from here
http://www.motorcycle-usa.com/11/435/Motorcycle-Article/2006-450F-MX-Shootout.aspx
2006 450F MX Shootout
JC Hilderbrand
He’s been called dirty for plenty of reasons, but Hilde always likes it best when it involves two wheels. Riding crappy bikes since age 13 and devouring every moto mag in sight, he’s an off-road enthusiast through and through.
We don't recommend staring down these 450 machines. Make a habit out of it and sooner or later they're bound to kick your ass. From left, the ATK 450 MX, Suzuki RM-Z450, Honda CRF450R and Kawasaki KX450F.
The bigger the better, eh? Well that is the American way, and motocross in the USA will live and die by that cardinal rule. The 450cc thumpers are the supreme motocross weapon. All the big names have officially traded in their pipey pre-mixers for the booming bikes, and even the race series' names indicate supremacy; Supercross with a capital S. The biggest stars race the biggest bikes for the biggest purse in what has become the world's greatest supercross series.
Ride one of these bikes and it's obvious why they are so highly touted. Their performance is unmatched, and the only thing coming even remotely close is the number of manic grins concealed behind a rider's chin guard.
MotorcycleUSA wanted to find out what these mean machines are all about, so we rounded a few of them up for a shootout. A few is actually something of an understatement. In reality we put in calls and lined up not only the four Japanese brands, but went ahead and made it the Big Five with the increasingly popular European KTM marque. Just for some additional flavor, and since the best racing in the world now happens within the boundaries of the continental United States, it seemed only appropriate to see what the red, white and blue had to offer. ATK, the only American manufacturer of off-road bikes, lent us a 450 MX to bring our count to six.
The stage was set for MotorcycleUSA's biggest MX shootout ever, but life has a way of building you up just to knock you down. Unfortunately, we got punked by two manufacturers at the last minute, turning our scheduled six-bike shootout into a scaled-down version consisting of Honda's CRF450R, the new KX450F from Kawasaki, the Suzuki RM-Z450 and the aforementioned ATK 450 MX. If you'll notice, there's a distinct lack of blue and orange in the photo gallery which is by no means the fault of our photographer.
Regardless of the shortcomings we grabbed what we could and ran for the San Bernardino hills, then jaunting over to the drastically changing lakebed soils of Lake Elsinore. Our regular test monkey, Mike Mandahl came out to give the fo-fiddies a spin and brought along his pal Anthony Rondon for a second opinion. Here's how it all shook down.
After jumping the gate repeatedly on our first day of testing, Ken (left), who was on hand for video duties and the occasional stand in only, pronounced himself the Holeshot King and pranced through the pits shirtless staring down small children saying, "What you looking at punk, what?" We knew right away that it was going to be an awesome test.
Motor Mania
The heart of the 450's success lies in the motor. Sure, the rest of the bike's components are important too, but these machines kick 2-stroke tail primarily because they can yard anything except another 450 off the line. Having the power to pull starts, clear jumps and out-drag competitors into the next turn is where 450F pilots will gain huge advantages.
None of the bikes we tested had any problem pulling second-gear starts, and with massive holeshots and welted chests becoming the norm, that's just a given these days. Where you want to go from there depends on rider weight, track conditions and personal preference. Our guys ranged from 150 pounds to 180, and not one of the bikes liked to keep the front wheel on the ground while ripping away from the gate.
Our test riders put the CRF ahead of the rest in the motor department. There's no denying that the Honda cranks it out, as it posted the highest horsepower numbers when we revved them out on the Two Brothers Racing dyno. The Honda was consistently above the competition through the entire powerband, maxing at 50.6 hp. From a seat-of-the-pants perspective, our test riders agreed by noting strong performance across the rpm spectrum. Rondon was particularly fond of the red bike's motor, believing that it makes more down low than it did in '05.
Our first day of testing was at the tortuous Glen Helen circuit. Battling gusty winds and this gnarly uphill in particular, the brutal racetrack gave us plenty of obstacles to assault.
Honda's Eric Crippa was the technician on hand to help tweak the bike throughout our testing. From his experience in previous testing and other magazine shootouts, he went ahead and installed different jetting specs that he says should have come stock in the 40mm Keihin FCR carburetor. We take his word for it because the combination in our bike was spot on at both Glen Helen and Lake Elsinore. Crippa replaced the stock 45 pilot jet with a 48 and tossed in a slightly leaner NCVQ needle with the clip in the fourth position along with a #168 main jet.
