Cycle News - Archive Issues - 1990's

tomer bikes such as the Ga ttolo ne or De Cecco te a m h a rd w are in the cr ucia l 6000-10,000-rp m midran ge powerba nd, th e pos t-Kyalami evo/uz ;one wor ks motor (see technical side bar) has a really smooth e n try i n to th e s u pe rpower stakes above 9000 rpm . From there on up, the engi ne p icks u p s peed really quickly but still controllably. This kin d of res po nse is w orthy of a Gra nd Pri x two-stro ke, bu t belied by the glorious boom ou t of th e b ig-bore works Termignoni exhaust that could only come from a desmo twi n otto valvo/e. But this one is a ducaione (Big Du ke) tha t has recaptured th e tra ditiona l Ducati quali tie s of smooth, muscu lar to rq u e coupled wit h an appeti te for revs . How eve r , a cco rd ing to PierFrancesco Chili, the pre-K yalarni motor liked to be buzzed to 12,200 rpm. On this later, more flexibl e powerplant, he thinks it is best to change up a t 11,500 rpm, riding the torque curve up to that point. It's easy to see why. Holding a gear and letting the en gine run on - like past the A-I Ring finish line before you ha ve to sta rt braking for the slow first turn you can feel the engi ne s tart to tail off above 11,800 rpm. Though it will re v to th e 12,200 rev lim iter, it seemed there was no advantage in doing so excep t to save yourself a shift. Still, T roy Co rs er sa ys he rev s his bike out to 12,000 in every gea r because it doesn't feel as pot en t as his '96 World title winner, w hic h he u sed to sp in as high as 12,800 rpm withou t the power tailin g off (thoug h the eng ines did bre ak a lotl). He also consid ers di aling in the op timu m mixture settin gs for th e new '98 Mar elli EFl is the sing le most cru cial factory in current pre-race setu p. "It's a very thin line between getting it right and making the eng ine hard to rid e," he savs. "If we're as little as 3 to 4 percen t ou't according to th e la mbd a p ro be on the ex ha ust, th e bike won't accelerate as good. Plus we get the problem of the aggressiveness of the thro ttle pickup - if it's too lean, then the power co mes in very uncon tro llably fr om a closed throttle, usually when you're leaned over in a turn; or if it's too rich, you dial u p some throttle and there's no body hom e. It's so critical, that even a 2-pe rcent cha nge, like if the douds come over d u ri ng a race, ca n affect performan ce - w hic h is one reason we ha ve the do ub le mapping system on the bike, so you can sw itc h to op tio n B if you need to. There doesn' t seem to be th e flexibility in the new EFI pa ckag e we had wi th the old one, where you could access d ifferen t parts of the map a nd clean u p a section of the power cu rve at each track. Now it seems any changes we make affect the whole rev ran ge, not just the parts that count." , Well, with han d on heart, I cou ldn't notice mor e than a fractiona l diff erence in engine respon se sw ap ping back and fort h bet ween the duo of maps on Cor ser ' s or Chili' s bi kes. Th en agai n, the Du ca ti ce r ta in ly did n 't h a v e such a fierce pickup fro m a closed th rottle as A ki ra Yanaga wa's work s Ka w asa ki, w hich I rode a few weeks later. Th is means that ge tti ng dri ve ou t of a turn is mu ch easier - well, p rovided yo u push yo ur weight forw ard by stand ing on the foo tpegs lik e Ch ili d oes w hen ex it ing the slow ones to keep it from wheelyin g on exit. The wi de-ope n power-shifter worked great on the Chili bike, but it was so stiff on Co rser' s [ en d ed up cha ng in g gea r norm ally - ob viously a probl em th a t needed attenti on. Corse r thinks the Du cati has a bigger perma nent handicap, though: the lack of a casse tte gea r clus te r t ha t, b eing extracta b le, would a llow th e team to dial in the ideal gea r ratios for each circu it. "Honda ha s th is," he says. "And I can see the result whe n I follow Aaron (Slig ht) - he 's hold in g a gear for long sec tions of track where I'm losing time, makin g two or thr ee gea r cha nges to try to kee p up. At tracks like the Nurbtirgring or here a t Zeltweg, wh ere there are slow co rners leadin g on to faster sections, tha t's a big bo nus, and it explains w hy