Cycle News - Archive Issues - 1990's

In The Paddock at wizardry is this? After rising to crushing domination of the 250cc Grand Prix class, Aprilia has returned to the 500cc class - not with th.e much-vaunted forthcoming V-four, but with their old V-twin, a machine that many thought had passed its sell-by date when it was retired at the end of the 1997 season. And instead of loitering around midfield, harrying the big bikes through the corners only to be overwhelmed every time serious acceleration was called for, the revived V-twin Aprilia has come up .all shiny. It was on the rostrum in France, the second round of the European sea-· son, and all but replicated third place in the next round, at Mugello, with Tetsuya Harada surging past one V-four after another after a bad start to catch right up to Tadayuki Okada's NSR500 Honda at the finish line. More surprising still, in both cases, is that both of those circuits have notably long straights - Paul Ricard actually has two straights, both approached in a low gear, making them nothing but drag strips - exactly the conditions where the Aprilia should be off the pace and out of the picture. If the bike can make the rostrum there, just how much better will it be at circuits such as Assen and Donington Park, where comers run one into the next, and straight-line speed is of secondary importance? So what exactly has happened? One thing is obvious. The rider is the most important ingredient of .any race package, 'and in this case it is the redoubtable Tetsuya Harada. And the 28year-old Japanese rider took to the 500 from his very first attempt, in preseason tests at Jerez. It was his performance there that made the factory decide to go ahead with their so-far ill-favored lightweight 500, a decision that has already paid off, and may offer still greater dividends - at least according to the bike's designer, Aprilia's racing chief Jan Witteveen, a well-padded Dutchman who has lived in Italy for more than 15 years. "Because technically we are still at quite an early stage of tuning the latest version of the engine, there is more per, formance to come," Witte.veen said. "With We our strong results in France and Italy, I believe that we will be able to win races outright in the not-too-distant future." Witteveen agrees that Harada's riding has provided a. vital key to present and future success. Harada, a 250cc-class veteran, may have won only one World Championship, back in 1993, but he has been a major force throughout a career that ran into the doldrums as the Yamaha he started on, already relatively short of .power, was robbed of its handling advantage by a switch to Michelin tires. A move to Aprilia and his preferred Dunlops put him back on the rails, and he would have been champion again last year but for a" couple of costly breakdowns, an uncharacteristic crash in practice... and being knocked off the track at the last comer of the last race of the year by teammate Loris Capirossi. Harada's hallmarks are his smoothness, high corner speed, clever tactics and - when the occasion demands aggression as well. These attributes are obvious winners in the 250cc class, but are not considered so valuable in 500s, where raw power requires mastery of techniques employing. wheelspin to help turn the heavier machines. This brings us to the very nub of the theory behind the V-twin, conceived by Witteveen and first brought to the tracks in 1994 - as a 410cc "super-250." That theory is one that preserves the smaller machine's rev, power and chassis characteristics as far as possible in an attempt to exploit not only the 33-pound weight saving allowed over the V-fours by the regulations, but also the clumsy cornering of the full-sized bikes. It's also a theory in which Witteveen has never stopped believing, in spite of apparent evidence to the contrary, as riders Loris Reggiani and Doriano Romboni struggled to .do more than merely qualify well. Well, the 1999 version can still do that - Harada was on pole position at Mugel10, in spite of being more than 6 mph down on top speed. And now it can race effectively as well. Witteveen pooh-poohs ideas of extraspecial new ingredients, though it is obvious that the factory has at least kept 30 YEARS AGO... JULY 8, 1969 ddie Wirth (BSA) had a great week on the AMA Grand National Championship circuit, roaring to victory at the Santa Fe IT in Hinsdale, Illinois. I Wirth was followed across the line by Gene Romero (Tri) and Mert Lawwill (H-D) ... At the Columbus, Ohio, Charity Ne.wsies National Mert LawwilI led wire to wire in the 20-lapper. Reigning Grand National Champion Gary Nixon (Tri) crashed I and finished second to last... Dave Damron and Art Baumann rode their Team Ocelot Suzuki to the win in the 12-hour production endurance 'road race at Willow Springs International Raceway in Rosamond, California... Hadey-Davidson took out a two-page spread advertisement to boast of its "sweep" of the Greenhorn National Enduro. Harleys finished on top in four classes, occupying the top three spots in the A Trailbike class... Evel Knievel was getting set to attempt to jump his American Eagle over 17 Gars at Ascot Park in Gardena, California. E abreast of the latest technology, particularly in the matter of piston mass, where it is rumored the aero-engine industry has been the source of special materials for the big' 250cc-size slugs. The current machine is the result of simple step-bystep development, he insists, as well as a gradual growth to full 500cc capacity for the first time this year. Plus one other breakthrough although this came from