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Jan Thiel, Mr. 2 Strokes

Jan Thiel with the PIOVATICCI 50cc engine

Born on June 3, 1940 (Amsterdam/Netherlands), Jan Thiel is one of the greatest exponents of the development of 2T engines. At a time when computers were not available, test benches were inaccessible to most, electronics were basic and the means available for design and mechanical construction were minimal, he and other contemporaries produced 50cc/2T engines with more than 20 hp. , something like 400 hp of specific power - power per litre, capable of projecting the small bolides at more than 200 km/h!

Valentino Rossi (APRILIA), Angel Nieto (GARELLI and MINARELLI) and Ricardo Tormo (BULTACO) are three of the many riders who worked with Jan Thiel

An impressive track record of, as a technician, 51 world titles, 25 for riders and 26 for manufacturers, at the service of various brands (BULTACO, MINARELLI, GARELLI and APRILIA), gives him a well-deserved status as a legend. Today, he is retired and lives with his family in Thailand.


At about ten years old, Jan attended his first motorcycle race, from then on, together with a schoolmate, he developed the habit of cycling to Zandvoort on Sundays to watch the races. In 1954 he went to Assen for the first time, curiously, that was the last time that the original route of this mythical circuit was used, this occasion reinforced his taste for the modality and forever he has the memory of watching Drikus Veer at the controls of the fantastic 4-cylinder GILERA 500cc, this was the episode that, definitively, marked his destiny.

Drikus Veer, GILERA 500cc, Assen 1955

From that moment on, Jan unilaterally decided that he didn't want to go to school anymore, he wanted to make a career in racing and work on engines! The idea did not please his father and they had a big argument that resulted in the fact that for the next thirteen years they did not see each other again. However, his maternal grandparents who raised him, practically never dealt with his mother who was hospitalized in a psychiatric clinic, they let him do what he wanted!


In 1955, he met and became friends with Cees van Dongen and, accompanying him, went behind the scenes of racing. In 1959, he began a short and unproductive career as a pilot, at the same time, he began his journey as a technician.

Jan Thiel in his first participation as a rider, 1959, at Etten, riding a two-speed HMW 50cc

From 1962 (inclusive), the 50cc class was created in the World ​​Championship. It was at this time that Jan met another ingenious rider/fitter: Martin Mijwaart, they started a collaboration in which the first fruit was the preparation of a KREIDLER cylinder for the ITOM with which Martin, at the time, competed. With a ROYAL NORD, acquired used from Andre Huige, where they mounted a KREIDLER cylinder prepared by both, in addition to having created a head and a 6-speed gearbox of their own production, Martin became Dutch Junior Champion. Until 1964, inclusive, the duo Jan and Martin were evolving their technical capacity and building hybrids limited by the lack of financial capacity. At this stage, they baptized their creations with the name TANSINI, an Italian engine brand that had promised them support.


However, TANSINI went bankrupt and, in 1965, they decided to run under their own brand: JAMATHI (JA by Jan, MA by Martin and THI by Thiel). In 1966, Jan decided to leave his racing career and the vacancy was filled by Paul Lodewijkx, a pilot friend of the two and who would prove to be a very important virtuoso for the brand's future notoriety. In 1967, with Martin and Paul at the controls, there were no major technical changes and, although they started the project for a new engine, it was never finalized, although the 9-speed gearbox idealized at this time was used the following year. . At the end of the year, the team's bikes were sold as a way to raise capital for the following season. For 1968, a completely new bike ('68er) was created and, thus, they managed to ascend to a new level in the class, where they began to, precisely, deserve the respect of the other brands. On June 26, 1968, at the Dutch GP, things got off to a bad start on the first day of practice when both bikes, Martin and Paul, had technical problems. They worked all night and tested the solutions on a rural road, the next day, Paul slayed the competition by taking pole position more than 2 seconds from Hans Georg Anscheidt (SUZUKI official rider who manned the 2-cylinder bike). At the end of practice, Paul said: "We worked all night, I was tired, I couldn't get everything off the bike. I hope I can finish the race." The race was epic, initially Paul and Hans Georg rode together alternating control, but from a certain point on Paul started to delay and came to ride more than 100m from the leader, when everything seemed lost, he started a fulminant recovery that earned him the victory by the length of a wheel! The legend was released! At the end of the season, they once again had to sell their prototypes. However, G. Joh came to an agreement. Bruinsma, the Dutch importer of KAWASAKI at the time, to finance the project of a road moped with the intention of going into series production.

