Cycle News - Archive Issues - 2000's

Yamaha YZ426F Vor 530mX The one that originally sparked all this "lightweight production four-stroke" interest back in '98, Yamaha's extremely popular YZF is still a serious contender. W~ightwise. the fifthyear ('02) version is third-best. with only the Honda and KTM tipping the scales at less tonnage. Motor-wise, the Yami's titanium valves (it's a patented five-valve system) allow lighter-rate valve springs and higher revs for the dual-overhead cam design. Suspensionwise, the same top·shelf Kayaba components that consistently win praise on the two· stroke YZS are mounted. For '02, Yamaha gave its big thumper an altered ignition curve, and we were surprised at the difference it made. In addition, the front hub is wider (from 50mm to 70), and the swingarm and linkages are new. The shock is slightly longer, the fork has new intemals, the rear brake rotor is 5mm larger. The 426 has a manual compression release, and it's got a (revised) hot·start button on the carbo The Yamaha remains the only four-stroke to win an AMA Pro Racing title, and the only four-stroke to win an AMA supercross. This is another Italian bike, and it, too, is quite unique. The Vor uses a single overhead camshaft, which is driven by gears instead of a chain, and the engine fires up via a forward-swinging kickstart lever. The 530 is another machine with a removable cassette gearbox, and it utilizes a hydraulic clutch. The Vor features Braking wave rotors and an aluminum bulge handlebar, and its frame is of a chrome-moly, perimeter variety. The tank extends down below the seat. where the airbox also resides. Suspension duties are handled by Paioli components, and the beautiful aluminum swingarm is made from three pieces that are connected by high-tech glues and bolts (no welding). Weight on the Vor is right in there with the Vertemati and Cannondale. (lighter than the Husaberg, but heftier than the Honda, KTM and Yamaha). KTM 520 SX Cannondale X440S The lone American entrant provided us with its "Interim" model, as the new-generation X440 isn't yet available, though it should be soon. The relatively affordable X440S that we tested is a big improvement over the MX400 we tested last year, with much better fuel injection and claimed increased durability (our 'Dale never hiccupped over three days of non-stop abuse). The Cannondale's cylinder is backward, breathing in through the front and relieving itself through the rear, and the transmission can be pulled out without pulling the motor. If you do need to yank the mill, the trick aluminum frame's removable engine cradles should simplify the task. Suspension duties are handled by an Ohlins fork and shock, the exhaust is by FMF, and the brakes are by Nlssin. The X440S is the only bike in this shootout with electronic fuel injection and an electric starter, but the presence of a battery and a starter motor don't make it the heaviest (it's lighter than the Husaberg and Vertemati, and is the same weight as the Vorl. When it does hit dealer floors, Cannondale says the new·generation X440 will have a narrower chassis, a 20mm lower subframe, a displacement increase, and a lighter weight (by about 10 pounds). KTM sometimes feels that its big four-stroke doesn't get the respect it deserves, and to be honest, they might have a point. After all, the SX is the second-lightest bike in this shootout, coming in heavier than only the red bike, and several pounds lighter than the blue bike. The 520 uses a trick single-overhead-cam design that allows a short engine and low center of gravity. The KTM is the only bike in our shootout that uses a four-speed transmission. It's suspended by WP components (including a PDS shock that mounts directly to the swingarm). New for '02 are a bigger diameter (48mm) on the inverted fork, which features not only compression and rebound clickers, but an extemal preload adjuster. The shock now has a forged (instead of cast) body and updated valving. As for the big 520cc engine (third-largest displacement in this group), it gets a new O-ring seal on the countershaft, reinforced ignition and clutch covers, new clutch plates (the fiber ones have more contact area to the basket, and the steel disks are thicker for better heat dissipation), a sealed baJJ bearing on the camshaft, and a newly designed water-pump seal carrier. liTHE YAMAHA IS A WONDERFUL BIKE THAT INSPIRES A LOT OF CONFIDENCE. IT LIKES TO BE RIDDEN AGGRESSIVELY. U (RIght) Pro tester Chris Spnlnkel is better at riding than he is at husUlng. (Below) The only thing better than riding these bikes on the Honey Lake track was the post-shootout bash in the Woslco' bam. Honda CRF450R VertelDad C500 The Vertemati brothers have been involved with two of the other companies in this shootout, but the Italian siblings would hold that hand-built bikes that currently bare their name are the most advanced rendition. Indeed, the C500 boasts a plethora of works-like accoutrements, most notably the ultra-trick works-level WP suspension (the fork has a 48mm diameter nitride coating, while the shock boasts both high· and low-speed compression damping). The clutch is a hydraulic Brembo unit, the fuel tank is located under the seat (which comes off easily via a Dzus fastener), and the airbox goes where you'd expect to find the fuel cell. Even the seat base is made from carbon fiber. Braking makes the rotors, and Talon supplies the trick aluminum hubs. The kickstart lever swings forward instead of backward, and decompression is automatic during starting. As for the powerplant, it's got a single-overhead-cam configuration, and while the camshaft is driven by gears as with the Vor, it's a completely different design. The bike should be super-easy to work on, as the camshaft pulls out the side of the engine, as does the cassette gearbox, and the clutch uses a circlip mounting design that allows it to be yanked out extremely quickly. The cylinder and case are one piece, and there's a floating cylinder sleeve that can be easily removed. Interestingly, the bike comes with a six-speed tranny and a lighting coil, which should help in the versatility department. Vertemati is small, which means they can offer a variety of configurations. Look for a 450cc motocrosser to be released soon. This is the bike that both raised the stakes and made it clear that the four-stroke MX category is an important battleground. Most importantly, the bike is significantly lighter than the competition, measuring about 15 pounds less than the nearest competitor on our highly inaccurate scales. So heavy has the press coverage of the CRF been that there's no reason to get too detailed on the tech stuff, but some of its cooler elements are its titanium intake valves and shorty piston, both of which help the motor to rev to the moon. The engine oil and transmission oil are separate to prevent contamination. (Honda has had a few problems with customers under-filling the tranny cavity, so be sure to add exactly 590cc upon draining the motor.) Allowing a lower center of gravity is the shortish engine, which - like the KTM - utilizes a single overhead cam. Helping to achieve the bike's feathery weight are a titanium exhaust header and an aluminum perimeter frame. To make starting easier, there's an automatic decompression system and a bar-mounted hot-start button. Husaberg Fe550 This is one of the original lightweight four-strokes. and although it's not quite as trick as some of the new-fangled steeds, most of them wouldn't have been possible were it not for the Husaberg. Not only that, but the 'Berg got a new-generation motor in 2001, and the revised mill reduces engine vibration and engine inertia with a counter-balancer that rotates in the opposite direction as the crank. Interestingly, the engine features no cylinder; instead, a plasma-lined cylinder liner is sandwiched between the two extended center cases, on top of which the head bolts are placed. And speaking of the cylinder, the 550 is the biggest-displacement bike in this shootout, though the Swedish company seils a 470cc model as well. Suspension duties are handled by a WP fork and a WP PDS link-less shock, the latter mounting to a very trick aluminum swingarm (the axle holders are not welded on, but instead are a part of the entire unit). The H'berg is the heaviest bike of this shootout, but not by much. Oh, and every purchase of an FC model includes a set of the trick aftermarket graphics shown on our bike in these photos. cue I • n • _ 50 DECEMBER 12,2001 11

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