Comparison test four-stroke crosser

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Comparison test four-stroke crosser

attack…

… is the best defense. With the lively YZ 400 F, Yamaha landed a real hit in 1998. Now the initially shocked competition, above all KTM with the new 520 SX Racing, strikes back.

In road racing, the fronts are clearly defined in terms of speed: 500s are faster than 250s, which in turn have the eight-liter racers under control – it’s that simple. With the Cross it looks different. It is difficult to say who would see the checkered flag first, Moto Cross would be a classless society. Probably often a 250, maybe a 125 here and there. At 500? Or even at 630 four-stroke? Usually this question does not arise, apart from the annual national cross with its class mix.
If the differences in performance and chassis are marginal within the two smaller categories, the search for the best compromise in the large displacement class has resulted in a variety that is as colorful as it is spectacular. First, the more docile four-stroke drummers mixed in with the brutal 500 cc two-stroke engines. Then some pilots discovered the "small", aggressive 360 ​​two-stroke. And finally, Yamaha surprised in 1997 with the lively 400cc four-stroke, the success of which will ultimately lead to the decline of the large two-stroke. Now the competition in the world championship is focused on the four-strokes, which compete with very different concepts.
This also applies to the series machines. Yamaha has only slightly increased the displacement of the YZ 426 F to compensate for the performance deficit, especially at the start. KTM relies on just over 500 cc for the new 520 SX, otherwise the concept with the compact 250cc chassis is similar to that of the Yamaha. Husaberg gives the customer the choice with the thoroughly renovated Millennium model: While some professionals still use the gun license 600, amateurs prefer the more civil FC 501. Husqvarna remains true to the old line with the well-known TC 610. Plenty of everything: displacement, torque, power – and weight.
From the technician’s point of view, Yamaha earned the most applause. Their miniature turbine can boast with two camshafts, five valves, a balancer shaft and a complex ignition system. The single shakes speeds over 11000 rpm easily and loosely like a 125 out of its sleeve. In practice, however, the small increase in displacement has noticeably changed the characteristics. While a halfway talented pilot could squeeze the previous 400 engine close to the limiter, even top drivers are satisfied with a few thousand revolutions less with the 426. There the engine doesn’t pound off brutally, but rather grips gently, but with force. The fact that the YZ can be adjusted so playfully using the throttle often results in valuable tenths of a second when accelerating, and the throttle can be opened early in the curve. You are quick with the YZ, but you don’t notice it.
The KTM achieves a similar level of maneuverability and throttle response, although it can only serve with a camshaft and is therefore dependent on sluggish rocker arms that limit the speed. Your cylinder head is not a new design, but derived from that of the Husabergab. Instead, a balance shaft was neatly integrated into the housing. With the Keihin carburetor, whose flat slide controls the digital ignition like the Yamaha, the KTM’s engine management is up to date. The latter seems to make the slight difference in terms of controllability of the four-stroke engines. However, the SX is much more intense than the YZ. Even a top driver practically never experiences situations in which the desire for more pressure arises, the SX pushes forward powerfully in every situation. However: Implementing the performance is often difficult, also because the KTM hindquarters do not always stick to the ground in an exemplary manner. The speed range seems endless, especially since the ignition does not switch off suddenly as with the YZ. It is astonishing that the test stand protocol certifies only a little more top performance than the YZ, and all testers have bet house and yard on considerably more pressure.
Both YZ and SX run with little vibration in all areas due to the balance shafts, and due to the low centrifugal mass, they spin up in a flash. It’s amazing how such a small wave with a few hundred grams can change the character. Even the toughest will have to admit that this progress is worthwhile because of the smooth running and the ability to turn, the stamina is spared.
