Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/128239
Ducat; ST3 But where the new desmotre ST3 is easier to switch from side t o sp o rt s t ourer rea lly d o e s score over side a lo ng t w i sty hillside tracks o r it s desmoquattro sister is in the ea se ro l li n g countr y r o ads , and the fact a n d l i ghtn es s w it h wh i ch it steers . th at its handleba r is w id er, an d thus Though it's a b igge r b ike physically gives ex t ra leverage com p ared to the t h an , sa y , a Mu l ti s tra d a, th e r e ' s a p rev ious m o d el , is he lpful , to o . It' s a si mila r f1 ic kabilit y that makes th e ST3 bi k e that fee ls ve ry reassuring to rid e so much f un to rid e . ha rd - t he r i d in g s ta nce is we ll B ec a u se its eng ine is less h e av y thoug ht-out , si tti ng j u st on t he sporty an d b ul k y t ha n the f our-va lver , t he s ide o f an u p r i ght to u r ing p o sture . Ducati's Desmotre: ~ f]j]@[JLJ[§]@D5 [ft&JfJlJD5[}y'J [fJ[l@@(][}@fJ5@[JLJ Ducatl' s new desmo tre m otor is an in- ho use product in more ways Th e view of the cockpit in c lude s a dash w ith all of the Info you could ever require, and also a view of the height-adjustable handlebars. speed g earbox in th e ST3 se ems to have been furth er improved b y M en gol i a n d h is m en . It has a sm o o t h , posi tiv e a cti on and w e ll - m a tc h e d, evenl y spread ratios. It's a pity th e clutch is stil l as h eav y as e v e r, though . When w ill Ducati ev er fix th is last c h i n k in it s V - tw i n e ngi ne s ' a rmor? Th e r ed esign ed bo d y wo rk m a y h a v e unashamedl y Ho n d a - e squ e sports tourer is fr om the old o ne , in t erms o f lo oks if no th ing else . The ST2 app e ars di s t in ct l y o l d f as h io ne d b y c omp ari son wi t h t h e n ew m odel, as w ell as smaller - but th at' s b e c aus e it is , thank s t o t he ST3 ' s wider and m ore protectiv e fa ir - st y l i n g, but it look s infinit e ly m ore m odern co m p a r e d t o the o l d ST2 . Parking the n ew b ike next to o ne of th es e in Du c ati ' s Repa rto Sperim entale o n my return f ro m an en j oyabl e d ay 's ri d e in the h ill cou ntry south of Bol ogna e m p has ized what an eq ua ll y big c h a n ge th e n ew Du ca t i in g . That f ai r i n g ha s a ta ller w ind screen a n d broad er flanks that giv e no ticeably better p rotection than on th e o lder bike, so th at wh il e c ruising at 100 mph , with th e ta chometer nee dle park ed on t he 5800 r p m mark barely halfway to redline, yo u can sit rela xed and focu sed , without h aving to w o r ry about c ombating undu e bl ast or fight ing wind noise. E v en at an ind ic ate d 142 m p h bl ast, the ST3 i s a stable and re lativ ely s il e long- legged mileater o f a tou rer , w ith fran k l real -worl d pe the m 14 N OV EMB ER 5 , 2003' c ue • .. n e wv s th an one. Th e six -v alve singleca m 90 -d egre e V -tw in eng i ne design with the Italian company's trademark desmodromic valvegear was originally conceive d as the subject of the Bologna University l.Mech.E degree thesis of 29 year -old Diego Mengoli , the son o f Duca ti 's t ech n ic a l direc tor Gianluig i Mengo li. With Junior safely in posses sion of his engineering degree as a dir ect result of the successfu l co m p l et io n of the project two ye ars ago , what would be more natural than for dad to take a hard look at putting the result into metal and bringing it to the market. "We'd been kicking the idea of a three -valve cylinder head around for at least 10 years: said 55-yea r-old Gigi Mengoli , for many years the right -hand man to legendary Ducati technical guru Fabio Taglioni then after his reti rem ent to his youthful successor Massimo Bord i before taki ng over the role of chief engineer himse lf in the wake of the American rescue of Ducati seven years ago. It's an interesting reflection on the compa ny's enduring technical heritage that , in the past 50 years, Ducati has had just three men in total occ upyi ng the role of chief engineer. "But Ing. Bordi was very muc h opposed to the idea: continues Gigi, "so nothing ever came of it. But then a couple of