50cc Racing History from 1953 through to 1983 - JEEP (AKA  J. E. Elton-Payne) 
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TOMOS

From a Licenced Moped Assembly Line to a World Beater. 


The Origins of Tomos:  Until the outbreak of the Second World War, nearly all industry in the Primorska (Littoral) region was concentrated within the  industrial centres of Trieste, Monfalcone and Gorizia, providing  employment to the inhabitants of the region.

Following the end of hostilities, the long and apparently intractable problems over the borderline between Italy and Yugoslavia effectively cut the population of the neighbouring Karst region off from the industrial heartland. Many factory workers finding themselves on the wrong side of the border lost their jobs, and the rural population lost the principal market for the sale of their crops. 

In order to create new employment opportunities, the Karst region secured the gradual establishment of new factories in the textile, wood-processing and electronic industries, and there were also favourable conditions for metal processing. An investment plan for a motorcycle factory was subsequently prepared by Mr Franc Pecar, Director of Litostroi (a heavy engineering company), based in Ljubljana, and on 16th July 1954 the Seiana District Peoples Committee (DPC) announced the decision to establish a new motorcycle factory in Sezana.       

ln an announcement dated 27th July 1954, the title TOMOS -an acronym of the full title T0varna M0tornih koles Seiana [Motorcycle Factory Seiana] appeared for the first time.  However, when the London Memorandum was signed on 5th October 1954 it provided the final answer over the line of of demarcation for the Italo-Yugoslav border, and as a consequence, the destiny of what had been known as ‘Zone B of the Free Territory of Trieste. Trieste was now in Italy. 

The new Slovenian government now decided to build the motorcycle plant in Koper and not Seiana. Koper was rapidly developing into another industrial centre in this part of the littoral region and needed new commercial facilities to provide employment for the local population on the coast and the immediate Karst hinterland as many of whom had previously worked in neighbouring Trieste, which was now across in Italy, had become unemployed.  Picture: The first, temporary assembly plant in the second half of 1950's (TMS photo collection).

In the early 1960's, Tomas had around 2,000 employees from Koper and the area around it, under the influence of its control. The company acquired, for its own use, the services of a local bus fleet for transporting workers. A year later, they offered their personnel favourable loans to purchase Colibris for their transport (TMS photo collection].

Bus fleet for transporting workers

A Loan to buy a Tomos - Puch VS50 (Colibri),

At the time, views on the feasibility of an assembly plant for motorcycle production in the region were divided. The idea of a new factory met with some resistance. Many argued that the population's purchasing power was still too low to buy large quantities of motorcycles units. However, a rapid boom in motor vehicle ownership over the following years proved the decision to be correct.  

In their first brochures and advertising campaigns the company pointed out the characteristics of Puch, and the Scooter market and even before the foundation of the new factory had been laid, its representatives discussed collaborating with motorcycle manufacturers in Italy, Germany and Austria. A contract with Steyr-Daimler-Puch was duly signed by Franc Pecar, the first director of Tomos. The selection of a suitable licence partner was influenced by several factors. The first was that Tomos was not bound to strict cash payments but only by the quantities of motorcycles and components purchased from their Austrian partners. 



Another reason in favour of the Graz-based company was probably the fact that Puch motorcycles were economical and robust, being designed for the badly maintained roads [with steep gradients] then common in Austria. In addition, Steyr-Daimler-Puch also exported its motorcycles to some very demanding markets, such as the United States of America. 

It has also been claimed that Puch offered Tomos very favourable licence conditions because the Austrian company doubted that Tomos would ever become a successful independent business and have their own motorcycles.

More than 100 motorcycles are loaded on a truck destined to supply the Yugoslav and European markets. (TMS photo collection).  

The Yugoslav President Josip Broz Tito who officially inaugurated the new Tomas plant often brouht foreign statesmen to Koper (TMS photo collection)

At the beginning, temporary production lines and workshops were set up within the former Slavica trading company buildings in Koper.

 



Production commenced on site in 1955; the first vehicle assembled was a Puch SG 250cc motorcycle and in that year the company manufactured a total of 137 of these, together with 124 RL 125cc scooters and 100 50cc mopeds. 

 

From the beginning Tomos was licensed, by the Austrian PUCH Company, to build the PUCH MS50 moped, developed in 1954, and also motorbike versions. For most of their early days they concentrated on the 50cc bikes and mopeds working towards designing and building their own range of models. The model on the left was manufactured two years later and is the 1957 Tomos Colibri VS50K, much of its Puch heritage can be seen in this model. 

The following year, when the product range had expanded to include the SV175 motorcycle, production of mopeds was outstripping all other products, with 1721 units assembled, alongside 615 motorcycles (of which 147 were the SV175s) and 532 scooters. From this year on, the ratio in favour of mopeds constantly increased. 

This mirrored what was happening across all European markets, where the demand for heavier motorcycles decreased whereas the demand for cheaper scooters and mopeds was on a constant increase. Taking note of this new market situation, Tomos modified its product range and doubled the planned annual production of mopeds. Although the manufacture of motorcycles and scooters continued, the idea of having their own in-house research and development department was abandoned.

They also wanted to complete their product range by introducing delivery tricycles with a loading capacity between 350-500kg. Puch however, were not making such vehicles and so Tomos considered looking for another licence partner. This situation was also aggravated by other problems within their existing partnership. The problems were that Puch components were acquired through the services of Autocommerce, which was Puch's official representative in Yugoslavia. However, one of the problematic supply issues surrounding this arrangement was that foreign currency assets could only be acquired using the foreign currency reserves of the National Bank of Yugoslavia, but these were not sufficient to meet the rapidly increasing demand.

