Cycle News - Archive Issues - 1990's

If this sounds like a recipe for a ner vous, twitchy, fast-s teering motorcycle, think again, for the Harada Yamaha is almost old-fashioned in its steering geometry. The rear ride height is relatively low, contributing toa kicked-out feel to the front end in sp ite of the 22.5degree head angle, with seemingly more trail than the 79 /85mm variable -he works with. Yet watching Harada in a GP fight, taking comp let ely different lines from the bevy of Hondas around him, confirms that this is a free-thinker's bike, set up to fulfill his eve ry wish. Watch him rid e up the outside of his rivals into a tum, go much deeper past the ap ex under braking, then square the comer off as he turns the bike very suddenly, and uses the explosive mid-range power to shoot out of the comer with the power on sooner and harder than them on an insi de line. Then 'yo u ' ll understan d why th e bike is set up this way. This m eans that , u nlike most other m od e rn 250 cc-class GP r acers , the Yamaha doesn 't have a heavy front-end weight bias, no r a kicked-up rear ride height, nor a steep effective head angle. Instead, it has a near-50/50% weight d istrib u tion, aimed at maximizing traction out of turns with th e power hard on; a relatively low build which no t on ly helps delive r imp ressive stability around fast sweepers ( like the extremely demanding down hill left-hander at Fukuroi, which is like Don ington 's Craner Curves or .Ia r a m a ' s Bugat ti approach), but also makes it easy to flip from side to side in a chicane; and steeriI1g geometry which delivers a very assured and controlled tum-in, aided by the more triangular profile of the British Dunlops he prefers to use, which speed up the change of direction in spite of the wide 3.75-inch front wheel he uses . Harada's style is, like many Japanese riders I've observed at all levels, quite different from that of Europeans in tha t he likes to get the bike up right as soon as poss ible exiting a tum, and accelerate using the fat part of the tire, rather than use a lot of angle and ask more of the edge of the tire. The Yamaha is perfectly attuned to bei ng ridden this way, and once you start to d o so, the handling that at firs t feels rather strange, begins to make sense and come together as a package. One downside of using this 50/50 weight distribution is that although it h e lps load up the ba ck wheel and improves traction under accelera tion, this is inevitably accompanied by a loss of weight on the front wheel which makes this bike a wheelie-hound out of slow turns like the pair of Fuk uroi hairpins. The way to counter this is to move your body weight around an the bike, and it's noticeable that altho ugh Tetsuya is seve ra l inches (like maybe a dozen!) sh orter than m e, I co uld tuck down beh ind the ca refully-s haped screen without too much of a squeeze. This is because he's left himself a lot of space to shift his weight forward and backwards on the bike by doing wi thout a backpad on the sea t, but without a correspondingly wide fuel tank to give more room . Ins tea d, the tank is kept as na rrow as poss ibl e to h el p reduce the o ve ra ll width of the bike in order to maximize straight line s peed .Fuel ca p aci ty is ob tained, instead , by filling in the gaps between th e cylinders w ith fuel ta n k, and using a fuel pump which you can hear whirrin g away as you push s tart the bike to fire up the engine. This also has the effect of maintainin g a near constant weight distribution as the fuel load is used up . Clever, Yamaha admits to wor king on fuel .-------- - - - - - -- - - - -- - - - - - - - - --- - - - - - - - - - - - -----, . ? . -~ Attach Label Here .. ,... .... ..... For FASTEST service attach mailing label. Please allow 3 weeks for change 'to take effect. (]Jffi ~ If label is not available print your name and old address in this box. Print your NEW address here. NAME • • ADDRESS • • __ L CITY • ~ STATE ZIP Mail to: Circulation Dept. Cycle News, Inc. 2201 Cherry Avenue, Long Beach, CA 90806 ~

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