Cycle News - Archive Issues - 2000's

Cycle News 2004 01 21

Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles

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w ill wreak major changes in the characte r of this mot o rcycle from the very beginning - he' ll wa nt to take it back to t he basics, with a more user-friendly powerband at the top of his wish-list and less electro nic co ntrol in pursuit of a simpler bike imparting more feel to t he rider. As it is, you feel slightly detache d fro m what the Yamaha's doing - physically, you feel a part of the M I, thanks to its well, t hought-out architecture - but me ntally not . I can't rea llysee the po int of such extreme electro nic management on the e ngine braking, except to satisfy riders w ho were brought up racing ring-dings and haven't been able to adapt to riding fo ur-stro kes , because t he Ducati brakes even bette r withou t any of th is electronic intervention, just a good old-fashioned slipper clutch like the Yamaha already has. Bet cha one of t he first things Valentino te lls Y amaha is to bin the dot.corn stuff in favor of a syste m that gives mor e than a mod icum of e ngine braking and w here t he rider knows he's in charge of t he bike, not a compute r. He'll also be looking for a w ide r power band with extra midra nge engine pe rformance compare d to the MI as I rode it, wh ich is much peak ier t han the Ho nda I samp led two days later, with a mo re aggressive power delive ry. W hereas with the Honda V5 you can fire it out of a be nd hard on the gas much earlier than the Yamaha and keep the throttle pinned , with the front wheel just hovering off the groun d as you're irres istibly trans ported to warp facto r 10, o n the MI it's hard to keep acce lerat ing wide ope n all the time because the power deiivery is so much mo re peaky, as br utal in its de livery as a two-st roke of yesteryear. but wit h even more power on tap . The Yamaha is the "nearly" bike of mod ern-day MotoGP - it nearly proved a matc h for the Ho ndas in 2002 , thanks to t he brilliance of Max Biaggi, who sco red two GP victories o n it fo r the facto ry t hen got fired for te lling it like it is about a bike on w hich he won races in spite of, as much as because of, its e ngineeri ng DNA. Yamaha implicitly recognized he might have had a point by making the host of changes that resu lted in t he 2003 bike I rode at Valencia - but while brimming w ith pot enti al, this too is a nea rly competitive package that just lacks the last fractiona l per centage to be on par with the Hond as - and, now. the Ducatis as we ll! - o n every kind of circuit. By hiring Rossi, Yamaha has shown it's not afraid to go for broke - because if Valentino isn't winning on t he YZF-MI by t his time a year from now, then it'll be the bike's fault, and if he do es succeed in turning it into a winner, then of course he'll get a big slice of the kudos. But t hen Ichiroh Yoda and his men in Yamaha Raci ng Divisio n will have the satisfaction of knowing they turne d the ta bles on Ho nda - if this happens, and it's a big if. But with the number 46 on the fairing and its owner in the hot seat , chances are that things w ill change next seaso n - but only after a lot of alte rat ions aime d at simplifying wha t seems to be an unduly com plex design, improving the handling and smoothing o ut the power delivery. It'll be nice to ride the YZF-M I again a year from now, after twelve months of Rossi refinement. I bet it'll be a very different motorcycle from the one I rode at Valencia eN th is time arou nd. But doesn't t his have a neg ative effect on the handling? Q A Y because last year es, at first we had some chassis prob- ems with understeering, especially under acceleration. Basically, this came from weight transfer fron t to rear, so we A A We began thinki ng top speed will be most important, so we ~esigned good streamlin ing for the bike . But now we rea l- ize an easy change o f direction is the biggest factor we must aim tried several engine positions to change weight distribution and for, so we cut some area o f the cowling for a more compact and found the proper location in this w ay. We reduced forward slant aggressive-looking fairing, which we introduced at Suzuka at the areas of handling - we have a lot of experience of reverse crank , of the cylinders to allow this and altered weight balance by about start of this season. This red uces the crosswind drag coe fficient normal crankor twin crank! But it is hard to say if rearwards rotation affects rear o r front grip - indeed, we found it affects 3 perce nt. Our aim was to concentrate mass and reduce polar by 20 percent com pared to the original M I fairing design, but movement as much as po ssible to achieve better balance in without detriment to the straight- line aerodynamics . suspensionbehavior less than normal system. Basically we . handling by bringing the center of mass and center o f gravity found damping balance or spring characte r or rigidity all have close together. N ow our weight distribution is SS/4S-percent more influence than cranks haft rotation . I don't want to experi- static, which you will find is very common in the MotoGP pad- ment with a differen t rotation at present. dock, to reduce wheelies . Ya ma ha naturally uses an electronic engine ma nageme nt system wit h the fue l injectio n. Does t his include t raction co nt roll Q We tested this many times on the YZRSO and some other O ~otorcycles . and for sure crankshaft rotation affects some Q A Yes. of course . We have control off the start line, then ~gai n in the race if the tire is going down; the rider can select a different map with softer drive . And also, we have a choice of less engine braking or more engine braking . as he wis hes, as well as a ramp-type slipper clutch. A A I hope that won't be necessary - but we will do whatever ~s necessary to make M r. Rossi wi n for Yamaha . We badly I can't tell you exactly why, but this just seems to work best want to win - very much . Since 199 2 we did not win the Riders' with Michelin's 17-inch tire , whic h we presently use. They world title, so this is a good chance for us to change that! asked us to try 16.S-inch tires front and rear, w hich seems to be the way they are working for the future , with m ore rubber on the tarmac this way. Although this makes the steering more heavy, if the riders have more grip, they w ill be content . But we tried 16.S-inch front tire many times, and with our bike it just Did you mo dify the M I's intake system for 2003, with t he adoption of fue l injection? doesn't work! Yes - the pressurized carbon airbox is 20 percent larger Q Q A ThiS also he lps fron t -end gr ip - is t his why you use a 3.6-inch front wheel, for a la rg er contact patch, ra ther than t he more usual 3.S-inch one? But let 's imagine t hat Valen tino fina lly tests the bike in t he second ha lf of Janu ary, and he doesn't like it - he asks yo u t o make big changes in its de sign . Wh at will you do t he n - are you prepared to t ear up t he curre nt design and start all over again? Q M.now thanwhen we began MotoGp, andthisisfed bya mod ified high-pressure ram air intake system with a different intake A IS t he M I right on t he 14Skg (320 Ibs.) four -cylinder we ight limit ? From the beginning our machine was very light - with car- mou th to prevent sacrificing the engine's cooling. But this #-\i,uretors fitted, it weighed 143kg (315 Ibs.), so we must increased airbox capacity is a direct result of the new low-slung add ballast! But at the moment, with injection and other attach - fuel tank. which carries most o f its capacity low in the chassis lay- ments, it is a little bit over - 147kg(323 Ibs.) or so, even with- out to provide space for the larger airbox . This also has extra out the TV cameras we must carry. So many cameras now , bene fits, by low ering the center of gravity and reducing the pitch- sometimesnearly ISOkg (330 Ibs.) ifthey are very heavy. We ing effectexperienced under heavy braking witha full fuel load. must tell the riders , please don't eat breakfast! ln pursuit of t hose aims , did you ex pe rime nt very mu ch with engi ne locat ion in developi ng the M I's chassis? s o Valentino must look forward t o going on a diet . How ab out streamlining - he's pretty tall, so what a re Yamaha's t ho ugh ts about this ? Q Q www.cyclenews.com CYC LE N EWS • JANUARY 21 , 2004 33

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