Singles Party
SINGLES PARTY
CW COMPARISON
FROM MOTOCROSS TO MEXICO ON THE WORLD'S BEST FOUR-STROKE DIRTBIKES
FOUR-STROKE SINGLES ARE EASY to love. Clubs form to celebrate them, race promoters cater to their bellowing exhaust notes, and in last year’s 500cc World Motocross Championship, Thumpers garnered two of the top three places. Chalk it up to tradition, ridability or simply their great booming sounds, but off-road four-strokes have never been more popular.
This year’s contenders for King Thumper come from five countries and offer enough variety to whet the appetite of any dirtbike enthusiast. From a hard-edged, cut-and-thrust racer to the Lincoln Towncar of trailbikes, this class has it all. They are, in alphabetical order: the ATK 605ES Cross Country, Honda XR600R, Husaberg FC501, Husqvarna 610 WXC, Kawasaki KLX650R and KTM 620 LC4. If you’re an off-road enthusiast with a penchant for straight gas, you’ll find your fix in this bunch.
For our comparison, we trucked the six contenders to Sunrise Raceway in Adelanto, California, for a day of motocross and a bit of impromptu dirt-track action on the facility’s fifthmile oval. Next on the list was a three-day tour through the cow trails and jeep roads of Baja, Mexico, where adventure and serious mileage awaited. Some 600 miles later, we had our winner.
HUSABERG FC501
The Husaberg FC501 is a racebike. Plain and simple. At 249 pounds, it is extremely light. It also has the quickest-revving engine of the bunch. The Husaberg’s dohc, four-valve, 50lcc engine is very responsive, but has little flywheel and stalls easily. The transmission feels solid, but is notchy and resists neutral unless the bike is rolling.
Riders praised the FC’s narrow feel and light weight. For Mexico, we installed an auxiliary fuel tank from Eric’s Motorcycle Company, boosting the bike’s fuel range from 65 miles to nearly 100 miles. The aluminum tank resides where the airbox on a conventional bike would go; the Husaberg’s airbox is located on the side of the frame under the gas tank. Controls were noticeably high-effort and designed for riders with large hands. The front brake needs more stopping power, while the rear is too touchy.
Although it made plenty of friends during the motocross portion of the test, the 501 lost points in Mexico. One of the bike’s best traits, its knife-like cornering prowess, comes at the expense of stability; headshake is a problem. “This is not a trail bike,” muttered more than one tester. Also high on the list of complaints was the overly stiff suspension, which tended to deflect away from rocks and other obstacles instead of absorbing them. While this is less of a problem on a motocross track, it can be downright scary on the trail. Less compression damping at both ends helped, but did not cure the problem. Husaberg trail riders will need a suspension specialist.
The Bottom Line: Aside from its engine, the Husaberg FC501 has few four-stroke characteristics. Indeed, the bike’s low center of gravity, spectacular cornering ability and unmatched acceleration out of tight turns mimic that of a high-performance two-stroke. So much for its ability to win an all-around four-stroke comparison-unless you’re as much of a racer as this bike, that is.
ATK 605ES I --9ÊÊÊ CROSS COUNTRY
Can we call the ATK 605 a first-year effort? In many respects, that’s exactly what it represents. Even so, ATK has managed to build or source the right components, and its much-improved 605 is now in the hunt.
A few years ago, electric starting was a dream come true. Now, it’s more of a convenience-as long as the proper starting procedure was followed, the other bikes were first-kick starters-but it’s a nice feature nonetheless, especially on a long day of start-and-stop trail riding. Other niceties include an Answer Pro-Taper handlebar, goldanodized billet hubs and an impressively slim, 5-gallon fuel tank.
Steering is precise with no sign of headshake, and the suspension-sprung softly for trail riding-kept riders comfortable and the wheels tracking. Lessaggressive riders really appreciated the setup. The layout is roomy and the seat comfortable, making it easy to move around on the bike, especially when sliding forward for turns. The ATK’s Nissin brakes are strong, but required more effort than those of the Japanese bikes, also Nissin-equipped.
