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hey say that from a scientific point of view, the bumblebee cannot fly. But what does the bumblebee know about science?

The modern 250F motocross bike is like that. If you told an engineer from 2001 that a production 250cc four-stroke was capable of turning nearly 14,000 rpm and producing 45 horsepower, he would have given you two or three laws of physics that would present nearly insurmountable barriers. A corporate accountant would cite several more laws of economics that would keep that kind of technology from ever reaching production. But, here we are. The 2015 250F motocross bikes are here, and they make as much power as the open-class four-strokes of the last generation, with barely any more weight than a two-stroke. We used to think of the 250F class as sort of a stepping stone to bigger things, yet this kind of performance is now a destination in itself.

In model year 2014, the big news was the arrival of the Yamaha YZ250F, which pushed the technology limit farther than ever into unheard-of regions. It came late and in limited quantities, giving the rest of the industry a chance to regroup and come back firing on all cylinders. For 2015 we have significant, but not revolutionary, changes to most of the bikes, including the Yamaha, and we have one new entry: the Husqvarna FC250. We got all six together to find the bottom line for the new year. All the bikes got fresh Dunlop MX32 tires and were taken to various Southern California tracks, including Glen Helen, Elsinore, Milestone and Piru. Here are the strong points and weak points of each one.

HONDA CRF250R

A new air in the 250 class

Honda likes to be the maverick of the  250 class. It has a single overhead cam, a steering damper and very different feel from the others. Now it has one more thing that sets it apart; it’s the first 250 with an air fork. The 2015 model comes with a Showa SFF Triple air in front. It also gets push-button EFI mapping changes and a less restrictive exhaust this year.

In 2014, the Honda was regarded as one of the most novice-friendly bikes in the class. It was light, soft and comfortable, with a very easy-to-use powerband. More experienced riders complained that it needed more power to keep up.

STRONG POINTS

We have to give credit to the new fork from a performance point of view. It works well, and it survives most of the knee-jerk complaints leveled against replacing old-fashioned springs with air. If you just leave it in stock form and check the pressure before each ride, you’ll like it. Virtually everyone does. If you weigh more than about 165 pounds, you might increase the pressure in the upper chamber. If you’re less than 140, go down a little. But, don’t make the air pressure your first stop for all handling complaints. Go there after you’ve tried damping changes, just as if it were a spring fork. Remember, the Honda has a steering damper too. A few clicks on the HPSD can have a noticeable result.

Just like last year, the Honda’s most profound strength is its appeal to novices and beginners. It feels super light and easy to manage. It is, in fact, tied with the Yamaha for lightest-in-test honors at 222 pounds without fuel. It actually feels much lighter than the YZ. The exhaust is still quiet, the clutch pull is super light and the brakes are good, with a new oversize rotor in front.

WEAK POINTS

There wasn’t a significant increase in horsepower for 2015, and that’s what the CRF needed most. The three ignition settings would be more useful if the Honda had power to spare. As it is, everyone liked the most aggressive setting the most. Many riders also complain about the Honda’s stability. Much of this can be handled with an increase in the damper setting—don’t forget it’s there! As we pointed out, most riders go straight to air pressure, and generally mess up the surprisingly good settings. Even though we like the fork, we don’t see infinite adjustability as an asset. In the real world, it will result in a lot of poorly setup forks. And it does need to be checked. It would be nice if Honda supplied the pressure gauge.

BOTTOM LINE

Honda made a very bold move with the air fork, but it’s a diversion from the real issue. The bike already had good front suspension. It needed more power, and it still does. The bike remains a favorite among the rank-and-file riders who populate most of the dirt bike world, but will still need heavy engine work to be competitive in the higher ranks.

HUSQVARNA FC250

The dust has settled and Husky is back

For years, Husqvarna faced a very unclear future. Those days are gone. From this point forward, the company has a clear mission and is on solid financial ground under the ownership of KTM. That’s the good news. The bad news is that the motorcycles are almost identical to counterparts in the KTM line. The FC250 is very similar to the KTM 250SX-F, although that will probably change in the future, as Husqvarna becomes a “premium” line under the corporate umbrella.