Tomos searched for solutions to the  problem, including making compensation transactions (the so-called  “import for export") being actively promoted by the National Bank. In order to import all the components they needed in 1956, for example, the company was exporting amongst other things, wood from the Poplar tree, wine, resin, tar and alumina! Tomos was also not satisfied with the attitude of is license partner due to the fact that Puch allegedly demanded advanced payments, whilst their shipments out to them were sometimes deficient. 

In 1956 their relations became so aggravated that Tomos intended to terminate the contract. In searching of a new partner they contacted the Czech motorcycle manufacturer Jawa, but they eventually abandoned the idea of a new partner and decided to repair relations with Puch. 

With production underway in Koper, the need for new and bespoke factory buildings was pressing. It was originally planned that the new factory would be completed in 1957, but the funds for its construction were delayed. The Federal Executive Council (the executive body of Yugoslavia) which initially approved these funds, 'Cooled' in their support for the project and only after further discussions did they reach agreement to extend the construction period to 1959. The factory was officially inaugurated on 14th June 1959 by the President of Yugoslavia, Josip Broz Tito.

During its initial trial operation in 1959, they had to master new production technologies using machinery and equipment that anticipated the manufacture of heavier motorcycles and which posed new problems that needed to be overcome. However, Tomos was now effectively a new and fully-fledged company, and as such, was constituted in the first half of 1960 allowing  a workers council to be elected. The company was entered in the Companies Register on 1st July 1960, and production could now commence. Picture: Assembly of Colibri mopeds in he 60s. On the right at the back are the Herkul tricycles. (TMS Photo Collection) Sorry for the poor quality. 

A contract with Steyr-Daimler-Puch dating from 1954 shows that the factory's product range originally included the MS50 moped, the RL125 scooter and the 250SG and 250SGS motorcycles". In 1956 the range was completed with the introduction of the SV175 motorcycle. The RL125 was later replaced with the better performing SR and SRA150 models. The latter was also fitted with an electric starter. 

In their search for a delivery tricycle Tomos finally chose the Italian motorcycle manufacturer Moto Guzzi as licence partner for the production of delivery tricycles.  In 1956 they started to assemble a tricycle model called Herkul (Hercules) that was aimed particularly at farmers who needed an affordable vehicle for the transport of their products and crops. They were manufactured until 1961 in two versions: with or without a cabin, and with an open or closed cargo space. Their engine was a 192cc two-stroke with four gears. Picture: From a Moto Guzzi advertisement. Tomos made small adjustments.

Still wanting to provide a delivery vehicle within their product range TOMOS, in 1976 designed and manufactured a tricycle using the concept of the Colibri design. This had the carrier box to the front and was steered using a rack and pinion steering system to the front wheels. This model was called the Tomos Tricikel and was powered by the 1976 T15 engine. The frame was an adaption of the moped unit. As you will see from the picture that this engine was the 49cc two-stroke unit developing 2.4bhp@5000rpm with a 4 speed gearbox. It was capable of 25 miles per hour and weighed 220lbs.

During this period, a total of 310 units were assembled and one of them is stored in a depot of the Technical Museum of Slovenia.  Their own market research findings seemed to prove that the demand for heavier motorcycles in Europe was on the decrease, and accordingly they adapted their range of products and oriented production exclusively towards vehicles with two-stroke engines with a capacity of 50cc. Some other products - the most significant being cars and chainsaws - were however assembled on the basis of co-operative agreements with foreign partners. Picture: Tomos motorcycles were also used by the police (TMS photo collection).

Tomos only ever attempted to develop four-stroke engines for stationary use. In 1977, the Tomos Institute tested a single-cylinder four-stroke engine, the UMO 50 with a capacity of 500cc that was intended for agricultural machinery and generators". Small four-stroke stationary engines were eventually launched on to the market in the form of the UMO 41 and these were the fruit of  co-operation with the Italian company ACME.

Outboard engines  

The first outboard engine they manufactured was also based around the Puch MS50 moped engine. Beginning in 1958, the company manufactured three units and mass production started two years later. The adapted upper part of a Colibri fuel tank served as the casing of the first mass-produced outboard engines. As with the stationary engines, Tomos also increased the engine capacity to 60cc because they were not subject to any legal provision as to the volume restrictions. 

The first generation of mass-produced outboard engines the Lamo 05K followed by the Lamo 06K were manufactured by 1964. Some were also exported to the Western European market. In 1965, the Lamo 06K was replaced by a new model (Lamo 06N), a prototype of which was made in 1963. It had a new engine with the possibility of left and right direction of rotation (due to the requirements of stationary engines). It was also visually different from its predecessor because it was protected against water at the bottom; the aluminium casing was covered by an angular engine cover made of plastic and the fuel tank was separated from the engine. Picture: The popular Colibri moped (on the left) provided the Lamo outboard engine, which was one of the first in-house products, with both the engine and upper part of the fuel tank (TMS photo collection, Tomos).

Moped and motorcycle development 

The primary products of Tomos were motorcycles and mopeds, accounting for a total of 52 percent of their entire production until 1997. A moped is defined as a type of light motorcycle designed to provide economical and relatively safe transport with minimal licensing requirements. Mopeds were once all equipped with bicycle like pedals (the source of the term, motor + pedal) and so the term would perhaps be better suited to a bicycle with an auxiliary motor. However, the term moped has been increasingly applied to all motorcycles with an engine capacity up to 50cc and regardless of whether they are started by pedals or a kick-starter. In 1957, the price of the Colibri 03 moped in Slovenia amounted to approximately 10 average monthly wages. Very few people could afford to purchase one outright.

