Almost two-and-a-half years ago, Asphalt & Rubber broke the story that Aprilia was working on a twin-cylinder sport bike, which would be a more affordable and approachable option than the company’s flagship RSV4 superbike offering.

After teasing us at EICMA with the prototype in 2018, and then with the production model a year later, we were set for the Aprilia RS 660 to debut as a 2020 model…but then, the coronavirus outbreak changed all that.

With Italy no longer under lockdown, this bike is finally ready to take the stage, and of course the 2021 Aprilia RS 660 is headed stateside, with the first examples of it landing at dealerships in time for Christmas (and what a present that would be under the tree).

It has been a long wait for this eagerly anticipated motorcycle, and last week the American motorcycle press got their first miles on this middleweight-twin.

Riding the canyon roads near Santa Barbara, we put the Aprilia RS 660 through its paces on some of the best roads California has to offer (in this author’s opinion, at least), to see how this unique creation from Noale stacked up.

Would it live up to the hype? Is this the new twins class killer? Does Aprilia have another opus on its hands? That is what we aim to explain to you in this review.

That New, New Middleweight

If you will allow me to spend some pixels giving some background to the Aprilia RS 660 before getting into the nitty gritty of this new model, I think it will help understand the space the Italians are playing in with this motorcycle.

The middleweight-twin category is perhaps the most overlooked space in the motorcycle industry, which is really a mote in the motorcycle industry’s eye.

The category is defined by price-point motorcycles that are long in the tooth (the Suzuki SV650 and Kawasaki Ninja 650), and even the latest entry into the category, the Yamaha MT-07 is showing its age.

All of that changed though when the KTM 790 Duke showed up.

Yes, this Austrian bike was thousands of dollars more than the models I just listed, but the price tag was still in the “affordable” side of the equation for many riders, and more importantly for that added cost, the KTM 790 Duke brought a bevy of big-bike features to the table.

Suddenly, there was a premium and performance side of the middleweight-twin category that no one has bothered exploring.

More importantly, the category created a space for OEMs to recapture the customers abandoned by the stagnating 600cc supersport segment.

The result has been stark, and has led us to name the KTM 790 Duke the best dollars-to-donuts sport bike on the market.

Now, Aprilia wants in on the game, and the Italian brand is betting big with its 660cc platform.

First on the market is the Aprilia RS 660, but we expect soon to see the Aprilia Tuono 660 naked bike, and perhaps this time next year, the Aprilia Tuareg 660 ADV machine. And these are the bikes that we know about…

With a price tag of $11,299 on the 2021 Aprilia RS 660, the Italian brand is making a bold appeal to riders.

Defined By What Though?

While the Aprilia RS 660 is very much part of this new middleweight-twin revolution, it is oddly a tough motorcycle to compare to other models. On price and features, the KTM 790 Duke might be the best fit.

But, the Austrian bike is a touch cheaper, has no fairings, and is very, very likely not going to be around for the 2021 model year in the United States. What will the base model KTM 890 Duke look like when it finally gets announced? We’ll have to wait and see…and that point, isn’t it really a middleweight-twin?

Aprilia’s rival Italian brand brings the fully faired Ducati Supersport to market, and the two bikes share a similar ethos in use and ergonomics, but the Supersport comes with a price tag that is roughly $2,000 more than the RS 660 – and the Ducati flirts with the liter-bike category, with a 950cc engine displacement.

The Japanese brands? They are in a completely different pricing category, not to mention feature-set and state of tune.

Besides, the Suzuki SV650 and Yamaha MT-07 are again naked models, though the Kawasaki Ninja 650 does come with a full fairing design.

Is there a customer overlap between these purely budget-bikes from Japan and the more value-focused propositions that are coming out of Europe? Smart minds could easily disagree on that point.

This makes the Aprilia RS 660 a tough bike to review in comparison to what is available in the marketplace, and the upcoming Aprilia Tuono 660 is perhaps the better apples-to-apples comparison in many regards.