It's important to remember the way the power is delivered makes a big difference in a rider's impression. Two of our four bikes had four-speed transmissions, which meant that power delivery was very different from the others. I too liked the CRF's motor, but the five-speed transmission wasn't as useful to me for motocross applications. The KX-F and RM-Z both felt more robust, especially in the low end and midrange, primarily as a result of their four-speed trannies.
Second and third gears on the Kawi and Suzuki were awesome utility gears that allow for riders to get around the track with far fewer shifts. Lugging the four-speeds through corners was no problem, while the CRF was by far the easiest to stall. I never had any stalling problems with the ATK, but the other riders killed the motor on occasion. In either case, it's hardly worth mentioning because the ATK's electric start combined with fuel injection meant that it was up and running again faster than any bike on the track.
Honda won the motor war with the only bike to top 50 horsepower during our dyno runs. As you can see, Anthony was pretty happy with the CRF.
The Kawi and RM-Z received the same score for motor performance but reached their marks through different ways. Both Rondon and Mandahl ranked the KX450F second, praising the linear powerband and ease of use as its strongest features. I agree that it was the easiest to ride for long periods of time, but I actually preferred the Suzuki powerplant over the entire group.
Riding the yellow bike was very similar to the KX-F in terms of power delivery, but it had a bit of a surge in the midrange that really made it fun to ride. Usually I would shy away from a midrange hit, especially on brutes such as these, but the RM-Z managed to retain its controllable nature while providing that extra bit of adrenaline. Doling out 48.5 and 49.3 hp, respectively, the RM-Z falls just short of the Kawasaki on the dyno but that single top-end pony is tough to detect on the track.
Each motor follows the four-valve, DOHC configuration, producing 449cc of displacement, with the exception of the Honda which uses a Unicam, four-valve orientation. However, that's about all the ATK has in common with the other three.
Instead of the normal rear-mounted carburetor and forward facing exhaust port, the cylinder is reversed on the American bike. In place of the carb, ATK uses an electronic fuel-injection system to deliver combustibles. It's located opposite conventional carb placement and is at the front, between the enormous single-piece radiator and cylinder. The cool thing about EFI, though we didn't get to toy around with it, is that the system's computer can be remapped to suit a variety of conditions. The ECU also has a diagnostic hookup for monitoring precise engine performance information.
According to the Two Brothers Racing dyno, Honda ruled the horsepower chart while the fuel-injected ATK brought up the rear. We included some figures for the Yamaha YZ450F as well which demonstrate how competitive the motor is. Too bad we're not cool enough to get one.
Because we got the ATK through our local dealer, Oregons Best Cars it was the only manufacturer that wasn't represented by a trained technician. Having someone there would have been ideal to help set up its suspension and to simply help explain some of the ass-backwards engineering found on the ATK. However, the U.S.-made motor ran like a champ even if there was a lot of engine noise. Engine braking was the most notable of the group thanks to its 12.5:1 compression ratio, easily the highest of the bunch. But the bike never sputtered or coughed and not once did it backfire under deceleration.
Despite the excellent running condition of the motor, all of our test riders noted that it was drastically underpowered in comparison to the Japanese bikes. Producing a mere 45.5 hp at the Two Bros shop, the shortcomings were only magnified on the track by a significant amount of extra poundage courtesy of the only electric-start components. A docile motor coupled with excess weight gives the ATK more of an off-road bike characteristic. The bike is actually the same as the 450 Enduro but the off-road model has a revised ignition mapping and includes lights. We'll be testing the altered settings later in our 450 enduro shootout.
Even though we didn't get to test the Yamaha, we were able to grab some dyno numbers from the guys at Two Brothers simply for a quick comparison. The YZ450F they tested, which was sitting there mocking us, pumped out 50.2 hp and 33.9 lb-ft of torque. That horsepower figure falls beneath only the mighty Honda, and just barely, while the torque output lands it in third behind the 34-plus figures of the CRF and RM-Z. Don't you really wish we'd have gotten to test it now?
