Cycle News - Archive Issues - 1990's

have ridden both the latest Cagiva and its 1989 predecessor can measure the true scale of the Italian company's achievement: it's immense. That '89 bike was an animal: with an extreme 60/40 forward weight bias, tra ction was a con stant pr oblem, pl us it was very nervous an d twitchy even in a straigh t line, and braki ng hard at the end of any ha lf-decent stra igh t h ad th e back wheel trying to flip the bike into somersault mode . Not very rideable - but th e engi ne was alm ost worse, wi th a razor-edge p owerband that saw power come in sharply at 10,000 rp m and peter out so abrup tly at 12,200 rp m you had to beware sma sh ing the screen with your helm et as you ran into the metaphorical brick wal l. It was also severely do wn on speed to the japanese opposition . If the Castiglionis had pulled out of racing then, you cou ldn 't have blamed them, the bike was tha t bad. Yet in the space of little more than a year, ' Cagi va p roduced the pr esent bi ke which my Pergu sa ride proved to me is ligh t year s better than its flawed forebear. A lot of the credit for tha t goes to race engineer Fiorenzo Fanali, La wson's former mecha n ic in h is Agostini Yamaha days who joined Cagiva a year ahead of Eddie, an d is largely responsible for the ordered development and pragmatic engineerin g that ensued. (Worth noting that Fana li joined Cagiva for the 1990 seaso n, Eddie Lawson in 1991 , followed by non e ot her tha n Ago himself, recen tly announced as Cagiva's team man ager, for 19921 Full circle!) FanaIi's influence, co up led with that of Ron Haslam during his sin g le inju rytroubled year as a Cagiva rider, resul ted in 'a 1990 bike that was already a considerable impro vemen t on the '89 house of horrors, bu t still only rep res-' en ted a steppi n g-sto ne to 1991 's paragon of virt ue. So wh ile a more rational chassis design (wi th 53/ 47% weight distribution ) and less radical steering geometry made the bike more sta b le, th ere was st ill a tr actio n p roblem, and th ough the engi ne had a 400-500 rpm overrev capaci ty for the first time, it didn 't make good power' low down , and in th e form I rode it at Rijeka a t the 1990 season 's end, had a hole in the powerband around 9500-' 10,000 rp m that really affected accelera tion out of a slowish turn. More work needed, signori - on ly th is time you have Eddie La wson aboard to sup p ly a constant flow of feedback, su ggestion s, a dvice an d encouragemen t, Proof of how readily Cagi va' s engi -. neers responded came sooner rather than later in 1991, and in the sixth race of the GP season, on the world's fastest GP race track at H o cken h eim in Germany, we ha d the in credible sig ht of Lawson qualifying the Cagiva in third place on the grid, ahead of the entire fleet of factory Yamahas . All those ma ny clever people at the Italian factory needed was some focu s, and leadershi p from a rider they respected. T hat's how GP raci ng' s mi nor miracle happened in 1991. That, and a lot of hard work wh ich saw a constant flow of new parts and changes both minor an d major to setu p throughout the season, including five different basic chassis designs, six different versions of the five transfer/ three exhaust port cylinders, an d 10 differe nt exhaust pipe designs, keepi n g the red bike on the pace all season long. Cagiva didn't just match the pa ce of japanese factory development, they exceeded it for the first time ever, aided by the teleme try they employed all season long wh ich gave a constant flow of valuable da ta. So, wh en Lawson identified a front end problem most probably due to the engine bein g in the wrong place, chassis design er Luigi Botta or his mid -season successor Romano Albesiano, who took over after Botta was drafted over to pen the chassis for the upcomi ng four-stroke Cagiva-Ferrari four-cylinder street bike, were able to produce an all-new fram e in two days flat - from blank sheet of paper to finished pr od uct! Tha t's mind-blowingly quick by an y standards, and gives some idea of how slick an opera tio n the Cagiva effort now is. Making that major a chan ge so fast - an d gett ing it righ t - is something even the j apan ese factories wou ld have a hard time doing, especially midseas on. Cagiva 's reaction time is a key factor in their sudden compet itivity - but first they needed som eon e who could point them in the right direction: that's La wson, and listen in g to him has put the team on the righ t road. T ha t's especially true of the V591's ' en gine performance, wh ich is far more user-friendly than anything from th e pre-Lawson era, th ou gh to be fair the team already had thei r all-new '91 engi ne cast up ready for assem bly whe n the Ca stiglio nis a nnounced their temporary pullou t at the end of the 1990 season. says engine development man Andrea Goggi, and the same at 10,000 revs: that's a lot, compared to 'on ly' 3% more powe r at the top end, and emphasizes the direction that 500cc GP development is currently targeted at: ma king the phenomenal power outputs of these half-liter projectiles more .con trollable low down, to broaden the powerband and soften the delivery. You notice the differen ce immediately when you ride the bike, especially on a patchily da mp Pergusa track where the sudden p ower delivery of th e V591's pre decessors would have sent my pulse rate into fast forward. Whereas the 'S9 Cagiva was