Husaberg and Husky are made of different types of meal. Oven-strokes of the old guard who don’t hide the fact that they are powered by an explosion machine. The Husaberg engine corresponds to the KTM engine in terms of bore and stroke. So the difference is all the more astonishing: The Husaberg hammer away with an ultra brutal hammer. Every straight line becomes an impressive physical experience that the Husaberg hammers into the brain. You can hardly escape this fascination. But the hard punch wears down in the long run, arms like Joel Smets’ should be included in Husaberg’s kit. Incidentally, it almost doesn’t matter which of the two selectable ignition characteristics is switched on. In the Hi position, which was practically always used in the test, the engine turns off more readily. Low brings no advantages, the libertine cannot be tamed by it.
Anyone who thinks they can cope with even more brute force in the lower speed range sits on the Husky. Apologies about performance then no longer apply. Only the very best manage to exhaust this. On the other hand, amateurs can also roll around with the Husky, in the partial load range the TC behaves almost civilized. In addition, the transitions during load changes are more elegant than with the Husaberg, so that the search for traction on slippery surfaces is easy.
When it comes to the chassis, Husaberg is actually a pioneer in the current trend of the four-stroke engine in the 250cc chassis. The most modern designs are provided by KTM and Yamaha, which can use the current, in-house quarter-lot models. This is reflected in the handling, whereby the Yamaha can be steered a touch more directly around tight turns. The KTM requires more attention when turning. The Husaberg demands much higher demands on concentration, often a little physical effort has to be helped. The husky always needs an energetic, guiding hand on winding slopes. The TC prefers to look for wide curves with clearly defined berms.
In return, it then exudes stoic calm on the straights, which is only affected by a little restlessness in the steering when the brakes are applied. There can be no question of fluttering tendencies as in some situations at Husaberg (more) and Yamaha (less). The KTM is surprisingly stable and neutral: the driver can always let the kidneys loose, the SX steadfastly stays in the chosen direction. Neutrality and stability in an almost perfect combination.
The oven Crossers offer little variety in terms of suspension elements. Upside-down forks are again mandatory these days, at least on the hindquarters KTM and Husaberg provide variety with their leverless PDS suspensions. Although these two rely on the same elements of White Power both in front and in the back, the KTM Holding is obviously going very different ways when it comes to coordination. The Swedish machine seems to have been born on Nordic sand slopes, the damping, especially of the shock absorber, is extremely tight. Anyone who gets lost on bombed French stone slopes with this series setup should be prepared for a wild ride. Even if you can keep the Husaberg in check with brutal force, you often lose traction and time.
The WP suspension of the KTM is much more elegant on such hard stretches, but without appearing too lax in the sand. Above all, the really excellent working fork in the KTM can show its qualities to its full advantage, free from disturbing influences from the hindquarters. The directly linked PDS system is now – in the third generation – fully developed. Just when accelerating over very bad edges, the grip is inferior to the good lever systems of the Yamaha and Husky. With the YZ 426, the fork plays the somewhat weaker part, it should respond better and would need more damping in the middle area. The Husky’s Marzocchi fork, which sometimes begins to pump heavily on brake shafts, is not very convincing. This cannot be brought under control by playing with the adjustment screws. The Husky could use a firmer suspension overall.
When it comes to the last tenths, brakes, clutches and gears play a role that should not be underestimated. The level of the brake systems is quite decent; real outliers up or down cannot be noted. For the taste of some testers, the Husky grabs a bit snappy at the front, with the KTM that applies at the back. The Husky’s easy-to-dose mechanical coupling proves that the simplest is often the best solution. KTM and Husaberg work hydraulically – with very different results. The Husaberg clutch is extremely smooth, but more of a shifting character: out or in, no dosage possible. Drivers who play with the slip on the clutch when braking and cornering will not love the callous hydraulics, which dampen the mechanical feedback. At KTM, the design is better. The high forces of the mechanical clutch on the Yamaha are objectionable.
B.The bottom line is: four machines, four very different characters. Every weekend, national and international races prove that victories are possible with all machines. KTM and Yamaha, however, offer the best prerequisites and promising concepts in the series trim. Husaberg and Husqvarna with a more traditional four-stroke philosophy also have a lot of potential, but they need a little more attention.

