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/143869
A claimed dry weig ht of 280 pounds (oil and w ater but no fuel) is attribut ed to the square t ube alloy f ram e. "I'm im pressed with the bike a n d wi th the team," says Jon. " T houg h it's still very new the basics are all there, and th ere's a terrific air of ent h us iasm in the team- th ey're n ot scared of criticism , and everyone wa n ts to be helpful. I definitely th ink th e bike has the potential to get in th e championship points, and I hope I'll be ridi n g it when it does." The new machine outwardly resem bles the R G 500 Suzuki, but there are many de tail differences. It does, h owever, sh are the RG's co m pact dimensions and inclined cylinders. O n the Cagiva, though, th ese measure 56 x 50mm each, gi ving a clai med 122 bh p a t the rear wheel at 11,600 rpm . U n li ke the Suzuki, th e two cran ks ar e contra-ro ta tin g, with the p ri mary dri ve coming off th e bottom crank. Ekero ld says this makes the bike easier for him to ride. " I never rea lly got on with the Suzuki, which is a torq u ey motor with th e cranks rotating in the same direction. The Cagiva's more like riding a 350, which sui ts me better. You have to keep th e revs up, and ri ght now they're tryi n g to compress the rev band so th a t instead of th e power comin g in at 6,000 as it does at present, th en goin g up to 11,500 or so , we get a narrower, but fiercer powerband star ting a t around 7,500. It 's definitely a quick. engine already." The cranks an d rods are made by Cagiva themselves, with single-ring Mahle pistons running in 8 p ort (7 . transfer, I ex haust) barrels. The en gine cases and cylinders are all cast locally in magnesiu m , co n tributin g to a low power unit wei gh t of 95 pounds, withou t carbs; a privateer RG500 engine weighs around 119 pounds, accordin g to Ek ero ld. Dry weigh t of th e whole machin e with oil a nd water but no fuel is 280 pounds, con tr ibu ted to by the sq uare- tu be alloy frame designed and made by chief mechanic Gilberto Milani, himself a successfu l former G P rider from the day s wh en the Cagiva factory made Aermacch is. Engine designer is Ezio Mascheron i, who was responsible for the development work of th e little four-stroke p us h rod singles that are still so active in classic racing today. The new 500 Cagiva breathes through 36mm magnesiu m Mikunis, though comparable Dell'Ortos will be tried in due cou rse once the en gi n e has been sorted. "Mikunis are expensive to replace if you have an accident, and anyway we want to keep the bike as Italian as possible, " says Milani. The 6-speed gearbox is made by CMA in Bol ogna, mated to a 13plate dry clu tch. H it ach i ignition running without a battery provides the sparks. The alloy frame weighs a ligh t 16.5 pounds, and though Ekerold's firs t reaction was that the team would have been better off taking the engine to Massimo Tamburini of Bimota and getting him to make them a chassis - he admits that the handling exceeded his expectations. Rear risingrate rocker arm suspension uses a Kayaba unit, with the same Japanese manufacturer's RG500-type anti-dive 40mm forks up front. Changing to these from the Forcelli Italia units originally fitted was Boer van Dulmen's principal modifica tion, an d Ekerold agrees. "There isn't a better fork made anywhere today than the Kayaba, so why use anything else?" he says. A 16 inch front wheel uses specially made floating steel discs mounted on titanium carriers. Eke ro ld didn't like th e loo k of the high spots on the discs, an d testing confirmed that the braking effect is lumpy, so expect a switch to Za nza n i alloy units soon. Brembo ca lipers are use d front and rear, with an 18 inch rear wheel. Michelins were fitted to th e bike for its Mu gello test session. There's no doubt th e 500 Cagiva is a m uch more com petitive bike straigh t off the dra wing board than its ill fate d predecessor. Boet van Du lmen com p lained that it took about two seconds for any th rottle effect to reac h the engine, since the induction tra ct from the flat m ounted carbs, through the belt driven discs to the cylinders, was so long. It seems curious that a. tea m with so much accumulated racing experience acquired over the past 20 yea rs, a nd with five 250 and 350cc World Champ io nships under their belt courtesy of Walter Villa in th e mid-70s, shou ld have persevered for so long wi th this peculiar desi gn . Now th ey've produced the bike th ey shoul d h ave had all along. With a ri der of Ekerold's talent and determina tion a board, expect the little grey Cagiva elephant mascot to be wea rin g a smi le before too long. • ..., ., ... '_ .~ I ~ '. , l~i.J . Klotz Speclel Form ula Products, Inc. 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