Cycle News - Archive Issues - 1990's

~ ROADRACE World Championshi~erbike Tech Review: Part 1 ~ valves (still with 30mm exhausts) and a revised range of EPROM chips for the EFI to suit. Word is that Polen's bike has even larger inlets, at 36mm. A Corsa was tested on a relial5le dyno to give 124 bhp at the clutch on delivery, rising to 131 bhp after tuning. "The big difference is the weight," says Edwin Weibel's tuner Edgar Schnyder. "We reckon I kg. (2.2 lb.) equals I bhp, so that's a big handicap we can only reduce at some expense, which is far enough - we're already able to compete with the best of the four-cylinder bikes, which is how it should be." Because they can add weight to save cost, the exhaust system on this year's Ducati is stainless steel, not titanium, although the bike still features plenty of carbon fiber. Polen uses a one steel and one carbon front discbiake setup made by C-CAT. It's interesting to note that Ducati now has the luxury of adding weight where appropriate to save cost - the exhaust system used this season is stainless steel, for example, not tita~ nium - but there's almost as much carbon fiber on' the chassis as metal, especially with the advent of Marchesini carbon wheels and Brembo (Falappa) or C-CAT American-made (Polen) carbon discs on the Italian Vtwins. The wheels are still in an early stage of development and are not yet standardized - surprisingly, Falappa was running one on the rear in Spain, rather on the front where it would seem to have most value; with the reduced gyroscopic effect in turns - but Polen for example uses the carbon brakes all the time, and indeed markets them through his HyPerformance International component distributor in Texas. After experimenting with a double carbon setup, he's now settled on a Wayne Gardner cocktail of one steel and one carbon front disc to have the best of both worlds, but unlike with Brembo or AP carbon brakes, the CCATs are made in the same diameter as the 320mm Brembo steel rotors, which mades changing wheels in a hurry to fit rain tires 'much easier, since you don't also have to change one of the brake caliper mountings to suit a larger disc - only the pads. Businessman to the last, the reigning World Champion points out that the U.S.made discs are also extremely cost-' effective as well as title-winners around $2000 for a complete Superbike - disc set including discs, carriers and carbon-carbon pads, compared to over twice that for an AP set, for example. C-CATs are also available for TZ250s and the like at around $1500, and designer Brad Sawyer is especially proud of the fact that the discs don't need shrouds to elevate the tempera18 ture because they work at ambient temperaturs, since they're based on' a carbon fiber cloth construction, rather than the random fiber, aircraft-type construction of AP, or Brembo equipment. Polen confirms this: "I don't bother to change' to steel discs for ~ wet race," he says. "We used the carbon brake in the first damp race at Albacete when it was pretty cold, too, and it worked great. This is a proper motorcycle carbon brake, not something spun off from cars or airplanes, like the European stuff." The latest version of Ducati's works motor has been more midrange than before, says Giancarlo Falappa, Polen's partner in the Police/Vogartbacked factory team run this season by the latest in the Castiglioni brothers' stable of ex-World Champion team managers: after Lucchinelli, Ferrari and Agostini, now it's their turn to give employment to Franco Uncini. Falappa better win the title soon if he wants a job for life after racing ... Meantime, both he and Polen are maximizing the punch of the desmo 8-valve motor, with both of them gearing to use just four of the six speeds in the gearbox at Albacete, and four and five respectively at Donington (all six at Hockenheim!). "The power comes on very strong at 8000 rpm," says Falappa, "And though we've been told we can rev it to 12,000 safely, I J:1onestly don't use much more than 11,000 rpm - the bike is so tractable lower down and in midrange, I don't need too. The other big thing this year is the new clutch, which makes it much et,lsier to get good starts. Now you can slip it properly, instead of before when the only way to stop it grabbing was to put oil on the plates to get a clean startl" Ducati won't reveal what compression ratios they're using on the works bikes this season - last year it was just over 13:1, still running on regular pump fuel sourced allegedly from a convenient local filling station! - but this year it's surely even higher, helping both the noticeable jump out of