Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/128350
EXCLUSIVE: Rossi's New M I W o rld Champion Valentino Rossi made his debut on the brand-new 2005 Yamaha MI at the Ricardo Torma Circuit in Valencia, Spain, on Wednesday, November 3, just two days after the 2004 World Championship wrapped up at the same venue. On just his third lap, Rossi was down to a straight I:34 lap time - as good as Alex Barros had managed to do in the race on his Repsol Honda . Rossi went on to set a best of I:33.45, which compares favorably to the best lap turned in by Max Biagg; in the race - a 1:33.58. Still called the MI, this bike could easily be called an M2, as there really doesn't appear to be any part carried over. Although there are similarities to the previous M I design, (rom what we can see behind the immaculately made fairings, the engine, the frame and the swingarnn look completely new. Using a design a similar to that seen on the RIIR6 engines, the clutch is now much higher and sits just in front of the rider's right shin. This has allowed Yamaha to shorten the engine block and use a swingarnn approximately 20mm longer at the front . This also has the effect of raising the center of gravity of the engine. When Rossi and crew chief Jerry limit its perfornnance potential in MotoGP. One of the biggest problems is the lift generated at high speed. At a few places this season, you could see that Rossi's bike wanted to lift at high speed (over the crest on the main straight at Mugello would be a good example) . But it's not just straight-line lift that can be a problem - what really gets scary is that lift at high speeds can really damage front-tire grip in long corners. Minimizing that problem will allow Rossi to attack highspeed corners wi th more aggression. 8y raising the he ight of the Burgess arrived at Yamaha, their first by over 20mm. enabling the bike to stop and change direction quicker. They also lengthened the swingarnn to let Rossi use his body weight to adjust traction while riding. Simply taking an old design and raising it. however. had some side effects that would actions were to raise the old bike 6 NOVEMBER 17,2004 • bike, Burge ss solved some problems but got close to creating others. That was all right this season. but it won't be if Yamaha is to stay on top . To stop high-speed lift from becoming a problem, Yamaha needed to get the height of the bike down but wanted to keep the cen ter of gravity as high as it was this season. Going back to a bike as low as the one it started this year with. but with a higher weight inside the bike. would give Yamaha the chance of having everything it needed to make the bike worlk in all situations. for the gearbox sprocket and swingarnn pivot. While the benefit he achieved was worth it at the time. this redesign will see that distortion corrected, allowing Rossi more control of the rear as well. To move things around inside this much meant that a completely new chassis and engine layout was needed, and that's what we can see here. All the adjustments on the old bike were at their extremes. while the new one allows Rossi and Burgess to spend the next five months dialing this one in. With the clutch now up on the back of the engine block. the weight of that and the it have been raised. The new vertical layout gearbox is also shorter, allowing for a longer swingarnn. The decision to show the bike this early at a public test might seem crazy. but it shows how confident the team is after this season. The bike we see here is very much a finished piece • new engine layout, new bodywork. better aerodynamics - and if you are an opposing team, you now know that you either have a lot of new stuff already on the way to improve your own bike, or you are in trouble . Changes for the '05 M I • New engine layout with clutch further up the back of the engine: This will mean a shorter vertical layout gearbox. Engine probably uses the 2004 motors crankshaft. pistons and head - possibly with improved stuff to follow later. • New chassis allowing weight further up, but keeping overall bike low. Different front engine mounts to keep the right frame flex and allow a better exit for the hot air from the radiator. All adjustments are now in the middle of their ranges. allowing Rossi and Burgess room to adjust. • New longer swingarm: Easier to By raising the bike, Burgess had also distorted the relationship Yamaha had designed CYCLE NEWS gearbox shaft and gears that will be behind 40th Anniversary get the right flex and stability . • New carbon fiber fairing and bodywork; better radiator exhaust duets and cleaner air intake area on the nose. • Carbon fuel tank for ultra-light weight . • An Ohlins fork with a different clamp on the bottom. and the old "non extended" top - presumably a modified version of the TT25 used on the '04 model. • Yamaha and Rossi are on the pace already and they has fIVe months to fiddle with the setup and get it right. Neil Spalding