Interview Jan Thiel


All the old motorcycle fans still know him. People all over the world still talk about him with great respect! A long time ago, seems like yesterday Jan together with Martin Mijwaard and Paul Lodewijkx formed the famous Jamathi trio. Jan was taking care of the horsepower, Martin for the chassis and Paul was very good at controlling the throttle. How good this trio was, was shown at 1968 Dutch TT in Assen. They beat in a straight duel Hans Georg Anscheidt on his factory Suzuki. Paul and Martin are sadly not with us anymore but Jan who walked his whole life on sandals is still around. After that Jamathi time Jan worked for big factories. Big names like Angel Nieto and Valentino Rossi have won many races and World Championships on bikes that where constructed by Jan. Together with Jaap Timmer who is called Mister TT I would like to give the same predicate, Jan Thiel Mister Twee Takt (Mister Two Stroke). Jan is now retired, to relive the past here are 33 questions which Mister Two Stroke has answered by e-mail.


Is it correct that you shut the door for the last time at the Aprilia factory?
It is already a few years ago that I stopped working, the last day was the 30 November 2007. I had chosen not to renew my contract as a technical consultant. There is a time you have to stop, and my wife wanted to go back to Thailand. Also the future of the 2 stroke engine was unsure. Now after a few years I think I stopped at the right time, with four World Championships in 2006 and 2007.

Let`s go back to the beginning, how did you get into the sport?
I was already reading motor magazines when I was at elementary school and saw my first race in 1950 at Zandvoort. At that time you had cars and bikes racing on the same day. Later on I went with a school friend on Sundays using our bicycles to watch the racing. The first time I saw the Dutch TT was in 1954, that was the last race on the old circuit. Drikus Veer rode a 4 cylinder Gilera, just great! I dreamt of going racing myself. I did not want to go to school anymore but wanted to work on bikes to learn even more. My father did not agree, after that we did not see each other for 13 years. I lived with my grandparents (the parents of my mother), they let me do what I wanted. I never really knew my mother because she was in a mental hospital. I became a 50cc enthusiast when I saw Cees van dongen riding on his DMF, I think it was in 1955. Later we became good friends. My first bike was a 125cc Grefa with Villiers engine, with used parts and a HMV 2 speed engine I made a race bike. I really did not like to race with it. My first race was in 1959 finishing at the back of the field.

In the early years you met Martin Mijwaart, a man who you worked with for many years. What was the secret that you worked for so long together?
Martin and I met for the first time at the races in Rockanje 1962. I was riding with the Inters and I think it was his first race with his self build Itom. Later we met again at the GP in Francochamps, that is where we had our first talk, and watched the races. After that I visited his house a few times and also he visited me. At a certain time we agreed that we would work together, our first project was a Kreidler cylinder on the Itom. It worked very well. We could work together very well because we agreed on a lot of things. He was good at making things, and I was good at thinking what to do. I learnt a lot from him.
We worked a long time together but in 1981 he decided to go back to the Netherlands. He thought it would be better for his kids to go to school in the Netherlands. So he gave up racing, and I think it was not really his hobby anymore.

In the 60`s almost every rider chose Kreidler, you and Martin started to develop your own bike. What was the reason?
In the 60”s Kreidler were not so good, races were won by Itom`s and Cees van Dongen on a 6 speed Royal Nord which was the fastest 50cc in the Netherlands. Cees and his father helped us a lot. From Grandpa Van Dongen I learned how to calculate a gearbox.and also how to make parts. We bought Royal Nord crankcases from Andre Huige in Rotterdam and we made a 6speed gearbox for it and also the crankshaft I think. We used a Kreidler cylinder with our own made cylinder head. Martin was 50cc Dutch champion on it with the nationals. So for us it was obvious that was the direction to go.

