In 1997, Kenny Roberts surprised the racing world by leaving Yamaha after a splendid racing career to create his own motorcycle team.
Basing his new company in Banbury, England to capitalize on the Formula 1 industry, Kenny Roberts had a 500cc three-cylinder 2-stroke engine built by Tom Walkinshaw Racing.
The bike managed to secure a pole position with Jeremy McWilliams at the 2002 Australian Grand Prix against the new generation of MotoGP but it seems obvious that the regulations now favor the 4cc 990-strokes.
During the winter of 2002/2003, with the financial contribution of the Malaysian company Proton (Malaysian car manufacturer, owner of Lotus since 1998), Kenny Roberts therefore designed a 5-cylinder V-shaped engine (3 in front, 2 behind) by John Barnard, the former chief engineer of the Ferrari F1 team, like the engine of the Honda RC211V at 75,5°. The 5° V60 Proton is manufactured by Lotus.
Kenny roberts : « We studied the regulations, took into account the different possibilities and, like Honda, we concluded that the five-cylinder was the best choice. Four- and five-cylinder motorcycles have the same weight limit: 145 kilos. So why would we want to make a four-cylinder? Once the decision was made, the engine architecture imposed itself. The new Proton KR is similar to the Honda with its transverse V engine, with three cylinders in front and two behind; the Honda block is however much more open with a V at 75.5°. The angle of our motor is 60°; We chose this angle after running computer simulations and studying the problem with our engineers. We think the engine is more compact this way. In F1, everyone uses V10s, but no one accuses anyone of copying from someone else. We don't want to try to reinvent the wheel, as was the case with the 2-stroke. That's the last thing we want. We are a small independent engineering company and we do not want to embark on a three-year research and development program. This is why we do not want to take inspiration from F1, from pneumatic distribution for example. We want to develop a machine that is in the game from the start. »
Initially expected in Jerez, the KR5 was delayed and the KR3 2-strokes, slower but lighter, were used again.
Kenny roberts : « Development of the new bike is going as fast as possible, but it won't be entered into racing until it's ready. It's irritating, but that's what we expected. »
Chuck Aksland, team manager, confirms: “Our first target was Jerez, but when everything comes together then you run into the next problem. It's a very complex new bike and there are a lot of systems to try before we know how much faster it is than the two-stroke. »
Finally, the V5 engine made its debut during the 2003 Italian Grand Prix, at Mugello, again with Jeremy McWilliams et Nobuatsu Aoki. Powerful, the KR5's engine, however, needs more electronic development to fully exploit its potential, as well as more competitive tires. The best result of his career was achieved, once again, by Jeremy McWilliams during the 2003 Australian Grand Prix (11th in the race while he was 6th in France with the KR3).
In 2004, only one machine is lined up regularly to Nobuatsu Aoki (and sometimes one for Kurtis Roberts ou James Haydon), and despite a 13th place finish at Mugello, it becomes obvious that the team Kenny roberts is unable to develop the engine to compete with the dominant Japanese factories.
Kenny roberts therefore signs a partnership with KTM for the supply of a 4 degree V75 for 2005, rated at 230 hp at 15 rpm, pneumatic valve return, titanium connecting rods, plain bearings, dry clutch, dry sump, gearbox cassette and camshaft by cascade of gears.
Indeed, after considering setting up an official team, the Austrians finally accepted an agreement with Kenny Roberts to integrate their engine into his Proton KR chassis. KTM provides the engines, the driver's salary (Shane Byrne) and Michelin tires, Kenny roberts takes care of the rest. In total, around fifteen engines will be built.
Nobuatsu Aoki makes the first taxi in Brno (photo below), then Jeremy McWilliams, who left for Aprilia for a year, was called back as reinforcement to carry out the first tests on the Jerez circuit. The Briton clocked his best time in 1'43.00 and believes he could have beaten the race lap record (1'42.788) set by Valentino Rossi in 2003.
Jeremy McWilliams : « I probably could have done better. If I had had one or two more days, I could have gone down to 1'42.0. I was impressed. I did not expect this. There is a lot of potential, but the bike is already easy to ride. The sensations are deceptive: I didn't think I would go so fast. The behavior is great and the engine is flexible and docile. This machine is nothing like the Proton V5 I rode in 2003. It is much better in every way. The chassis is efficient and the engine is powerful, with a fairly wide range of use and great revs. During these tests, we were only four or five km/h away from the Hondas at top speed! »
Chuck Aksland, team manager, shares the general enthusiasm: “This is the first time that the driver has not asked for more horsepower. We had a higher version of the engine, but Jeremy didn't want to try it. The one he tested already worked so well! These good times crowned an overall very positive test session. Thanks to the help of Michelin, we were able to test a combination, between our chassis, the KTM engine and their tires, which could allow us to be competitive. It took us eight years to get here, acquiring knowledge and experience, often with difficulty. Technically, it's the best package we've ever had. »
Only one motorcycle is lined up for the first Grand Prix in Jerez, with Shane byrne on his handlebars.
Unfortunately, the euphoria quickly fades and, due to the lack of a high-performance ECU, the Proton-KTM will never be able to do better than 15th at Laguna Seca. Despite a final planned stint for Jeremy Mc Williams, and due to a lack of financial agreement with the American champion, the Austrian firm withdrew during the season, on the eve of the Czech Republic Grand Prix in Brno, leaving the legendary American's team without engine for 6 races.
The decision, the result of long deliberations within KTM management, does not affect the brand's 125 and 250 programs.
Among the reasons for this decision, the change in regulations reducing the capacity of engines to 800cc from 2007, while KTM debuted in MotoGP this year with a 4cc V990. The press release published by KTM also indicates that the firm's desire was, originally, to be a simple engine manufacturer in MotoGP, and not to officially support a team. KTM, however, provided financial assistance to Team Roberts, allowing it to hire Shane Byrne and be able to race on Michelin tires. KTM also took into account the interest presented by the development of a 990cc condemned to be replaced in the short term.
With the help of Honda, the Proton was finally equipped with the 5-cylinder RC211V, at the last minute for the last Grand Prix of the year in Valencia.
Things immediately got better and 2006 saw Kenny Roberts Junior seize 6th place in the world championship!
2007 saw the introduction of new regulations concerning MotoGP engines, limited to 800cc, and Honda once again met the demand of the American three-time 500cc world champion by supplying RC212Vs.
But, all that is already another story because since the end of 2005, Proton no longer finances the team, and it will have to cease these activities at the end of 2007, due to the lack of financial support...
Sources: MotoGP.com and KTM.