Nevertheless, we never shy away from offering an opinion here at Asphalt & Rubber, so let’s get to it.

The Aprilia RS 660, By the Numbers

Diving into the technical specifications, the starting point has to be the 659cc parallel-twin on the Aprilia RS 660, with its 270° crank configuration.

The engine features an 81mm bore, just like on the Aprilia RSV4 1100 Factory, which is where the engine derives its inspiration.

Aprilia quotes just under 100hp for the American-bound models, with 49 lbs•ft of torque hitting at 8,500 rpm. Make no mistake, the RS 660 engine is making its power through revs (redline is just shy of 12,000 rpm), and not through cylinder pressure. 

This means the bulk of the action on the Aprilia RS 660 happens north of 7,000 rpm, and at times the motor can feel a little uninspired at the lower rev ranges. I was impressed though with how Aprilia has managed to keep the RS 660 from being a peaky machine.

In fact, above 7,000 rpm, the torque curve is so smooth before it tappers off at 10,000 rpm that it can be hard to discern when you should grab the next gear. The customizable shift light helps in this regard.

The power might be up top, but it is a broad power band that one can play with, and the mid-range grunt certainly isn’t anemic either…just not as much as I would like to see. A rear sprocket change could be a benefit here.

Augmenting the power and engine performance is a full electronics suite, which features an integrated IMU. This means lean-sensing traction control, dedicated wheelie control, cornering ABS, as well as engine braking control.

A launch control feature is planned as well for a still-to-be-announced racing package. Cruise control comes standard as well, along with five riding modes with three engine maps – though honestly, we can see little reason to get out of full power on the RS 660, unless it is raining.

The ABS can be configured to be front-wheel only, which helps the hooligan factor (especially when the wheelie control is turned off as well). Of note, the ABS cannot be disabled, but the least-intrusive level is very much that, non-intrusive.

Our street riding didn’t give too many opportunities to play with the rider aids, but certainly nothing glaring presented itself in this regard.

Aprilia claims a curb weight of 403 lbs, and I would tend to believe them on that number. The Aprilia RS 660 feels very light and compact between the rider’s legs.

The Italian brand says that it aimed to have the RS 660 fall between the Yamaha YZF-R6 and Kawasaki Ninja 650 in terms of rider positioning and comfort, and this is actually a pretty good way to describe the Aprilia RS 660 overall.

The arm and torso positioning is not nearly as extreme as a full-fledged supersport, but yet it’s not upright like a standard bike would be. The legs are definitely sporty though, while still keep the rider “in” the bike, rather than “on” it.

This makes for a riding positioning that is adept at carving canyons, but still suitable for some highway miles. The seat isn’t unbearable either. Aced it!

The controls on the handlebars are fairly intuitive, and include a dedicated mode button on the right-hand side switchgear. I found the cable clutch lever a bit hard to grasp, but with the up/down quickshifter, it’s not like I was using the clutch too often.

The 5″ TFT dash isn’t game-changing by industry standards, but certainly stands apart in this category. The menus are easy to navigate though, and the dash layout is a little busy for my taste, but still intuitive.

Perhaps my favorite feature on the Aprilia RS 660 is the rear seat, though. As strange as that might sound, Aprilia has designed something here that is surely going to be copied by other brands in the future.

There is of course the RSV4-esque rear cowl cover, with its now iconic twin-fin design. But, should you choose to have a passenger, Aprilia has made a proper seat for your companion.

By sport bike standards, the seat is rather large and looks reasonably comfortable. The killer feature though is that underneath the removable seat padding, there is a mounting platform for a top box / milk crate / whatever.

This makes for a very utilitarian approach to the pillion, and just increases the practicality of this twin-cylinder machine. Not to mention, it is just downright clever. +5 points to whomever came up with that one.

Like Father, Like Son

Out of the city, and into the canyons, the DNA of the Aprilia RS 660 is evident. This might be an approachable street bike, with some clever features for the around-town rider, but this pint-sized middleweight-twin was born to run.