In 1968 Jamathi was on a high level, it was so good that Paul Lodewijkx won the Dutch TT. How do you look back on this, and how does it feel when your bike wins your home GP?
It was totally unexpected because I thought Anscheidt was playing with Paul, the first feeling was disbelief and after that the satisfaction. We were very lucky that the big-end stayed in one piece. It was a weak spot that already broke in practice, and a week later it did again on the finishing line in Francochamps. Winning the TT or a World Championship are things that change your life for good! It is strange and you never forget. Winning races after that never give so much satisfaction. I still remember the reporters and TV crews coming to us but we really did not like that.

What kind of man was Paul and what were his strongest sides as a rider?
Paul was a really nice guy to work with, also his family. I was there a lot and it was always good fun. As a rider he was good in fast corners, although he was very tall he could make himself very small behind the fairing. Also he could learn a new circuit very quickly. Nieto told me later that the only rider he really was afraid of was Paul. Sadly after the accident things never were the same with the Jamathi team again. But as they say life goes on.

You were working during the day and developing and building the bikes in your free hours with very little money. Was it not frustrating and did you never think of quitting?
Financially it was hard, we worked four days a week to get one day extra for racing, of course, you also had less money to spend. We paid everything ourselves and had a poor life outside the racing. There was no money for a car, luxury or clothing, I only had one pair of sandals. I have been riding a Batavus moped which I bought for very little money because it had a broken conrod. We did not mind at the time and never thought about quitting. Sometimes at the end of the season we sold the old bikes to have money to buy new ones.

After your success in the GP`s therein was a Jamathi moped developed to bring in money. Was not that too much work for the small team and was there still time enough to develop the race bikes?
The development of the Jamathi moped had more negative sides than positive. In February 1969 we finally could start building a new race bike, it was already very late. The moped never brought in money.
That year we went to Yugoslavia and Italy with no money for the trip home. That all depended on the starting money. Paul won both so we had some more money than we came with. In the winter we built a new chassis for the moped Jamathi type 2 and when it was ready it was built by another company. It went into production too soon without too much testing so it gave a lot of problems. But thankfully to the moped there is still a Jamathi Club of which I am very proud.

When you were building a new Jamathi engine, would you calculate and draw everything new or just use the experience from the last engine?
We made some calculations very simple on a piece of paper, we did not have a drawing board. I worked at home, mostly on Sunday afternoons, just on the table with some simple drawing tools which I still had from school. A new engine is built through experience with engines before and new ideas and look around to see what others are doing.

The exhaust is a part that for many people is still a mystery. There are many thousands made in garages and factories. Mostly not better than the original ones. How do you make a good exhaust?
Mostly you have an existing one and start experimenting. Through the years you know what changes gives what result. For example, if you make two from the same drawing they can be totally different. Also when you see improvements on the test bench it is not always better on the circuit. Mostly the problem is the difference in temperatures. In the Garreli time we put a fan in front of the exhaust and on the circuit we wrapped asbestos tape around the exhaust. In the Jamathi time we did not have a test bench, we just used a straight piece of road. Probably the best way but not easy with traffic. In 1970 we were on the Sachsenring and the engine was not running well in practice. We wanted to test it on a road to try carburation and a different length exhaust, but it was very busy with traffic. I asked a policeman where we could try? Surprisingly the road was closed and 15 minutes later we got it right and Aalt Toersen won easy. Lower air pressure, less power. Then you get lower gas temperatures in your exhaust, that results in slower pressure waves. Shorten the exhaust a few mm, problem solved. At Bultaco I once tested an engine without the exhaust. Power went down from 18 to 2,5 bhp.

What is the maximum power you got out of a Jamathi engine?
The highest was about 15 bhp on our roller bench in Breukelen 1974 at the back wheel. With the same engines at Bultaco we came to 19 bhp on the gearbox output.