Motor Ranking:
1. Honda
2. (tie) Suzuki, Kawasaki
4. ATK
The KX-F wasn't the lightest on the scales at 232 pounds, and it didn't feel the lightest on the track. Regardless, a supremely well-balanced package make the Kawi a particularly nasty airborne pathogen.
The Skinny
I mentioned the extra pork on the ATK discovered by our scales. We could tell a difference just from attempting to lift it onto a stand, but the point is that weight is another all-important factor in class supremacy. Indeed, bigger is better, but the one area in which manus discredit our fundamental rule of thumb is with weight. Unfortunately for the American bike, our scales showed it to be 25 pounds heavier than the next-closest RM-Z. Honda proved to be the queen of vanity by trimming it's waistline to a skimpy 229 pounds. The Kawi's 232-pound tank-empty weight was slightly less than the RM-Z's 239 pounds.
Moving around on the CRF is simple thanks to its thin layout, and piloting around the track is also aided greatly by the weight savings. All of us were able to feel the difference in weight on the track and the Red thumper is definitely the sveltest of the crew. One way it was easy to tell was simply by getting into the air during our first day of testing at Glen Helen. With 30-mile-per-hour winds gusting the entire day, the Honda suffered worst in the dusty gale. I had the front end blown completely off the side of a tabletop that resulted in a trip over the bars. Luckily I'm not in the habit of going big on jumps, wind or no wind, so the crash was more of a flop than anything.
All of the bikes are excellent fliers, even the hefty ATK, if you dare. Jumping is where weight becomes most obvious to a rider. As you can see from our photo gallery, Mandahl was able to get all of the bikes moving around in the air, but the Honda and Kawasaki were consistently his favorite. Okay, so he didn't actually whip the ATK, but that's a hell of a lot of metal to be getting out of line.
None of the bikes were all that close to one another on the scales, something we didn't expect. What we did expect, however was the CRF to be pretty damn light, and Honda didn't disappoint.
The numbers in parenthesis represent the percentage of weight on the front wheel.
I hate to keep bringing up comments about the '06 Yamaha YZ450F, but it felt the most agile out of all the 450Fs I've ridden when I tested it at Competitive Edge during its press intro. We didn't have it for a straight up comparison, but it is definitely worth mentioning that I loved jumping the blue bike.
Nickel & Dime
Talking about engine braking and weight naturally leads into a discussion about cornering ability. While the RM-Z has the shortest wheelbase at 58.3 inches and sharpest 25.5 degrees of rake, it still couldn't overcome the hard-charging Kawasaki. and Honda in the handling department.
The Suzuki and Kawasaki both have Honda-inspired twin-spar aluminum perimeter frames, but each has just a tad bit of individuality. Suzuki engineers have placed rectangular indentations in the biggest spars for a unique look and an additional bit of knee grip. Rondon and Mandahl both didn't notice a difference, but I preferred the indented style to the smooth frames of the Honda and Kawi not only for its grip, but for the extra robotic look it adds to an already chiseled physic. Kawasaki managed to squeeze the KX's overall width down to 32.3 inches, the smallest of our test.
Each of these bikes turns on a dime. Well, the ATK might run you two bits, but the Japanese trio knife through corners like a rabid teppanyaki chef with a pound of sirloin. The lightweight CRF has by far the most history with aluminum twin-spar perimeter frame chassis, so it was no surprise that the Honda gave excellent feel while avoiding harshness.
Sharp handling is one of Suzuki's known strong points. Even with the highest seat in the class, the RM-Z will blitz through the corners. Test rider, Mike Mandahl fell in love with this inside rut.
The only machine to top the Honda in chassis performance was the KX450F. A 27.1 degree rake and 4.6 inches of trail is less aggressive than either of the other Japanese bikes, which accounts for the extreme stability in rough sections and through turns. I found the Kawi frame to have the highest amount of flex, but it was by no means soft. Not that any were particularly harsh, but the KX-F transferred the least amount of jolt to the rider. This is Kawasaki's first year producing twin-spar alloy frames, and this one utilizes three-part technology to form their chassis out of cast, forged and extruded aluminum components similar to the CRF and RM-Z.
Our smallest rider found the KX-F to fit his 5'5'' frame the best. "The bar and peg height fit perfect for a small rider like me," Rondon said. As for myself, I found that moving the bars forward pulled me out of the swept-back position and increased the amount of grip at the front tire, greatly increasing my confidence and turning capabilities.
