This is Aprilia's much anticipated 450cc v-twin racer with which the Noale based company will make its assault on the off-road market, with plans to enter both the FIM Motocross and SuperMoto World Championships - with factory teams - in 2004.

However, the machine will be making its competition debut as early as this weekend, in Supermoto spec (pictured) at the SuperMoto Grand Prix of Spa-Francorchamps - where it will be ridden by 125cc Motorcycle Grand Prix ace Alex De Angelis.

The revolutionary new bike, called the Aprilia SXV 4.5, is powered by a ground-breaking single shaft, 77? twin-cylinder engine (rival machines of similar size are single cylinder) with electronic ignition, in a steel perimeter frame with alloy uprights.

The engine has been designed and built in record time, and the progress shown in bench testing has convinced Aprilia to bring forward its racing debut in order to gain valuable experience directly on the track.

The bike will be entered directly by the team responsible for its testing and development, who see the Spa-Francorchamps meeting as an opportunity to gather information essential to success in 2004.

"It's a great honour for me to have been chosen to ride in this race," said de Angelis. "I'm determined to do my best to develop this machine. Supermotard riding is tremendous fun, even though with my background I'm more at home on the asphalt than off it. It's certainly going to be a tremendous experience!"

Aprilia may also enter the new bike in the last race of the season, to be held over the last weekend in November in Benidorm, Spain.

"Youthstream thanks Aprilia for their belief and their support in SuperMoto and Motocross," said Giuseppe Luongo, president of championship promoters Youthstream. "We wish all the best and hope they have a fair and great competition with the other manufactures present."

Aprilia are yet to formally announce their team line-ups for 2004, but Javier Garcia-Vico is believed to have already signed to ride for the motocross team.