Review: 2021 Aprilia RS660

2021 Aprilia RS660 | Motorcycle Review
Middleweight sportbikes are phenomenally fun on a race track, but their sporty breeding makes them suffer in routine street duties and during longer-distance riding. All four of the Japanese four-cylinder 600s are thrilling rides, but none of them are as comfortable or as technologically advanced as the Aprilia RS660.

This new Aprilia throws an invigorating new option to sporting middleweight customers. It has, by far, the most elaborate electronics in its class, is powerful enough to satisfy most street riders, and displays high-level cornering chops that will please aspiring racers.

“This is the beginning of a range of bikes we’re working on,” says Miguel Galluzzi, head of Piaggio Design Center, who famously penned Ducati’s original Monster as well as Aprilia’s RSV4 and this new 660. Coming soon will be a Tuono version (see sidebar), and later this year, an adventure-styled Tuareg model.

2021 Aprilia RS660 | Motorcycle Review
2021 Aprilia RS660

The Heart

An engine is any motorcycle’s heart, and the RS660’s powerplant is nearly all new. In overly simple terms, Aprilia cut off the forward two cylinders from its RSV4/Tuono 1100 to create the compact 659cc parallel-twin seen here. The same engine will underpin the upcoming models.

The powerplant retains the 81mm bore of its V-4 brother, but uses a longer 63.9mm stroke. It’s purported to deliver 100 (crankshaft) horsepower at 10,500 rpm, an entertaining amount that’s nonetheless down about 20 horses from a four-cylinder 600cc supersport.

For what the RS660 lacks in horsepower compared to its four-pot competition, it claws back a smidgeon in torque production. Peak torque of 49 lb-ft arrives at a modest 8,500 rpm, slightly more than Yamaha’s R6 produces at its peak, all the way up at 11,000 revs.

So, the engine output is adequate, but even more important to consumers is how the machine pleases eyeballs. The RS660 is strikingly attractive. There are few external hints the RS is anything but a top-line sportbike, an impression reinforced by the large-diameter exhaust headers (sleeved up from the cylinder exits) visible on the right side. Its three-headlight face with high-end LED lighting “brings the concept of the RSV4 forward,” Galluzzi comments.

Aerodynamics were also important, but—as Galluzzi says—“for comfort, not top speed, and to take away heat from the rider.” MotoGP-derived winglets are becoming part of contemporary sportbike language, but the RS660’s wing devices are placed vertically at the leading edges of the side fairings. “The aerodynamics are inside the bike,” says Galluzzi, “no mustache wings.”

2021 Aprilia RS660 | Motorcycle Review
2021 Aprilia RS660

Cockpit Electronics

The aluminum-framed RS660 is agreeably light when lifting it off its sidestand, with the manufacturer claiming a weight of just 403 pounds with its four-gallon tank full. The saddle is surprisingly plush for a sportbike and pushes the seat height to 32.3 inches. It feels lower once aboard, though. The narrow engine allows the footpegs to be placed tightly to the center of the chassis, allowing them to be lower than most bikes in the supersport class while retaining considerable cornering clearance.

A 4.3-inch TFT color screen, controlled by switchgear on the left handlebar, comprises the instrument panel. A new engine control unit (ECU) provides the brains of the RS660, bumping the processing speed of the RSV4’s computer from 50mhz to 200mhz and from 1 MB of memory to 4 MB. This uprated ECU will also be used in future Aprilia models. The RS is the first Aprilia to meet Euro 5 regulations.

The faster ECU combines with a six-axis inertial measurement unit (IMU) to provide the full gamut of electronic rider aids, including adjustable engine braking the RSV4 doesn’t have. Cornering-ABS is part of the RS660 package, as are ride modes, adjustable traction control, and wheelie control. Cruise control, self-canceling signals, and auxiliary headlights that peek into corners earn the bike bonus tech points.

2021 Aprilia RS660 | Motorcycle Review
2021 Aprilia RS660

Riding Impression

Firing up the RS, your ears pick up a deep burble from the under-engine exhaust canister. The 660’s 270-degree crankshaft arrangement mimics the note of a V-twin and retains a bit of the snarl from its V-4 big brother. The slip/assist clutch offers a light lever pull and cooperative friction zone for effortless getaways. A shockingly generous amount of steering lock eases maneuvers in tight confines.

