factory specification as possible.
1971 DEMM 50 Super Sport HF
This model was launched out on the Italian market to demonstrate the sheer beauty of the company's 50cc sports moped. There is little information available on the model and so donations of information very welcome. This model was not actively marketed in the UK and this on was brought in direct from an owner in Italy. (Photographs from the internet through Auto Moto Classic Sales)
The DEMM Four Stroke Engines and Models
As I have previously mentioned Demm was actively involved in competitions, setting 24 world speed records in the 50cc class in 1956. The Museum of Motorcycles and Mopeds DEMM They display the Siluro streamliner that was used at Monza.
The cut outs in the bodywork next to the front wheel were for the rider’s legs so he could keep the bike upright when at rest. | In 1961 DEMM won the Italian 50cc championship with a DOHC single |
and winning the Italian Mountain Championship's 50cc category in 1961. The machine used to win that championship was a twin-overhead-camshaft four-stroke of advanced design.
Slightly over-square with dimensions of 40mm/39mm bore/stroke, the single-cylinder Demm's engine drove its upstairs camshafts via a vertical shaft and bevel gears and used an outside flywheel.
The carburettor was a 16mm Dell'Orto with separate rubber-mounted float chamber, while other noteworthy features included twin-plug battery/coil ignition, geared primary drive, a multi-plate dry clutch, and an integral six-speed gearbox.
This exquisite little power unit was carried in a duplex loop frame equipped with telescopic front fork and swinging-arm rear suspension, while the tyres were a skinny 2.00"x 18". Thus equipped, Demm's 50cc racer tipped the scales at only 55kg (121lb).
It was rumoured at the time that Demm would move up to the international stage for 1962, the first year of the 50cc World Championship, but the marque appears to have had little impact outside of its native Italy.
The Motorcycle (magazine)1961
Of course DEMM will compete again in the Italian events in 1962 and it is likely to 'Go Foreign' if all goes well. At present the single cylinder double overhead cam is considered the principle weapon for the 1962 season by the DEMM racing department.
A full gallery of Phil's work at the Museum can be seen at the following URL. | http://philaphoto.com/imageLibrary/thumbnails.php?album=255 |
A Gallery of Photographs for the DEMM Double Overhead Camshaft and Single Camshaft 50cc Racer and Engines.
1957 DEMM 175 PRODUCTION RACER
Prior to the DOHC engine the Company produced a OHC 175cc 'Over the Counter', single cylinder racer. There is little information available and I thank Hessink’s, founded in 1993 as VendueHuis Zwolle, was one of the leading auction houses in the Netherlands, for this inclusion in this story.
The general design of the racer was orthodox for the period and it carried a single cylinder OHC engine of 172.4cc capacity. It came came complete with a 'Slipper Style' fairing.
The Bore & stroke of 60 x 61 mm gave a long-stroke approach with a compression ratio of 7.0:1. This gave a maximum power output of 9 bpm [HP] @ 6,500 rpm. The power-to-weight ratio: 3.25.
the Cylinder was cast in a special iron and the cylinder head cast in aluminium. The cam drive shaft ran up through the barrel in an off-set manner to action the cams. The head was fitted with two withdrawable valve seats and guide sets. The cams operated through a single shaft which in turn actioned the overhead valves which are set off the vertical. The drive shaft to cam shaft link was effected through two pairs of ‘Gleason’ helical cut bevel gears.
The Ignition is satisfied through an automatic advance dynamo coil at 45 Watt, 6 Volts. There is one plug, Auto-Lite, off-set from centre in the head. The carburettor is a Dell'Orto SS1 with a remote float chamber. The cylinder is air cooled.
Lubrication is by an internal pump driven from the crankshaft and force feeds oil to the crankshaft and rocker system. The primary transmission is through helical cut shaved gearing with a final drive to the rear wheel by chain. The multi-plate Clutch runs wet discs in a 'chain-case' oil bath. This engine runs a 4-speed, foot-change gearbox.
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