the H onda seems to accelera te so well. It' s not a ques tion of more ou tright pow er so much as being able to gea r the bike to ma ximize the torqu e they have, whereas we have to use the same gearbo x for eve ry circuit, and make the best of it . Th e Hon d a a lw a ys h ad th e top sp ee d, b ut n e ver th e ac cel era tio n to m at ch th e Duca ti o ff th e be n d . Well , n ow it does , a n d th a t's d own to th e extractable gea rbo x. We need one badl y, too." Still, even witho u t that , wha t you' re left wit h on the '98 Ducati is a six-gra nd p owerba nd th at ha s n o s te ps o r fl at s po ts , ju st a s tro n g, mea ty p u ll th a t makes the V-twin such a de ligh t to rid e- yet is punchy enough to make you want to pull it quickl y upright exiting a slow turn , so as to u se the fa t p art of th e Michelin 17-incher, 500cc GP style. Side grip is a key fac tor when yo u h a ve this mu c h to rqu e o n tap . But there's no violent attack of the shakes as there is on the '97 Ducati w hen you got th at pu lling hard ou t of tu rns, so th a t in s te ad of w eavin g and s h im mying abo u t under acceleration, the '98 d esm o V-twi n h old s it s li ne reall y w ell a n d seems mu ch more contro lled - and contro llable - in its power delivery. An even grea ter di fference can be felt in th e wa y the power (remembering, too, that there is a good deal more of it this season, quite apart from the way it's delivered ) is transferred to the ground . Here there was a big difference in the two bikes tested, all down to the different setup opted for by eac h rider. Troy is a stability freak, so he likes less fork offset for more trail, a lower rea r rid e height a n d the new IOmm-Io nger swi ngarm fo r extra w heelbase, p lu s a progressive li nk for the rea r Oh lin s, w hereas Chili and Fogarty both pr efer a flatt er one . The result is a very balan ced b i ke th at was in deed s u pe r-s t a b le aroun d Zeltweg's fast dow nhill sweepers but took work to turn into those to tigh t turns a n d al so s till p u s hed th e fro n t en d under p ower, eve n w ith the p ro g ressive li n k to stop th e rear en d from squatting so mu ch on acceleration, just like the '97 on e did. Chili ' s, by co n tra st, felt no ticea b ly s hor te r a n d more co m pa ct to s it on , thanks to his d ropped bars, higher rear ri de h e ig h t, r e te n ti o n o f th e IOm mshor ter swingarm for a shorter wh eelbase and im proved traction (because of Some 172 hp Is produced by the reworked desmo powerplant , silting In a modified chassis (to accommodate the airbox) introdu ced at the Kyalaml round. more weight on the ba ck wheel), more offse t for less tra il, and reduced fron twheel weigh t bias. The result felt more compact and agile, especi ally on turn-in, w ith out a sacrifi ce in sta bilit y exce pt under hard b ra king . In fact, both bikes moved around a lot and there wasn' t as m uch bite as ex pec ted fro m th e b ig 320mm Brembos. Fitted this season wi th fo u r p ad s on each fo ur -po t ca lipe r ra ther than tw o as befor e (so they can employ larger-diameter pistons), these have also given problems with sti cking on in tu rns, upsetting the handling as a result as well as, obviously, sacrificing speed . Still, Duca ti 's t radi tio nal fo r te of being able to use loads of engi ne braking means you can still use engi ne overru n to brake harder and deeper into the turn than with any other su perbike. But if you use only the front brakes as norm al on m any race b ik es, th e weig h t trans fer see ms excessive, se n di ng th e Du ca ti into a s na ki ng weave, w hic h makes pickin g the right line in a turn a question of skill and ju d gmen t - hence 'Co rser's advice to use the back stopper as well. "I use the bac k br ake quite a bit for ex tra stability," he sa ys . " It low er s the rear and stops it from comi ng up on its nose, but also help s get the back coming arou nd as you slow up, to get yourself read y for the d rive out of the turn. Give it a try!" Aboa rd the Chili bike, I tried it, an d alth ough it g oes aga ins t th e V-twin 00 0\ 0\ .- 01 ' l-< iJ) .c S iJ) u iJ) c 21

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