Jamathi also worked with Herman Meyer from Laren. Did you share information on preparing the engines?
Working with Herman brings back good memories. He is one of the nicest people I have ever known. He made the transmission gears for us because we did not have a big milling machine which he did have. Until the Bultaco time he still made them and also for the Piovaticci. So Nieto became World Champion 50cc in 1976 with transmission gears made by Herman. Herman also rode a Jamathi. After Assen Henk Vink did not want Leo Commu to ride the Jamathi anymore. Leo was tall and too heavy. He wanted Piet van der Wal the 500cc Dutch Champion to ride it. We would go testing at Zandvoort, and I said that I wanted a friend of mine to ride it also. Vink did not want to but did not refuse! Van der Wal rode first and was going in the corners fast but came out slow. His times were very slow. Then it was Herman`s turn, he went in the corners slower but came out faster. The result was that Herman lap times was 10 seconds faster than Van der Wal and equalled the lap record. Vink had no other choice than to let Herman ride in Francochamps on the Jamathi. After that I think that Vink had lost the fun of racing because we did not do what he wanted. At the end of 1971 the collaboration with Bruinsma ended. After all the work on the Jamati moped we lost a lot of time on developing the race bike. Only after that we went to Piovaticci we made progress again. Herman went his own way, he could have done very well but I think he was tired of it. Meeting Herman again after many years was great, the same good feelings was right back again. Luckily he felt the same way!

In 1970 Aalt Toersen started riding for Jamathi, did it bring back the motivation again?
When I was sure that Paul could not ride we thought it maybe would end. We never thought that Aalt Toersen would leave Van Veen. We did not know that Van Veen did not pay their riders very well and some other things went wrong. So it was a surprise that Aalt would ride for us. We did get along very well in racing and also personally, we are still good friends. I think that 1970 Aalt had his best year as a rider, his victory after a poor start in Francochamps was great. At that time we made our own pistons which was more and more a big disadvantage. After practice in Assen the bike was running bad, we did not know what to do so we took an old one and with that Aalt was 7 seconds faster and had pole position. Sadly he crashed during the race. We won at Francochamps, Sachsenring and Brno with the same piston but it was finished then. The engine never did run that good after that. We did not have the money to let Mahle make us new pistons, we had to order 20 or 30 and we just couldn`t afford that!

Again you did not get the World Championship, have you ever been mad about Nieto`s riding style (Ulster GP 1969) ?
Mad no! Why? It was just racing and at the Ulster GP in 1969 it was hard racing. They touched and both went off, Nieto was lucky that he could continue. Sadly it was the end of our World Championship but we had a lot of problems that year. Our bike was only ready at the beginning of June, because the moped had taken all our time.

After a few years with Theo Timmer and Jan Bruins in GP`s the Jamathi time ended, how did that feel?
With Theo Timmer we worked very well but at a certain time he wanted to go further alone, Martin and I felt sorry but it was Theo`s decision. We tried another year with Jan Bruins but that did not work out very well, there was too much self-interest. At the beginning of 1973 Jan Huberts telephoned me. He asked me if I would like to work for Morbidelli. I asked him if it would include all the team, but he said it is only you. I said no because I did not want to leave the others alone. Also there was an offer from Minarelli for me alone, and I did not do that either. Halfway through 1974 I wrote a letter to Morbidelli asking if I could work for them, Jamathi was at its end. Also I had a lot of problems with my father whom I lived with. My boss also asked me what I wanted because on Saturdays I never was there and that was the busiest day of the week. The choice was easy bike racing, but I had to live from that! Looking back I should have done it earlier. I got a letter back from Morbidelli that they had somebody else. After a week I got a letter from Piovaticci, (a friend of Morbidelli) if I would work for him. We talked in Assen with Lazzarini who rode for Piovaticci and agreed to go to Pesaro in August for a few days. Martin and I earned no more than 120 guilder a week, Piovaticci offered us 1600 guilder a month including a free apartment. Finally we could work without worrying about money.

Before we continue with Piovaticci we would like to hear what was the greatest moment in the Jamathi time?
Personally in the Jamathi time it was the victory from Paul at Brno, without TV and press. We had a difficult few weeks to get the bike running well. In Brno we were in the wrong paddock which was for the Eastern Bloc riders. We arrived late in the evening and luckily did not know and just parked where there was place to park. The next days were very interesting, we met a lot of new people and the Tjechs had beautiful handmade bikes. Olda Fisser became a good friend and was until he died. Other great moments are, of course, the victory at Assen and Aalt`s fantastic victory at Francochamps after a poor start.
The biggest surprise was the victory of Theo in Hockenheim 1973. Martin and I already left to make new cylinders for the next race. Theo phoned us to tell he had won!!

