The MXV 450 boasts a specific seat-tank combo which makes it possible to access the filter directly, without having to lift the tank -- a must-have for any dirt bike. Derived from the RXV and SXV, the frame gets a more traditional swingarm that's lighter and, above all, more flexible in order to improve shock absorption and rideability over bumpy stretches.
Overall, the MXV 450 is a true technological weapon designed for hardcore thrill-seekers. The aforementioned split personality of the timing system is a world's first that promises interesting potential for all Vtwin-powered bikes.
With irresistible looks and unique, typically Italian technical solutions, the 2009 Aprilia MXV 450 is a performance toy unlike any other for riders who want to stand out.
Big Bang and Screamer
|The seat-tank combo makes it possible to access the filter directly, without having to lift the tank.|
With the 4-stroke MXV 450, ignitions are spaced 77 degrees apart in the crankshaft rotation (almost similar to a single-cylinder engine). This means that, after the second ignition, the crankshaft rotates 643 degrees (360+360-77) before the next series of ignitions starts. Such sequence creates a single extended "bang", resulting in optimum power delivery when coming out of corners.
However, this timing limits engine revs and therefore maximum useable power in order not to overload the engine and transmission due to the violence of the dual ignition.
If the Big Bang timing does not suit you, the good news is that you can reprogram the engine control unit of the MXV 450 simply by using a PC and Aprilia software.
The new timing map will have the second ignition happen during the subsequent engine revolution, or 437 (77+360) degrees later in the crankshaft rotation. Engine firing is more regular than with the "Big Bang" setting. The crankshaft then rotates another 283 (360-77) degrees before the next series of ignitions starts.
To complete the transformation, a technician must reconfigure the cams of cylinder # 2 so as to coordinate intake and ignition. This timing sequence is called "Screamer" since the engine revs higher and produces a high-pitched exhaust note. It delivers explosive engine performance and offers expert riders a feeling of power and straight-line accelerations that no single-cylinder on the planet can match.Photo Credit : Aprilia