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Driving report Aprilia SXV 4.5 / 5.5

Vidi, veni, vici

Every manufacturer dreams of this: Aprilia saw opportunities in the Supermoto World Championship, came with a completely new two-cylinder? and immediately became world champion. MOTORRAD was able to test the factory machines from both Supermoto categories.

There are several strategies for targeting a world title. One is to bet on the Rossi Effect and
to hire a high-flyer driver. Another to try superior technique. Aprilia decided on this path, dispensed with star pilots such as supermoto crack Thierry van den Bosch or cross star Stefan Everts and attacked at the beginning of 2004 with a completely new concept in off-road sport: an ultra-light two-cylinder machine. In motocross, however, the operation began with a bitter bankruptcy, the two works riders struggled in the back of the MX1 World Championship. In return, the Italians were all the more successful with the Supermoto variant of the two-cylinder (see box on page 133)..
The idea: The small 77-degree V-Twin should be as light have a single-cylinder, but offer more potential. All the stops were pulled out for this. The four titanium valves per head are controlled via a camshaft, as in the unicam principle of the Honda Crosser, which actuates the intake valves directly and the exhaust valves via a fork rocker arm. The lubrication works with separate circuits for clutch / gearbox and crank / valve train, for the latter oil is stored in the tank behind the control head. While the Crosser get by with four gears, the Supermotos have a tight five-speed gearbox. The technicians inserted the cylinder liners directly into the crankcase to save weight. The crankshaft also appears extremely light, although the cheeks have been enlarged in the course of development. At 29 kilograms, the SXV-Twin is on par with the current 450 single-cylinder, and the dimensions are also similar. Aprilia designer Ampelio Macchi, who previously designed engines for Husqvarna, is silent about the key data of the engine. However, MOTORRAD was able to research a piston diameter of 76 millimeters, which would mean a stroke of 49.5 millimeters for the 450 engine. This would mean that it would be designed with a slightly shorter stroke than current cross engines. A Dellorto injection prepares the mixture, the throttle valve diameter is 38 millimeters S.XV 4.5 and 40 millimeters for the 5.5.
The unconventional engine is conditional
an equally novel chassis structure. The front tubular structure made of welded steel tubes ?? depending on the application with different geometry ?? is pressed and glued with large cast aluminum parts. The seven liter tank is located above the airbox. The titanium silencer was placed behind the shock absorber by the specialist Leovince.
MOTORRAD was able to test what part of the success the unusual concept has on the angled kart track in Jesolo near Venice. A push of the button, the two-cylinder immediately bubbles away. So out on the only short straight on the course. The 4.5 sweaters evenly through the speed range. Tea punch that the current singles offer in the middle range is missing. To provoke a wheelie, the driver has to pull the handlebars even when rolling slowly. That almost makes the V-Twin appear a bit weak, especially since the end is quite abrupt at 13,000 rpm.
The unspectacular impression is not least due to the civilized behavior of the Aprilia. Vibrations are barely noticeable, and it blows out of the titanium exhaust at a very low level. However, there has to be enough power, because the Aprilias are always at the forefront at the start of the Supermoto World Championship. The 450 is rumored to have around 60 hp, the 550 is said to be around 70 hp. One of the strengths of the two-cylinder is certainly the excellent traction at the limit and on slippery terrain.
Another, rather surprising advantage: The handling of the SXV is phenomenal, although it is because of the electric starter that
Battery and injection a few kilos more than the single-cylinder competition
brings on the scales. First, the center of gravity of the motor is low, and second, the moving masses and thus the inertial forces are low. The SXV can be easily turned around a curve
swivel into the next, the easier ones
Single cylinders look more stubborn in comparison. The easy handling is from a
very direct steering behavior supported. The wheelbase and steering head angle move at 1485 millimeters and 63.5 degrees
within the usual framework, the caster can be offset by 17,
20 or 23 millimeters can be changed. The SXV is just as easy to control on the brakes, thanks to the anti-hopping clutch, it goes into drift as smooth as butter.
The rear wheel seems to be sticking to the ground, nothing rattles.
The larger-displacement SXV 5.5 is much more powerful, but rough. According to Carlo Botto Poala, at Aprilia for
responsible for the off-road area, it has not yet reached the development stage of the smaller version, but lags a few months behind. The speed tidy seems too narrow, although the 5.5 supposedly turns up to 12000 rpm. It also goes very hard at the apex of the corner
Gas, and the high idle speed doesn’t exactly make control easier. In terms of performance, the 5.5 can match the 700 cc, around 80 hp KTM single-
Certainly not enough to alleviate, but she too obviously benefited from the good handling and the excellent traction on the consistently narrow World Championship slopes.
Technically, neither of the supermoto twins seem to be clearly superior. In order to win the world champion title, everything has to fit together anyway, and last but not least, you need a lot of luck-
to. Everyone interested should soon
get the opportunity, the potential
to sound out the SXV: Eligible
Aprilia wants production bikes at the end of 2005
as enduro and supermoto variants on the market.

World champion straight away

In MotoGP street racing, things didn’t go well for the Aprilia three-cylinder, the Italians withdrawing from the top category in 2005. Perhaps the budget saved will benefit off-road use, because the new V-twin did a splendid job there in 2004. The 24-year-old French Jerome Giraudo won the Supermoto World Championship in the smaller S2 category on his Aprilia SXV 4.5, where he made up a seemingly impossible lead of the Italian Massimo Verderosa in the last race of the season with the luck of the capable and finally with all four Punktchen was ahead . His teammate, the former cross world champion Frederic Bolley, followed suit
various falls, after all, sixth place in the final ranking, on which Max Manzo also landed in the hotly contested S1 class on the SXV 5.5.
Aprilia plans to continue this commitment, and the Italians do not want to be deterred by the poor results in the Cross-Country World Cup and continue there in 2005 with Thomas Traversini.

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