Carving through Chuckwalla Valley Raceway’s bowl, on my way to setting a personal best lap time on a completely stock motorcycle, I came to a realization: Aprilia’s Tuono 660 Factory is a cheat code to the middleweight naked bike class and sporty riding in general. On the surface, it is unintimidating with a flat handlebar and seemingly modestly sized 660cc engine, but roll into the throttle and click through the gears, and you will quickly realize this bike is so much more than a run-of-the-mill middleweight naked. Tuono is thunder in Italian, but this middleweight naked is more of a lightning bolt–sharp and exciting.

The Tuono 660 Factory is Aprilia’s thunderous (sorry!) naked-bike recipe applied to the middleweight segment. With more than 100 hp and fancy bits–including fully adjustable Öhlins suspension, Brembo brakes, and an electronics suite powered by a six-axis IMU–the Factory offers premium features and serious performance. Despite one of the smallest displacements in the middleweight naked class, it’s still very wicked and spicy, but much more manageable and less intimidating than its superbike-based big brother, the Tuono V4 Factory. For street riding and the occasional trackday, the Aprilia Tuono 660 Factory might be the sweet spot for performance naked bikes. With an MSRP of $11,599, it’s far less spendy than larger, exotic hyper-nakeds that typically cost twice as much, all while offering many of the high-end features found on those bigger bikes. EngineThe Tuono 660 Factory shares the same engine as Aprilia’s RS 660 and Tuareg 660 platforms. It’s a 659cc parallel-twin engine with a 270-degree crank and six-speed transmission. With 52mm throttle bodies (4mm larger than the standard model) and redesigned exhaust header pipes, the Tuono 660 Factory produces 5 more horsepower than the standard model.

On paper, the Tuono 660’s engine is at a disadvantage compared to larger parallel-twin engines in the class like Yamaha’s 689cc CP2, Honda’s 755cc, and Suzuki’s 776cc, but the Tuono makes the most power out of the bunch with a claimed 105 hp. The closest bike in the middleweight class to put out similar hp numbers is Triumph’s three-cylinder Trident 660 with a claimed 94 hp. So while the saying, “there is no replacement for displacement,” can be true, with tuning, Aprilia’s smaller 660 engine produces class-leading power with fewer cubes. The Tuono’s engine impresses with its strong midrange punch and top-end that pulls hard until redline. The engine’s tractable low-end makes it easy to launch the bike from a stop, and the pulses from the engine and sound of the exhaust are charismatic and enjoyable around town. In twisty canyons, the midrange punch provides instant response, and with a quick dip of the clutch, wheelies are achievable in first, second, and third gear. Zoom down a highway or blitz a straightaway at the track, and the engine’s top-end performance shines. It rewards waiting until the very last tick of the digital tach to shift into a higher gear. The Tuono’s engine spins up towards the rev limiter with a voraciousness of something larger or with more cylinders.

Similar to KTM’s 790, 890, and 990 parallel-twins, Aprilia’s 660cc twin is extremely rewarding at high rpm. At the other end of the rpm range, the Tuono’s low-end response is not as playful at slow speeds as Yamaha’s CP2 engine. It’s clear the Tuono 660 Factory is tuned for high-revving performance, but it still has enough down low for everyday utility. The only shortcomings of the Tuono’s engine that we experienced is a vague fueling response at the initial crack of the throttle and hard starting when hot. During initial throttle pickup, engine response lags, making slow-speed on- and off-throttle application unpredictable. And a few times on hot days after riding the bike hard, the engine took a few extra cranks to fire up. ElectronicsThe Tuono 660 Factory is equipped with Aprila’s Performance Ride Control (a-PRC) electronics package, which Aprilia says is derived from its MotoGP racing experience. On the Tuono 660 Factory, the suite offers an extensive range of rider aids and features, including wheelie control, launch control, cruise control, multiple ride modes, multiple levels of TC, adjustable ABS, adjustable engine braking, and a bidirectional quickshifter. Information is displayed across a 5-inch color TFT and supported by backlit switchgear.

With a claimed 105 hp and grippy Pirelli Diablo Rosso IV rubber, we spent most of our miles in a custom ride mode with full power, traction control reduced to its least intrusive setting, wheelie control turned off, and rear ABS disabled. Tractable and easy-to-meter power combined with soft Pirelli rubber doesn’t completely negate the need for TC, but in most instances the tire and engine combo allow for a loosening of the electronic reins. Having wheelie control intervention separate from traction control is a feature every rider with a wild streak can appreciate. It’s great to have the safety net of traction control midcorner while also being able to lift the front wheel when the mood strikes.