For now, the only significant differences between the two are the cosmetics and the Husqvarna’s composite airbox/subframe combo. The Husky also has a map switch on the handlebar and minor differences in the exhaust.

STRONG POINTS

At the risk of sounding lazy, we love the electric starter. This is the only engine in the 250F motocross world that starts with the push of a button, and we love it. Years ago we would have seen the lack of a backup kick-starter as a weakness. But, the Husky’s charging system is so good that you can begin the day with a dead battery, bump-start the bike, and then charge while you ride. You won’t have to bump it twice. Like the KTM, the Husky is extremely well-made. The hydraulic clutch is indestructible, and the six-speed tranny shifts almost too easily. The rear suspension is excellent, and the incredibly strong brakes are rivaled only by those of the KTM. Some riders say they like the ergos of the Husky better than those of the KTM—the bike is slightly wider, which offers a good leg grip, and it sits lower at the rear of the seat.

WEAK POINTS

Unfortunately, the Husky misses out on the KTM’s biggest asset. The airbox is more restrictive, and that costs the FC250 almost two horsepower on top. The bummer is that the KTM motor only makes power on top. There’s not much on the bottom or in the middle, so when you take away the peak, you don’t have much left.  It turns out that the subframe is also about 3 pounds heavier than that of the KTM, so the Husky comes in as the heaviest bike in the test.

We still consider the new WP 4CS fork a big improvement over the previous closed-cartridge fork from WP, but it’s still harsh. Almost every rider turns the left-side adjuster out to make the fork a little more forgiving, but it doesn’t have much of an effect. That controls only high-speed compression damping, whereas the fork suffers most on low-speed impacts.

BOTTOM LINE

Everyone marvels at the Husky. It generates more admiration and conversation than any other bike. People instinctively like it and want to see Husqvarna succeed. At this point, though, it still isn’t a premium version of the KTM. It’s essentially the same bike with an easily solved breathing problem.  For the record, we know that it can be made into an absolute rocket with very little work.

KAWASAKI KX250F

More fuel for the green express

The Kawasaki KX250F has won more pro races than any motorcycle in the 250F world. That’s an undebatable fact. Most people point to the Pro Circuit Kawasaki team as the underlying reason, but that’s selling the production bike a little short. The KX250 is innovative and cutting edge.

Mechanically, the KX’s most notable engine feature is the use of an upstream EFI injector, which sprays fuel in the airboot, well in advance of the throttle body. The chassis stands out because of its adjustability. Not only can the handlebar be moved to any one of four locations, the footpegs can be adjusted up or down. This year the bike received suspension and mapping changes, as well as a new piston, a heavier flywheel and a lighter subframe. The front brake rotor is now 270mm and is made by Braking.

STRONG POINTS

It’s hard to find someone who actually doesn’t like the KX250F. Maybe impossible. All that adjustability has something to do with it, but the excellent powerband is a very big factor. The KX’s motor has no weak points. It has top, middle and bottom; it has great throttle response; and it runs cleanly all the way through. The days when it has the most power in the class are gone, but it’s still very fast. You can alter the powerband by swapping around three electronic couplers. The green (standard) and white (lean) were the favorites for most tracks. The Kawasaki also has the holeshot mode button, although there aren’t many situations where it’s really useful.

Kawasaki was the first on board with the Showa SFF fork, which still is excellent. This version has a single fork spring, not to be confused with the Honda SFF, which has no springs at all. The Kawasaki rates just as highly in performance without the hassle of checking air pressure before each ride. The rear suspension is excellent, and the brakes are the best of the Japanese bikes.

WEAK POINTS

You have to get out the magnifying glass to see any flaws in the KX250F. Its most serious problem is that it no longer leads the class in any category. It’s not the fastest or the lightest. It’s not especially stable at speeds. The clutch is a little weak, the exhaust is a little loud and the handlebar is a little little. The grips are painful and short.

BOTTOM LINE

You can’t go wrong with the Kawasaki in this class. It’s a great motorcycle, and it will continue to win in 2015. The fact that it hasn’t seen much change recently isn’t a big deal, but you can’t stay still for long in this class.