Tomos commenced development of their own (TOMOS branded) in-house designed mopeds in the late 1950’s with the production of numerous models based on the Puch MS 50, collectively referred to as the Colibri. The first Colibri was the VS 50 which over the following years saw variations numbered from 1 to 13 according to the differing accessories fitted. Some versions were intended for foreign markets and adapted to the regulations of the import countries. In 1959, they manufactured over 17,000 such models and signed a contract for the first significant export to Sweden (1,750 units). Picture: Tomos advertising brochures clearly showing the market they were aiming at in the early 1960’s (TMS photo collection).

This period also saw the creation of the first racing model. This machine was also based on the Puch MS50, and it did well in races at home and abroad.  The most successful of these many models was the Colibri T12, first shown at the Belgrade Engineering Fair in 1961. It became the most popular moped in the country during the 1960’s. In 1966, Tomos manufactured 31,950 T12’s which accounted for 70.2% of total moped production by the company and 66% of the total production of motorcycles and mopeds in the whole of Yugoslavia. Although these mopeds can be considered the company’s own product after 1959, they still used a lot of imported components supplied by their former licence partner, PUCH, and other manufacturers.

In the mid-1960’s, Tomos struggled to meet the demand from the domestic market. Generally, mopeds were purchased by those on low to average wages, with wealthier individuals being more interested in cars. A moped allowed people who lived in rural areas with poorly developed public transport to reach employment some distance from their place of residence. A moped was also the most suitable motor vehicle to drive along local or narrow access roads and along forest roads in both low and highland areas. As a result, mopeds were used to run everyday errands by farmers, foresters, postmen, hunters, and many others. Picture: (Tomos Colibri T12 - MUSEUM ŽERAVICA)

Due to the inherited design of the frame, fuel tank, seat and leg-shield, the Colibri T14-V looked  very much like its predecessor, the T12. In addition to a new engine, the more attentive observer could however spot new front forks with a headlight, new wheels, a new design of front mudguard and a modified chain guard.  Picture: The model Colibri T14 (at the front) did not achieve the popularity of its predecessor, the Colibri T 12 (at the rear) (TMS photo collection). 

 People who had bought a moped as their first vehicle usually still retained it, even after buying a car to use as an additional means of transport. Those who bought a car in the first place also found the moped useful as an alternate means of transport, as did the urban population, and these users often went for lighter and more agile cycles with auxiliary motors (the Automatic family). Fitted with a luggage carrier or a basket they were more suitable for daily shopping and a ride in a city centre. 

The highest performance mass-produced Tomos motorcycles with an engine capacity of 50cc were from the T15 range. When it comes to engine capability, these machines were only just behind the Cross 50 Junior, which was primarily intended for motocross competitions, although it was also accessorized for road use. The designer was Janez Imperl, who was also responsible for the development of their racing motorcycles. Picture: Tomos 1978 Cross 50cc Junior (Sheldon's Emu)

The engine of the Cross 50 Junior is an even better illustration of the advancement of their 50cc capacity engines. It is based around the engine of the new generation models, with an output of 7.5bhp at 7500 rpm and with the same bore and stroke. Tomos achieved this through a modification of the timing, the opening and closing periods of the ports and a larger main jet on the carburettor. 

The output of the successor to the Junior, the Cross 50 Senior, was 10.6bhp at 9800 rpm, though it should be noted that the Senior was exclusively a competition bike. The gearbox of the Cross 50 Junior was also slightly modified. According to the factory data, its maximum speed was about 50mph and the steepest gradient it could tackle was 80%. By replacing the sprockets, the user could adapt it for off-road or road racing, where, with the proper combination of sprockets, they could achieve a maximum speed of 68 to 70 mph.


Tomos and Motorcycle Road Racing

TOMOS DMGP Record Breaking 126.76mph-1979 

In over 100 years of history, motorcycle racing has proved to be one of the best opportunities for the promotion of the quality and performance of a machine. During races, manufacturers test new and more advanced technical solutions and designs under the most extreme conditions, and the experience gained is often usefully applied to their mass-produced models.

In the late 1950’s, Tomos helped pave the way for 50cc capacity motorcycles to achieve success in the world of motor sport. With their racing machines winning several National and International competitions.  Thanks to their victories in these road races during the transition into the 1960’s, this previously unknown motorcycle manufacturer was soon a familiar name in Europe, and soon Worldwide. 

The need for speed and the will to compete had been with the Tomos factory since its very beginning and its lessons and racing experiences have been put back into the production of its other motorcycle models to very good effect. Racing competitions, from physical to mechanical, have been run in Yugoslavia and other countries that were termed “Behind The Iron Curtain” for more than a century and these latter, motor driven trials of prowess, were Tomos' best opportunity for the promotion of quality and durability of its two-wheelers. Tomos started with its racing activity as early as the late fifties and recorded its best international achievements in the motorcycling sport with its 50cc racing motorcycles.

Puch 250cc SGSS model

The Tomos company called this period “The glorious beginnings”, and started it with a race prepared Puch 250cc SGSS model. In 1956, Tomos set up a racing team which participated in the International competitions in Leningrad and won in the 125cc and 250 cc classes: this was in its very first year of racing. In 1961 and 1962 this team also won, with their Puch 250 SGSS motorcycles, the Yugoslavian motorcycle races in the class up to 250 cc. It was during this time that Tomos was already focusing on the races featuring motorcycles under 50cc. 

1956 PUCH 250cc SGSS split single at the Zolder GP in 1986, not from the Tomos stable, but used to good effect in the East European races.

