Cycle News - Archive Issues - 2000's

/from the tHi TRACK: TRACK STYL.E: CONDITIONS: L.ake Whitney Hotocross Pork: L.ake Whitney. Texas Outdoors. fast. rolling Smooth: wet & slick in morning. dry & slick In afternoon: some loom & sand: elevation: 520 feet WEATHER: Afrlca-hot. tropics-humid TIHE ON BIKE: 7 hours RIDERS: One Pro. One Vet Intermediate SETUP: Set 102mm rider sag: stiffened fork compression damping (from 12 clicks out to 8 clicks out) and rebound damping (from 12 clicks out to 10 clicks out): stiffened shock compression damping (from 12 clicks out to 8 clicks oul) and rebound damping (from 12 clicks oul to 8 clicks out); turned shock's high-speed compression adjuster In 1/8 turn (stock Is 11/2 turns out). Whereas Sprenkel had to use a bit of reserve when riding the 2002 VZ426F, he felt he could go much closer to his limit on the new 450. But a glance at the scoreboard reveals that, even in the brief history of elite-level MX thumpers, Honda has a ways to go before it can pose a threat to the rule of the mighty YZF. That bike won its first supercross race (at Las Vegas in 1997, at the hands of Doug Henry) and was victorious in its first attempt at the 250cc AMA National Motocross Championship in production form (in '98, again with Henry aboard). More recently (fOllOWing the bike's 2000 evolution into a 426cc package), Jimmy Button and Timmy Ferry have pulled off National Motocross wins, and Stefan Everts collected the 2001 and 2002 500cc World Championship titles on a 500cc factory version. By comparison, Honda's CRF - almost unanimously considered a great bike - has yet to win a major title. Not only that, but no other Japanese manufacturer yet sells a serious moto four-stroke, and none has even come up with a competitor for Yamaha's 125ccclass-legal YZ250F. At any rate, it didn't take Yamaha long to respond to Honda's attack. Exactly one year after the lightweight, 450cc red thumper set MX pundits abuzz, Yamaha is returning the favor with a lightweight, 450cc thumper of its own - the 2003 YZ450F - which meets the new FIM and AMA fourstroke limit for the 250cc class and weighs in (according to Yamaha; we haven't yet gotten it on our scales) at a pound less than the CRF. Clearly, Yamaha is dead-serious about this bike - more serious, in fact, than can be plausibly justified by simple profit motive. "This bike shows our quick response to technology," says Mark Porter, the head of Yamaha USA's engineering department. "Before Yamaha came out with a four-stroke motocrosser, Honda had the best four-stroke, and we couldn't build a four-stroke. Well, all of a sudden, Yamaha gets into it, and we proved that we can build a competitive fourstroke motocrosser. There's a lot of pride in that part of it - showing we can do it." Not only that, but having an image leader like the YZ450F offers lesstangible benefits, increasing sales of anything that even looks remotely like the bike - right down to the IT-R play bikes and even street bikes. "With a four-stroke, you can still build I think that. with such an important new bike. Yamaha must have really wanted to impress the media, which is probably why they had such a cool press intro. It was a blast - the best test I've ever done. And I had fun not only riding, but hanging out with everyone especially the Japanese, who I found to be really receptive. Really, though, the bike was so good that they needn't have bothered with all the wining and dining - I'd have loved it anyway I Still, I'll never complain about being treated so well - even after I bent up their bike by high-siding it down Lake Whitney's downhill. Besides, it's good to spend so much time on one bike, and to try out a new scene and an unfamiliar track style, since it challenges the bike in different ways. Of course, we'll also get the opportunity to try it on our local tracks in the near future. It didn't take long to feel some of the changes. I've been riding Cycle News' test YZ426F a lot lately, and I noticed the lighter weight of this bike as I lifted it off of the stand. When I swung a leg over the seat, I immediately detected the new ergonomics and the flatter seat - I felt comfortable right away - and the bike fired up on the first kick! The track was a little loose at first - slippery and wet - and I was sliding a bit on the flat comers as I tried to make my lines. Still, I could make errors without much of a threat of going down: the bike is light, so you can pull it back where it should be with a lot more ease than with the 426. After a while, I became unconscious of this fact and simply rode the bike closer to the edge (on the 426, I always left a little bit of a safety margin, but I can ride the new one more like I would a two-stroke). The 450 handles well and is easier to position on the track than the old bike, so I didn't