Four-Stroke Force

Four-Stroke FORCE

The uncanny world of cammy motocrossers

JIMMY LEWIS

Cannondale MX400 Husqvarna TC57O KTM 520SX Yamaha YZ426F

IT'S A THUMPER WORLD, RIGHT? WELL, NOT QUITE, BUT THE booming quadra-strokes have been stealing all the headlines lately. They're winning in the woods, out in the desert, in Supercross and on the World MX circuit. Spy photos of Honda’s upcoming CR450F wallpaper the Internet. Heck, there’s even a made-in-USA cam-n-valve carrier with its head bolted on backwards!

We’ve assembled four motocross Thumpers, one each from Italy, Austria, Japan and good old Bedford, Pennsylvania, for a berm-bustin’, roost-roarin’ good time. Don’t let the greybeards fool ya, when it comes to four-stroke dirtbikes, these are the good old days.

Cannondale MX400

Building a brand-new motorcycle from the ground up is an ambitious project-even if we’re talking 50cc scooters. Making a top-flight motocrosser is downright insane, but that didn’t stop bicycle-maker Cannondale. The company has had its share of stumbling blocks (production delays, vendor problems, fuel injection bugs, etc.), not to mention a word processorinduced lashing from the dirt-only moto-mags.'

We like the Caimondale, -/ have since our first ride last year (CW, August, 2000). We came away impressed with 90 percent of the bike,

but there were some flaws needing serious attention, mostly the spotty mapping of the fuel-injection system. Cannondale has addressed this and just about every other area of concern. Our MX400 testbike was much more finished-not perfect, but in the 97 percent range if we were to assign a value. And we stick to our guns when we say you can win races on this bike. The Cannondale is different in the same way European bikes have felt different from Japanese bikes in the past.

And all the oddities-intake-forward head, fuel-injection, linkageless suspension-make little difference in the big picture of performance. The Cannon’s 95 x 61mm, dohc, four-valve Single puts out very smooth, almost electric power with sharp throttle response. There’s no real “hit” anywhere in the powerband, so it’s very easy to ride. Lack of flywheel did keep riders from dipping into the

CANNONDALE MX400

$7950

APPS Stable as a f reight train Electric starting Feels much lighter than it looks owns How much?! Where do I get those tools?

HUSQVARNA TC570

$6299

IUps A Meet the new Husky A Real four-stroke power A Easy to work on-you can actually reach the carb! owns V Only a four-speed V Big-bike feel V Needs a pipe for life

ultra low-end, while excruciating noise (intake, mechanical and exhaust) had us upshifting early until we learned to let ’er rev. Plus this bike had the most compression braking, something strangely missing on the other machines. It took some time to get used to.

With a tight first-through-fourth transmission but a tall fifth gear, the MX400, like the Yamaha, is versatile enough for use in off-road GPs. And upshifting on the Cannondale, especially full-gas, no-clutch bangs, is incredible, almost like an automatic. Downshifts can be a bit harder, though, as the shorty shift lever lacks leverage.

The MX400 looks heavy, and with electric starting it is the beefiest here, but on the track it doesn’t feel any heavier than the Yamaha. Handling is very neutral. It has that old Husky desert-

bike kind of stability, yet it still turns. The Öhlins suspension is class-leading stuff, with the plushest feel and excellent bottoming character. In fact, we’d go so far as saying the Cannondale linkageless rear end worked better than KTM’s version, though the showroom bounce test will scare you away (stiff “dead” feeling). Extra points for the cushy seat, something missing on modem MX bikes

So where is the 3 percent that needs fixing? First the hardware: Torx heads on the motor and ugly-looking metric hardware shouldn’t be on the most expensive bike here.

And we broke a swingann-pivot bolt, a part that fortunately has since been upgraded. Also, the noise really needs attention. Bring earplugs!

Husqvarna TC570

Though displacement hasn't changed, the numbers on the Husky's sidepanels are now a bit closer to reality. No longer called a 610, the new 570 is a meaner, lighter bike for 2001.

KTM 520SX

$6698

A Featherweight amongst heavies A Insane motor! A Starts like a two-stroke `~owns v Keeping front wheel near ground almost impossible V Atadtwitchy v Only four speeds, limits versatility

At 576cc, the TC is the biggest bike here and the only one with traditional “Big Bang” four-stroke power delivery. Yet this ain’t your dad’s Husky, no way. The new seat/tank/sidepanels bring styling up to date, and the riding position is more aggressive-you’re on the bike, not down in it.

