The Aprilia RS660 is a sport bike designed and produced by Italian manufacturer Aprilia since 2020. Created as a mid-size contender for racing championships, it has two road legal models being the RS 660 and the RS 660 Factory. There is also a track only variant, the RS 660 Trofeo.
The engine, a 659 cm<sup>3</sup> twin-cylinder with a double overhead camshaft and connecting rod pins at 270ð, is capable of delivering 98 peak horse power at 10500 rpm and 67 Nm of torque at 8500 rpm. The frame is an aluminum double beam contributing to a total weight of 169 kg dry. The shock absorbers are adjustable with 41 mm upside-down Kayaba front forks. Electronics are the dedicated Marelli APRC sports system, which gives five performance settings, eight-level traction control, anti-wheelie, ABS, three levels of engine braking, and ride-by-wire throttle control.
In 2025, a new engine was introduced that increased the power output to 105 Hp and added some extra features to the electronics package. These included an extra rider profile, and Aprilia launch control (ALC).
In 2019 Aprilia displayed two sports prototypes, the RS 660 and the Tuono 660, at the 2019 EICMA show. The two were intended to fill a void in the range from the Noale manufacturer, to be able to compete with Japanese companies in the medium-displacement motorcycle sector. Designed as a smaller version of the new RSV4 1100, it shares its lines and chassis, the result of a project born in Piaggio Group Style Center.
The machine finished second in the UK National Sportbike Championship, a new race series for 2024.
In the spring of 2022, the factory version was introduced, which brought a technical update.
At the end of the year, a version called RS 660 Extrema was introduced, with modifications to the chassis for track use and lightening of some parts, reducing the weight to 166 kg.