Cycle News - Archive Issues - 2000's

!he heritage of !he lanky Mr. Rossi, !he Italian bike fit me very well. The Rolfo Honda I'd earlier sampled at Catalunya, which had finished runner-up behind him, was already a tight squeeze for a 6-foot rider, so Ifelt more draped over !he bike than sitting on it or especially in it, as you do in the more streamlined Aprilia. What on earth was the Pedrosa RS250R-W going to feel like? Well, it was not as bad as Iwas expecting when I came to sling a leg over it in pit lane at Jerez - but only after the Telefonica Honda mechanics had modified the bike a little, retaining Pedrosa's narrow, minimalist bodywork and tiny, abbreviated screen, but fitting Aoyama's footrests (the same height as Pedrosa's, but further back - seemingly excessively so) plus his seat, which was deprived of the IOem-thick carbon/rubber seat pad the Spaniard uses to push what little bodyweight he has further forward to load up the front wheel. The Honda also bore Aoyama's handlebars, flatter and more raised than the steeply dropped c1ipons derived from Pedrosa's 12Scc GP days. In spite of this, there was a lot of bodyweight on my shoulders and not a whole lot of leverage to correct a slide, though the fact that the grippy but forgiving Dunlop tires give you early warning of this made that less of a concern. The result felt very close-coupled and compact, but I did manage to feel more or less at home on it for a few laps before my right leg started to get a Rolfo-Iike cramp! Out on the track, the single biggest improvement over the Rolfo bike from a year ago came to the fore immediately, because while all the attention of its rivals has been misdirected at whinging about weight, and while they themselves perhaps got sidetracked witlh the chassis issue, HRC's engineers have been busy working at what they do best: getting more power without compromising rideability out of the 54xS4.5mm 75-degree V-twin crankcase reed-valve engine, whose single-crank format and closed-up cylinder angle (a key element in helping Honda deliver such a compact 2SOcc GP-class contender) dictates fitting a balance shaft to smooth out vibrations. Honda has not only gotten more power out of the engine at peak revs, it has also significantly broadened the spread of power and above all given the 250 two-stroke an 600 Supersport. So, compared to a year ago, the Pedrosa (Left) The proper factory cockpltllpCl.... and Spartan. (Cen....) Internals exposed. (Right) "I'd probably be better oH with the full-scare version, dan'tcha think?I" RS250R-W pulls strongly from a thousand revs lower than Rolfo's '03 bike, driving well from 8000 rpm upward out of the slow turntwo hairpin and accelerating strongly to the I I,Soo-rpm mark, where it really catches fire and builds power fast to the I3,BOO-rpm peak. Even there, it doesn't falloff the pipe suddenly, allowing you to hold a gear between turns if you need to. By any standards (meaning tlhe more potent but peakier Aprilia!) this is an ultraflexible, torquey motor witlh a huge spread of power for tlhe 250cc GP class. You can even short-shift witlh impunity to get a good, balanced drive around the pair of left-handers opposite tlhe pits. The 2004 RS250R-W represents an effective counter to the Aprilia's undoubted horsepower advantage, because a year ago the Honda produced maximum power 1000 revs lower at 12,500 rpm and was all done just SOO revs above that. It fell off the pipe quite steeply, and there was very little overrev. A 4000 rpm powerband means you must be extremely precise in the way you ride - hard to do in the no-prisoners arena tlhat is 2SOcc Grand Prix racing. It also dictates even more careful setup of tlhe internal gear ratios for each circuit on a bike that would have had to be ridden right on tlhe limit in every turn, every lap to redress the performance disadvantage between a glorified production racer with its 10-year-old basic engine design and the latest example of Aprilia's factory hardware. Honda engineers did a good job of transforming this into a title-winning package, because by comparison, Pedrosa's World Champion bike felt torquey and powerful, with that legendary Honda rideability tlhat makes you feel it's responding to what you ask it to do, not telling you this is how it must be ridden. That applies to the chassis, too. So