450 off road shootout: Do 450 motocrossers mix with versatile?

In one short year the 450-moto world has evolved dramatically. In ’08 Suzuki was the lone fuel injected machine in a foursome of Keihin FCR aspirated machines. With Honda and Kawasaki flushing their carburetors for throttle bodies and armed with the knowledge that Yamaha is almost certainly going FI and KTM already having the wherewithall to power the fuel injection since they’re a button starter, the evolution of the dirt bike has reached a new plateau. The other interesting piece in the ongoing puzzle is the success of the injected Suzuki RM-Z450 in off-road racing. Not having to deal with issues that plague a machine in off-road conditions such as mud, water crossings and choking dust, all of which dramatically taint a four-stroke’s performance, starting tendencies and ride-ability, there is no doubt that fuel injection is a great thing for the big-bore off-roader.
But testing this handful of missiles in an off-road habitat that more often than not is hackier than a motocross track after an Amateur National with  the added charm of rocks, snot, logs and mud makes the scenario one where the machine must be equipped with tractability and versatility plus a dose of suspension cush. Too much power and too stiff makes the steed too nasty in an off-road environment. And just to add one more bug in the ointment is the fact that while the majority of the manufacturers offer an off-road legal 450, only KTM sells an off-road, six speed version of the 450SX. The 450XCF has a little cushier suspension, a larger tank, an 18-inch rear wheel and a larger tank. Oh, it also has the button. Here are the ratings in order.

KTM 450SX
THE WHY
Incredibly, every one of our testers went for the KTM450SX, as the  broad power, and HUGE amounts of it, highlight the performance. Oddly enough it actually should have received a second place since its brother the 450XCF would have actually decimated the off-road shootout. Still, top marks went to the monster volumes of juice, enough so that no one felt anything weird or annoying about the four-speed gearbox. The chassis feels almost ordinary, the adjustability lets the rider alter the cockpit with numerous bar positions, and the suspension, albeit a skosh stiff, offers a wonderfully balanced ride with just enough plushness to keep the 450SX quite happy in the off-road atmosphere. Zipping up the baggie is the electric start, which basically sends this machine into the ‘total desirable’ category of racer.
THE QUESTIONABLE
Just a couple of snivels here; the clutch pull is too stiff and when the bike gets harassed on mongo hill climbs she turns into a Stanley Steamer. It was weird that last year’s four-speed drove us bonkers, but far better jetting and suspension compliance really elevated the stature.
THE OPTIONS
Easy, for 98 percent of the planet—get the 450XCF. It has the same exact engine, smoother suspension, bigger tank and an 18-incher out back.

SUZUKI RM-Z450
THE WHY
The Suzuki actually finished oh so close to the KTM by virtue of a potent, tractable fuel injected five-speed powerplant. We’ve flogged our bike (both the ’08 and ’09) hard, and the engine has proved to be a pillar of steel. Add in cornering habits that mock every other machine in the shootout and it quickly becomes apparent that the RM-Z not only makes proper power for the woods, its natural ability to flick and carve aid in its off-road appeal. Last year we were concerned about mileage and the lack of aftermarket tanks, but IMS cured that. Their 2.6-gallon plastic tank is nearly as inoffensive as the stock aluminum fuel cell.
THE QUESTIONABLE
Only one big gripe surfaced: stability at speed. Naturally we haven’t found a machine on this earth that craves both corners and Lucerne whoops. There’s always a tradeoff, and the RM-Z is a shade on the nervous side.
THE OPTIONS
Everything on this side of the Yangtze River can be had for the RM-Z. Team Suzuki’s winning record and their affiliations with FMF, IMS and Zip-Ty Racing alone give the RM-Z pilot looking to accessorize a full plate of goods.

KAWASAKI KX450F
THE WHY
It may seem weird that last year’s off-road winner dropped down the ladder into third place when it pretty much dominated the motocross portion of this shootout. And in the off-road world, the Kawasaki is a major player, yet the areas that helped transform the KXF into a full blood motocross weapon have irritated its softer, off-road demeanor. What does it do that’s great? How about stellar power from the time the throttle remotely edges open, through a strong middle that cohabits with a robust enough peak power curve to keep even the skilled pilot on his game while he’s in the wicked zone. The machine feels totally planted, corners well (not a whip and twist like the RM-Z, more of a plant, point and work it) and the high-speed stability rates up with the best.
THE QUESTIONABLE
The suspension action is stiff, the frame feels too rigid, and a large amount of feedback tends to come back to the rider. Most of our riders really felt that the KX-F would do better with a steering damper. Also, she’s way too loud and would be impossible to sneak down a freeway at rush hour.
THE OPTIONS
Because of Team Green’s penchant for off-road you can bet your whistle that a plethora of off-road slanted product will surface for the KX-F. IMS has a tank, Scotts has a damper, and Pro Circuit has suspension valving that will transform this steed into a winner.

YAMAHA YZ450F
THE WHY
 In some circles the Yamaha YZ450F rates higher than a pedestrian fourth. In reality, first through fourth place are mere ticks from each other and the Yamaha really fits into the tight woods world quite nicely and makes for a good GP wagon. The machine’s roar has been softened via the shorty but incredibly adept muffler (which is great for off-road) and the suspension, close to being on the soft side for MX,  snugs nicely into the wild variations in off-road. In fact, it rated near top marks from all testers. While cornering sluggishness still itches, the faster world of west coast GPs showcases its stable manners. It’s the easiest starting four-stroke (other than the KTM’s button) and the five-speed gearbox has just enough in top gear for speedier circuits.
THE QUESTIONABLE
Low bottom power haunts the off-road taste, though its easily fixed with a new rear exhaust muffler. Still, that usually equals racket, which we’re totally opposed to. Cornering is still vague, sit-down woods zones are fine, ruts are sometimes problematic and require large amounts of input. Normal sized riders felt comfy ergonomically; over-six-footers felt that the saddle/peg marriage was too tight.
THE OPTIONS
There are scads of aftermarket parts that lean towards off-road for the YZF. FMF and Pro Circuit both sell excellent exhaust systems that up the power and when tuned with the quiet options keep the dB level down. Both IMS and Clarke sell tanks that hold a gallon more petrol and other than installing an O-ring chain for off-road, the YZF is equipped with quality hardware.

HONDA CRF450R
THE WHY
There’s really no mystery as to the Honda’s finish here. In spite of the linear powerband, which lends itself to the controlled world of off-road, there’s just not enough of a planted feel in the chassis to make the machine comfortable in the broad world of off-road. Not one tester had anything but praise for the power, and in the high desert world of mongo hill climbs the CRF is stellar. The machine is slim, super maneuverable, ergonomically stellar and has the mojo to eventually become an off-road threat.
THE QUESTIONABLE
On the soft side, the Honda is just plain hard to start. It tends to flame out at inopportune times and when you sandwich this with the inherent handling complexities, the majority of our testers would rather switch than fight.
THE OPTIONS
There’s very little aftermarket as of this writing, though we know that Team Valli (the new Bonds/Garrison/­ummers Off-road team) is getting their machines ready for the ’09 WORCS series. We talked with Bones at Pro Circuit about suspension and he’s up to his guts in blood looking for the answers to the CRF’s handling nuances. FMF, Pro Circuit and Dr. D offer excellent exhaust systems that broaden the powerband and give it little zest.