Once the RS660 is rolling, you’re no longer required to touch the clutch lever, as the little ‘Priller is equipped with a fine-tuned up/down quickshifter that executes seamless gear swapping. A broadly tuned powerband (80% of peak torque at just 4,000 rpm) requires fewer shifts than a typical supersport, while a counterbalancer keeps vibration from reaching obtrusive levels. You’re treated to relatively expansive wind protection, with air flowing over the windscreen at about shoulder height. Engine heat is effectively routed away from your legs.

Okay, so most any modern motorcycle is amenable on urban roads and highways, but it’s in the twisties when engineering and R&D efforts either disappoint or shine. Aprilia’s racing heritage has translated well to the RS660, which offers spritely turn-in response thanks to sporty steering geometry and a tidy 53.9-inch wheelbase, as well as confidence-inspiring feedback when leaned over in corners. The Kayaba suspension can be tweaked for preload and rebound damping, but lacks compression-damping adjustments. It displayed a nice balance of comfort and control.

The friendly powerplant surges with increased urgency after 7,500 rpm, pulling willingly to its 11,500 redline. It’s not as fast as a four-cylinder 600, but the RS quite easily pushed past 120 mph on a deserted stretch of highway with more to come, so it’s definitely not slow. The brakes, with Brembo four-piston radially mounted calipers and 320mm discs up front operating via a radial-pump master cylinder, are fully capable if not stunning. Cornering-ABS is a favorable feature in this class.

2021 Aprilia RS660 | Motorcycle Review
2021 Aprilia RS660


Aprilia’s new middleweight platform represents a unique motorcycle proposition. The RS660 is a sleek Italian sportbike but without eyeball-flattening power, punishing ergonomics, or a lofty price.

It’s like a steroid-injected Yamaha MT-07 in fine Italian clothes with state-of-the-art technology and Honda CBR600F4 (1999) ergonomics. It’s an accessible yet serious sport motorcycle that appeals to riders from the relatively inexperienced to jaded veterans.

The RS660 is available in Lava Red or our test bike’s Apex Black, retailing for $ 11,299. The arresting Acid Gold version has a $ 300 premium.

2021 Aprilia Tuono 660 Preview

Sister to the RS660, the new Tuono version is a semi-naked sportbike counterpart to its sibling, with more hospitable ergonomics. All of the good stuff in the RS660 carries over to the Tuono, including its advanced electronics, color TFT instrumentation, delightful powertrain, and lightweight chassis.

The key distinctions can be seen in the Tuono’s friendlier riding layout, pared-away fairing, and bikini windscreen. The handlebar resides higher and farther back than the RS’s clip-ons, while the footpegs remain in the same amenable position. The RS660’s rider triangle is already quite hospitable, so the Tuono is sure to be quite comfy for street duties. The seat height appears to be the same as on the RS, but no official height was disclosed. Weight remains at 403 pounds.

The Tuono’s engine tuning is mechanically unchanged from the RS, although the power rating dips to 95 claimed horsepower, likely simply due to electronic tuning. A shorter final-drive ratio should yield snappier acceleration. In terms of electronics, the Tuono gives up nothing, retaining cornering-ABS, the up/down quickshifter, wheelie and traction controls, cruise control and self-canceling turn signals.

The Tuono 660 will be available at the end of Q1, priced at $ 10,499 in black or grey. The Acid Gold version costs $ 200 extra.

Technical Specs

+ advanced rider aids, Italian style, distinct

– limited dealer network,  not as fast as some 600s

Distributor Piaggio Group Americas
MSRP $ 11,299
Engine liquid-cooled, DOHC, 4-valve, parallel-twin
Displacement 659cc  
Power 100hp @11,500rpm; 49lb-ft @8,500rpm
Transmission 6-speed, slip/assist wet clutch, chain final drive
Rake/Trail 24.1°/4.1in
Wet Weight 403lbs (claimed, full tank)
Seat Height 32.3in (820mm)
Fuel Capacity 4gal
Fuel Consumption 47mpg (claimed)
Fuel Grade premium
Color Lava Red, Apex Black, Acid Gold