Comparison test of 450 cc motocrosss

Comparison test 450 cc motocross 2011

Crossers from Honda, Kawasaki, KTM, Suzuki and Yamaha

Ironically, in the top motocross class (MX1, 450 cm³), a 350cc machine flew to the world title last year with the KTM 350 SX-F. The MX1 series crosser society is reorganized in the year one after the revolution?

Performance is not everything – this motto runs through the development of the 450cc motocrosser in recent years. Hardly controllable power beyond the 50 hp mark has long been out. Instead, simple drivability and easy handling move up the priority list. Ultimately, the reason why KTM wants to stir up the MX1 class with an unorthodox concept: The 350 SX-F is supposed to combine the handling of a 250 with the performance of a 450. Whether this concept will also be successful as a production bike after the factory machine’s world championship title? 

Comparison test 450 cc motocross 2011

Crossers from Honda, Kawasaki, KTM, Suzuki and Yamaha

Suzuki RM-Z 450

Motociclismo

In 2008, Suzuki was the first manufacturer to apply an injection.

For a long time it seemed as if Suzuki had generated its respectable market presence primarily through competitive prices. That has changed. Not only did the yellow Crosser finally catch up with the competition in terms of price, but the substance was also worked hard. After all, the RM-Z 250 won the comparison test of the MX2 class (MOTORRAD 1/2011) for the second year in a row.
However: The homogeneity with which the quarter-liter Crosser is convincing does not really want to adjust to the MX1-Suzi. Above all, the rough, appealing Showa fork and the rough-running engine put a strain on the relationship between horse and rider. The fact that the RM-Z is rehabilitating itself in many other areas almost disappears against this background.

After all, the Dohc single is already pushing out of the speed range and skilfully overwrites its only moderately pronounced ease of revving with a strong middle range. The handling is designed to match the strength in the narrow run. The RM-Z circles precisely and precisely through tight turns. Nevertheless: A feeling of heaviness, probably caused by the mechanically slow-running engine, always comes along here and especially when jumping or bending. Not a broken leg, but still reason enough to fall a little behind the increasingly meticulously coordinated competition.

Kawasaki KX 450 F

Kawasaki

Fine tuning: the Kawa is only going into the coming season with a gentle touch up.

New mapping, revised circuit and those for the coming season
More efficient soundproofing is mandatory for all manufacturers – the Kawa engineers only handled the KX 450 F with kid gloves for the 2011 season. Understandable, because after all, the KX has already impressed in the past two years with an excellently applied gasoline injection, optimally metered power output and smoothly working spring elements. But it also disappointed so many fans with the low-hanging rear when driving, the associated awkward handling and the sweeping ergonomics. The current KX has retained these features.

The slightly more gently tuned motor continues to push forward with vehement, yet easy-to-dose power, inspires in the air and in push mode with minimal mechanical friction, switches well and hardly vibrates. We are also heading in the right direction when it comes to comfort.

The sensitive Kayaba spring elements swallow even unpleasant acceleration edges. But continuity also has its downsides, because the competition for the test winner of the 2009 season has stepped up since then. Honda corrected the problems of the CRF 450 R with the start behavior and the suspension set-up, KTM upgraded the Crosser with redirection and a slim plastic cover, and Yamaha immediately sent a completely new design into the field. One can still argue about the voluminous dimensions of the KX. Larger pilots will appreciate the freedom of movement, while smaller pilots will want a more compact design. But all types of drivers will find fault with the comparatively tough handling of the KX.

Although less pronounced than on last year’s model, the hindquarters still hang low when driving, which means that the front tends to be pushed outwards in tight bends. This phenomenon could not be dealt with by using a more pretensioned spring of the monoshock (sag without driver: 25 millimeters) or by inserting the fork legs further, so that the Kawa has to be a tad behind the leading trio in the extremely narrow test field (see scoring on page 54).

Yamaha YZ 450 F.