Astride the Suzuki, its pegs feel tilted forward just a skosh, helping keep the rider forward on the seat and feeling aggressive. The seat height on the yellow bike is a whopping 39.2 inches. That's more than an inch higher than the Kawi and ATK, both 38 inches, and nearly two inches higher than the CRF's 36.8-inch tall butt rest. As a result the Suzuki feels top-heavy and just plain tall. Merely watching our shortest test rider attempting to kick the Suzuki to life after a stall was painful. All of the bikes require a good, solid kick and they'll light up, except for the ATK which is electric start only, but it proved to be an extreme challenge for our short tester, Rondon, who would have benefited from a sole extension on his left Sidi.
The oft-copied Honda aluminum twin-spar frame is light, strong and gives positive rider feedback on the track. Turning the narrow machine is greatly aided by these attributes.
Ergonomics on all the Japanese bikes were very similar when compared to the ATK. Despite the same seat height as the KX-F, the 450 MX feels long and low from the saddle. A 58.5-inch wheelbase isn't much different than the others, but the soft seat allows the rider to settle in and the Henry/Reed Pro-Taper bars felt like ape-hangers when coupled with the 27.5 inches of rake at the steering head.
"It's like driving a diesel rig when the others are like Toyota Tacomas," Rondon said. But before you write off the good ol' U.S. of A., let's look back a little to see where this whole situation stemmed from. Here's the short version.
Bicycle manufacturer Cannondale threw their helmet into the motocross ring when it released the MX400 in 2001. Bike reviews for the new machine were consistently blase' but the potential for improvement was definitely there. Unfortunately, Cannondale Motorsports was forced to file bankruptcy early in 2003, leaving the business up for grabs in an auction bidding war. And this is exactly where ATK USA comes in.
ATK has never been a major player in motocross or supercross, but its quietly been selling a small share of motorcycles each year. When Cannondale went under, their surplus inventory was snatched up by the former sponsor of Wheelie-King Doug Domokos to make it their own. Well, kind of. The current 450 MX model still has a Cannondale engine cover on the left side, though they have gotten around to installing an ATK brand cover on the right side for 2006.
Once you get that thing tipped over, don't let off until the next obstacle. Anthony Rondon demonstrates how to rail a 262-pound beast.
Knowing that the 450 MX hasn't seen a lot of external changes since the Cannondale days between 2001 and 2003, but it has seen significant improvements in reliability of the powerplant. Still, the ATK comes out of the gate behind the times and they know it. That isn't to say that the machine isn't competent on the track in the right hands, but getting thrown head-to-head against bikes with the most cutting edge technology is a tough order to fill.
Handling/Chassis Ranking:
1. Kawasaki
2. Honda
3. Suzuki
4. ATK
There's nothing better than telling someone what's happening on the track and having them fix it for you with minimal guesswork. We've all been there, spinning suspension clickers helplessly and wondering just how the hell to get it all back to stock settings.
Suspended Animation
Victorious in the ever-important suspension wars was again the brand-new KX-F. In a ground-breaking move for the company, Kawi used Showa components on its '06 250F. Apparently one big change was enough because the engineers stuck with their longtime suspension partner, Kayaba, on the 450. Public Relations man Russ Brenan assured us that it was a decision based solely on the findings of rigorous performance testing during Kawi R&D sessions. We absolutely loved the Showa stuff on the 250F, but since we don't have the opportunity to try it out on the 450F, we'll just have to accept his words as the truth.
A 48mm Air-Oil Separate (AOS) Kayaba inverted fork handles all duties up front, and handles them well. There weren't any reports of unpredictable behavior which turned out to be a consistent theme with the Kawi. The fork refused to dive excessively under hard braking, which the Kawi is exceptionally good at, no matter how ham-fisted we got at the lever.
Softening the compression three clicks from stock accommodated my slower pace with much more comfort than the standard fork settings. As Kawi's technician, Spencer Bloomer pointed out a flaw in my jumping technique, an additional three clicks of rebound was all it took to level out my front-end-high flying style. Ah, the beauty of a knowledgeable suspension guru. Thanks, Spencer. Because the method wasn't Kawasaki-specific, it has and will continue to lessen my boner-airs on all brands.