Even with its quiet-but-restrictive muffler, the smooth and torquey Rotax Single is an impressive performer, but a notch below the KTM and Kawasaki, the class powerhouses. ATK says an aftermarket exhaust will boost performance significantly. Still, the comparative lack of power forced testers to shift more often, and some complained of false neutrals. Also, the chain guide is noisy and its buffer pad wears out quickly, and the kickstand bends easily and fell off twice.
The Bottom Line: Positions 5 through 3 are almost a draw. Make no mistake, this is an excellent motorcycle. But at $7295, the ATK is $1100 more than the Husaberg and nearly $3000 more than the Honda. More than anything, that takes it out of the running in this comparison. But if you’re after a fun Thumper that’s made in the USA, and you have deep enough pockets to pay for it, move the ATK up several notches in ranking-maybe even all the way to the top.
t^M: 6^0 LC4
The 620 LC4 is the horsepower king of this group. This year’s 60cc displacement increase provides additional pulling power. Initially, we thought the KTM owed its roll-on acceleration to lower gearing, but that was disproved when the 620 ran away from everything but the Husky on top end. The motor revs quickly-though not as swiftly as the Husaberg-yet has enough flywheel weight to keep it tractable in slow going. If the KTM were a little smoother off the bottom, it would have the best motor. In its current form, the engine is a close second to the Kawasaki’s.
While its motor performs well, the rest of the bike is slightly off the pace. The new chassis resembles that of the KTM motocrossers, but the suspension feels unbalanced. On the trail, the faster the bike was ridden, the better its suspension worked. The same cannot be said of its performance on the motocross track. Like the Kawasaki, the LC4 feels a bit top-heavy. And compared to the Husky or Honda, the KTM requires more rider effort. Due to its front-end weight bias, the 620 needs a firm tug on the bars to bring the front wheel up.
The riding position is comfortable, with the exception of a hard spot in the seat’s center. Controls are right where they should be, but the rear-brake pedal can be difficult to locate. Bonus points should be awarded for the light-effort clutch and well-thought-out kickstand.
The 3-gallon fuel tank borders on being too small. That, combined with low fuel mileage, added up to little more than 70 miles between fill-ups. Also, the 38mm Dell’Orto carburetor is sensitive to altitude changes or a dirty air filter. (A quarter-turn adjustment on the low-speed fuel-mixture screw solved the problem.) The muffler is very quiet and doesn’t seem to restrict the motor.
The Bottom Line: Like the ATK, the KTM has a lot going for it and could easily move up in the rankings. It has all the right parts; with a bit of fine tuning-and a slightly lower price tag-the 620 LC4 would be a serious threat.
KAWASAKI KLX650R
Give Kawasaki credit for sticking to its guns. Last year, the KLX650R performed well, but was let down by a few fatal flaws. In contrast, the ’94 model has only minor shortcomings. Overheating problems have been fixed by a new head gasket that slows the flow of coolant through the head, and by fitting a cooling fan to the right-side radiator (during testing, our bike never got hot enough to activate the fan). Remaining glitches? A small, 2.1-gallon fuel tank and a non-O-ring chain that shouldn’t even be used on a minibike. We opted to adjust the chain every 60 miles or so, and for trailriding, swapped the stock tank for a 3.6-gallon IMS tank, which, though a little bulky, bumped the bike’s range to 100 miles.
In many ways, the KLX is a better trailbike than the Honda XR600R. The Kawi’s liquid-cooled, dohc Single definitely has a performance edge. (We tested the bike with the supplied jetting update, and the airbox lid and muffler restrictor removed.) In top-gear roll-ons, the KLX was second to the powerful KTM, but only by the smallest margin. The Kawasaki’s advantage is a linear power spread and ultra-smooth low-end pull; great for tight trails. The power does flatten out on top, but for allaround use the KLX’s engine is a winner.
At speed, the Kawasaki is also the most stable of the six Thumpers, though this hampers its turning performance in tight-going somewhat, as does its 300-pound dry weight, the most in the class. Suspension is suited to trail use and works very well within its limits. At near-racing speeds, shortcomings begin to show. On the motocross course, the Kawasaki bottomed heavily and regularly dug its footpegs into the ground. In Mexico, though, the compliant suspension allowed the bike to cruise comfortably over loose rocks and rain ruts.