In 1975 Martin and you went to Piovaticci, how was it finally work out your ideas without worrying about money?
At the beginning it was not easy because we did not speak Italian, but that was only temporary. It was great to just work only on the bikes and not worry about everything else. The first race of the season was at Modena, we had pole position and Piovaticci celebrated that with a dinner with 30 other people. The next day we won with a big lead. We never experienced anything like that before, it looked like there was no lack of money. We worked hard and sometimes Piovaticci came with the President of the Motorcycle Club, the Mayor, chief of the Police and some others. They were all very enthusiastic about bike racing. Bike racing was at that time more important than football. Every day you would hear the latest news, if there was something at Morbidelli we would know it in a few hours. and also the other way. It was a fantastic time!! Lazzarini was very small, we went testing at Misano with the Jamathi in Piovaticci colours. He stopped after one lap because he could not reach the handlebars, the bike was too long for him. We had to shorten the chassis, after that he broke the lap record at Misano. Martin and I made a new chassis for his size. It was very small and was also the first 50cc with cast wheels.

In that same year you had also a 125 2 cylinder (Dutch TT 1975). Was it always a wish to get into the bigger classes?
We were thinking about it for a long time but in the Jamathi time we did not have the resourses to build one. Sadly we made a big mistake at the design and drive. I made the drive from the middle of the crank which also the Japanese had. It was a big disadvantage! Jorg Muller after his experience with the Bridgestone from Jos Schurgers did much better. The idea to put all the power of a 125 2 cylinder transfer through one big end pin on the side was a big risk. Morbidelli sold production racers with the same construction and they broke down a lot because of that.

At the end of 1975 Piovaticci had to stop, although you were doing very good. Did that make you despondent?
That Piovaticci had to stop was a big disappointment, and have never understood what happened. It went very fast. I think there was a problem with a loan from the bank. Not the racing itself. But he was also easy on spending money, he never checked the expenses. The disappointment for himself was even bigger because he lost his factory. A short time after that he died. Martin and I had already an offer to work for Angel Nieto in Spain.

1976 a new start with Bultaco and Nieto. Was it strange to work for Nieto after all those years you were racing against him?
In 1976 we started with Bultaco only with Nieto, two riders would have been impossible. When we got to the factory in January there was nothing. It was not even sure that the equipment from Pesaro would arrive. They could have sold it to others and asked suddenly for more money than what was agreed. At the end of January finally everything came to Spain and stayed another week at customs. The first race of the Spanish Championship was on the first half of February so we only could paint the Piovaticci in Butaco colours. That was our first race with Nieto and we won, our main competitor was Ricardo Tormo on a Kreidler. Right from the start we could get along very well with Angel, never was a problem. It never changed!

We all know Nieto as a rider, but how was he as a human being?
Nieto, as a person was very special, normal and easy going. He had a special gift to turn around things the way he wanted and nothing or no one would get in his way. After winning his first World Championship he was introduced to Spanish dictator Franco. After Franco congratulated him that it was nice but that he had to stop racing. Franco asked why, I cannot earn enough from racing to live on. He then got a life time payment! In 1972 he won two World Championships in Barcelona. The next day he came to the Derbi factory where the owner Sr. Rabassa told him that Derbi had stopped with GP racing because they could not get any more success. The advice Angel got was that it would be better to stop also. He then arranged using the telephone in Rabassa`s office to call Giancarlo Morbidelli to go racing for them the next year.
He is also very superstitious. If you go to have something to eat and there are 13 people at the table one has to go. He does not like to get called 13 times World Champion. So it is 12+1.

