That rapid growth has been based on a string of exciting bikes - mostly small-capacity screamers with ultra-trendy colour schemes and hi-tech features plus an aggressive racing policy. Last season, Aprilia swept aside mighty Honda to win the 125cc and 250cc road-racing world championships, and promptly followed that triumph by launching a fast, streamlined two-stroke race-replica roadster called the RS250.
Aprilia's latest bike, the Moto 6.5, is a very different machine, albeit one that follows the Italian firm's tradition for style. It was created by French star designer Philippe Starck, whose portfolio includes everything from boats, toys and lemon squeezers to numerous buildings and interiors, including the recent museum at Groningen in the Netherlands and Bordeaux airport's control tower, his latest project.
Mr Starck is a keen motorcyclist and has produced a distinctive non-aggressive roadster, aimed particularly at tempting urban travellers away from cars, buses and trains. The Moto 6.5 certainly looks like nothing else on two wheels, thanks to its fuel tank and seat/sidepanels.
It is powered by the 650cc single-cylinder unit from Aprilia's Pegaso 650 trail bike. Detuned slightly for this bike, the watercooled, five- valve engine produces a maximum of about 45bhp.
The chassis is based around a steel frame whose main tubes form a graceful curve. That shape is followed by the visible pan of the exhaust system, much of which is hidden beneath the engine. Unlike the Pegaso, the Moto 6.5 is intended to be ridden only on the road, and has considerably less suspension travel than the trail bike. Its telescopic forks and single rear shock unit, both from Italian specialist Marzocchi, hold wire-spoked wheels whose tyres are designed purely for the street.
Riders of average height or less will quickly notice one advantage of the road-biased suspension: the Moto 6.5's seat is reasonably close to the ground. The Aprilia is very light, too, at just 150kg which, in conjunction with the softly tuned engine, makes it both lively and easy to ride.
Simply twisting back the throttle sends the Aprilia chugging forward almost regardless of revs (just as well since the wacky instrument console does not actually include a rev counter), and means that you do not have to worry too much about flicking through the five-speed gearbox.
Performance at town speeds is more than enough to keep the Aprilia ahead of even the most aggressively driven taxi. On the open road, the bike cruises easily at the legal limit, the engine's balancer shaft doing a good job of smoothing the traditional single-cylinder vibration. At that speed, there is some acceleration in hand to a top speed of just under 100mph. But, like most unfaired bikes, the Aprilia is better suited to a gentler pace.
The Moto 6.5's chassis also prefers a more leisurely approach, because the forces fed through the handlebars at speed are sometimes enough to trigger a gentle weave. In normal use the bike handles well, though, its light weight and wide handlebars giving quick, easy steering - perfect for flicking through tight gaps in city traffic.
Suspension at both ends is firm enough to encourage brisk cornering, but soft enough to make the Aprilia reasonably comfortable. Tyres and brakes are competent, the single front disc brake requiring a reasonably firm squeeze of the lever.
Starck's emphasis on appearance has resulted in a few practical drawbacks. The fuel tank is far smaller than it appears, reducing range to less than 100 miles. (Strangely, its tap is on the throttle side - not ideal if the tank suddenly runs on to reserve when there is a bus on your back wheel.) And the neatly shaped pillion seat would doubtless be described in less generous terms by anyone forced to sit on it for any long distance.
This is not a bike for riders seeking either speed or touring ability but, provided its limitations are accepted, the Moto 6.5 works well. Its pounds 4,795 price is reasonable, too, and does not reflect the designer label. There are motorcycles that provide more versatility for similar money. (Suzuki's cheaper GSF600 Bandit and BMW's F650, which is actually built by Aprilia, spring to mind.) But Starck's creation backs up its stylish looks by being nippy, practical - and much more fun than public transport.
Details of dealers in Britain are available from Aprilia Moto UK: 0161 476 5770.