basically u nridea ble much below five-figure mode, and h it the powerba nd with a fierce belt that eit her created or added to its tra ction problems, the '91 bike is practicall y a super-roa dster in G P raci ng disgu ise, making usable power as low as 7500 rpm and peaking at 12,000 revs. That's a lready a b ig im pro vement in useability, but th e real crack is the midrange p erformance, which bears no comparison wi th th e pr eviou s mo tor : instead of the flat spot arou nd 10 grand I grappled with on the '90 bike at Rijeka - a hole in the powerband tha t pu t the Cagiva at a severe disadvantage with its rivals the '91 model has a really noticeable dri ve ou t of turns, meant Cagiva had to in crease power low dow n, they didn 't neglect th e ot her en d of th e pow erband, because for the first time there's a really strong degree of overrev on tap, beyond the 12,000 rp m peak power figure. Holdi ng a gear in the mi dd le of the 'lon g' second chicane at Pergu sa saw the needle run up to 12,SOO rp m before the po wer really star ted to dip, making it possi ble to save a couple of gear changes without power tailing off. However, wh ereas before th is was a vital m issing link in Cagiva engine develop ment, because there wasn' t so much power low dow n, now it's just a conven ien t added bon us th at migh t come in usefu l occasionally, bu t isn' t so importan t, Because the engine makes much better power low down, so long as the gearb ox is correctly setup using th e choice of six di fferent ratios for each of the six speeds, you don' t need to use all th ose revs: just shift up a bit over the peak of the 12 grand power mountain to make sure you took full advantage of it, and save th e rest of the overre v unless you really need it. Riding the bike like th is would al so be a factor in the Cagiva's A+ mechanical re liab ility record last season - only one machinerela ted retirement, at j ararn a, with a dud ignition, but whi le th at says a lot about th e way the red bikes are built and prepared these days, it's almost a com ment on the way they 're ridden. Though the powerband is so much wider than before on the Cagivas, the japanese haven't been idle either, an d with the '91 Roberts Yama has reputed to be revving to 13,000, and the Honda making strong power smooth ly fro m even lower than the I talian bikes, there's still mo re work to be done, especially in term s of broadening that explosive midrange acceleration band: at the moment, the Cagiva's pow er delivery has ra ther too many layers it needs to be more linear, an d for the engine to pick up revs faster all the way through the p owerb and. But they're surely get ting there. surge in engine revs from 9000 to 11 ,000 rpm: engine speed p icks up very quic kly an d if you, ahe m, aren' t read y for the dose of extra revs and power your right hand has sudden ly presented you with, this can cause a lurid slide on a da mp track . Cagiva now has the luxury of sometimes soften ing thi s rus h of power - wh ich is only caused by the speed with which the engine picks up revs, not a hiccup in the power delivery - by lean ing out the midrange on the 35mm Mikuni carbs, which from Assen onwards were fitted with electronic power jets for the first time , giving improved acceleration as a resu lt. But if Lawson 's riding style, which places a lot of emphasis on bottom end One thing that h asn ' t cha nged , th ough, is th e tradi tio nal ra ther notch y Cagiva gear change, wh ich is still as mech anical-feeling as ever compared to a japanese works bi ke, and on the bike I rode, h as such a hars h change between bottom and second that I tried to avoid using it altogether, even on the slowest of the Pergu sa chicanes before the p its. Felt li ke excessive backlash as you go through neutra l in either direction, so maybe only a function of the way that gearb ox was assembled or had worn, but it wasn't a specially nice change, even in the other ra tios. No such reserva tions about th e chassis, which is th e final versio n designed by Romano Albesiano for the The 286 lb. V591 seems very small for a 500cc GP bike. It offers easy steering and brillian t braking. Work only restarted in No vember when it became clear Lawson was going to sign, an d that meant the '91 bik e that q ualified and finished sixt h in the first race of th e season in japan was buil t in jus t :three months including designing two new chassis after the IRTA tests at Jerez in Febru ary. But the basic engine configuration stayed the same all year, with a wider SO-degree included angle between the two pairs of cylinders on the twin -cran k, cran kcase reed-valve V4 - 10 degrees wider than in 1990 so as to change the in let shape an d increase the total area of the reed boxes. H owever, every race saw a new flow of parts, especially different shapes and layouts of th e reeds wh ich combined with different cylinders, exhausts and variab le ignition timing, obtained by cha nging p rogram m ab le EPROM chips on the Kokkusa n digital system, to vary the power curve depending on the needs of the circuit, This was the key area of eng ine development the team focused on - not so much outrigh t power, though the '91 motor gives 169 bhp at 12,000 rpm, 5 bhp more than last year, but improving the bottom end deli very and acceleration. The V591 Cagiva has 15% more power at SO rp m than its predecessor, OO 13

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