Half an RSV4 — literally
Took 1/2 the V4 superbike engine
The RS 660 engine is the front bank of the RSV4's V4 — same bore, very similar head architecture, parallel-twin layout with 270° crank for V-twin character. Aprilia decided in 2018-19 they wanted a modern middleweight supersport; rather than design a new engine they cut the RSV4 in half.
Saved the supersport class
First viable mid-supersport since R6 died
When the RS 660 launched in 2020, the supersport class had collapsed. Yamaha R6 was track-only. Honda CBR600RR EU-discontinued. Triumph Daytona dead. Suzuki GSX-R600 dying. Aprilia entered a market everyone else had abandoned — and proved there was demand. Arguably enabled the Yamaha R9 (2025) and Triumph Daytona 660 (2024) revivals.
World's first MotoGP-style winglets on a middleweight
2025 update added them
The 2025/2026 RS 660 became the first sub-1000cc production sportbike with proper aerodynamic winglets — borrowed from Aprilia's MotoGP RS-GP race bike via the RSV4. Provides downforce at high speeds, helping front-end grip during cornering. Ducati Panigale V2 doesn't have them. Yamaha R9 doesn't have them.
$10,499 vs $20,995 RSV4
Half the bike, half the price, twice the practicality
The RS 660 costs roughly half what an RSV4 does ($10,499 vs $20,995). Half the cylinders, half the displacement, half the price. But for road riding it's arguably the better choice: lower seat (820mm vs 845mm), lighter (183kg vs 199kg), tighter steering, less intimidating. The RSV4 is a track weapon you ride on the road; the RS 660 is a road bike you take to track days.
105bhp at 11,500rpm — accessible peak
Lower-revving than R6, more torque
Old R6 peaked at 14,500rpm. RS 660 peaks at 11,500rpm. Less screaming, more usable midrange. Peak torque 67Nm at 8,500rpm. Reviewers (MCN, Bennetts) describe it as 'always in the right gear' — the wide torque curve means you don't need to constantly chase the redline.
Class-leading electronics suite
IMU + 5 modes + cornering ABS Pro
The RS 660 ships with the most comprehensive electronics package in its class: 6-axis IMU, cornering ABS Pro, lean-sensitive traction control, wheelie control, slide control, engine brake control, launch control (added 2026), 5 ride modes including 3 customisable. Yamaha R9 matches it. Honda CBR650R doesn't come close.
