Aprilia SXV 550, 2011
DESIGN
As with all Aprilias, a tremendous amount of care and attention has been lavished on even the smallest details on the SXV. As a result the SXV boasts a unique, unmistakable styling that is nevertheless fully functional in achieving unrivalled performance, because first and foremost even the standard SXV is a genuine competition motorcycle.
The SXV is not just a pretty face. Your gaze is held by an abundance of advanced technology. One glance at the V2 engine, mixed trellis and aluminium frame, mighty swingarm and central exhaust system with twinned silencers under the rear mudguard, and you cannot escape its magical attraction.
Whatever side you look at it from, the SXV presents a host of stunning technical solutions, all enhanced by original racing colours to express the aggressive nature of this born-to-race mean machine.
As you would expect from Aprilia, the latest SXV is packed with intelligent design solutions. Fixed air ducts, for example, allow the fuel tank to tilt up for easy access to the airbox. And the quest for technical perfection has led the design team to tweak even small details on the basis of input from the champions who have raced the SXV.
ENGINE: CONTINUOUS EVOLUTION
The amazing 45.2 engine is, of course, the centre piece of SXV technology. Aprilia was the first manufacturer in the world to believe in the validity of the V twin for supermotards, a segment in which all other marques still cling rigidly to single cylinder engines. Aprilia’s high-tech V twin design has already proved 100% reliable in competition. Even homologation for road use has not compromised the technology and performance of this exceptional engine, which is produced entirely by Aprilia. Since the earliest stages of the design process, the 45.2 has evolved to keep pace with chassis development and to give the SXV an unbeatable mix of power and handling.
The 77° V angle is the result of extensive testing, aimed not only at boosting power but also at reducing vibration. As a result Aprilia’s engineers have been able to eliminate engine balancer shafts.
Despite this the 45.2 engine still vibrates far less than any single cylinder alternative.
The cylinders themselves are integrated in the crankcase and have replaceable wet liners. This unique layout has allowed the engine ancillaries to be arranged in a way that achieves extremely compact dimensions. The results are amazing: the Aprilia V twin is one of the most compact V twins in the world, and smaller in size than many singles of similar displacement. All design choices have been taken in order to obtain maximum power plus an extended useful power band. The sophisticated electronic engine management system, developed by Aprilia Racing, incorporates numerous innovations for the off-road sector.
The injection system features 38 mm throttle bodies (40 mm on the 550) and is managed by a programmable control unit. The ECU will be able to switch between two different mappings at the touch of a switch on the handlebars. This extremely useful innovation offers a full power mapping for use in conditions of good grip, and a second, softer mapping for smoother power delivery under difficult conditions. The system provides an extremely valid aid to control and has been welcomed both by expert riders (the system was actually tested in the final phases of the world championship) and by supermotard fans in general. All you need is one quick click to select exactly the right power for the circumstances.
Reduced unitary displacement has allowed Aprilia to develop an extremely compact and lightweight crankshaft. The engine is more responsive to variations in throttle opening as a result, and the bike as a whole is faster and more manoeuvrable thanks to the reduced gyroscopic effect from the crankshaft.
The single overhead cam configuration with four titanium valves per cylinder head represents an ideal compromise between compact size, light weight and high performance.
Thanks to its advanced technology, the 45.2 is also an extremely silent running and ecological engine. Technology, after all, should mean reliability and longevity as well as high performance. The 45.2 engine touches new heights in this direction, and permits extremely easy access to parts requiring regular maintenance like the spark plugs, oil filter and air filter.
Just as much effort has been put into weight reduction, and the 45.2 engine sets a new record for a V twin with an electric starter. Abundant use has been made of prestige lightweight materials. The central crankcase sections are in aluminium-silicon alloy; external engine casings are in magnesium; the valves are in titanium; and all gears are exceptionally light in weight.
The choke is new too, and features a knob on the airbox instead of a handlebar control. Even the air filter has been improved and is now made from a sponge material derived from that used on Aprilia’s official racing machines.