Chassis and HandlingAt a claimed 399 pounds, the Aprilia Tuono 660 Factory has one of the best power-to-weight ratios in the middleweight naked bike class at 3.8 pounds per horsepower. For reference, the new KTM 790 Duke has a nearly identical power-to-weight ratio of 3.9 pounds per horsepower. On the opposite side of the class, Suzuki’s GSX-8S has a power-to-weight ratio of 5.4 pounds per horsepower. Utilizing the engine as a stressed member, the Tuono 660 Factory employs the same twin-spar aluminium frame and engine-mounted cast aluminium swingarm as the standard model, but both are now painted black. This chassis design creates a motorcycle that is exceptionally light and compact, great for sporty riding. But despite its compact and lightweight chassis, the Aprilia Tuono 660 Factory’s handling is not overly sensitive or immediate to a fault, but is instead direct and precise, mirroring the rider’s inputs.

While some bikes that are light can feel nervous and unsettled, the Tuono’s handling is beautifully balanced and neutral. Certainly not slow to steer, the Aprilia requires just a bit of intent and purpose to turn the motorcycle without being strenuous. This results in handling that is responsive without being unpredictable. The Aprilia is planted, stable, and balanced through any set of curves. Öhlins suspension further enhances the Factory’s handling and composure. Replacing Kayaba components on the standard model, Aprilia gave the Factory a fully adjustable Öhlins 43mm NIX30 fork and Öhlins STX46 shock. These components are performance-driven, which pays off during sporty riding, but sacrifices comfort on small bumps during urban riding, especially without adjustment from track settings.

On flowing canyon roads, the suspension predictably moves through the upper part of the stroke with a firm and composed action. As the bike transitions from one side to the other, the tires stay planted and the relationship between the front wheel and the rider’s hands is very connected. At the racetrack where the demands are much higher, the suspension lives up to the “Factory” emblem painted on the side of the bike. Whether ripping off an apex with a handful of throttle or loading the front with a handful of brakes on corner entry, the suspension stays firm without sacrificing feel or grip.

Dual four-piston, radial-mount Brembo calipers with 320mm floating discs offer excellent performance on road and track. Strong initial bite with progressive stopping power allowed for hard and late braking on the track without brake fade. ABS calibration is spot on; even on the track, intervention is activated only when absolutely necessary.

Aprilia’s Tuono 660 Factory is a well-balanced package. Every component complements the other. The engine, suspension, chassis, tires, and brakes all match each other in performance and are supported by a comprehensive electronics suite. Aprilia’s Tuono 660 Factory might be the ultimate daily streetbike/track bike. And part of that consensus is based on comfort. Ergonomics

Aprilia’s line of Tuonos is an exercise in comfortable performance. A close look at the origin of the Tuono 660 Factory reveals it’s essentially the RS 660 Factory supersport, but with a one-piece handlebar and less bodywork. And that’s all the Noale factory needed to do to create a killer naked that can run with the best supersports on the track, but be more practical and comfortable in day-to-day use. The cockpit is more cramped than other standards on the market, but the Tuono’s high footpeg placement relative to its 32.3-inch seat height provides the cornering clearance needed to attack a racetrack without excessively dragging hard parts.

CompetitionRight now, the middleweight segment is stacked. There is an option from just about every manufacturer. This class currently employs the most cross-platform sharing, reducing costs, and increasing refinement. Many manufacturers offer midsize motorcycles with nearly identical underpinnings in a variety of segments, including nakeds, supersports, retros, and ADVs.

For midsize motorcycle shoppers, the good options seem endless. And honestly, they are, because most of the bikes are really good. But some are special. If you value performance, features, style, and the exotica that comes with owning an Italian machine, the Aprilia Tuono 660 Factory is a great choice.Of course Ducati’s middleweight street offerings in the Streetfighter V2, Streetfighter V2 S, and Monster+, are exceptional machines, but with displacements of 890cc and an MSRPs of $15,995, $18,995, and $14,995, respectively, all have a higher cost of entry than Aprilia’s Tuono 660 Factory. Conversely, bikes with sub-800cc engines and similar or lower price tags such as the Honda Hornet 750, Suzuki GSX-8S, Yamaha MT-07, Kawasaki Z650, Triumph Trident 800, and KTM 790 Duke, few can compete with the Factory in terms of outright performance, features, and adjustability. Is the 2026 Aprilia Tuono 660 Factory the Sweet Spot In the Middleweight Naked Segment?With all Aprilia’s sporting bikes, performance is at the forefront of design. Aprilia’s Tuono 660 Factory shares a nearly identical spec sheet to its more track-focused sibling, the RS 660 Factory. Merely a change in bodywork and ergonomics is all the Noale factory has to do to create an entertaining and spirited naked that is more than equipped to ride on track. And while the Tuono may have a displacement disadvantage compared to the larger engines in class, its competitive power-to-weight ratio and top-notch chassis and handling make up for it when the road gets twisty. While we can’t confirm (yet) which bike in class is best overall this year, we can confidently conclude that the middleweight class is the sweet spot in terms of performance, features, utility, and price. But there is no denying the Tuono 660 Factory is a standout in that sweet spot.

2026 Aprilia Tuono 660 Factory Specs