Manufacturer

After tilted cylinders, upside-down cylinder heads, air filters in front of the tank – the Yamaha is still causing a stir one year after the model change.

The YZ 450 F was the topic of conversation last year. The cylinder tilted backwards, the cylinder head turned upside down, the air filter placed behind the steering head – the YZ broke with many conventions. But the courage to try something new also carries risks.
The YZ was not necessarily superior to the more traditional concepts, which had been honed for years, had to be relegated to the places above all by the handiness of the Honda and the efficient engine of the KTM. Meanwhile, the hype has subsided, the 450 YZ continues unchanged into the next season. What is initially reminiscent of the intake snorkeling from the air filter box located high above.

And the engine too. From the lowest speed range to the highest regions, the injection-equipped unit is defined by impressive power. Especially in the upper speed range, the Yamaha accelerates vehemently, with the record value of 54 hp, demands a firm grip on the handlebars – and on terrain with little traction for a finely dosed throttle hand. A characteristic that will please the high society of drivers, but will also show some amateur crossers their limits. After all, when it comes to suspension, the YZ remains a bit closer to the people, combined with excellent responsiveness and practical progressive damping adjustment, the demands of amateurs and experienced pilots.

Opinions differ, especially when it comes to handling – the focus was ultimately on optimizing it. The uncomfortably wide radiator fairing caused by the airbox has a disturbing effect. In return, the YZ preserved the front-wheel-oriented driving feeling that is typical of the Yamaha crossers. As if on rails, the 450 steers in and can be accelerated stoically calmly out of the bends. A characteristic that inspires confidence. However, the Yamaha only partially meets the expectations of a new dimension in agility in a 450cc Crosser. The mix of traditional driving experience and state-of-the-art technology brings the YZ with the Kawa to fourth place.

KTM 350 SX-F

Motociclismo

With the 350 concept, KTM is shaking the MX-1 class to the core.

Combining the handiness of a 250cc machine with the performance of a 450cc Crosser – the KTM 350 SX-F enters the ring for the first time with this daring claim. When it comes to top performance, the hermaphrodite has kept its word. With a hefty 49 hp, the 350 is on a par with the MX1 competition, but there is always enough steam to keep up with the big bikes on the slopes. If the pilot doesn’t forget to pull the cable hard. Because the thrust that sets in unexpectedly early in the speed range conceals the fact that the majority of the ponies only start trolling from mid-speed, which means that the injection engine must be kept running in the style of a 250. But the recipe for success lies precisely in the combination of an easily controllable start and sufficient power. Compared to a 450 machine, the 350 is more forgiving of driving errors and is easy on the stamina. Perfect? Not quite.

Incomprehensibly, the engine vibrates more violently than most 450 units, understandably the lower torque slows down the 350 when starting. In attempts to take off, the SX-F lost a good three after 60 meters
Meters on the 450. A shortcoming, which – given the immense importance of the start in motocross – tarnishes the largely positive image of the 350 concept. 

And the subject of handling? In terms of weight, the 350 series – including the electric starter – moves at 105 kilograms on the level of the lightest in the test field, the Honda CRF 450 R. However, the lower rotating mass of the crankshaft (KTM: 3490 grams, Honda: 4030 grams) leaves the 350 series subjective appear lighter. Only the front, which tends to understeer in tight turns, is irritating. But because the 350 SX-F benefits not only from its high-revving engine and good handling, but also from the get up system and the resulting improved driving comfort, the displacement hybrid is in third place in the middle of the 450 phalanx.

KTM 450 SX-F

Motociclismo

Redirection and a new plastic cover – the 450 also benefits from the upheaval at KTM.