During the development of its lighter racing bikes Tomos sponsored the introduction of a special category of motorcycles, not previously seen namely the 'Up To 50cc' class, at the Slovenian leg of the 1959 International Races held in Portorož. This was to enable them to introduce their first Tomos racing 50cc motorcycle. 

Tomos participated in road racing from 1959 onwards, but only when the 50cc class participated in solely national level competitions: Also during this time Tomos and many of the racing world's 50cc manufacturers tried to persuade the International Motorcycle Association (FIM) to accept this category into the race calendar for the European and World Championships. This happened in 1962, and continued until 1983, when the FIM cancelled this category in the World Championships.

During this period, Tomos developed a series of racing machines of which most could be considered unique specimens. It would be difficult to list all variations of their racing motorcycles, but we can identify them roughly into about 10 generations. More later.

The Colibri D3 Special 50cc Racer. This motorcycle was developed, from the production Colibri (the license-built Puch MS 50), and was their first, factory built, racing motorcycle, which that very same year won the International Races held in Portorož. 

This was named the model D3.  There were only two of these racers created. This racing bike, the Colibri D3, was the pioneer of road racing in this class within the Eastern Block and won competitions at times reaching an average speed of 93 kmh. During the next year (1960), the Tomos moped again won in its class and competed successfully in classes up to 125cc. 

It clearly differed from the production Colibri as it was designed to have its handlebars lowered, allowing a racing crouch to be developed by the rider, an oblong fuel tank later replaced the moped one, a sport seat, and a specially adapted tuned exhaust system. It was fitted with a manual, three-stage gear cluster with the gear handle mounted directly on the changing shaft. Although there wasn’t a visible difference between the serial production and racing engine, the alterations to this aspect contributed the most to its success in the races. The highest engine output was 3.7kW (5bhp), twice that of the production Colibri engine.

This motorcycle was given to the Technical Museum of Slovenia by the Tomos factory in 1997 and it represents a part of the valuable and exceptional TOMOS collection.

This video is of the 1959 Tomos D3. Developed from the production Colibri (a license-built Puch MS 50)

The so-called “Tomos Specials” were the most effective racing motorbikes, in contrast to the serial production machines, and were usually produced in very small numbers and intended only as factory racers. These racing bikes (except the serial ones) did not have any official names, but the Tomos race team, for internal requirements, named them either according to their number of gears (for example, D5, D6,etc.), or after the public presentation they named them after the a specific race season (GP 75, etc.).

In 1960, the Tomos Team also participated in an international motorcycle race abroad for the first time. The 50cc racing bike was tested at the Moto-Cup race in Hockenheim organised specifically for the lightweights and mopeds of this class.

Tomos and its D5 racer: 

Only German racers were allowed to compete with East European motorcycles. Among 32 competitors, riding 5 different makes of  motorcycle,  the winner was Heinrich Rosenbusch on the Tomos Colibri-D3 Special, which was  a great sensation, the bike was the forerunner to the D5, as it had a 5 speed close ratio gear box replacing the 3 speed of the Colibri. Rosenbusch also set a track record for this category of 113.1 km/h. Due to its number of gears, the ‘winner’ at Hockenheim was called the D5, and it represented the second generation of Tomos racing motorcycles. Picture: 60-61 Motocup Race-Tomos D3 Colibri and Heinrich Rosenbusch.

Less than a year later, the Hockenheim race was part of the European Championship of the FIM and allowed racers from other countries to compete. Tomos won again, or to be more precise, it was Miro Zelnik riding the Tomos D-5, racing moped. Picture far right: The winner of the Hockenheim European Cup road racing competition in the capacity class up to 50cc was the Slovene Miro Zelnik on a Tomos racing motorbike TMS photo collection 





 

Due to its number of gears, the ‘winner’ at Hockenheim was called the D5 - Right side view

 

Due to its number of gears, the ‘winner’ at Hockenheim was called the D5 - Left side view

 

Due to great interest in high-speed racing motorcycles in the category up to 50cc at home and abroad, the first batch of racing motorcycles, type D-5, were produced at the Tomos factory, in 1962, which was further improved in 1964 and improved again following year. 

This was when major construction changes were made to the racer and the engine changes allowed the unit to make 8.5 bhp and the changes to the frame gave better handling. In 1964, Tomos won the title of the National Championship of the Netherlands, and then in 1965, the same title in Sweden. 

These constructional changes gave the factory a single cylinder two-stroke with conventional piston port induction; the engine unit was modified by fitting a five-speed close ratio gear cluster, special cylinder head and an equally special cylinder barrel in aluminium, finned horizontally, similar to the Moto Guzzi. The engine breathing was taken care of by a real factory, off the shelf, racing Italian Dell’Orto SS carburettor with remote float chamber; whilst the exhaust system was very long, with a slender elegant expansion chamber. An example of the D5 with its engine running can be seen here. 

The D5 had a maximum speed that was in the region of 75-80mph depending upon gearing. Tomos claimed 8 bhp at 11,000rpm which seems about right compared with the other 50cc two-strokes. These results indicate that the Tomos development team were as good as the best at that time. For 1962, and a full crack at world championship honours, the Tomos engineers headed by Ing. Imperl came up with an all-new effort which owed nothing to the Puch heritage.

From 1962 until 1964/5, 100 racing machines were made by the factory and in 1964 ten of these D5 racers were later to be ordered by John Pomfret, a motorcycle dealer from Bolton in Great Britain to boost the 50c racing scene and perhaps give greater competition to the Honda CR110. 