The lineage from the RSV4 to the RS 660 might be most obvious on the spec sheet with the engine, but the paternity test shows its strongest result in how the chassis handles on this twin.

Cranked over, going through a high-speed turns, the feeling from the RS 660 is the same as what you would find on the RSV4.

These Aprilias feel planted when they are on the side of the tire, which is truly confidence inspiring, and while on the RSV4 you trade the attribute for a slow roll rate, the RS 660 feels noticeably easier to flick from side-to-side.

I thank the lower rotating mass on the RS 660 engine, and overall lighter curb weight, for this difference, and I can only imagine what a little scalpel the Aprilia RS 660 could become with some lighter wheels.

Even in stock trim though, the Aprilia RS 660 is a joy to ride hard, and yet totally approachable should you want to soften things up.

It is not all great out of the box though, as Aprilia’s stock suspension settings are certainly too soft for this rider’s taste. Thankfully, the Kayaba forks and rear shock have preload and rebound adjustability (sorry, no compression damping control here).

A few twist and clicks, and the bike was feeling proper enough to shred the asphalt with confidence – not that you should do such a thing on an open road. Our endeavors in this regard were purely for science. For science.

There is a subtle vibration to the Aprilia RS 660 while at speed. I wouldn’t call its BMW S1000RR harsh, but it treads that line between being a complaint and something better described as a “character” of the motorcycle.

I spent some time thinking about this between apexes, and ultimately landed on the latter. I only mention it here to highlight that the parallel-twin from Noale isn’t silky smooth like some four-cylinder offerings, nor is it soulless like some other twins on the market.

If we continue down the line of thought on “things Jensen likes” the gearbox ranks fairly high, as the RS 660 gave us no troubles in this regard.

The quickshifter can be a little harsh when you are not on full gas (especially in first-to-second), and mashing down gears with the QS is a bit rougher than it should be. But, all of our shifts were solid, and there were no false-neutrals or missed shifts.

For budget pieces, the brakes impressed as well, with good bite and feel. I dare say that the brakes on the Aprilia RS 660 lead the class in the middleweight-twin segment…quite easily, though this isn’t a high bar to beat.

One surprise though was how quiet the exhaust is from this parallel-twin engine.

“Non-existent” is how I would describe the note, though one gets plenty of rowdiness from the intake. In the world of Euro5 and stringent EPA noise criteria, this is the new normal.

I have every confidence that the aftermarket will bestow a solution upon those who hate their neighbors.

Bonus points go to Aprilia too for putting proper road rubber on the RS 660, with Pirelli Diablo Rosso Corsa 2 tires coming stock. I have already called these tires the best sport bike tires on the market, so I won’t rehash it here, but it is worth noting that this is another item where Aprilia didn’t skimp…which again is serious point to make in this segment.

While we have exhausted some words on the various points of the Aprilia RS 660, the summation is that this is a bike that is more than just all of its parts put together.

The fit and finish on the Aprilia RS 660 is rather good (though, the “Aprilia” sticker, placed ajar on the triple clamp, will keep me up at night), and even in its restricted street-legal form, there is a pedigree here that is ready to race.

I’m not saying that I saw over 134 mph before I ran out of road for sixth gear, but…yeah, I did.

A Natural Born Killer

Our test ride was without a track portion, which is a disappointment, since I know many club racers are eager to see the Aprilia RS 660 on the track, and some of the features on this machine can truly only show their potential on a closed course environment.

The MotoAmerica paddock right now is buzzing about this hot Italian, and I suspect you will see a flurry of SV650 and MT-07 race bikes for sale in the coming months.

The reason for that is obvious: the potential for 100hp / 403 lbs street bike with a full electronics package is a game-changer in the Middleweight / Twins racing classes.

Even with the added price tag, the Aprilia RS 660 has the potential to be a cheaper option than other bikes in the class built to a similar spec.

While I will reserve judgment on how the Aprilia RS 660 performs in a track or race capacity (I should get a chance to flog one at a track day next month), there are a couple items would-be racers should be aware of about the RS 660.