The test team

If you want to evaluate cross machines comprehensively, you not only have to try them out on tracks with different characteristics, but also obtain opinions from very different drivers. In addition to the author, 43, not a beginner, MOTORRAD therefore relied on a cross-section of drivers. The Frenchman Yves Demaria is a World Championship driver, temporarily led the World Championship last year on a factory Husqvarna and then had to back off due to injury. This year the 28-year-old competes in the 250 World Championship. Of course, he has very different standards than an amateur, primarily a powerful engine and good handling. On the fast track in Pernes-Les-Fontaines, he is extremely impressed by the KTM, which he is riding for the first time. Yves does not want to give a judgment on the YZ 426, which he has already used in races, after all, Yamaha is now his bread maker. The only thing he can tell about Husky is that the difference between a production motorcycle and his former factory motorcycle is huge. He finds the hearty vibrations of the Husaberg, who moved the brutal 630 series steam hammers from Husqvarna last year, almost unbelievable. Yann Guedard, 33, already a French champion in Moto Cross and Super Cross, who has only been racing sporadically for a few years, was also involved. He too sees the KTM ahead of the Yamaha on the fast natural slope near Avignon, but clearly prefers the Husaberg to the Husky. Jorg Albrecht, 32-year-old DM driver and former cup winner in the 500 class, was responsible for the lap times and a large part of the test work. The test interests him because he wants to start in 2000 with a four-stroke engine. He vacillates between the more potent KTM and the Yamaha, which he sees ahead on many narrow tracks in Germany. Max Ritter, 16, is a 125cc young driver and grew up with a modern two-stroke. He sees the test more fun-oriented. Therefore, only Yamaha and KTM come into question for him anyway, although he is more drawn to the Japanese machine.

The time is running

The comparison of lap times is not without problems in motocross: routes often change within a day, every driving error destroys the lap. And finally you need serious drivers, in top shape and experienced – not kamikaze pilots. Four to five timed laps were driven in each case, plus one or two introductory laps, and the two best trips were counted. To understand: The routes are examples, the results cannot be transferred at will. Other machines can be ahead we fast, no-slip roads. The first course was Beauvoisin, south of Avignon. A technically difficult, extensive route with steep ascents and descents. The piste presented itself in moderate condition, hard and dry, but not well maintained and with a narrow ideal line. Performance is definitely desired here, but because of the slippery surface, the ability to adjust it is crucial. A parade discipline of the gently acting Yamaha, which always achieved the fastest times here. In addition, the YZ shines with a neutral chassis and razor-sharp steering behavior. It’s KTM’s turn, but on average remains a good second behind. Although the Husaberg benefits from its weight in the technical sections, it negates the advantage of the hard-running engine. In contrast, the rather bumpy, bony route in Tarascon places high demands on the chassis and handling. The grip is good here, tight turns and countless tables keep the driver on the go. Here, too, the YZ is top, it can even break away from the pursuers by more than three seconds. The KTM can hardly follow the Yamaha for two reasons: On the one hand, it does not turn around the tight corners quite as fast as an arrow, on the other hand, it lacks traction here and there when accelerating. That is also the problem with the Husaberg, whose stubborn chassis abuses the driver. The husky just doesn’t like the narrow run.

3rd place – Husaberg FC 501 goal

The beast: often bitchy, sometimes a bit sneaky, in any case always exciting. Those who can tame the Husaberg can get intoxicated by the catapult-like thrust. The engine has endless pressure, the stubborn chassis and rough vibrations demand a good deal of suffering from the driver. A machine for the toughest and those who want to become one.

3rd place – Husqvarna TC 610

The gentle giant: powerful, good-natured, but often looking a bit clumsy. The massive Italian oldie defends himself as much as he can against the nimble newcomers. The not very lively, but powerful drive still makes the hearts of real four-stroke fans beat faster. Slightly overweight and slow handling cost time on steep slopes.

1st place – KTM SX 520

The bodybuilder: fit, athletic, tanning salon-tanned. As an opponent, eating cherries with the SX is not good, but the manners are elegant. The engine is phenomenal: powerful, predictable and smooth-running. In addition, a lively chassis and good suspension elements. Now the KTM only has to prove its stability.

2nd place – Yamaha YZ 426 F

The agile: with a penchant for understatement, but always brisk, never at a loss for an answer. The Yamaha easily compensates for the smallest displacement with the endless speed range. The 426 has gained in power compared to the 400 without losing its liveliness and controllability. No four-stroke engine drives so easily, so unspectacularly, but still so fast.

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