Cycle News - Archive Issues - 1990's

RACER TEST Tadayuki Okada's Honda NSR250 in practice you need to work the superbaction speed-shifter hard enough to keep it revving above nine grand, where serious power comes on strong. But while the '94 bike J rode seemed to flatten out a little as it approached peak power at 13,000 rpm (with a useful over~ rev to 14,000 to sa ve a gear change if needed, before power drops off steeply), this year's bike has more top-end punch. That's assuming they jet it the same for the press test each year, using the detonation sensor which became a valued tool of Honda tuners in '94, with the new fuel. But feedback from the lease teams does hold that carburetion settings on the '95 SR250 with it bigger, Power-Jet-equipped carbs, are critical in getting good speed. One reason offered for Waldmann's pre-eminence as top Honda rider this season is that his tuner Sepp Schlogl learned the art of razoredged carb jetting during the years he honed Toni Mang's rotary-valve Kawasakis to a fistful of world titles, as an apprenticeship to his 10 years tunning NSR250s for Toni, then Helmut Bradl and now Waldmann. What goes around, comes around - but of course, works Hondas never seize, do they? They just have "ignition failure" .... Helping you keep the Honda hunting up high is a new gizmo introduced this season, borrowed from the racing (Above) An allonew, wider frame was used to By Alan Cathcart Photos by Emilio Jimenez I t has been a long time since Honda was reduced to making up the numbers in the 250cc Grand Prix class, but in 1995 that's what eventually happened. While the year started off auspiciously enough, with NSR250-mounted Ralf Waldmann taking an early lead in the World Championship after winning two of the first three races, Honda's season went downhill after that. Though Waldmann won one more GP in France, and Doriano Romboni completed the roster of '95 Honda GP victories in Brazil, the race for the title became a straight fight betw~n Biaggi's dominant rotary-valve Aprilia and Harada's muchimproved Yamaha. Even '94 championship. runner-up Tadayuki Okada on HRC's own fuJI-works NSR250 couldn't challenge for victory, winding up fourth in the points table behind Waldmann, after never getting higher than third on the ro trum all season. The fact that the '95 NSR250 failed to deliver on its early-season promise must have been a keen disappointment for HRC's engineers, as well as their halfdozen customer lease teams, given the major changes they wrought on the bike for this season. But Loris Capirossi's departure to the 500cc class and Romboni's critically underfunded '95 operation were two big handicaps compared to 1994, the year Honda came very dose to winning the title. However, the fact that the bike had been completely redesigned for this season, with an allnew frame intended to sharpen the handling and remove the understeer which NSR250 riders have been complaining of ever since the current 75-degree Vtwin made its title-winning debut in Luca Cadalora's hands back in 1992, had augured for better, especially as Honda also improved the performance of the address handling problems. The extra width also made room for a larger alrbox. (Right) Attar gsttIng a strong start to the '95 _son, Honda's 250cc fortunes fall. Though Ralf Waldmann and Tadayukl Okada finished third and fourth, respectlvaly, In the championship, It was a disappointment after the axtenslve changes made to the NSR. reed-valve motor. This powerplant was progressively developed during the season to deliver 3-4 bhp more at the top end compared to 1994, thanks to new cylinders which debuted at Suzuka in April, as well as slightly revised exhausts - though improvement in midrange power, already very strong and usable, was only slight. But the extra horses must mean that Honda has now breached the 100-bhp barrier on their works 250 (believed to deliver 97 bhp last year) - a fact that augurs well for HRC's latest project, announced at the Catalunya GP the same weekend J came to the Spanish circuit to test Okada's bike: a 100-degree V-twin 500, presumably quite closely based on the NSR250, which Okada will race in 1996 in a development season aimed at putting the model into production for customer sale in 1997. Light, slim, easy-handling and forgiving, with a good power-to-weight ratio - those are the existing qualities of the NSR250 that HRC's team of development engineers will surely be focusing on replicating on its half-liter big brother, qualities that come to the fore when you squeeze yourself aboard a bike that in its latest guise seems even more diminutive than its predecessor - or maybe it just seemed that way because I'd been riding Mick Doohan's NSR500 right beforehand! In fact, the new chassis is actually wider than before, with curved spars rather than the R5250-type straight beams, which in tu m gives space for a larger airbox for the twin 39mm Keihin carbs (lmm bigger than previously) to breathe in. The engine has new crankcases compared to the '94 bike, has been rotated forward and sits higher in the frame than last season's, all aimed at putting more weight on the front wheel to obtain improved balance and make it hold a line better under power, says NSR250 chief engineer Hisashi Kadomasu. And the power is there: Was it ever not, on a Honda? Well, yes, last season, when I rode Okada's bike and wrote that it hadn't felt as much like the , "J-coulda-been-a-500-contender" as Honda's works 250 has always seemed: not as much zip as before. Maybe that was due to the new low-octane fuel regulations introduced for '94, which apparently affected the reed-valve Japanese bikes more than the Italian rotary-valve stallion. But whatever the cause, Okada's latest bike has recovered its missing zing. As before, it will pull forgivingly from as low as 7000 rpm, but car world and John Britten, whose Vtwin racers had it from (nearly) day one - a red light incorporated in the face of the tachometer that flashes when you get close to peak revs (at about 12,800 rpm) and tells you when it's time to change up. Having a reminder when to hit that precise-but-not-oversensitive, wide-open gear shifter is a real bonus -" especially if, like me, you're struggling to tuck several inches of excess height away behind that beautifully shaped aerodynamic screen, and can't read the tach properly while doing so. For Okada-san and his teammates, though, it underlines the importance of maximizing the uprated SR250 motor's extra top-end performance, by keeping it revving extremely high as much as possible. Internal ratio selection for the side-loading gear cluster must now be even more critical for Honda riders on most circuits - but don't get the impression from this that the NSR250 has become peaky and unforgiving. Thanks to a clever, mainly electronic, juggling act by HRC engineers, it's still just as torquey and ridable in midrange as ever before. Only that, to try to keep up with Mad Max's ever-more-potent Aprilia in a straight line or on acceleration out of turns, you have to go for the increased

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