The road JAMATHI 50cc whose hasty entry into production compromised commercial success

A completely new motorcycle was built for 1969, the engine became narrower as a result of the use of a 6-speed gearbox, the maximum that the regulations allowed from then on, the cylinder became perpendicular to the crankcase and the frame started to to be lower and narrower, the front suspension was a MARZOCCHI, rear shock absorbers SUZUKI and front brake became a double drum FONTANA. With this bike, Paul won 3 GP: Czechoslovakia, Nations (Italy) and Yugoslavia. The end of this season also marked the premature end of Paul Lodewijkx's career, a road accident left him very badly treated and during his recovery it was found that, as a result of the accident, he became epileptic, he still tried to return racing in 1972, but never got back into good shape. An epileptic seizure was the cause of his death in 1988, Angel Nieto said that Paul was the rider he feared the most. The 1970 bike was a small evolution of its predecessor, due to the scarcity of means, Martin Mijwaart manned the new model, while the rider replacing Paul, Aalt Toersen, was entitled to the bike from the previous year. At the end of the year, they had 3 more GP victories: Belgium, East Germany and Czechoslovakia. Still with Aalt Toersen, in 1971 an evolution of the previous year was built, the biggest difference being the adoption of a new electronic ignition. Also original was the fact that they used a single rear shock absorber developed by KONI (right side), which freed up the left side for the exhaust. The aerodynamics were developed with FOKKER specialists, it weighed 55kg dry and developed 17CV at 16,000rpm, the development costs of this bike once again depleted the JAMATHI "safes", at the end of the year they sold all the stock of prototypes of race they had.

Paul Lodewijkx (1969) and Jan Bruins (1974)

With the liquidity that the sale of stock provided them, plus a public fundraising carried out by the Dutch magazine MOTOR, they designed a completely new and revolutionary motorcycle for 1972. Theo Timmer replaced Aalt Toersen in the spearhead position of JAMATHI. The engine crankcase and gearbox are no longer cast and are now made of aluminum worked in the mass, for this reason it was easier to create a greater watertightness, and at the same time they created a quick way to intervene in the gearbox, a solution that later became usual in GPs. The cylinder left its vertical position and started to work lying down, the circulation of the coolant was controlled by a pump and a new electronic ignition was applied. The frame was also a revolutionary steel monocoque and, once again, the rear suspension was given over to just one shock absorber. Theo Timmer won at the East German GP. In 1973 a completely new monocoque chassis was built, the radiator was moved to the upper front, which made it possible to dispense with the water pump and the engine was built with the same principles but in a more elaborate way, which allowed it to deliver 19 hp at 15,800 rpm, with this bike, Theo Timmer won the East German GP.

The JAMATHI 50cc of 1968

The JAMATHI 50cc from 1969 to 1974

For 1974, with the help of a new sponsor and the help of the famous Dutch writer Henk Keulemans (who also wrote: "THE JAMATHI TEAM"), development continued along the same lines as the previous year, however Martin's illness and chronic lack of of means, expanded with the disaster of the series production of the road moped, dictated the end of the JAMATHI adventure, at the end of this season, the engine developed an impressive 21.4CV!!!


The end of JAMATHI marked the beginning of a short adventure at PIOVATICCI. During the '74 season, Jan and Martin started talks with Eugenio Lazzarini, whose main sponsor was a furniture manufacturer, Egidio Piovaticci from Pesaro/Italy, as a result of these talks they were hired and went to live in Pesaro, despite not speaking Italian, to build a 50cc and a 125cc to be driven by Lazzarini. Mr. Piovaticci acquired the previous year's JAMATHI stock and that was in fact the basis of the new 50cc, a new frame was built that took into account Lazzarini's small stature, on this occasion the bike already used cast wheels and disc brakes. The pair PIOVATICCI/Lazzarini was very fast, at the end of the season they were second in the championship behind Angel Nieto.

