“Then it was difficult to make Honda build a four-stroke to different standards. When the factory thinks of four-strokes, they think of XRs; big, no-maintenance playbikes. We had to convince them to build a four-stroke to two-stroke standards. It had to be light, powerful and more highly-stressed. It had to be a race bike.” So the CRF project was finally underway in 1998. There were no false starts or discarded prototypes, as was speculated. The bike you see now is the only one that ever existed in Honda?s R&D department. It has been the longest awaited bike in dirt bike history. Now that it?s finally here, it signals the beginning of the counter-revolution. Every other Japanese company will eventually have a line of four-stroke MX bikes. Yamaha will finally have to share the spotlight.
WHAT IS IT?
The 2002 CRF450R is exactly what it should be; a full-race four-stroke. The engine is nothing like any Honda before it. It?s a single overhead cam, four-valve powerplant with the cam located directly over the two titanium intake valves. A rocker arm operates the two exhaust valves. Honda says this setup is lighter than a double overhead cam setup and still allows them to place the spark plug where it needs to be?dead center. Like Yamaha, KTM and Suzuki, the CRF sucks through a Keihin FCR carb, only it?s 40mm instead of 39.
The clutch is straight out of a CR250 two-stroke and it has its own oil bath. The engine oil has its own compartment so it can use oils with molybdenum (good for pistons & valves, bad for clutches). The piston has almost no skirt; even less than a YZ426F?s. Honda engineers say that it has no tendency to rock in the cylinder because the crank is offset 8mm to the rear of the bore?s centerline. For more insight into the engine see “The Heart of the Beast,” in this issue.
The rest of the bike looks just like a 2002 CR250. But almost no parts interchange. It has a different gas tank, a different seat, different numberplates and, of course, a different frame. It does get the same suspension components with different settings. The fork springs are burly 0.47kg/mm.
So what?s the bottom line on the whole package? What?s it really weigh? On the incredibly accurate Dirt Bike proton scale, the Honda balances out at 233 pounds without fuel. That?s 16 pounds lighter than a 2001 Yamaha YZ426F. It?s even lighter than a KTM or a Husaberg.
HOW GOOD IS IT?
Test riders have daydreamed about the ultimate four-stroke for years. If only a bike could have an engine like a KTM 520 and a frame like a YZ426. That?s pretty close to being the CRF. The Honda engine has a much smoother power delivery than a Yamaha. Where the YZ426 has a hard, supercross-like burst of power right off the bottom, the Honda has a softer, easier to manage power that builds quickly and smoothly to a screaming climax. Yes, the Honda has a little more power on top than a YZ, but not nearly as much as a KTM 520 (don?t be silly). The CRF is as fast as any motocrosser in his right mind needs. It?ll wax a 250 two-stroke out of the gate. The hardest part is just giving it full throttle. That?s not as easy as it sounds. When you twist hard, the front end comes up and you flat move. With every gear, the front end comes up again. If you?re used to an Open two-stroke or a 426, you know how to deal with it. But smooth delivery aside, you have to think of the CRF as an Open bike or a big thumper. That?s what it is.
Still, the Honda has less flywheel effect than any other big thumper, including a YZ. Rev the bike in neutral and it?s super responsive. It gains rpm quickly, and loses it just as quickly. Next on the It?s-Not-a-YZ-List is engine braking. The Honda has very little compared to other four-strokes. Some riders truly hate engine braking; it?s one of the things that keeps them from joining the party. Just like any other bike, the amount of engine braking you get out of the Honda depends on rpm. If you?re screaming the motor and suddenly chop the throttle, you?ll get a lot. If you?re loping along at low rpm, you?ll get little more than a two-stroke.
WEIGHT & A LACK THEREOF
Back in 1995, the Kawasaki KX250 weighed 236 pounds. It was considered slightly heavy, but no one really complained. Heck, by 1998 it won the 250 shootout at the weight of 232. Bottom line; for the first time in four-stroke history, weight just isn?t a factor. Sure, there might be lighter thumpers in the future, but the dragon has been slain. At 233 pounds, weight is the last thing on your mind when you ride the CRF. It stops on a penny. It changes lines. It even makes a YZ426 feel like a fat blind date.
In typical Honda fashion, turning is at the top of the CRF?s list of good traits. It goes to the inside like it?s been sucked there by a giant magnet. Ryan Hughes once praised the bike because he could change lines at any point in a turn. Frankly, Rhyno would have been better off if the CRF kept him from changing lines in the middle of each turn, but that?s another topic. He was right. The CRF doesn?t just get into one groove and stay there without question. It?s absolutely neutral. If you want the bike to go somewhere else, you just push the Somewhere Else button and go. Aside from being light, the CRF is simply a good-handling motorcycle. As always, a lot of the credit goes to the motor. It?s so smooth that it makes you a better rider.
At speed, the CRF isn?t quite as stable as a CR250R. It is a very different motorcycle with a different frame and different traits. The four-stroke can break into a slow headshake when it?s in a bad mood. It doesn?t happen often, and it doesn?t continue for long, but it?s something we never noticed on the 2002 250R. The suspension also feels very different from its two-stroke bother. Both bikes have Showa components but the four-stroke is much stiffer. That makes sense, not only because of the 20-pound weight difference, but because a four-stroke simply acts differently. In the rear, the CRF is excellent. The bike doesn?t swap in rolling whoops and absorbs square edges well. We spent one day on a tight supercross-like track that had no bumps but a whole bunch of jump landings. The rear handled that well, with only a couple of extra clicks on the low-speed compression damping.
We never got quite as comfortable with the fork. On the jump track, we thought it was too soft. On Glen Helen?s national track, it was a little harsh and stiff. In both cases, we managed to adjust our way to some level of contentment. Actually, it was a change in the rear suspension that gave us the most satisfaction at Glen Helen. By stiffening the high-speed compression, we shifted a little more weight to the front end and that made the fork more compliant.
Check out the November Issue of Dirt Bike Magazine for the complete test!