Another competitor at that time was Jorg Muler. Did you see each other as colleagues and did you talk to each other, or was there no contact at all?
With Jorg Muller we had a good relationship. When we were in Pesaro sometimes we went for something to eat and he visited me sometimes at my home. We were invited to Morbidelli`s home which was fun. On a Saturday the people from Piovaticci race department visted the race deparment of Morbidelli. After that we went on Morbidelli`s fishing boat, a fishnet was thrown in the water and spaghetti was made. Then there was drinks which were stored everywhere in huge amounts. After a short while we drank a lot of drinks until the Police boat arrived. We were not allowed to fish so we got a ticket. When they left again Morbidelli said I will take care of that tomorrow, I will call his boss. We brought the fish to a restaurant and it was eaten by us in the evening, we had a lot of fun. It was a great time in Pesaro but sadly at the end of that year it was finished and we went to Spain. Jorg is someone who likes peoples’ attention, but in this business you have to understand that the people who pay the bills not always are nice. They pay money to race and to get their name known. When we started working for Minarelli it was very clear that the main goal was to win without Jorg Mulller. Also Jorg and Angel were no friends either, obvious they wanted both attention. We did not have that problem. A few years ago I met Jorg in Bologna, it was nice to see him again. We would have worked together with Italjet, but Italjet went bankrupt.

When Martin went back to the Netherlands you were on your own. After working for so many years how did that feel?
That Martin at the end of 1981 went back to the Netherlands was clear for a long time. I think he was not really happy at Minarelli and also he wanted his children to go to school in the Netherlands. We still stayed friends and I always visit him when I am in the Netherlands. Sadly he did not get old.

The last few years you were only developing the 2 stroke engine and not the chassis. How did you manage to improve every year finding something new?
You try to find more power through small changes on the transfer ports, different shapes and which is done through cnc machining. Also with different exhausts sizes. But the last years there was little progress. The last big step was the electronically controlled power jet.

Were you ever working on development of injection on a 2 stroke?
Not really, it was made for the 500 2 cylinder and tried on a 125 only on the test bench. Normally on the test bench it would work good, Van Veen had already tried it in 1969, I think. And also Jan Eggens has tried it to, but the problems only happen on the circuit. Cagiva have worked on it and it seemed to work, also Honda did but never made a final version to use on 2 stroke bikes. The best would be direct injection but is hard to make and you would need another lubrication system. Maybe it will come one day but there is no money for 2 stroke development.

Do you think there will be improvements in the next years in 2 stroke development?
It will be difficult to get more power out of the existing 2 strokes. Variable intake timing could bring something, more torque in bottom and top rpm. Also to study the flow from the crankcase to the transfer ports could bring something, You never know what is happening between the bottom of the piston and crank. A big step forward could be another flushing system (Frits Overmars, FOS or Luc Fokkema`s FST). Only time will tell!

You are now retired does that mean you stopped with everything or is it possible we see you on a race somewhere?
Maybe I will go to a GP, probably Malaysia, it`s not so far from here. I do not expect to go to Europe again but never say never, there are stranger things could happened to me.

Ok Jan we wanted to know all details but as a last question what is the most strange thing that has happened to you?
The 250 race was stopped when it started to rain. The time schedule was a puzzle after that and nobody knew when the 125cc race would start. We saw other riders so we got to the start, we were just in time. A few others including Tormo were too late 20 or 25 seconds. Zegwaard, a Dutchman went to the organisers to say some were too late. These 2 or 3 riders were not allowed to start. Tormo went to Nieto to tell him, Angel gave me his bike and went to the organisers. While this was going on the sign 1 minute was shown. And there I was very nervous. The start was delayed. After 5 minutes the race started and everybody was allowed to race. The next day we could read in the newspaper that when all riders had left the organisers decided to disqualify the riders that were late. Very unsporting from the organisation, it is a sport not a concentration camp. When I think about it now it still makes me mad!

Jan, Thanks for this interview on behalf of all bike fans!!
Thanks for what you did with a small team, giving us a lot of pleasure to watch racing!!

We Will Never Forget JAMATHI.

Ben Looijen 2009 translated by David McCallister