Eugenio Lazzarini on PIOVATICCI 50cc

A 125cc two-cylinder prototype was still produced, but due to some wrong technical choices and, later, lack of means, it never had the proper development, despite some important results such as 3rd position in the Swedish GP.


At the end of the 1975 season, Mr. Piovaticci had financial problems and, once again, Jan and Martin were dismounted.


In 1976 they headed to Spain to work with BULTACO, with Angel Nieto as rider. At that time, the financial health of this Spanish brand was no longer bright and, interestingly, Jan and Martin's salaries were paid by the RFME (the Spanish motorcycling federation). Once again, the means were scarcer than promised and, initially, they were dependent on the material, stock PIOVATICCI of 1974, which had to be sent from Pesaro and of whose delivery they themselves doubted the respective delivery, finally the material arrived at the end January, having been held in customs for another week. The first race was a Spanish championship race in mid-February, Angel Nieto won, ahead of Ricardo Tormo in KREIDLER, with BULTACO which was in fact Eugenio Lazzarini's PIOVATICCI decorated in the colors of the Spanish brand.

Mr. Bultó was amazed that they were able to build the bikes without previous designs. Later they were helped by Marcelo Cama, at that time a former MONTESA pilot, to make some sketches and, later, they had the help of a professional to design the projects as they should be. Working in a factory was a new experience, until then they had always worked alone and now they had access to technical means that allowed them to enhance their achievements, in July, they had the competition department ready. At the Nurburgring, Angel Nieto became World Champion and BULTACO won the constructors' title, in what was the debut in the titles for the brand and for the Jan-Martin duo, winning the title had the bonus of being at the house of KREIDLER, the biggest rival. In 125cc, Nieto was 2nd in the championship, having won the Belgian GP. In 1977, in 50cc, Ricardo Tormo joined the team and, at the end of the year, once again, Nieto was crowned champion while the new recruit reached the third position. In the 125cc class, Nieto finished third despite having won three times at the GPs in Venezuela, Holland and Sweden.

For 1978, by imposition of Nieto, they carried out the production of a 250cc, but the lack of means could not bring the project to fruition. Realizing the notorious lack of means, Nieto left BULTACO and joined MINARELLI. Ricardo Tormo won the 50cc title. In 1979, Mr. Bultó was murdered by terrorists and that was the end of BULTACO because he was the one who was financially rescuing the brand.

In 1981, without Jan and Martin in the line-up, although using his 50cc machine, Ricardo Tormo was once again World Champion.


In 1980, Jan and Martin headed once again to Italy, this time working for MINARELLI, now they worked for a major European engine manufacturer and inherited the well-done job of Jorg Moller, another Dutch technician of great standing. While they were at the service of this brand, until the end of 1981, they won, in 1981, a riders' title, Nieto, and a constructors' title.

During the MINARELLI period, Giuseppe Ascareggi and Constructors were also protagonists, in 1981, of the European 50cc riders' title. Ascareggi won the 50cc race at Vila Real in 1981 scoring for the European Championship. It is also interesting to mention that the rider from Porto José Pereira would ride the factory bike, the same bike as Ascareggi from the previous year, in the 1982 European, but an accident during the beginning of the first race, when he was in charge, left him very badly treated and unable to do the rest of the championship, on this sad occasion, the first real opportunity to see a Portuguese rider fighting for an international motorcycle title was lost. It was also during this period that Martin Mijwaart left the Jan-Martin duo, at the end of 1981 he decided to go to live in Holland where he wanted his children to study, unfortunately he died prematurely from illness in 1988. The death of the founder, Vittorio Minarelli, in August 1981 left the company to his heirs who did not sympathize with the competition and ended up managing to stop the brand's sports project at the end of 1983.