KTM 250SX-F

Is horsepower enough?

KTM has caused the dirt bike world to shift on its axis in recent years. It’s now a technological leader in the industry, and everyone else is scrambling to keep up. The 250SX-F has more high-end features than any other bike in the class, aside from its near twin, the Husky FC250. It has an electric starter. It has a six-speed gearbox. It has a hydraulic clutch. And, it’s the most powerful bike in the bunch.

The 2015 version didn’t change much. It now has the WP 4CS fork instead of the older closed-cartridge WP front end. It has new linkage and a longer shock. And, there are minor changes in the oil pump and starter. As we pointed out earlier, it’s nearly identical to the Husky, aside from bodywork and subframe.

STRONG POINTS

Like we said, the KTM is the horsepower leader. It owes its peak power advantage entirely to rpm. The motor is extremely well-made and can withstand the stress of revs approaching 14,000. The truth is that the KTM is still making more power when the ignition’s rev limiter calls the police and has the party shut down.

Another indicator of how far KTM has come is the way the bike handles. It turns well, it’s stable at speed and has none of the quirks that made the KTMs of old a little spooky. The rear suspension keeps the bike going straight, and the overall package is predictable.

We’re big fans of all those premium items that we mentioned earlier. The electric starter is awesome. The bars and levers are excellent, and we like the fact that the clutch is hydraulic and won’t fade. The brakes are amazing.

WEAK POINTS

KTM still needs to come up with more bottom-end power. The days when 250 four-strokes got a hall pass on torque are gone. All the other bikes have better power down low where most people, at least occasionally, ride. Pros might not notice. Number two on the pain parade is the fork. Yes, it’s better than the older WP fork, but it’s not enough better, particularly on small bumps.

The seat and grips are hard, and the clutch pull is surprisingly stiff. This is one of the last motors in the KTM line to use a coil-spring clutch, and has a harder pull than even the 450SX-F, which has the diaphragm spring clutch. The KTM is the second-heaviest bike behind the Husky.

BOTTOM LINE

The faster you go, the more you’ll like the KTM. The top-end power is awesome if you keep it flying. Likewise, if you’re strong and hit things hard, you won’t think about the small comfort issues; you’ll just like the fact that you’re flying around the track. That’s what the KTM does best.

SUZUKI RM-Z250

Running in place, but still running

The Suzuki RM-Z 250 was the best-kept secret in motocross. For years it was almost invisible on the pro level. While the Kawasaki KX250F and the Honda CRF250R gathered championship after championship, Suzuki quietly made the best bike in the class for about five years.

Time moves on, though, and while KTM, Yamaha and Kawasaki pushed the power boundary higher and higher, Suzuki did very little. For 2015, the bike is completely unchanged. For that matter, it’s been almost unchanged for a very long time. Two years ago it got a Showa SFF front end, similar to the Kawasaki’s. The motor also has plug-and-play electronic couplers that allow you to alter the powerband for different situations.

STRONG POINTS

The fact that the Suzuki could go almost unchanged for so long and still be competitive in such a technology-intensive class is amazing, and shows how good the Suzuki was in the first place. The bike still ranks as the best in turns. You get the feeling that you can come in way too hot and somehow everything comes out okay. Some bikes only corner under power. Others make you steer your way around a turn. The Suzuki allows you to do either. And, it doesn’t extract a penalty at the other end of the handling range, either. It’s stable, goes straight and never gets you in trouble for trying too hard. Good suspension is part of the reason. The Showa SFF fork is excellent and does it with one spring tied behind its back. The Suzuki comes with excellent bars and controls. Even the stock tires are excellent.

WEAK POINTS

The Suzuki motor only makes competitive power right in the middle of the rev range. It doesn’t pull from the bottom especially well, and it doesn’t rev as high as most of the other bikes. But, it gets the job done if you shift at the right time.

Test riders often condemn the RM-Z with faint praise. The brakes are okay, but not as strong as some. The clutch is okay, but a little vague. It usually starts easily. And, it’s a little heavy, but within the realm of acceptability.

BOTTOM LINE

The Suzuki ranks near the top of every rider’s list. It’s one of those bikes that makes you like riding and makes you feel a little more talented than you really are. But, no one chose it as his favorite in the test. In this class, you just can’t stand still for very long.