Get past the funky left-side kickstarter, get over the long feel of the TC, and you begin to appreciate this bike for what it is: maybe the best Husky ever. It’s not light, and feels the heaviest of these four (it isn’t), but it is competitive. Yes, you can flick this Husky around as much as any of the other bikes, it just warns you sooner about the dangers of throwing 250 pounds around. Be warned, Supercross isn’t really what this bike craves, due to its slowrevving motor. It likes outdoor motocross, the longer the turns, the more flowing the track, the better. It really hooks up through its four-speed transmission, making shifting less of a concern than with any of the others. Stock, the TC comes with a Euro-spec muffler that really takes the bark out of the motor, but at the request of the importer we installed a Pro Circuit pipe and muffler ($500) that really woke the bike up. We also dropped the rear sprocket two teeth to a 50 to let the engine pull longer.

KTM 520SX

Last year’s 520 was a response to Yamaha’s stunning YZ-F series, and boy howdy, did the Austrians deliver! For the 2001 season, they’ve worked hard on the refinements, focusing on suspension settings and upping durability. The result is an even sharper track bike.

Nothing even comes close to the KTM in the power-toweight category-which may be the bike’s biggest blessing and greatest fault rolled into one. This really is a monster motor stuffed into a 250-class chassis, and when you ride it you begin to realize why other manufacturers maybe weren’t so quick to follow: The KTM can be a real handful. With its quickrevving, hard-hitting motor, keeping the front wheel on the ground is less of a concern than simply keeping yourself from launching into orbit!

Our fast Pros also found the bike slightly twitchy and not as planted at speed as the other bikes here. Not all bad, as you can flick, whip and thrust just like on a 125, but with twice the power available and no wind-up time. This is Supercross stuff-jump out of a tum and fly through the air like no other bike here.

But here’s the paradox: Get a bit lazy and not so crazy, and the 520, strangely, shines. The suspension that seemed to use too much of its stroke for faster riders had our Vets all smiles, with a plushness matched only by the Cannondale. And with so much power just above idle, the guys who weren’t into high revs but still wanted snap loved the righthere, right-now nature of the SX’s low-end.

KTM also gets points for the easy kickstarting via autodecompression, for a four-way adjustable handlebar position and for fit-and-finish that is tops.

YAMAHA YZ426F

$5999

APPS Ready for the starting line Almost indestructible Value pricing leaves cash for handlebars and a good chain. owns v Really needs handlebars and good chain v A little heavy up high v Rims seem to go square more easily than others

Yamaha YZ42GF

Staying on top of the four-stroke MX game is a tough business. Though we favored the KTM over the YZ-F last year, it was a teetering decision based on the lightness of the KTM and how much fun it was to ride. In fact, last year’s Yamaha 426 was-dare we say it?—a bit boring.

Some of that carries over to this year. The YZ426F is the Plain Jane of this shootout, doing nothing spectacular-but also nothing wrong.

Impressive was how well it worked and how little attention it needed the whole time we rode it. Aside from a throttle-cable adjustment, the F is a good set of handlebars and a decent chain away from perfection.

Refine, refine, refine has been the battle cry of the 426, implemented via a diet plan and subtle performance increases. Though PR forms claim a weight loss, our scale reported none. As for the boost in the roost, we agree. The 426 got a smoothing of the power spread, courtesy of five titanium valves with lighter springs to match. Aiding are revised carb settings and a smoother sploosh of fuel from the pumper mechanism, making the bike less prone to stalling or spinning the rear knob in a burst of throttle. Improved response off idle fills in the gap where last year’s cammy, low-rpm snap gave you a shove, ready or not. As always, revs just keep on pulling and pulling right up to the rev limiter, which abruptly halts the fun.

The Yamaha suspension is on par with all top-flight motocross machinery, needing very little tuning from Novice to Pro, provided your weight isn’t off the scale.

Holding itself well up in the suspension stroke, the YZ is decently stable while almost as tight a turner as the KTM. Bottoming resistance is tied with the Cannondale for best here. Our only real gripes are that the YZ feels a bit top-heavy, plus starting is a drill compared to the kick-and-go KTM.

Conclusion

Here’s our take, then, after sampling the Four-Stroke Force, 2001: Following years of subtle, ineffectual changes, Husqvarna has hauled out a major re-do to put its bike back in the hunt. This is an impressive piece, and the only bike here if you’re looking for dig-down-deep bigbore Thumper power.

Cannondale, the Johnny-Come-Lately-a bit more lately than expected-has some class-leading features held back by a few loose ends and a hefty price tag. But with newfound momentum thanks to the release of the company’s four-stroke ATV, watch the improvements happen in rapid fashion.

KTM’s 520SX is what many of us have been lusting for in a four-stroke MXer-mega power and ultra light weight. But remember the warning about being careful what you ask for! A little more fine-tuning, though, and the SX will truly be in a league of its own.

Our winner was an easy choice. It’s the most complete package here, with the fewest faults and the lowest price, a happy blend of twoand four-stroke traits. Yamaha reopened the book of Thumper history with the YZ400F, and the YZ426s have only gotten better.