Aprilia 450 v-twin

In the run up to the Milan show Aprilia were teasing us by telling us they were launching a "45.v2". We were expecting a motocross bike with a development of Yamaha's 450cc single. Aprilia's boss Ivano Beggio has been hinting for some time that a return to off-road and dual purpose bikes was dear to his heart.

What we got was not the bike, but the just the engine. And what a brave and significant move that engine is. V-twins aren't exactly common in motocross.

Developed entirely in house, the 77° V-twin is amazingly compact. It's clearly smaller than many of it's single cylinder competitors. Whilst not actually revealing it's weight, Aprilia claim it's lighter too. With use of light weight materials such as magnesium for the covers and titanium for the eight valves, who are we to argue. The cylinders have a chain driven single cam, which for compactness is mounted over the inlet valves. A forked rocker on a third cam lobe operates the exhaust valves (explaining the unusually shaped red rocker cover). The alternator is big enough to drive an electronic fuel injection system, as well things like electric start. It's been reliably up to 14,000 rpm on the bench. It is also suitable for boring out to larger capacities, with a 550cc version known to be on the cards.

Aprilia say that the v-twin's lighter drive shaft and smaller bore and stroke reduces the inertia and gyroscopic effects, improving responsiveness and handling.

There are no power figures available, but we think it could reach 70 bhp in some variants.

They also say that this engine configuration is well positioned to stay ahead of future tightening noise and emission legislation. Something that could kill off some of the competition perhaps.

The bike itself should be revealed in early 2004 for use in the FIM World Championship Motocross Series, and expect this engine to be used in a variety of off-road, dual purpose and even road bikes. The engine would allegedly fit in a RS250 frame to make a RSV450 as temporary fill for the current gap between the RS125 and RSVR 1000. Although Aprilia's R&D department is already running at capacity, we're sure they'd prefer to build an all new RSV 45, or will they call it a RS450?

The fact that this was an in-house project is significant, and shows that Aprilia have moved on from their Rotax days, and now have the capability to develop a complete range of engines of different configurations. Rumours that engineers have started work on triples have been doing the rounds of late, and with Laverda's triple heritage, at least one variant will be going there, with Aprilia holding onto others for their own models.

Now howsabout putting two 45.v2 engines together to make a 900cc v-four in a "big bang" firing configuration.......Mmmmmm.

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Aprilia 450