For starters, this is still a bike built to a price point, which means that some corners have been cut. Aprilia has been smart (relatively) about where those corners reside, however.

The Brembo brakes are nothing spectacular, though they are mated to 320 discs and a radial pump master cylinder. Still, this package is lightyears ahead of what KTM, or anyone else is bringing to the table in this category.

Racers will surely be looking for more performance here, but for track day users, the stock package should be easily adequate. It doesn’t seem to fade easily, and the feeling/power is quite good.

The same can be said for the stock suspension. With preload and rebound adjustability only (no compression), the upside down forks are a step-up for the category, but still not quite adjustable enough for the race track.

Fork cartridges and a different rear shock unit will be popular upgrades, I imagine, especially considering the lack of a rear shock linkage on the swingarm.

The real issue comes when you take a look at the handlebars and rearset configurations, as these are items where Aprilia’s cost-cutting has made for some challenges for would-be racers.

This is because on the Aprilia RS 660, the handlebars and top triple clamp are all one unit. To get clip-ons, one will also need a new top piece to the triple clamp. Not a difficult swap to make, but perhaps a silly one.

Similarly, to put new rearsets on the Aprilia RS 660 (a modification I would want), one will need to pull out the swingarm pivot, as it goes through the rearset, the swinargm, and then the motor on each side.

The design surely saves some weight and cost, but it makes a relatively simple modification a bit of an undertaking for the casual rider.

Lastly, the cockpit is a bit cramped when in a full tuck, and my large frame would definitely need a taller windscreen for the 140mph-ish top speed this bike promises (a little more room on the seat to scoot back would be nice too).

All this being considered though, I am fairly confident that with a set of Pirelli slicks, I could break the OMRRA Middleweight Supersport lap record at Portland International Raceway with a bone stock Aprilia RS 660 – on either course configuration.

This is of course why the Aprilia RS 660 sings such a siren’s song to club racers and professionals alike.

A true 100 rear-wheel horsepower isn’t difficult to imagine with some basic modifications and fuel, and one has to wonder what is achievable when a proper superbike build is performed.

While Aprilia won’t commit fully to saying so, it seems like an almost certainty that race-prepped versions of the Aprilia RS 660 will be available from Aprilia Racing, through the company’s Factory Works program.

It is debatable whether those bikes would be ready for the 2021 season in the United States, however.

Yeah, But Would You Buy It?

Now far the part that surely many of you skipped straight to, as we look to answer the question of whether I would spend my hard-earned blogging dollars on the 2021 Aprilia RS 660. I’m going to warn you, you will find the answer disappointing.

For over two years, I have been eager to ride the Aprilia RS 660. I am fully onboard with this new take on the middleweight-twin category, and its been a long time coming for the folks in Noale to deliver a compatriot to the opus that is the RSV4.

Half and the engine at half the price is a winning combination, and in short, the Aprilia RS 660 lives up to the hype that its spec sheet promises. This bike is surely going to be banned in some club racing leagues – it is that good.

Beyond the spec sheet though, the RS 660 is a surprisingly excellent street bike – and this might be the machine’s secret weapon.

While the spec sheet screams “race me” the motorcycle is still entirely approachable for street riders, especially novices to the sport.

Our 160-mile ride wasn’t nearly the torture rack it would have been on some other sport bike models, even for this 6’2″ rider who is well outside the archetype of Italian test riders.

The broad power band, though it leans to the top-end, still leaves enough meat on the bone for mid-range throttle pulls.

We would still suggest a sprocket change for a little more grunt, but overall Aprilia has walked the line between a full-on supersport and upright street bike quite well – creating something truly in-between.

In the marketplace, the only bike that truly gets my head to turn away from the Aprilia RS 660 is the KTM 790 Duke, but as I mentioned at the start of this review, that is an imperfect comparison.