while the Honda does feel a little nervous and falls right on its side as soon as you even tlhink about laying it into a tum, it is slim, light-steering, fast-handling and comes smoothly on to the tlhrottle exiting a tum in terms of tlhe pickup and power delivery, allowing you to make the most of tlhat much wider powerband than its predecessor. But in spite of what is obviously a pretty short wheelbase, witlh radical steering geometry that helps make the bike so agile, it's still very stable though fast sweeping turns, such as the last two right-handers behind tlhe pits leading to the last tight left onto the pit straight at Jerez, and even (thanks to tlhe well set up 5howa suspension) one with a bump in tlhe middle, such as tlhe off-camber Sito Pons tlhird-gear right-hander leading onto the Jerez back straight. I have to admit I didn't feel very aerodynamic tlhere, though, as I hit top gear rocketing down that straight on the little bike with my shoulders and knees sticking out of tlhe abbreviated bodywork, not to mention my helmet parked in tlhe breeze above tlhe tiny screen. Where tlhe Honda really scores is with its light, fleet handling. It's very responsive, though the short wheelbase and quite fierce radial brakes did promote noticeable weight transfer so that the back wheel waved around in the air under tlhe hard braking still delivered by the downsized 255mm Brembo discs. These are smaller compared to the 296mm ones the heavier Rolfo had to use in 2003, so they are also a factor in making tlhe '04 Honda steer faster, thanks to their reduced gyroscopic mass and further reducing unsprung weight. The chassis is a lighter, stiffer, handmade version of the original RS frame, witlh detail improvements such as an Aprilia-style carbon-fiber seat unit that removes the need for an aluminum subframe, plus the Showa suspension is the tricked-out kind only used on factory bikes. The short wheelbase and Ioo-plus horsepower also meant the Honda's front wheel lifted each lap exiting tlhe last tum unless I made a point of weighting the footrests and moving my weight forward - a fact which underlined tlhe meaty torque delivered by the tiny bike's punchy engine, as tlhe blue shifter light on tlhe dash flashes in your eyes telling you now would be tlhe best time to hit another gear. Interestingly, the revs at which this happens are varied according to the gear selected: 12,500 rpm for tlhe bottom three improbable amount of midrange torque by !he standards of the class. It's almost as forgiving and friendly an engine as a four-stroke 40 APRIL 13, 2005 • CYCLE NEWS shifts, to help you ride that meaty torque curve, then 13,500 rpm for tlhe top two, to maximize the benefits of peak power. Nice touch, and typically Honda - as is the fact that the two exhaust expansion chambers (both fitted with Honda's trademark RCpowervalves) are each made from a different material: titanium for the upper one, which gets more cooling air thrown at it at speed; steel for the lower one, which is shrouded by the cylinder. The magnesiumbodied Keihin powerjet flatslide carbs are slightly bigger on the W-bike than the 3Bmm aluminum-made ones in the stock RS2S0R, and for sure, cylinder porting and the choice of maps for the digital ignition's CDU are also tricked-out. For this is a proper factory racer, complete with detonator sensor that flashes another light on the right of the dash when it pinks while also shOWing the number of detonations on a digital display on the dash, alongside the lap time and water temp readout. This would allow you to dial up another, less-radical ignition map when the count gets too high and you risk holing a piston - or it would if a handlebar button were actually fitted. This was probably removed from the test bike, as was the option of SWitching between EFI maps removed from the RC21 IV we were riding the same day. Can't trust a bunch of journalists not to play around with tlhe switches! Settling for second best has never been "the Honda way" - and witlh Dani Pedrosa's help, HRC's smart engineers created a winning package that allowed tlhem to regain their coveted 250cc World title, while still retaining tlheir l25cc supremacy. thanks to Andrea Dovizioso. Too bad tlhe Rossi factor spoiled Honda's hat trick of World titles! eN

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