have to line up my lines so perfectly. Instead, I could alter my lines and make adjustments without losing momentum. Also, I didn't get nearly as tired as the day went on - and with Frank Hoppen making me do multiple passes for photos, I spent a lot of time on the bike! I was also able to attack the track's jumps much more easily than with the 426, which was more difficult to flick sideways in order to scrub air. You had to kind of go with that bike - you couldn't push it down to the ground - but the 450 can be manhandled. Since you don't have to get everything all lined up and perfect before the jump's lip, you can cross-up lines on the jump's face or go off lips sideways. That gave me more line options, as I could seat-bounce from the inside or just rail along the outside. Also, I was able to just launch into the air like a mogul skier - not worrying much about where I would land whereas I used to prefer downsiding a bump or landing in the flats with the 426. Slowing down the suspension rebound made things even better, as I could land as hard as I wanted (even on the upside of a bump) without losing much momentum. The 450 is easier to tum, and I could take comers on the inside or the outside. At the same time, the bike didn't seem to lose any stability - even though the track was initially smooth, there were some rough spots by the end of the first day, and I never felt any headshake or twitches. When I stiffened up the damping, it felt even more stable and less wallowy. Before I did that, though, I rode most of the day with the stock settings, and although it was a little soft and bouncy, it was really plush - good for the majority of riders. With most stock suspensions, it's hard to get a significantly different feel with the clickers alone, but I was able to make a big difference without doing anything intemally (i.e., springs or valving). I'm quite happy with just stiffer dicker settings, which is rare. In addition, the chassis' front end felt more solid on slap-down landings (the 426 was a bit flexy) - perhaps due to the new tapered steering stem. The motor is also nice. To be honest, I don't know if I felt much of a difference from the '02, but it's really effective and useable. It's also versatile, as you can short-shift it or rev it out. Yamaha says the rev limit is the same - 1125 - but it felt to me like it flattened out a bit earlier. That could just be the taller internal gearing ratios, though. At any rate, it revs just as quickly as the 426. and since it has more torque, it accelerates better - even out of sandy comers. I was able to ride almost the whole track - including most comers in third gear. Sure, you could go down to second, but why not take advantage of the motor, increasing traction and keeping the suspension relaxed? As for the absent fifth gear, I never missed it - and there were some pretty fast sections on the track. The bike shifts nicely, as well - better than the 426 - and the clutch has an easy pull. Speaking of the clutch, our test bikes had a bit of a squeal when leaVing from a dead stop. Yamaha says a different basket will rectify the problem on production bikes, and it wasn't much of a problem on the track (you don't use the dutch as much on a fourstroke, anyway). I never felt it grab out of comers or anything, although I did stall the bike a few times when tuming around for repeated passes in front of Hoppen's lens (the problem seemed to worsen as the bike heated up, and the bike was hard to start in gear). It should be better for production, and apart from that complaint, I love Yamaha's clutches: the action is smooth and light, and it's easy to adjust (not truly an on-the-fly mechanism, but you can easily adjust it with no tools). I also like the lever shape, and the rubber boot protects everything well from roost and washing (my 426 cable never needed lube). The brakes are an improvement as well. The 426's front binder needed help - it had a solid feel, but lacked strength. That's rectified on the new bike, though I wouldn't mind even a bit more power (once you try an oversized rotor, it's hard to accept anything less). The rear brake is really nice, and both ends offer good control with no mushiness. As you can tell, I love what Yamaha did with its big four-stroke - and I already liked the 426 so much that I was one of the few riders to pick it over Honda's CRF450R in Cycle News' 2002 Shootout. What's more, managing editor Chris Jonnum - a Vet intermediate - was also raving about the bike (even with my stiffer suspension settingsl), which should attest to its versatility. It's definitely better, but how will it stack up to the Honda? Only time will tell, but it should be one heck of a battle. Chris Sprenkel cue. e n e _ os • SEPTEMBER 1 1 ,2002 43

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