YAMAHA YZ250F

The honeymoon continues

It came late and made a big entrance last year. The 2014 Yamaha YZ250F missed most of the selling season, but that didn’t stop it from making the motocross world stop and gawk. It was innovative, sophisticated and fast, and it followed up its grand debut with a 250 National Championship.

The Yamaha is a mixture of high tech and old-school. It still has the reverse engine with the rearward-tilted cylinder, of course, but it has a very traditional two-spring KYB fork. With the coming of fuel injection last year, it gained weight, but not as much as some. It’s tied for the honor of lightest in the class at 222 pounds without fuel. For 2015 it got a new exhaust cam, piston and exhaust valves, as well as new cosmetics. The fork has different valving, and the airbox has quick-release fasteners.

STRONG POINTS

In the 250 class, the motor is a very big deal, and the Yamaha has the best motor. It might not have as much peak as the KTM, but it’s stronger everywhere else. Things start happening right off the bottom and then transition into a fat, happy midrange. On top, the Yamaha is almost as much of a screamer as the KTM, but it starts shutting down a little earlier. By then, the motor has already proven itself.

We have to give that old-fashioned fork credit. Overall, the Yamaha has the best front suspension in the contest. It’s a little stiff for riders under 150 pounds, but even the featherweights in our test-riding troop say it’s still not harsh. Most people get on the bike and ride without touching the clickers.

Overall, the Yamaha still works best for riders who are aggressive in the turns. The more you twist the throttle, the better it corners. In a straight line, it’s probably the most stable bike in the test. And finally, it’s proven itself stone reliable in the last year. There were no first-year teething issues, and even the filter stays clean.

WEAK POINTS

The Yamaha is a well-rounded package without major faults. We would like more front-wheel bite when the throttle is chopped, and the rev limiter is very sudden and harsh when it cuts the power. The brakes are merely average, and the exhaust is loud.

BOTTOM LINE

The Yamaha is the favorite 250F of the collective Dirt Bike testing crew for the second year in a row. It’s a wild-looking machine with lots of technology in play, but interestingly, it isn’t the bling that makes the Yamaha so good. It’s old-fashioned suspension and power that do the trick. The engine configuration is said to make the bike feel light, but in the real world, it’s the actual weight that makes it feel that way. In the end, we’re not so concerned with how Yamaha did it; we’re just pleased with the results.

CONCLUSION

Whatever floats your valves

When the sun set on our last day of testing, the results were the same as those of last year’s shootout. But, it didn’t have to go that way. The Yamaha wowed us in 2014, and a year of reality could have shown its faults. New technology in the suspension world also could have altered the status quo. In the end, the Yamaha’s recipe of power, handling and reliability are tough to beat. Now that the bike is available in quantity, it will be interesting to see how quickly it infiltrates the amateur ranks.

Second place once again fell to the Kawasaki. In truth, it’s not far off the Yamaha. It uses the same basic formula for success; it has a great motor without dead zones, the suspension is excellent, and it’s a proven winner. At this point, the Yamaha just has more of everything except weight.

Third place is a testimony to the sound design of the Suzuki RM-Z250.This is a reality check—it’s easy to get carried away with new technology and hype, but at the end of the day, a bike that hasn’t changed much since 2010 can run with the best of them. The Suzuki is showing its age in motor output, but the handling is still untouchable.

The Honda could have been the big upset of the year. With a little more power, it might have been able to give the Yamaha and Kawasaki a run. Honda put all its new technology into front suspension this year, but it was never the fork that held the CRF back. And, we’re still on the fence about air—its real advantage is for riders who fall outside the description of the target 250 buyer.

The KTM and the Husky are fast motorcycles designed for experienced riders. There’s nothing soft and cuddly here; only high-rpm power and shut-up-and-ride suspension settings. The two bikes actually feel quite different, even if the list of different parts is short. We have to give the edge to the KTM because it, at least, is faster. At the end of the day, that’s the most important difference, aside from identity. o

For Dirt Bike’s 2015 450 MX shootout, click here.