Since the end of 1981, Lazzarini, meanwhile integrated into GARELLI, was trying to build a competitive 50cc model inspired by the JAMATHI, monocoque chassis and horizontal engine, which he knew well. Although he added technical skills to his driving skills, Eugenio did not achieve the desired results, in fact, the engine, designed by Ing. Mariani, turned out to be a disaster and is said to have never completed a lap at Monza. In fact, Lazzarini had already invited Jan, in 1980, to GARELLI, but at that time, Thiel had a contract that linked him to MINARELLI until the end of 1981. It was at the end of 1981 that GARELLI made a contract with MINARELLI to equip its series models with the engines of this brand, in parallel, it negotiated the supply of 125cc competition engines as well as the purchase of the competition department, including pilots under contract. . Jan Thiel had very good relations with Nieto and Lazzarini and was willing to join the brand, thus beginning a fruitful period with GARELLI. The Jan Thiel/GARELLI connection resulted in 5 riders' titles (125cc): Angel Nieto (1982, 1983 and 1984), Luca Cadalora (1986) and Fausto Gresini (1987); and, 4 builder titles (1982, 1984, 1986 and 1987). From 1988 (inclusive) there was a regulatory change that limited the 125cc GP to single-cylinder engines, this fact precipitated the abandonment of competition by this brand. After the GARELLI period, Jan passed without notable work for AGRATI and RUMI.



In 1995 he joined APRILIA where he remained until his retirement in 2008. This tie to Noale's brand took a brief break to work with DERBI for the 2004 and 2005 seasons. As DERBI already belonged, at that time, to the PIAGGIO group and since, from the end of 2004, APRILIA became part of the same industrial group, the return to APRILIA took place naturally.

Here he had a very productive season where he achieved several titles of manufacturers and riders in the 125cc and 250cc classes, he played a major role in the genesis and development of motorcycles that from their inception to the epilogue of the 2T engines were great protagonists imposing creativity European dimension in relation to the Japanese dimension.


Much more could be said of Jan Thiel, a simple man, whose brand image is sandals, who overcame enormous difficulties, demonstrating tenacity combined with intelligence and creativity that resulted in the technical capacity that made it possible to have been an important part of 51 world titles, 25 from riders and 26 from manufacturers. These are the riders who became world champions with Jan's technical collaboration:

1976 – BULTACO - 50cc - Angel Nieto

1977 – BULTACO - 50cc - Angel Nieto

1978 – BULTACO - 50cc - Ricardo Tormo

1981 – BULTACO - 50cc - Ricardo Tormo

1981 – MINARELLI - 125cc - Angel Nieto

1982 – GARELLI - 125cc - Angel Nieto

1983 – GARELLI - 125cc - Angel Nieto

1984 – GARELLI - 125cc - Angel Nieto

1985 – GARELLI - 125cc - Fausto Gresini

1986 – GARELLI - 125cc - Luca Cadalora

1987 – GARELLI - 125cc - Fausto Gresini

1995 – APRILIA - 250cc - Max Biaggi

1996 – APRILIA - 250cc - Max Biaggi

1997 – APRILIA - 125cc - Valentino Rossi

1998 – APRILIA - 125cc - Kazuto Sakata

1998 – APRILIA - 250cc - Loris Capirossi

1999 – APRILIA - 250cc - Valentino Rossi

2000 – APRILIA - 125cc - Roberto Locatelli

2002 – APRILIA - 125cc - Arnaud Vincent

2002 – APRILIA - 250cc - Marco Melandri

2003 – APRILIA - 250cc - Manuel Poggiali

2006 – APRILIA - 125cc - Álvaro Bautista

2006 – APRILIA - 250cc - Jorge Lorenzo

2007 – APRILIA - 125cc - Gábor Talmácsi

2007 – APRILIA - 250cc - Jorge Lorenzo



1 Comment

Jan 09

I am trying to contact Jan Theil to ask him if he ever met Zimmerman (whose design was the basis of Kaden’s work) or Erich Wolf of DKW? He can contact me at

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