News Flash 1964:  'Tomos racing machines will be imported into Britain' News of the latest developments came when the Australian privateer, Ron Robinson, visited the Tomos factory. Robinson saw several Puch-based production racers awaiting despatch to customers not just in Yugoslavia but also in Holland. In the latter country Ferdinand Swaep was to gain many victories during the 1960's on Tomos machinery and became National Champion on more than one occasion. This also led ultimately to the Dutch becoming Tomos’ main export market, a situation that existed for many years. This situation was quickly noted in the UK motorcycle press.

At the end of 1964, during the Autumn, came news that Tomos racing machines would be imported into Britain. The media latched onto this first racing machine to be imported into Britain from Yugoslavia when it shattered the winter quietness of Oulton Park. It was a five-speed 50cc Tomos two-stroke recently acquired by Bolton, Lancashire, dealer John Pomfret, who is the Father of a schoolboy road racer who, at the tender age of 16, is the lucky owner of a double-knocker 50cc Honda, he plans to import 10 of the 50 cc Tomos machines for sale in this country at well under £200 per bike. Initial tests of a somewhat under geared five-speed racer, in far from favourable conditions, suggested a competitive potential  which if the promise is fulfilled,  could give the 50cc clubman racing  a new lease of life.

Although there had been stories of a disc-valve Tomos engine, the Pomfret machine has a simple 49cc piston ported two-stroke engine. The alloy cylinder has a chromed bore and a very well made expansion chamber exhaust system. Cylinder dimensions are 38 by 43 mm bore and stroke. Compression ratio is 11 to 1.  No rev-counter was fitted but, Pomfret was told the engines are virtually un-burstable and able to exceed 10.000 rpm with safety.  A claim of 8bhp at 8,500 rpm cannot be confirmed but the Oulton Park outing indicated useful power at high revs. Since the engine of this D5 Tomos racer was brand new, the largest available jet was fitted to a 30 mm down-draught Dell' Orto carburettor. 

The test track was wet but both Dennis Holden, an experienced racer in the 50cc and larger classes, and Motor Cycle News staff man, Sean Wood, whose starting technique consisted of paddling with both feet, reported a useful power band. Fitted with an air lever and ignition cut out button, the Tomos production racer because it is based on a standard 50cc moped, manufactured at the Tomos plant makes spares easily obtainable. A pressed steel frame and other cycle parts are moped components but the engine-gearbox unit, featuring a geared primary drive and an outsize clutch unit, is designed especially for racing. Steel rimmed wheels have neat alloy brakes and 2.00 by 19 Continental tyres. Overall weight,  complete with a slick little fairing is only 98 lbs.

Quick gear changes on the bike were critical as the power band was so narrow. This fact had not gone unnoticed by the Slovenian  factory, and to make super-fast cog-swopping easier, the provided ignition cut-out button, MZ fashion, was used so that the clutch need not be used except, of course, for starting. With its launch in the Motor Cycle News, the D5 TOMOS had arrived on the UK scene.   

Tomos and its D7 racer:  

In 1962 the FIM officially accepted motorcycles with an engine capacity up to 50cc into the calendar of World Road Racing Championships, the GP and MOTO GP. The Tomos team had prepared for this season with a new competitive ‘Factory’ machine that right from the start was considered one of the favourites.

Coded D7-62 (seven-speed-1962), this was a factory made machine without parts from the PUCH MS50. The most important components of the new racing motorcycle, such as the frame and engine, were fully developed inhouse by Tomos. The heart of the newcomer was an entirely new engine unit; this sported a vertical cylinder and seven gears, with the clutch running at engine speed. But the features of most interest were hidden inside the engine itself, its oiling system, which was constructed on the nearside of the gearbox. Picture: Video of a TOMOS D7 being fired up. 

Lubrication was by a pump ensuring that the main bearings and big end assembly at the bottom end had ample oil delivery to safeguard against a failure. The dual contact breaker assembly was running at half engine speed, whilst the crankshaft flywheel assembly was of full circular design to obtain greater volumetric efficiency via less crankcase volume. But most unusual of all was the aluminium piston without any piston rings or even hardened stainless rubbing coils, which ran in a 38 mm plated alloy, conical, cylinder bore. The engine was air-cooled. It offered around 10bhp at the crankshaft which was at that time at the absolute top end of the smallest racing machines.  The new frame was longer and tubular, making it lighter and more rigid.  Picture: Tomos D7 Engine Lexmond Museum (JEEP)

Only 5 units, of the D7 model racers, were made by the factory. The 'D7' was made to win the company their first World Championship title but in the first race of the 1962 50cc World Championship series at Montjuich Park, Barcelona it had its major downfall. It was on a lovely sunny morning when the Spanish GP, organised by the Real Moto Club de Cataluña and held within a mile of the centre of Barcelona, got under way just after 9 o'clock in the morning. This was on Sunday 6th May and it was a 12 lap race of 28.29 miles for the 50 cc class.

The top marques from 1961, Kreidler and Tomos, were both expected to show up well against the might of the works entries from Honda, Suzuki and the local Derbi concern. But, unfortunately for the Yugoslavian team, both of the two D7-62s that were entered struck gearbox problems; although the Italian Gilberto Parlotti still managed to bring his machine home in 9th position. On the flat parts of the racing track the Tomos was faster than its rivals (Kreidler, Honda, and Suzuki), but the difficulties with the transmission stopped Parlotti from being ranked better than his ninth positon.

At the following World Championship race in Clermont a week later in France, the weather could not have been more different, bitterly cold and wet, their rider, Rajko Piciga with the Tomos D7 also crossed the finish line ninth. Team-mate Parlotti came home 17th. Both riders again suffered gear-box gremlins which effectively ruined their chances. 