Despite all the enthusiasm for the 350cc concept, the issue of user friendliness has long been a top priority for the 450cc bikes. Not only that the 450 SX-F – without any significant weight disadvantage – is the only 450er Crosser with an electric starter that immediately attracts sympathy, with the beefy, powerful yet easily controllable power output, the SX-F’s engine continues as before last year was quite unspectacular at the top of the engine classification. And while the Austrian has been slowed down again and again in the past by the sometimes more, sometimes less successful coordination of the PDS strut with the chassis, the reversing lever finally puts this topic on file. Tea modernized rear works sensitively, can be adjusted well and thus also relieves the fork. If you add the slim plastic lining and the more precise steering behavior compared to the 350, only two things remain: kudos and second place.

Honda CRF 450 R.

Motociclismo

Whether handling, engine running or suspension tuning – the CRF is a fine spirit of the off-road scene.

Finesse, homogeneity and weight saving are the leitmotifs to which Honda has dedicated itself and thusafter initial difficulties with the 2009 model – won the MOTORRAD-MX1 comparison last year. The most important change for the 2011 model, the reduction of the inlet cross-section from 50 to 46 millimeters, underlines this goal again. In fact, the Unicam engine pushes powerfully and yet easily controllable out of the lower speed range and is at its best in the middle regions. Enthusiastic: The extremely low mechanical friction, which not only allows the Single to react spontaneously to the slightest twist of the throttle, but also gives the lightest 450 with 105 kilograms an omnipresent feeling of lightness. No motocross track can be circumnavigated more effortlessly than with the CRF engine. With one exception: tight clutch springs require a courageous grip on the clutch lever. And the front brake, which tends to heat up, only remains at operating temperature after removing the cover.

The fact that the extremely compact Honda and not the 350 KTM ultimately sets the bar in terms of handling is mainly due to the unique steering precision. Aiming at neighboring residents, bend them and accelerate out, no 450 model makes this maneuver, the most vital of all maneuvers for quick lap times. Underpinned by a comfortable suspension set-up with sufficient reserves as well as the first-class ergonomics typical of Honda, the CRF 450 R confirms – albeit just – its claim to continue to be the boss in the ring of 450 crossers.

Technical specifications

Drawing: MOTORCYCLE

Measurements on Dynojet roller test stand 250, corrected according to 95/1 / EG, maximum possible deviation five percent.

Honda CRF 450 R.

engine
type design Water-cooled single-cylinder ohc four-stroke engine with four valves per cylinder
Displacement 449 cc
Boron x stroke 96 x 62.1 mm
Compression ratio 12th
Power * 36.8 kW (50 PS)
at speed * 8750 rpm
injection 46 mm
Corridors 5 landing gear frame Bridge frame made of aluminum
fork Kayaba
Guide tube diameter 48 mm
Strut Kayaba
Weight * 105 kg Price excluding additional costs   7990 euros

Kawasaki KX 450 F

engine
design type Water-cooled, single-cylinder, four-stroke dohc engine with four valves per cylinder
Displacement 449 cc
Boron x stroke 96 x 62.1 mm
Compression ratio 12.5
Power* 36.1 kW (49 hp)
at speed * 8500 rpm
injection 43 mm
Corridors 5 landing gear
frame Bridge frame made of aluminum
fork Kayaba
Guide tube diameter 48 mm
Strut Kayaba
Weight * 108 kg
Price excluding additional costs    7.790 euros

KTM 350 SX-F

engine
type design Water-cooled, single-cylinder, four-stroke dohc engine with four valves per cylinder
Displacement 350 cc
Boron x stroke 88 x 57.5 mm
Compression ratio 13.5
Power * 35.9 kW (49 hp)
at speed * 12500 rpm
injection 42 mm
Corridors 5 landing gear
frame Single-loop frame made of tubular steel
fork WP suspension
Guide tube diameter 48 mm
Strut WP suspension
Weight * 105 kg
Price excluding additional costs   8395 euros

KTM 450 SX-F

engine
type design Water-cooled, single-cylinder, four-stroke dohc engine with four valves per cylinder
Displacement 449 cc
Boron x stroke 97 x 60.8 mm
Compression ratio 12.5
Power * 38.2 kW (52 hp)
at speed * 8000 rpm
injection Carburetor / 41 mm
Corridors 5 landing gear
frame Single-loop frame made of tubular steel
fork WP suspension
Guide tube diameter 48 mm
Strut WP suspension
Weight * 109 kg
Price excluding additional costs   8.695 euros

