Cycle News - Archive Issues - 1990's

Tetsuya Harada's Yamaha TZM250 T 22 r ue g stron f craftiness - IS W at made ama a's Tetsuya Harada the 1993 250cc World Champion, in his debut season in Grand Prix racing. Anyone who watched the cheerful young Japanese star out-wit Loris Capirossi in the final GP of the year in jarama, Spain, couldn't fail to realize that here was one of the most astute riders of modem times at work. His dash and daring had turned the established order of 250cc GP racing on its head, and turned Yamaha's modified version of its TZ250 production racer into one of the most unexpected champions of recent years. Unexpected, because with so much of their corporate effort, and budget, expended on the high-profile 500cc . class, Yamaha's attempt to regain the 250cc world title - which they last won in 1990 (also against the odds) with the YZR250 and John Kocinski - was a true underdog challenge to the might of Honda and Aprilia. Heavily outnumbered by the seven works NSR250 Hondas and almost as many factory-backed Aprilias, the trio of TZ250M Yamahas ridden by [ochen Schmid and PierFrancesco Chili for the German Mitsui and Italian Valesi teams, respectively, (with newcomer Harada almost imposed on the Telkor-backed Italians as an afterthought - the price of getting factory Yamaha backing), weren't con- b tle s e title from on a s grasp, on a sower bike, had given some clue to his potential, which was confirmed by his explosive start to the '93 season when he outrode none other than John Kocinski to snatch victory in the first GP of the sea. son in Australia. Though his run of three wins and two second places in the first seven races was eventually diluted by two sixth-place finishes on fast tracks in Austria and Germany, where the Yamaha was outpowered by the Hondas, Harada seemed set to be a runaway World Champion. Then he was injured at Donington Park, through no fault of his own, when another rider fell off in front of him. True grit gained him crucial points in the next race in Czechoslovakia, and though he crashed again at Misano - probably by riding too hard while still injured, in an effort to stem Capirossi's charge - he out-thought the Italian to win at [arama and take the title, in a nerve-wracking finale to the season. The chance to ride Harada 's titlewinning TZ250M at Yamaha's Fukuroi test track put the scale of his achievement into perspective. Having previously sampled the works Aprilias and a pair of factory NSR25Q Hondas, I had a yardstick to compare the bike with. Frankly, it just doesn't match up - not because Yamaha couldn't deliver the same performance if they wanted to, cy after last winnin in 1990 with the Y concentrate their efforts on eve opmg a tricked-out version of their TZ250 production racer, with ensuing benefits for development of both their customer race bike and their street-legal race replicas in the ultra-eompetitive 250cc road market. In a way, the fact that they've managed to win the coveted world title while following this policy is not just icing on the cake, but implicit justification for adopting it in the first place. However, it also means that Harada is some kind of superman to win the World Championship in his first season of GP racing on a bike that is genuinely outpaced by the opposition - as the Hockenheim and Salzburg results confirmed. So why didn't Yamaha simply continue development of Kocinski's titlewinning YZR250 V-twin, with its more di rect spin-off benefits from the 500cc GP development program, rather than concentrate on the mirror-image TZ250? (The TZ250 has the left-hand cylinder of the single-crank, 90-degree, V-twin, crankcase reed-valve motor pointing upright and the right-hand one towards the ground, rather than the other way round on the YZR250) The reason, says Yamaha 's 250cc GP development engineer Ichiroh Yoda, is because the company wanted a direct link between the if; the chain r the to fit With an airbox an other assort road hardware. This compromise entails a more bulky engine package than the YZR's compact design, resulting in a small weight penalty which helps the TZ250M to scale 4 pounds over the class limit at 213.4 pounds dry • a handicap Yamaha could almost resolve by using magnesium crankcases, instead of the production-based aluminium ones they' employ, thereby saving 3.3 pounds. But this would mean having to change the crankcases more often to avoid reliability problems, says Yoda-san, in turn adding to costs in what is a strictly budgeted operation. Hence, too, the decision to tune the engine for midrange rather than high revs, so as to reduce component wear and hold costs down .a policy of direct relevance to the customer TZ250 racer. . "But next year I think we'll need more revs," says Yoda, "to try for more top-end speed to keep pace with the Hondas and:Aprilias. They are very fast!" Fast, yes, but not World Champions, eh, Ichiroh-san? After Yamaha terminated the YZR250 project - and there were some off-hand hints that they might be .thinking of reviving it, if necessary, to keep on the pace - they stayed in touch with the 250cc GP class by delivering Mtype TZ racers to Giacomo Agostini's

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