Cycle News - Archive Issues - 1990's

1996 Yamaha YZF1000R Thunderace th e 22-percen t-b ig g er su rface of t he cu rv ed rad ia tor wi th dual fans; which kept th e Ace cool, running at just 6Q d egrees on a 90-degree su m me r d ay. Part of the reason for th a t is the extra ven tilation for hot air extraction offered bv the slots in the side of the trick-lookiIl g bod yw ork, w hic h no t o nly gives good ri d er protect ion a t high s peeds (t houg h th e sc reen is to o lo w - th e curved one on the YZF600 is mu ch better) but is also wind -tun nel-develo ped to deliver optimu m aerodyna mics, with a CdA of 0.290 compa red to the FZR's 0.304. Th e meaty motor is slotte d in to an all-new allo y Deltabox chass is with the dimensions of Yamaha's 750 - the same 24-degree head ang le (26.4 d egrees on th e old FZRI 000) and 97mm trail (l08 mm), w ith onl y th e w hee lba se 10mm lon ger a t 1430mm (l470mm). The compari son with the old EXUP frame underlin es how m uc h more resp onsive an d quick-steering the Ace is on pap er than the one-liter mod el it replaces, but ou t on the roa d it stra ngely isn' t nearly as "n erv ous" as yo u mi ght exp ec t fro m By Robert Fawcett Photos by Gold & Goose a m a h a invented th e one -liter Su pe rs po rts b ik e with th e FZRl 000 back in 1987, and since then they' ve seen their supremacy in the catego ry grad ually eroded, abo ve all by the best-selling Hond a CBR900RR. It has been a bit of a mystery w hy it has taken Yama ha so long to resp ond to the CBR900 RR' s co mme rcia l succes s, bu t w hen the new YZFlOOOR Thunder'ace was lau nched at the Paris Show last a u tu m n, it see me d the b a ttle of th e gia n ts had been joined , th at Yama ha wa s fin all y cou n te ri ng the CBR' s su prema cy in the hyp ersp orts arena. Think again. While you might be forgiven for assuming that any bike bearing as agg ressive a moniker as Thunderace, especia lly one as rakishl y sty led as the shark-nosed YZFI000, could n' t help but be a sing le-mind ed con tender for s pe ed kin g supremacy in th e Supersports circu s, reality is so me thing else altogether. As two da ys spen t riding the Ace in every kin d of roa d cond itio n a t th e Sou th Africa n lau nch, p lu s a halfday sess ion at Cape Town 's bumpy but testing Killarney circuit proved, this is a v e ry different m oto r cycl e fr om th e Hond a, one that for all its race-track heritage, ai ms at a more ba lanced, wellrou nd ed , less highly-s trung pa cka ge. Really, the Thunderac e is targeted at the same kind of multipurp ose market as the Kawasak i ZX-9R; only, Yamah a has still go ne all out to bu ild a blad e-runnin g ri va l to th e H ond a co m pe tition, clai min g a cl a ss-l ea ding p o w er- toweight ra tio aimed at head ing the field in real-world riding conditions. To d o t hi s, Yam a h a to o k t h e ol d FZR's 75.5 x 56 mm 20-valve slan t-block four-cylinder motor and completely reengineered it internally to imp rove pickup a n d e s p eci a lly midrang e p ow er , thou gh strangely enough, they' ve op ted not to fit a ram-air system with p ressurized a irbox lik e on the new YZ F600 . Wit hin a cou p le o f mil es, yo u reali ze wh y: Yam aha' s priority was obv iously not to go for the big horsepower numbers at high revs that an airbox d elivers, but to focus on improvi ng rid ability and especia lly midrange roll-on . Althoug h a fully eng ineered dual-airbox sys tem like Y (Above) Set against the bac kdrop 01the South Alrican coas tl ine , Yamaha's VZF1000 Thu nderace represents Yamaha 's newes t entry in th e open sportblke classs. Will it reac h Ameri can shores soon? (Right) Cru ise mi ssile: What littl e carv ing capab ility the Thunderace may give up to its rivals is more than made up l or In comlort and stab ility, strik ing a better balance between rep Ii-racer and sport tourer. And the FZR gives away nothing In the horsepower department. the YZF600 T-Cat's cou ld also benefit midrange substa ntially, on the Ace there wa s n o n eed t o a do pt th is b ecau se Yamah a achieved its goa l b y o t h e r means. Ske p t ica l? T w is t th e wri s t a n d becom e a believer. At anywhere above 2000 rp m you can ride the Thundera ce's mega-tor que curve u p to the 11,500 rp m red -line. Or rev it out. The Ace is a musclebike in race repli ca clot hin g, and you can rid e it eit he r way, depending on time, place