Suzuki RM-Z 450

engine type design Water-cooled, single-cylinder, four-stroke dohc engine with four valves per cylinder
Displacement 449 cc
Boron x stroke 96 x 62.1 mm
Compression ratio 12.5
Power * 38.6 kW (52 hp)
at speed * 9000 rpm
injection 43 mm
Corridors 5
landing gear
frame Bridge frame made of aluminum
fork Showa
Guide tube diameter 47 mm
Strut Showa
Weight * 109 kg
Price excluding additional costs
  7830 euros

Yamaha YZ 450 F.

engine
design type Water-cooled, single-cylinder, four-stroke dohc engine with four valves per cylinder
Displacement 449 cc
Boron x stroke 97 x 60.8 mm
Compression ratio 12.5
Power * 39.9 kW (54 PS)
at speed * 9250 rpm
injection 44 mm
Corridors 5 landing gear
frame Bridge frame made of aluminum
fork Kayaba
Guide tube diameter 48 mm
Strut Kayaba
Weight * 108 kg
Price excluding additional costs   8,495 euros

Scoring and conclusion

Motociclismo

The bottom line is that with the Honda CRF there is a clear winner and surprisingly two fourth places.

ENGINE

Honda CRF 450 R, 106 points out of a possible 120.
Kawasaki KX 450 F, 107 points out of 120.
KTM 350 SX-F, 105 out of 120 possible points.
KTM 450 SX-F, 111 out of 120 possible points.
Suzuki RM-Z 450, 103 out of 120 possible points.
Yamaha YZ 450 F, 107 out of 120 possible points.

LANDING GEAR 

Honda CRF 450 R, 93 points out of 100.
Kawasaki KX 450 F, 88 points out of 100.
KTM 350 SX-F, 91 out of 100 possible points.
KTM 450 SX-F, 90 out of 100 possible points.
Suzuki RM-Z 450, 84 out of 100 possible points.
Yamaha YZ 450 F, 90 out of 100 possible points.

MISCELLANEOUS 

Honda CRF 450 R, 25 points out of 30.
Kawasaki KX 450 F, 24 points out of 30.
KTM 350 SX-F, 24 out of 30 possible points.
KTM 450 SX-F, 21 out of 30 possible points.
Suzuki RM-Z 450, 23 out of 30 possible points.
Yamaha YZ 450 F, 22 out of 30 possible points.

Overall rating & Conclusion

1st place – Honda CRF 450 R with 224 out of 250 possible points.
Whether smooth running, weight, suspension or steering precision – the Honda does not show any nakedness, convinces as a successful overall package. A crosser in pinstripes.

2nd place – KTM 450 SX-F with 222 out of 250 possible points.
The right way: KTM upgraded the successful base of the 450 SX-F with new ergonomics and rocker arms. This means that the Austrian is within striking distance of overall victory.

3rd place – KTM 350 SX-F with 220 out of 250 possible points.
Less can also be more. The 350 series immediately moved into the top group of big bikes. The fitness-friendly concept will especially delight amateur crossers.

4th place – Yamaha YZ 450 F with 219 out of 250 possible points.
Lively engine, good suspension – the KX could land far ahead. But even small weaknesses in handling and ergonomics have an impact in the narrow field.

4th place – Kawasaki KX 450 F with 219 out of 250 possible points.
Good steering precision and sensitive suspension speak for the YZ. But the ergonomics takes getting used to and the tremendous power (over) challenges not only normal crossers.

6th place – Suzuki RM-Z 450 with 210 out of 250 possible points.
The test victory of the RM-Z 250 proves that Suzuki can build good crossers. But the 450 cannot convince with its vibrating engine, moderate revving and stucking fork.

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