Next round on the championship trail was the Isle of 'Man TT, but although Tomos originally planned to enter two machines they never put in an appearance and no D7-62 ever took part in an international race again as, although after solving the transmission issues it was felt the D 7 could still be competitive, the Tomos team decided to withdraw it from all future World Championships.

In 1965 Tomos developed a new racing motorbike for a comeback into the world’s top racing competitions. This was called the 'D9' because of the number of gears. Due to a very light frame (made of reinforced polyester) as well as other technical solutions, such as light mechanical disc brakes with an inner grasp (Tomos patent), the motorcycle weighed only 38kg. The Tomos designers wanted to compensate for a modest engine output of 11bhp at 14,000 rpm from the air-cooled engine with a lower weight for the rolling chassis. 

The Tomos D9 – The Lightest Among the Smallest of Racing Motorcycles: 

The D9 was also the first Tomos racing motorcycle where the fuel supply was not classic. The intake was done directly on the crankshaft via a Dell'Orto carburettor, with a diameter of 22 mm, which was mounted on the rotary disc similar to  that used by other competitors for some years. The unit had 9 gears and was capable of 93mph.

The first races quickly showed that the engine overheated and would require the replacement of air-cooling with a water-cooling system. 

Given to Technical Museum of Slovenia by Tomos factory in 1997, a part of valuable and exceptional TOMOS collection. (Photo: Veronika Štampfl)

Adrijan Bernetić holds a Tomos D9 rolling chassis without an engine. Weight only 38kg

In 1967, the designer of Tomos racing motorcycles, Janez Imperl made some improvements to the D9 engine and many of its weaknesses were eliminated. 

Unfortunately, any further improvement plans for this engine were stopped due to the new rules introduced by FIM who set the lowest permissible weight of a 50cc motorcycle at 60kg and the maximum number of gears to six. The Tomos D9 did win the title of National Champion of Yugoslavia in 1965, 1966 and 1967, but the two models in the picture above never competed in international competitions because the FIM rules. After the creation of these models, Tomos started to develop the D6 model, which was to become the most popular Tomos racer.

The D6 Serial and D6 Special

Tomos developed for the 1969 season a whole new racing motorcycle intended to be mass-produced and set to replace the series production D5S. It was named the D6 after the number of gears. With a re-modelled frame of Puch design, and a Tomos “new generation” engine this was to become one of the most successful of the company’s racing machines of all time. Picture: Gilberto Parlotti TOMOS D6 50cc Sachsenring 1969

The model D6 ‘Special’ was designed for factory racing, whereas the D6 'Serial' was intended for clubs and private individuals. Its design included some tried and tested solutions, such as a metal sheet frame (Puch design), a new engine adapted from the mass production ‘new generation’ version, petrol induction into the cylinder by rotary disc, drum brakes, etc. The sloping, water-cooled engine was fitted with re-ported cylinder, piston, head, and exhaust pipe of a special design and had a power output of 10bhp at 10,000 rpm.

The Tomos Team had competed with this new racer in the Jugoslav National Championship in 1968; one year later they were participating in the World Championship races (GP). At the start of the season, the D6 was among the best, but eventually lagged behind its rivals. After two races, Gilberto Parlotti held third place in the World Championship but before the Grand Prix of Czechoslovakia in July he dropped down to sixth place. Gilberto Parlotti won the Italian National Championship in 1969 and 1970 with this bike. Tomos also won the title of National Champion in road racing competitions in Sweden and Finland.  

D6 TOMOS D6

D6 TOMOS D6-1

In September 1969 it was announced that the Tomos factory was to market a batch of 50cc racers for £210 each. The bikes, of which only 12 were to be constructed, would be ‘replicas’ of the D6 works bikes campaigned that year by Parlotti and Co. The specification included water-cooling, a six-speed gear-box, double-sided drum front brake and 12 bhp at 12,000 rpm. The engine was still based on the familiar Puch-type design.

Parlotti was to give Tomos their best ever GP with a rostrum position (3rd) in the 1970 West German GP before leaving to ride for the Italian Morbidelli team in the 125 cc class. He was replaced by another Italian, Luigi Rinaudo who rode the latest Tomos to 4th place in the Czech GP and 7th in the Spanish GP. 

Luigi Rinaudo (born 9 March 1939 in Trieste) an Italian motorcycle racer, who participated in the World Motorcycle Championship between 1969 and 1979. His best season was in 1971 when he finished thirteenth in the 50cc class Riding a TOMOS.


Tomos D6 at the Grobnik track - Grab The Flag 2017 - Race 1


Running up the engine of a Tomos D6 

1970 The GP D6 and GP71 Prototype: 

In that year Tomos developed a new prototype machine, the GP71 purely for the fit of for Gilberto Parlotti; with a frame of fibre-glass it had a disc valve, a water-cooled engine instead of the orthodox piston-port type used in the D6-S during 1969 and 1970. The frame was moulded in two halves which were then bonded together. To save weight it was designed and built to have its fuel tank incorporated into the frame and a transparent window was included so that the exact fuel levels could be seen at a glance.











The weight of the complete frame was only 6.8 kg (15 lb) but its design complemented the rest of he bike, making it a very forgiving and usable mount. The rear fork was made of pressed-steel and had a narrow pivot so that the rider could tuck his legs in close to reduce the frontal area. The engine had a bore and stroke of 40 x 39.6 mm and revved to 15,500 rpm. Maximum power output was 15.5 bhp. The primary drive was by straight-cut gears to a six-speed close ratio gearbox. The maximum speed was over 100 mph.