Consistency was again the name of the game on the rear end with the UNI-TRAK linkage system bolted to a Kayaba shock featuring new high-speed compression adjustment. Performing excellently all the way around the track, most notable of the KX-F's shock was its steadfastness on jump faces. Being able to charge rutted takeoffs or tackle kickers on jump lips gives riders the confidence to try more obstacles and the ability to be successful.
Suzuki received good marks from our testers for its Showa suspension components. Up front we battled the steering geometry, but once that was hashed out, the fork worked awesome.
As the primary interface between a rider and the terrain, the KX suspension was a smashing success. Kawasaki did a phenomenal job matching the suspension, chassis, and motor to give riders the ultimate control under all circumstances. Overall we definitely weren't disappointed with the KYB components; we just wonder what the Showas would have been like after such a strong showing on the little KX-F.
Often times a bike will get a bad rap as having sorry suspension because of a tendency to headshake. Unfortunately, the Suzuki did suffer from a nasty affliction, but it was no fault of the 47mm Showa. In stock form, the fork protrudes significantly from the top of the triple clamp, noticeably more so than the rest of the machines. Suzuki technicians were quick to recommend dropping the fork to a lower height for a little extra rake to produce added stability. I couldn't stop grinning like a fool on the first lap out after making the adjustment. Just 6mm lower and the entire nature of the bike was changed. Not only was the headshake almost entirely gone, but the bike cornered with more authority and never felt skittish mid-turn. Don't assume that the handling slowed down, because it didn't, it was actually easier to turn in because the front end had more feel and improved traction.
Once performing correctly, the fork was great at absorbing the jumps, but our faster riders complained of it bottoming too easily. Going to a heavier spring rate from the stock .46 kg/mm would likely turn this fork into a near perfect system for heavier or more aggressive riders.
Airbox? What airbox? The linkageless shock design lays more vertical than traditional Japansese suspension and tucks up under a unique fuel cell/airbox arrangement.
Two turns out on the shock's high-speed compression and one on the low-speed allowed for the RM-Z to settle into turns and soak up braking bumps much better. The rear handled the rough stuff well when under power, but bounced and deflected occasionally once the top-heavy weight transferred to the front upon braking.
"The Suzuki is very good through acceleration bumps and through braking bumps," said Rondon. "It tends to soak up everything."
Showa is owned by Honda, so it's no surprise to find its stuff on the CRF, too. We judged its equipment to be very good as well. Our test riders all appreciated the red machine, but we couldn't seem to agree on the suspension performance. The lightest of our trio found the CRF to be uncontrollable at times in the whoops, while Mandahl and I each praised the straight-line stability.
One thing that separated the Honda from the others in my book was the worn-out feel that allowed the suspension to move a little too much in its stroke. Adding compression damping to the fork didn't help, and neither did softening it. The adjustments would alter bump absorption, but failed to eliminate the jittery feeling the made it seem as though the internals were clapped out.
If any bike had the opposite feel it was the ATK. Beautiful, gold Ohlins components graced the front and rear and felt extremely solid.
"Ohlins are usually known for their tighter tolerances," said Tom Watson of Watson Performance. "It's usually pretty good stuff."
Even though he's improving, Hilde is still our Novice tester. His low-level skills were maximized by the Kawasaki and its predictable suspension.
Indeed it was. The initial impression a rider gets from merely sitting on the bike is that the front and rear units are on the stiff side. Once moving, though, the fork does a surprisingly good job of handling sharp hits and jump landings, and things are very similar out back. The linkageless design bolts the shock directly to the beefy aluminum swingarm, laying the shock at a sharp, vertical angle.
Considering the weight being suspended by these components, the Ohlins did a very good job of keeping things nice and smooth. Bottoming out was the biggest problem, and though it didn't happen often, when it did the result was much more harsh than with the Japanese bikes. In direct contrast to the exemplary mating of components on the Kawasaki, the Ohlins componentry was dealt a harsh blow simply by being attached to the rest of the bike.
Suspension Ranking
Fork:
1. Kawasaki
2. Suzuki
3. Honda
4. ATK
Shock:
1. Kawasaki
2. Suzuki
3. Honda
4. ATK
2006 produced some mighty fine hardware in the 450F class. With all the big-time racers committing to these monsters, don't you think it's time that you followed suit?