turns the bikes now, have, which can't only be explained away by light weight, as well as the fact it takes Eraldo Ferracci plus two strong pushers over a 50-yard sprint in pit lane to fire up Polen's race bike from cold - and that's if they get lucky: on race morning in Spain, it took them three goes, and that's with an engine management system ensuring perfect fuel injection model Ducati has had a complete re-'think about air intake for the injection system, too: whereas at first the hot tip was to raise the fuel tank to maximize air flow from any direction into the trumpets, now the whole space around the front of the tank has been sealed off with a (carbon-natch!) shroud so as to create a still air box force fed by the twin fairing ducts. The underside of the fuel tank has been completely re-designed to facilitate this, not itself contrary to the rules which say. only that the shape of the tank must be the same to external view. Kawasaki's airbox developments last season may have given rise to this change, but a further alteration was made after the second (and final) homologation date (July 1), and the revised bodywork fitted to the SP4 roadster version of the 888 now in production was then fitted to the race bikes. This is claimed to be considerably more aerodynamic and chassis, which allegedly may not be still enough now at the front end. Certainly, while the Japanese teams are adding metal round the steering head to their bikes, the Ducatis are still ungussetted in this vital area, so perhaps the experts have a point. Presumably the new Tamburinidesigned chassis due out in September when the 916 is launched will redress this problem, if it-exists. Or they may just weld in a couple of bracing tubes to the existing frames - and then fit the titanium exhaust to compensate for the extra weight! Finally, a word about tires, for whereas last season there were three major tire companies involved in World Superbike - Michelin, Dunlop and Pirelli - and Ducati was smart enough to ensure that at least one of each of those makes was used on their v'arious works bikes. Pirelli pulled out of motorcycle race tire manufacture at the end of last year, leaving the other two to slug it out alone. Mertens has found the task of switching to Dunlops from Pirellis hardest, as his results this year have shown, but applause to Falappa, who went from Michelin to Dunlop when he teamed with Polen (because that's what Doug uses - and he's the boss, 'cuz he's championl) and got right on the pace at once. Indeed, the two companies are much more evenly matched in World Superbike than they appear to be in 500cc GP racing, doubtless because they've each got some good riders to use their products. Metze1er is still on the fringes, too, but watch out for Bridgestone, who· is working hard on a Superbike range of tires, already have an excellent base product, and for sure will be joining in big time within the next two years. • The Kawasaki features chassis improvements, such as a completely redesigned rear suspension offering a higher rear ride height, more suspension travel and quicker steering. gives the Ducatis a top speed advantage over the past but not so different, but apparently less effective design, having' been developed in the Aermacchi wind tunnel near Cagiva (where the Italian factory's svelte 500 streamlining has also evolved). Too bad they didn't have it ready for Hockenheim - but as the results showed, they didn't really need it! ' Ducati's only major chassis change this year has been to fit the new Ohlins forks and rear shock, both of which have taken some time for everyone to dial in: it was noticeable at Donington, a very front-endy track, that several Ducatis had major chatter problems at the front end, leading to the voiced opinion that the combination of new forks and stickier tires was showing up a structural weakness in the Ducati Kawasaki: Greens going for gold Kawasaki was the only Japanese factory to mount a serious, consistent challenge to the Ducatis last season, with the singleton Team Kawasaki Australia works bike ridden by Rob Phillis. But a winter of intense development later, Phillis on the TKA bike sponsored by the Japanese Moving company has been joined by Kiwi Aaron'Slight on a second TKA machine, plus on occasion I)aytona 200 winner Scott Russell on Rob Muzzy's bike, and factory Japanese rider Takahiro Sohwa on a full works machine. That's in addition to all the astute privateers who've chosen the short-stroke ZXR750R, having relied on the factory to do what they have indeed done.

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