However later testing proved that the GP71 still couldn’t match the class-leading Derbi and Kreidler machinery who’s credentials were Derbi 50 – 15,5 bhp at 14.500 rpm and Kreidler Van Veen 50 –15,5 bhp at 14.500 rpm.. The next year (1972) Rinaudo was 5th in East Germany, whilst local riders Miklos (6th) and Seljak (9th) upheld Yugoslav honours in the domestic GP at Opatija.

Gilberto Parlotti (17 September 1940 – 9 June 1972) was an Italian professional motorcycle racer competing in the FIM World Championships between 1969 and 1972 . He competed for the Benelli, Derbi, Morbidelli and Tomos factories.

Gilberto Parlotti 

Gilberto on his Tomos 50 racing against Barry Sheene on his Kreidler

Gilberto Parlotti  helping the Yugoslav rider Bernetić-another Tomos rider- returning to the pits

Gilberto waiting in the pits at Imola while warming up his factory Tomos 50

Modena 1970, Gilberto waiting for the race with his Tomos 50

Gilberto Parlotti in the 1972 Ultra Lightweight 125cc TT Riding a Morbidelli

Parlotti was born in Zero Branco Treviso Italy. After winning the first two 125cc races of the 1972 Grand Prix motorcycle racing season West Germany and France, Parlotti decided to race at the 1972 Isle of Man TT Races to take advantage of his main championship rival Angel Nieto's absence from the Isle of Man Mountain Course. While lying in first place on the second lap during the 1972 125cc Ultra-Lightweight TT race held in heavy rain, Gilberto Parlotti crashed his 125cc Morbidelli motorcycle at the Veranda section on the A18 Mountain Road and died from his injuries. The death of Gilberto Parlotti was instrumental in bringing about the end of using the Isle of Man TT Races as a world championship event. After his death, his close friend Giacomo Agostini announced he would never again race at the Isle of Man TT Races although in later years he did paraded in the TTRA Classic Parade.

The GP (Grand Prix) Series

When the German Kreidler company won the title of the National Champion in 1975, after 13 victorious years of Tomos wins, the Tomos Company started developing a series of new road-racing motorcycles.  They were to be based on the prototype, GP/71, described above that was developed in 1971 and the pictures below gives an idea of the way Tomos was thinking.

These motorbikes were called the “Specials” and were improved and supplemented constantly until they finally made the model GP (Grand Prix) in 1975. This string of bikes continued through  GP 77, GP 78 and GP 79,  the latter reaching the top speed of 126.76 mph at the tests carried out at the Grobnik airport (see below); however, they were not allowed to use it at the official races, since the improvements were not in line with the applicable regulations. 

A Jump Forward.  It is now 1982 and Zdravko Matulja is on the runway of Grobnik airport and is sitting on the updated Tomos DM-GP motorcycle recently prepared for its next 50cc Grand Prix outing. The timing light goes green and Zdravko is off the line, the run takes seconds and he records a record speed of 126.76mph kilometres per hour. What an achievement!

An interesting fact is that the speed of this motorcycle, tested on the airfield strip on a number of occasions (description of the track below) , was, on a general test day, 123.6mph. The support team tried to understand how this difference in mph arose on this final run and they realised that, on this test day with an increase in the ambient temperature, and the heat from the previous runs and high speed, the tyres had expanded and their radius increased, resulting in approximately a three miles per hour increase in speed.

TOMOS DMGP record breaking 204kmh-1979

TOMOS DMGP record breaking 204kmh-1979

TOMOS DMGP record breaking 204kmh-1979

TOMOS DMGP record breaking 204kmh-1979

Nestling on the Croatian coast in the mountains above the city of Rijeka is the Automotodrom Grobnik, once home to the stars of the motorcycling world but now rather forgotten by international racing. Fast and flowing, it remains the only FIA and FIM-accredited circuit in Croatia. This racetrack was formed through the conversion of the old runways of the airfield and the surrounding land. 

Grobnik - Circuit History: While racing in the Kvaerner area of Yugoslavia has a long tradition, it was the decision of the FIM that the Opatija street circuit was simply too dangerous and that sparked an intense rush to prepare a permanent course. The reason: deaths of Urich Graf and Giovanni Ziggiotto plus 19 other rider injured on the circuit in 1977 proved the final straw and road racing was banned completely as a  World Championship meeting the following year. If the Yugoslavian Grand Prix was to be held, a modern circuit would be required.

The local motor club stepped up to the plate and a new course was designed and, within just two months, in late spring/early summer 1978, the circuit was constructed. The rapid pace of construction was aided by the use of prisoners and the army, the latter of whom was responsible for laying the track surface. Notably the asphalt used was extremely high in grip, especially in the wet, and has also proved very long lasting.

Despite many doubts, the circuit was in fact ready in time to host the Grand Prix on September 17th, the last race of the season - albeit without the 500cc class taking part. Australian Gregg Hansford enjoyed the most success at the inaugural event, with pole and a win in the 350cc class, followed by a 250cc victory. In the 125cc class, Angel Nieto took the win, while Ricardo Tormo passed the finishing line first in the 50cc race. All told, it was a remarkably successful first event. In the second half of 1978 the most important Yugoslavian motorcycle races for the Grand Prix of Yugoslavia were for the first time to be held at the new racing track in Grobnik near Rijeka.

The 1978 DM GP78.  