Things surely could have been different if all six of the original bikes slated for this test had showed up. With Yamaha joining the aluminum chassis club, but with a different and very sweet approach, the totally revised YZ450F has 300 different parts than the 2005 model! As for the KTM 450SX-F, it too has some notable changes that could have allowed it to dice with the rest of the bunch. Oh well, maybe next year.
To come up with our rankings, our test riders were asked to evaluate the major components of the bikes in order to compare the highs and lows of each bike with one another. They also ranked all four of the bikes as complete machines, taking into account everything including unique quirks, styling, ease of starting, etcetera. The tallied component scores were consistent with the overall numbers, leaving no doubt as to the victor of MotorcycleUSA's 2006 450F shootout.
As is probably rather obvious, the ATK, while interesting and unique on the track, didn't get the greatest performance reviews from any of our riders. Considering the antiquated, bulky chassis and tame motor, the ATK could have been simply neglected from the start, but our riders put in their time on the grey beast. There's plenty of good things about the 450 MX.
It isn't every day that you see a 450 MX at the local track. That's one of the biggest appeals of the ATK - rarity.
The ATK is a bit awkward and a bit funky, but it has more character and neat factor built in than the other three combined. Also, Ohlins suspension is high-quality stuff, and the fork and shock were certainly highlights for the bike. It also comes with ProTaper bars, a Magura hydraulic clutch, braided-steel brake lines and the best electric starting we've ever experienced on an off-road bike. All of our testers felt that with a little weight reduction, power gains and chassis upgrades, the ATK could easily become much more competitive. For 2006, however, it brings up the rear in our testing and is one spot off the shootout podium in fourth.
The closest battle for position was for second place between the Honda CRF450R and Suzuki RM-Z450. Despite higher marks for its four-speed transmission and suspension components, the Suzuki fell short by a slim margin to wind up in third place. Headshake was the biggest complaint from any of our riders, a product of the sharp steering geometry. Suzukis are notorious for quick handling, but there can be too much of a good thing. None of our riders gave special mention of handling superiority, but couldn't lay off the headshake issue.
Honda has won seemingly countless shootouts with its jaw-dropping CRF450R, but the competition has been learning with every defeat. Sooner or later it was bound to happen and the CRF couldn't sail away with victory this time around.
Longstanding champion of the 450F class, Honda hasn't been messing with their winning formula all that much. With the original aluminum frame, a great motor, strong brakes and lots of attention to detail, why should they? Yamaha pioneered the 4-stroke development, but it didn't take long for the majority of privateers to switch to red once the CRF450R came out. The 450R has probably won more shootouts since its release than any other big-bore thumper, but that's been changing very rapidly this year with Kawasaki arriving on the scene and the other manufacturers making long lists of improvements. However, with the exception of ATK, the Honda was the least revised for 2006.
The biggest change for the Honda this year is the repositioning of the motor and radiators 5mm lower to help improve steering prowess by lowering the center of gravity. I'm sure that Big Red doesn't like to be knocked off its pedestal, and it's probably safe to say that we'll see some major changes from Honda next year. Despite claiming the top spots in the motor and brakes departments, the CRF450R finishes runner-up to this year's MotorcycleUSA shootout winner.
Trying to pick a new bike can sometimes be like chasing your own tail. That wasn't the case in our shootout. We chased each other around the track, but when it came time to pick a winner, our decision was crystal clear.
It's been a rough few years for Kawasaki with its KX250 taking a beating at the hands of the other manus' big bikes. But that's all over with now, and the wait was well worth it. The KX-F cleaned house pretty much across the board, and was an easy pick for all of our testers. That makes it a clean MCUSA sweep this year for the Green company. Kawasaki has definitely gotten its MX act together, and the renewed emphasis on racing has launched the KX-F line to the front of the pack.
None of the established 450F builders are going to take kindly to being bullied on the playground, but for the time being, 2006 is a great year to be riding green. Mark my words, though, next year everything will be a little bit bigger and a little bit badder.
Get the scoop on our test riders, JC Hilderbrand, Mike Mandahl and Anthony Rondon to see what they'd really pick if forced to throw down.
Let us know what you think about the wicked new 2006 450Fs in the MCUSA Forum.
留言列表
