When the idea that valve engines would reign supreme in the future began to take over, Scorpa signed a new agreement with Yamaha to create the first modern trial bike powered by a 4-stroke engine.
After the resounding success of the TY 125F, the French technicians began intensive research and development work to create the new concept that is the subject of this report: the SY 250 F 4T.
JAPANESE SOUL
It is not the first time that Yamaha supplies its engines to Scorpa, in fact, the well-known SY 250 two-stroke version is equipped with an engine practically identical to that of the mythical Yamaha TYZ, and the small TY 125 4T inherits one of the most popular mechanics among Japanese trail bikes.
In the end, the five-valve engine of the WR 250 was chosen, in which various components were adapted to the demands of modern trials.
Basically, the developments of change have been shortened. Replaced flywheel, camshafts, ignition, cylinder head, exhaust and carburetor. At the moment Scorpa is not considering making the leap to injection, something that Sherco is doing, so possibly in 2007 this Scorpa will be the only four-stroke representative fueled by carburetor.
But without a doubt, what is most striking about the new SY-F is the exhaust system , built entirely of aluminum, and designed with the idea of exercising the functions of a rear subframe. In addition, the silencer is completely protected from any impact, and achieves a more logical weight distribution in the rear axle.
The adoption of this system has made it necessary to design a completely new filter box, also very compact, and easily accessible with the simple removal of a screw. The radiator, manufactured by KTM, has been built specifically for the geometries of the French chassis, and promises performance far superior to conventional ones. Another of the One of the peculiarities of this mechanic is that, unlike the WR in which the engine oil tank is located at the front of the frame, in the Scorpa all the oil goes inside the engine itself, and there is also a practical visor on the ignition cover to check its level.
If the thermodynamic set has broken your schemes, the cycle part is no wonder. Its impressive frame, which is advertised as the lightest on the market, is made ofaircraft-grade chrome-molybdenum tubes, with two side plates in cast aluminium where a slender swingarm, also made of this material, is anchored.
The suspensions have been entrusted to Paioli , both front and rear, where a linkless system similar to the one Sachs equips on the SY 250 2T and TY 125F continues to be maintained, but with the particularity of being anchored at the right end of the swingarm, and being 700 grams lighter. The brakes are still signed by AJP, although reinforced with new discs, equipped with a special design, and a thickness three millimeters greater in order to improve the feel.
However, the highlight of the Scorpa is, once again, the excellent quality of its finishes. Contemplating the beautiful workmanship of the seatposts, the handlebar support, the footpegs, the lightened eccentrics, or the original LED design of its rear light, are a series of unique details that enhance the exclusivity of the French motorcycle.
STABLE AND PROGRESSIVE
Contemplating the Scorpa is an accumulation of different sensations. At first it raises skepticism, but minutes go by and your eyes are still riveted on it, admiring the excellent finishes of each corner, and thinking about what its character will be like within the areas. The feel of its controls is correct, and if we look down we can see that, indeed, the chassis is slender, Its engine doesn’t protrude at all from the right side, but… Yes on the left, where the aluminium skid plate has a wide fold which, protects as well as it can, an ignition very exposed to possible shocks.
Without being able to wait a single second longer, we acted The mechanical cam of the choke, located next to the clutch, and with practically no effort, the five titanium valves begin to beat strongly. This cam does not hold on its own, and requires holding down until the engine reaches some temperature, about a minute. Once it slows down on its own, we rev the engine at a standstill to assess its noise: the decibel level emitted is similar to that of the Sherco 4T, much lower than that of Montesa, and harsher.
Before going out to shoot, it must be clarified that we were the first to use it, its carburetion was not the most ideal for the height of the central area, and as we were assured by Scorpa, the optimal behavior is reached from the fourth tank.
The first kilometres are spent on simple trails and forest roads, where the Scorpa shows an outstanding attitude: it pushes hard in high gears from low revs, with a perfect staggering between fourth and fifth gear, and of course, outstanding traction.
The most amazing thing about the SY-F is the stability. Its effective frame, aided by an almost perfect distribution of weights, makes it a born tracer, and forgives a large part of those absurd feet that are usually left to the imbalance.
This is the first time that we have been able to The mid-level areas are where she is most comfortable, as she has more space to face the obstacle, and does not require excessive movements when stationary. And why do we say this?
Well, for the simple reason that the SY-F is not an agile bike, its 78.5 Kg of weight in running order -1.1 Kg more than the 4RT-, And an engine with great mediums, but without forcefulness at low revs, means that the driver must compensate with technique for this lack of aggressiveness. As far as we could see, Unlike the Sherco 4T, the Scorpa has to be helped a lot with the clutch to lift it from revs and reach the revs where it really gives the “chest C”: medium and high. Its final stretch is practically endless, something that favors the use of first gear in all areas, except the most aggressive ones, where the progressivity of its clutch does not make it very easy to fire the engine at revs.
As for the Suspensions, the usual trend of the brand is still present, marked by rather soft tarages, with a bouncy fork that hides the overweight very well, and greatly facilitates the placement of the motorcycle. At the rear, the oblique position of the monoshock offers a completely different feeling from any rival, but dynamically we can see that, after a short period of adaptation, its good performance is beyond doubt. The brakes also more than fulfill their purpose , although something similar happens to the Montesa, and that is that the overweight of these sets prevents a greater forcefulness, although we insist, their performance is more than correct.
All in all, the Scorpa 4T is a perfect bike for the hobbyist because of its smoothness, ease of riding, and proven reliability.
Text: David Quer