things happened to change that: Bord i moved on, and Diego here had the idea to make such a design the subject of this thesis. That meant we started talking about such an engine quite a lot at home, and the idea of a three-valve desmo really began to appeal to me - and not just because nobody else had ever done one before. We laid out all the desmotre drawin gs I' d made over the past 10 years on the dining -room table, Diego sat down and began m aking all the calc ulations, work ing on the thermodynamics and actually figu ring out the ways in whic h such an engine could be integrated into our production faci lities up front - instead of later on at 3D stage - and in the end he finished the thesis successfully and was awarded his degree. But by then I'd decided we at Ducati mu st indeed produce such an engine, which has the advantag e of costing the same as the desmod ue to manufacture, but offers a level of performance very similar to the more costly desmoquattro." That's confirmed by a comparison of the relative engine's power and torque curves, whic h shows the desmotre equaling the four -valve desm o's ho rsepowe r figures up to 6500 rpm while exceeding the torq ue delivery of the supposed ly meatie r two -valver. This was sufficient to convince Ducati management to give Mengoli the go -ahead to produce such an engine in order to plug a self-evident power gap in the com pany 's prod ucts between the 84 hp 1000DS desmo due and 117 hp ST4S desm oquattro. It's a gap like ly to become even bigger wit h the inevitable replacement in relatively short order of the 18· year-old desmoquattro design by the much newer, mo re modem Testastretta format now powering Ducati's World Cham pion Superbikes . "We look ed at how others had dealt with such a design in the past : says Gigl, "and it interested us that Mercedes-Benz is employing th ree valves per cylinder on one of its latest engines, fitti ng dual ignition like us with the sparkpl ugs positioned either side of the exhaust valve but with a slightly sequential firing system, which we can't yet employ because our engine management ECU won' t permit it - yet. But the dual ignitio n allows you to obtain a cleaner bum at a lower number of revs, and from this we saw that such a three -valve design not only has dynamic and cost benefits, but also improves fuel con sumption and helps meet emissions targets . It' s an extremely attractive design in terms of overall benefits, and at t he stage that m anagem ent here decides to ph ase out the desmod ue, with this we have its successor already in place ." But what are those benefits that are such a key elemen t of the desmotre's appeal? "Compared to a desmoquattro, of course, you eliminate the need for a fourth valve and associated valve gear, as well as a second camsha ft, by placing six lobes - three each for opening and closing - on the same shaft: says Diego Mengoli. "Plus , there are oth er savings, too - reduced m achin ing on the cyl inder head, which is notab ly com pact and takes up no more space than a two -valv e head , less complicated belt driv e to the cam. and of course reduced weight - at 63kg dry [138 pounds) , including throttl e bodies, th is engine weighs l .5kg [3 .3 pound s) less than a desmodue. But while the im mediate benefits are conside rable, I believe in the future these will become even greater and more apparent. Th e desm ot re is an ideal comprom ise betw een incr eased pow er, redu ce d co sts and improved combustion, with the benefit s thi s brings with it. " What nobody at Duc ati will yet confirm is the eventual extension of the thr ee-valve concep t to other, sm aller -capacity engines below the 992cc capaci ty it's been introduced in. But off the record it's clear that development of such 620 -to-900cc mo tors has already begun: It' ll be up to comp any ma nagement to decide when and in what mo dels to extend the concept downward. But be certain that the Ducati engine famlly has a very prom ising . new member, arguably offering the best of both world s in the real-world road-bik e m arket - and the ST3 sports tourer is the Ideal vehicle in which to mak e Its debut.