outside. "Switching from leaded to unleaded fuel improved the bike immediately:' explains Witteveen. . The simple act of lowering the compression ratio immediately improved throttle response and ridability, at a stroke solving the persistent drawback of bad wheelies during acceleration from a too-positive response from the torquey engine. Also, because they were not on the ragged edge in terms of port shapes and other aspects of tuning, the power loss was less significant, explained Witteveen. Especially since the new no-lead fuel of 1998 coincided with the final increase in capacity to 5OOcc. "We made the engine full size last year, when we withdrew from racing for a season of development, with Jorge Martinez testing the bike," explained Witteveen, denying that it had been a mistake to start small, .since it now appears that they might as well have been full 500 size right away. "No, it wa~ not a mistake," he said. "We wanted to maintain all the characteristics of the 250cc engine, with the same ability to rev. We have been able to do that all the time, with the engine growing gradually - the first 410cc engine had those characteristics - but I do not believe we could then have built a full 500 that would have achieved that." The eng.ine grew bit by bit - 430cc, 460cc, and for its last races in 1997 to 48Occ. "All the time, the engine has made peak power at 12,000 rpm, with another 500-rpm overrev capability (that comes . in handy when slipstrearning faster bikes on the straight), said Witteveen. "This year's engine is the same." He also cites close cooperation with Dunlop as important to the current suc- cess, as well as design of a special chassis around Harada's compact frame - not to mention the weight saving of the diminutive racer from Chiba. "We have a good harmony, and balance, and Harada has a very good feel from the machine," Witteveen said. . Dunlop, for their part, are anxious to test the 250cc-style 16.5-inch rear tire on the 500, hoping for even better results. All the above rather glosses over the fact that Harada and his new mount made a slow start to the year, to the extent that there were even rumors after Jerez that they might cut the project short. Way down in 13th in Malaysia,' Harada had pulled out of his home GP at Motegi with tire problems in the wet, then pitted early in Spain as well, fearful of a possible gearbox seizure after missing gears on the first lap.. Witteveen cites a prosaic reason Harada's small foot is relatively ineffective at putting the required leverage on what is rather a heavy pedal. "He had' some similar problems of missed shifts on the 250:' he said. Technology to the rescue, with new software making for a two-stage quickshift mechanism. Where the conventional quick-shift merely cuts the ignition for long enough for the gear dogs to engage, Harada's new system only delivers partial power after the timed break, while a second sensor measures physically inside the gearbox whether full engagement has been accomplished. Only then does it release full power. Spirits are high right now' in the Aprilia 500 garage;with the Italian factory's tame Dutchman beaming at the vindication of his long-held belief in the rightness of the lightweight super-250 concept. "The machine has shown it is capable of good results - and it still has a lot more potential," Witteveen said. ''Now I want to concentrate on the motor, with the usual tuning of gas flow and so on, to maximize power. That way, I believe we can think about being capable of actually winning races. "I have always believed in the twincylinder concept. Now I believe in it even more.'" CII 20 YEARS AGO... JULY 4,1979 10 YEARS AGO... JUNE 28, 1989 teve Eklund (Ya m) I'\nded the win at the Santa Fe TT Grand National after coming from behind to just nip Jay Springsteen (H-D) at the wire. Early race leader 9ary Scott (Tri) wound up third ... Two days later they were doing it again, this time on the half mile in Columbus, Ohio, for the Charity Newsies Half Mile. Terry Poovey (H-D) led Mike Kidd (H-D) and Billy Labrie (H-D) 'across the line to claim the win ... Bob Hannah and Mike Bell left the competition in the dust during rounds 8/4 of the AMA 125/500cc National Championship MX Series. Hannah went 1-1 in the 250cc class, while Bell did the same in the 500cc class ... Kawasakis and underdogs were in force at the Ohio Valley. Raceway drags in Louisville, Kentucky. Kenny Annesley (Kaw) defeated Jim Bernard for the Top Fuel crown, and Sid Pogue (Kaw) outgunned Terry Vance (Suz) for the Pro Stock win. ayne Rainey was captured in flight on our coyer, and inside was a full in terview with the man destined to become a three-time World Champion ... Ron Lechien (Kaw) smoked the entire European motocross con tingent, inclu ding defending World SOOcc MX Champion Eric Geboers to win the 500cc U.s. GP motocross at Hollister Hills SVRA, in Hollister, California. Geboers put together 2-3 moto scores for second overall, and Australia's Jeff Leisk (Hon) finished with 4-4 moto placings for third overall. Jimmy Gaddis (Suz) won the 12Scc support race... Yoshimura rider Jamie James (Suz) claimed his first career AMA National Superbike victory at New Hampshire International Speedway in Loudon. John Kocinski (Yam) won the 250cc class, and Cam Roos (Yam) won his third straight 600cc Supersport race... Kevin Schwantz (Suz) won the 500cc Grand Prix in Yugoslovia... Terry Cunningham (Kaw) won the Idaho City ISDE Qualifier. Chris Carr won the Peoria 600cc National IT. S W CJl CJl CJl o CO') Q> c: :::> .., 91

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