For the 1978 series of races Tomos developed a completely self-supporting monocoque frame made of carbon fibre-reinforced plastic to compete for the internal racing series and the motorcycle World Championship round for the first time. The rear wheel was housed in a conventional steel swinging arm and the front fork unit was supplied by Marzocchi. Tomos presented this new racing motorcycle with this light frame made of reinforced polyester, giving it  a  model code of DM GP78. 

It was obvious at first sight that with this new GP78, the Tomos designers had paid a lot of attention to the reduction of air resistance. For this purpose they applied an innovative engine cooling system: instead of a large radiator in the centre, they fitted the engine with two smaller radiators at each side.

Other important improvements included the front forks and rear shock absorbers, disc brakes made of a light casting and sprayed molybdenum, and rims made of cast magnesium. Unfortunately the new GP78 did not cross the finish line at the Grand Prix of Yugoslavia during its birth year due to a design defect with the exhaust system. 

In 1979 more thought was given to the airflow through and around the complete package and the aerodynamics were tested in the wind tunnel of the Institute of Faculty of Mechanical Engineering in Belgrade at speeds up to 170 km/h (106mph).  The senior engineer of these tests was Josip Vlahović M.Sc. 

Special attention was  paid to the aerodynamics of the wheels and they studied the impact of other accessories that would further improve the overall aerodynamics, (the driver’s helmet, front mudguard, spoiler with front forks, the rear section of the seat, etc.) as well considering the  engine cooling system. With the aerodynamic design to these  particular details they managed to reduce the resistance by up to 22%. Some improvements (such as the back part of the seat) allowed the GP79 to reach improved speed during testing at Grobnik airfield with a maximum speed of over 200 km/h, which was above the  permissible racing speed set by the FIM. 

 According to the racer Zdravko Matulja, while testing at the Grobnik sports airfield near Rijeka, the GP 79 achieved 204km/h. 






The second picture above is from the collection of  Matulja, Tomos DM/GP under test 

The Tomos company’s investments in research and development bore fruit in 1982, when Zdravko Matulja won the title of the European Champion in the category up to 50cc with their new racing motorcycle DM/GP82 and GP83. In this period, the company has officially withdrawn from racing; however, it continued to support Zdravko Matulja financially and by providing equipment in the seasons from 1982 to 1983. 

In 1983 a Tomos racing motorcycle, again the DM/GP83 was a very close competitor to the then current competition of Kreidler, Bultaco, ABF, Garelli, etc. in the same 50cc category. The 1983 season was also the last one to include 50cc motorcycles in the World Championships. The gallery below is of the DM/GP83. The red and blue machine is an accurate replica of the No1 works motorcycle.













Although Tomos recorded excellent results in road racing competitions, it should also be pointed out that the company’s Cross 50 Junior and Senior machines took part in many motocross competitions in the 1970’s and significantly contributed to the popularisation of this sport, in particular amongst the younger generations. Further to this, Tomos also supported speedway racing with "off the shelf" production models as well as supporting other events as a good way of promoting and popularising the brand. Picture: Tomos Cross 50 Junior from 1980 in road trim.

CONCLUSION

Taking an overview of the Slovenian motorcycle industry as a whole, and at the  threshold of the new millennium, this document illustrates that only Group  Tomos – which following the bankruptcy of Tomos in 1989 became its new owner – is still manufacturing motorcycles that are entirely the result of the in-house design and development and the team that developed them. This ethos has been rolled out over the world to it's benefit.

Throughout its history, characterised by intensive R&D, Tomos met both its successes and failures, rises and falls in good form and learned from the experiences. In  addition to the achievements that form the main subject of the permanent exhibition in the Technical Museum of  Slovenia, it should also be noted that Tomos was a successful international company. To facilitate the launch of their  products, they founded joint-ventures with foreign  enterprises, such as Tomos-Nederland (1965), Tomos-Ghana  (1971) and Tomos-Gorizia (1980)97. and Tomos Norton. In 1974 the company  exported its products to 32 countries in Europe, North and South America, Asia, Africa and Australia. In 1984, the total  number of countries reached by their products to rose again by 10. 

Studying the market in 1983, Tomos was ranked between third and fourth place among the European manufacturers of motorcycles with the engine capacity up to 80cc, whilst with regard to marine outboard engine production, it  was number one in Europe

 

Tomos continued in the manufacture of small motorcycles with the first in a new 1980’s range being the APN 6 (successor of the  popular APN 4) launched at the Zagreb Fair in 1981. The most  important innovation was new in-house designed sheet metal frame that replaced the old Puch one. 1983 saw the AT 50 motorcycle launched. The design of the frame and engine was based on models from the 1960’s (the new generation engine) and the 1970’s the frame of the Cross (50 Junior), so considering the time needed to master the production of a new product we can come to the  conclusion that both of these motorcycles that were launched in the early 1980’s further testify to the fact that Tomos R&D had actually reached its peak in the 60’s and 70’s.  

APN6 1990

APN6 2006

TOMOS RACING BIKES CALENDER 2014








Appendix


* Because each racing motorcycle was a unique specimen it is difficult to classify them into generations and versions. The present table is just one possible rough set of classifications  of single versions of Tomos racing motorcycles that enables their clear presentation within the framework of this contribution. 
                       
1 Although from a developmental viewpoint we cannot talk about a new generation of Tomos racing motorcycles, the D5S is characterised as a new 4th generation machine in this table 
due to its mass production.

 




1 Both versions differentiate over their frame, and we could treat them separately as two generations, but in this case we shall treat them as versions, as both are of similar design. 

2 The DM GP from 1977 is, in regard to its design, a development from the DMS. However, because of radical improvements to the engine (its successors had the same), it is in this case treated as a new generation.  

 



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