Brakes are strong and progressive, and the sweptback handlebar places riders in the bike rather than on top of it. Testers disliked the handlebar for motocross use, but no one complained during the three-day Baja ride. Handguards are standard equipment.
The Bottom Line: In sum, the Kawasaki is a great trailbike; racers should opt for something else. It costs $250 more than the Honda, but for the extra money, buyers get liquid cooling, a perimeter frame and inverted forks. The KLX needs a few band-aids, but for those who must have the latest features, the Kawasaki is a worthy choice.
iJHHUSQVARNA jéTmmxc
Husqvarna set the standards for lightweight, performance Thumpers in the early ’80s. While the competition has certainly improved, the Italianowned manufacturer still commands the driver’s seat. Indeed, if one were to ask for a box-stock bike that could accomplish any off-road task, the WXC would be the perfect choice.
At the motocross track, the Husky was the Husaberg’s only challenger. And on the trail, the 610 can be ridden all day with little discomfort. Positive comments revolved around the suspension, which is nicely balanced and offers enough adjustments to satisfy a wide range of rider weights. In stock form, the suspension could be raced in both motocross and off-road venues. The same cannot be said of any other bike in this comparison. The Husky doesn’t possess the knife-like turning capability of the Husaberg, but its stability is much better.
The 577cc, dohc, fourvalve engine is very similar to that of the ’93 model. The biggest change is an internal decompression system, which eliminates last year’s external, cableoperated decompression system. Performance is impressive, with plenty of low-end and midrange grunt and superb top-end pull. Though the motor is not the fastest in terms of roll-ons-that credit goes to the KTM-the potent topend surge had several riders thinking otherwise.
Negative comments went to the lessthan-stellar brakes, redesigned sidestand and flimsy steel handlebar. Unfortunately, the twin-piston front and single-piston rear Nissin calipers are simply not as powerful as those fitted to the Honda, the class’ best stopper. More power and greater sensitivity are needed. And the new sidestand, which is tucked up and out of harm’s way, tends to release under hard landings and scrapes the swingarm under full compression.
The Bottom Line: Overall, the Husqvarna rates a very close second. Cost was its greatest drawback. At $5850, the 610 WXC was a bit too expensive for our trailriders, though our competition-oriented riders would definitely lay down the extra bucks.
HONDA XR600R
Honda’s off-road workhorse is still with us, unchanged but competitive. Even without a major update since 1991, the XR600R continues to be raced successfully off-road. Kitted Baja racers bear heavy modifications, but five-time national hare-scramble and cross-country champion Scott Summers continues to win on relatively stock equipment.
Considering its $4449 price tag, the XR is a bargain. That doesn’t mean buyers get less for their money. Quite the contrary. The Honda’s air-cooled motor and conventional fork may look dated, but their performance is impressive. Aside from exhaust alterations, the engine has not seen major upgrades since 1985. The 591cc, sohc Single pumps out competitive power in a broad, usable fashion. Compared to its competition, though, the XR’s engine merely gets the job done, even with its exhaust end-cap removed. In this form, the Honda was a little coldblooded on start-up, but otherwise carbureted perfectly.
Like its engine, the Honda’s chassis is beginning to show its age. The conventional cartridge fork, for example, is a little soft for aggressive riding, but within its limits drew no complaints. Ditto for the shock. For trail riding, the stock settings work well. Turn up the pace, though, and the suspension wallows. Still, handling is very predictable, and steering effort light. Indeed, lifting the Honda’s front end over logs and stream crossings is never a problem. Moving around on the bike is also easy, and some larger testers felt the XR was the most comfortable bike in the comparison. The brakes are the best in the class, as are the clutch and transmission. Thanks to excellent fuel mileage, the 2.6gallon gas tank provides nearly 100 miles on fireroads, though it will run out sooner in the tight stuff.
The Bottom Line:
There are no losers in this group, although some are better than others at certain tasks. And as an all around bike with heavy emphasis on trail riding, the Honda is the winner.
ATK 605
$7295
HUSABERG FC5O1
$6095
HUSQVARNA 610
$5750
KAWASAKI KLX650
$4749
KTM 620
$5598
HONDA XR600
$4499