and the mood you're in .'You can hold top gear and use the reserves of torqu e to scoop you effortlessly from o ne turn to a no ther, or stir th e new close-ra tio five-s peed gearbox with its well-ehosen ratios an average 800 rpm apa rt and tw ist the big engine hard to max out performance. The gearshift is a bit har sh, though, and neutral is often hard to find, though maybe that wo uld loosen u p more on a bike wit h more than 1250 miles on the odo meter, w hich is wha t th e clock showed when I took it over. That would be less of an excuse for the clutch action, though: it only works at the very end of th e lever ' s tr a vel , so yo u mist aken ly think you' re in neut ral when you ain' t. Needs work. When you dial up som e revs on the meat y mot or , yo u'll find a big kic k in the power curve just on 8000 rpm when th in g s s ta r t to h appe n e ve n fa s te r , th ou gh upw ard s of 10,000 revs w he n peak claimed power of 145 bhp is delivered, the engine starts to vibrate a little th ro ug h t he foo trests (though no t th rough th e ha nd leba rs, thanks to the big bala nce weig hts bolted to th eir ends), and you get the feeling it doesn't wa nt to rev ou t quite as eagerly as, say, Kawasa ki' s ZZ-Rl100. But that ' s okay , because not only are you by then travelling at an indicated 156 mph in top gear on a s lig h t incli ne ru nning al ong the Ind ian Ocean (claimed maximu m speed is 173 mph), bu t the Yamaha's definitely superior in the all-import an t 50- to lOGmph real-world region, and the reason is the crisp t hro ttl e resp on se a n d mid ran ge pun ch that the combina tion of trick electronics and red uced mecha nica l inertia have d e li v ered . Lig h te r, stronger forged pistons (ra ther than the cas t ones use d in the FZR) are rifted to a new lightweigh t crank, together reducing reciprocating weight by alm ost three pounds and giving improved p ickup from low rpm. A coordi nated electro nic pa ckage co m pli me n ts th is, wi th t h e 38mm Miku ni BDSR carbs rifted with a TPS throttle p ositio n sensor linked to the tac h. Th is tells the di gital igni tion when to ki ck in so me m ore a d va n ce according to engi ne speeds and thro ttle ope nings, as we ll as the gea r selected (mo nitored by the C PS senso r rifted to the new five-speed gea rbox), w hile the ignition in turn con trols th e open ing and closing of th e w ell-proven EXUP exhaust valve retained on the Ace. All this d eli vers th e sharper eng ine response you can' t he lp but no tice on the Thu nderace, as well as substantially boosti ng mid range torque by as much as . 15 percent in the cru cial 4000- to 7500rpm region, say Yam aha engi neers. But in sp ite of the extra pu nch, the engi ne runs a lot cooler than befor e, thanks to those figures. Even with a further -forw ar d sea ting p ositi on th anks to th e s h o r t er, fa t te r 5 .2-ga llo n fu e l ta n k (whi ch however does force you to ride with your knees splayed out, though the overall riding position was pretty com fortab le for two 300-mile sessions) that helps yo u load up th e fro nt en d with yo ur body we ight (ai ded by th e 31.1inc h sea t height, ro ug hly half a n in ch higher than the EXUP, though still some three-quarters 'of an inch lowe r than the ne w FZ R600), t he Th u n de race d oes require qu ite a lot of mu scle to make it change direction quickly from one side to a no th er - even a t re la tively lo w speeds on a bu mpy, wind ing coas t roa d . I wasn' t th e on ly one w ho wo ndere d how a bike w eighing just 15 p ounds mo re th an th e TR X850 twin th at the Yamaha mechan ics used to acco mpany us ou t into th e hills could seem quite heavier-s teering than the par allel twi n. A CBR it' s no t - but the payoff comes when you attack the swee ping turns out in the Cape Province win e country, big corners taken a t 125-135 mph or eve n more. The Thu nd era ce is supe r-stable at these speeds, and if there's a big bump in the midd le of the bend , the bike will shrug it off as if it didn't exist, whereas the more tau t-ha ndli ng Hon da wouldn' t be nearly so self-assu red . Almost certainly th e reason for this is the low er coefficien t of gravity tha t the Yamaha's slant-block engine helps deliver, ad ding to th e p lan ted feeling the b ike has in fast, bumpy comers - bu t also explain-

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