Aprilia made big waves when it unveiled its RS 660 sportsbike in concept form in 2018, boasting impressive performance figures and a class-leading electronics package.
While the bike is expected to make a full reveal in the coming months, overseas publication Visor Down believes it has spotted the bike on European roads.
With no apparent sensors or development devices strapped to the bike, it is likely a close-to-production example in its final stages of testing.

It is hard to make out any changes compared to the concept bike, however, it does feature a pillion seat and rear foot pegs, which the concept did not.
As previously reported, the Aprilia RS 660 features styling reminiscent of the larger RSV4, and uses a 660cc parallel-twin delivering 98 horsepower (73kW).
With that kind of output, and a dry weight of just 169 kilograms, it will surely be spritely, and handling is bolstered by adjustable Kayaba suspension, a double aero fairing, and an asymmetrical swingarm.
It also features high-end electronics including cornering ABS and traction control, a bi-directional quickshifter, five riding modes, cruise control, engine braking and wheelie control.
The electronics suite is managed on a full-colour TFT dash which supports smartphone connectivity.
This new platform will give birth to other models including a new Tuono model, which is expected to launch next year, while LAMS-approved variants may also be on the cards.

Spencer has a keen eye for hard news, and does some of his best living on deadline day. He loves more than anything to travel on his motorcycle, and is adamant that Melbourne Bitter is a world-class lager. He also knows how to operate the big computery thing in the office. By night, Spencer plays guitar with Melbourne punk outfit LOUTS.