Cycle News - Archive Issues - 1990's

.RACER "rEST Massimo Meregalli's Belgarda Yamaha YZF600R Thundercat \0 0\ 0\ M \0' I-< Q) "S Q) :> o Z 28 Ascari chicane ready for a hard drive out ·onto the back straight - not usually a luxury afforded by a high-revving 600cc four, where every last rpm traditionally makes a difference to your lap time. Yamaha has gone the Ducati route and beaten the desmo twins at their own game. Neat trick! ' The laws of physics prevent Yamaha from making an in-line four as nimble as a lengthwise V-twiJ:l, but it isn't far from making the YZF's updated FZR-based steel Deltabox chassis a match for the Ducati in tighter turns. The 1"-Cat f~ heavier than a Ducati changing from one side to another in a chicane, but not by much. 'Even with the stock wheelbase and steering geometry, the Belgarda bike steers very sweetly into a turn once you're off the brakes, and is impressively stable around a long, fast sweeper like the Curvone, where the blip in the screen allows you to squat down behind the. aerodynamic Tiger Shark bodywork quite comfortably. The riding position is fairly spacious and feels street bike-derived rather than c1ose-coupled like a superbike, allowing you to move easily around the bike to help it change direction. Belgarda has paid a lot of attention to the front suspension, fitting the stiffer, shorter springs from the Yamaha race kit to the 41mm stock forks, and carefully refining the result. Same thing at ,the rear, where an Ohlins race shock 15mm longer than stock but fitted with the street link has hel ped raise the rear end, to increase front-end weight bias and thus grip, as well as giving Maio a little more ground clearance - and the grip of the new-generation Michelin TX15 / 25 treaded tires are enough to let him lean the YZF over a long way as he maxes out corner speed. That's also why he runs a 120/70 front instead of the 120/60 the YZF is delivered with, and the result is a bike with a degree of front-end grip that wouldn't disgrace a slick-shod superbike - as Carl Fogarty obligingly helped underline when he zapped me on his factory Honda RC45 acceleratjrrg out of the second chicane at Monza, and I was able to tuck right in his wheel tracks through the Lesmo double right after that, which is as stern a test of a bike's front-end handling as you can find anywhere. Okay, so Carl was probably running in a new motor or' warming the tires but the comer speed the Michelin-shod Yamaha will allow you to maintain is truly impressive, with more feel from the new front Michelin than I'd expected those street forks would deliver. And as those third-gear power wheelies hoisting the front wheel cranked over at 11,000 rpm out of the first chicane proved, there's good grip at the rear, too. The stock rear link gives a nice, progressive response when you hit a bump hard on the gas, and has excellent traction out of the chicanes. One way you discover the excellence of the Yamaha's front-end grip, though, is by realizing that the one-piece Sumitomo four-piston brake calipers - which are one of the street YZF6OO's proudest pieces of trick hardware - don't really live up to their billing on the race track. Belgarda has dropped the Thundercat's 411-pound dry weight in street form to 385 half-dry, just 6.6 pounds over the supersport limit, without even resorting to carbon-fiber bodywork or the like. Yet the Sumitomos and their 298mm steel discs don't have the bite out on the race track that you'd expect them Belgarda Yamaha YZF600R SpecIbtions ~I_ s - x etnJke Liquid-cooled OOHC transverse in-line four·cylinder four·stroke with four valves per cylinder . 62 x 49.6mm Diaplac la.a It _ OUlpUt Complllilan I'IlIIo c...bua II '."lIIa. . _ _ 599cc 118 bhp@ 13,700 rpm 12.6:1 (4) Keihin 36mrn CVKD Yamaha COl six-speed Yamaha close-ratio Multiplate·wet Steel twin-spar Deltabox '.' T.._ Iliion Clutch _......•.... , ChouIa , . . . ., ..... ...........•.. _ , 25"/55.7 inches _...... . , 385 pounds with oil/water, no fuel Su., 'an Fraot Rear ,41 mm telescopic forks .steel swingarm with Ohlins shock and stock rislng·rate link F_ Dual 298mm Yamaha stainless-steel discs with four-piston one-piece Sumitomo calipers , , .single 24Smm Yamaha steel disc with two·piston Yamaha caliper B .... ....r Wh••lald,.. F.-t . 120170ZR17 Michelin TX 15 radial on 3.S0·inch Yamaha wheel ....r 170/60ZR17 Michelin TX2S Racing radial on S.oo·inch Yamaha wheel . 164.3 (Mugello) Top..... V_of _.....- aw-r to deliver after sampling them on the street, where they set a new standard in volume production roadster brakes. At Monza, I found myself having to brake earlier than I'd expected, and once you've found your braking points, you must stick to them whatever happens, because the Yamaha's stoppers leave nothing in reserve. It's a bit like riding a 250 or a Supermono with a single front disc: It stops, only not as good as with two. Here, the steel brakes and the Sumies work acceptably, only not as well as the much sharper Brembos on a Ducati 748, and if you dare to try to extend their potential, you'll end up instead exploring the outer Iimi ts of that super fron t Michelin's grip on the angle, because you have nothing in reserve. The Yamaha's brakes didn't fade, but they never worked as well as I'd thought they would in the first place. Bardi says that while Meregalli thinks they're okay without being exceptional, his teammate Guareschi (fourth,in the title race at midseason) has the same criticisms as I have. Considering he's the reigning Italian Supermono champion, he surely knows all about late braking and carrying a high corner speed! However, provided you treat your braking mark as a red stop light, and don't get tempted to amber-gamble because someone's alongside you, the Yamaha stops all right, but even with the stiffer fork springs, there's quite notable weight transfer. You can feel the back end getting very light and starting to weave around as you lay the bike into the turn still on the brakes. This is more off-putting than it would be with a slick-shod bike, because the weight transfer upsets front-tire stability with the treaded rubber, unsettling the front so the bars start to shake slightly in your hands as you lay the Yamaha into the turn on the brakes. The well-set-up suspension with stiffer springs keeps working okay - the forks don't freeze or chatter the wheel - but there isn't the precision you might expect from what's _ 1996 Belgarda Yamaha SpA, Lesmo, Italy (Above) An OhUns rear shock works In the stock link. (Right) Singlepiece Sumltomo calipers work on 298mm stainless discs. They work, but there's no room for error. otherwise a pretty competent race bike in terms of handling. After trying various solutions, I found that stamping hard on the back brake before squeezing the front brake lever helped reduce the weight transfer by initially.1oading up the back wheel, but only at the cost of extending your braking distance. It did improve stability, but didn't completely cure the problem, and cranking up the steering damper was no solution either, because it made the steering too heavy and kept the Yamaha from pretending it was a twin. Learn to live with it if you race a YZF600R in 1997 - but otherwise thank Yamaha for delivering an ultra-competitive, reliable Supersport package at reasonable cost. "It's not a new engine, but Yamaha transformed it and gave it a new life in the Thundercat," says Giulio Bardi. "The YZF600 is now the benchmark of the 600 class for the privateer, and next year I'm sure there'll be a lot more customer bikes out there which will be just as competitive as us, because they'll have access to the same parts as we do. "That's the great thing about Supersport racing, which we mustn't lose sight of when it becomes a world series in 1997. This isn't a mini-superbike class: the restrictions on tuning mean it's ingenuity which is rewarded rather than the size of your pocketbook, and the YZF600 gives you a great basis for winning at the highest level." Hard to argue with that: Maio Meregalli's results this season speak for themselves, and riding his bike at Monza proved that Yamaha has set the Cat among the pigeons in supersport racing with the debut of the YZF600. The Cat's whiskers? Sure is! (N

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