Grins for dollars, the KTM comes out ahead over the Aprilia, but the RS 660 makes considerably fewer compromises on its spec sheet, which maybe makes this too close to call.

The torque of the 790cc Austrian engine is a noticeable advantage for the KTM, which is of course to be expected with the larger engine displacement.

It remains to be seen though what KTM does with the 790 (or 890 as it would seem) for 2021, and still there are concerns about what brakes, suspension, and tires that bike will come with – as all three of those criteria fall short to what the Aprilia RS 660 offers.

Even then, I am left to wonder what a Tuono 660 to KTM 790/890 Duke comparison would look like, and as I go round-and-round on this topic, I wonder what a KTM RC790 would do the math.

The fact remains: if you want a full-fairing middleweight-twin, with real supersport features, then the Aprilia RS 660 is the only game in town, and it is a very strong game that is being played.

But would I buy the 2021 Aprilia RS 660 though? Perhaps…

A Caveat

I know that answer is frustratingly unclear, but there is a good reason for that, as I would be remiss in my journalistic duties if I didn’t disclose a series of issues that we had on the Aprilia RS 660 during our test ride.

The bikes on review were pre-production models, and before we turned a wheel, Aprilia disclosed to us that some minor issues with the fueling and calibration were still being ironed out on these bikes back in Noale.

Virtually all of the machines on our launch had intermittent issues with ABS lights flickering constantly. My model also threw out a “check engine” light at the beginning of our ride, which wouldn’t clear on a full key restart.

Making matters worse, my particular Aprilia RS 660 (the second one off the assembly line, by the way), suffered from being hard to start when the motor was hot.

The real icing on the cake was when the bike shutdown completely while at speed, not once, but twice on our ride on California’s Highway 33.

As good as a motorcycle can be in every other regard, it is hard to recommend a machine to a reader when it has the above issues, and we can only review the motorcycle that is presented to us – not the manufacturer’s future intentions.

Aprilia assures us that these issues are primarily calibration issues (due largely to Aprilia switching to a Magneti Marelli ECU setup), and perhaps early teething issues at the assembly line, and thus will be rectified on the production machines.

Then again, we have heard similar promises from other OEMs before, with varying degrees of those promises being made good.

It will be likely be until January when we can try a true production version of the Aprilia RS 660, which is a disappointment.

Out of all the motorcycle brands that need to make a good impression on consumers, and instill a sense of confidence in its products, dealers, and post-sale support, Aprilia is that brand in the motorcycle industry.

This misstep at their American press launch does nothing to advance that goal, where the #1 factor stopping a motorcyclist from buying an Aprilia motorcycle are all the horror stories of dealer difficulties.

I will add another disappointment to this list as well, though it is considerably minor. Swapping the Aprilia RS 660 to a GP-shift patterns, as some street riders will surely want to do, and many track riders insist upon, is going to be an interesting affair with Noale.

Mechanically, this is very easy to do on the Aprilia RS 660 – one simply flips the shift linkage at the engine upside down, as one has done on so many other production motorcycles for the past 30 years or so.

Except, you can’t do that with the Aprilia RS 660 without an ECU reflash to make the quickshifter operate properly.

Aprilia’s current plan is to have this “track” feature available as a dealer add-on, which comes with an added fee.

That fee seems more-than-likely to be in the hundreds of dollars range, even though it requires a fairly simple amount of computer programming to achieve.

Quite frankly, our opinion is that the quickshifter feature should come standard on the Aprilia RS 660, and that the motorcycle industry’s approach to “Motorcycles as a Service” is a foolish path for brands to undertake if that want any sort of customer loyalty and goodwill.

I made this appeal to Aprilia USA at the launch when discussing quickshifter issue, as I have just done here in this story, and hopefully the Noale factory is listening.

You cannot be the premium option in a segment, and still nickel-and-dime your customers as if they are budget buyers. The champagne is always free in first class, after all.

Would all this stop me from buying the Aprilia RS 660? That’s hard to say. I would certainly need to see the electronic issues sorted out on the production models before I could consider a purchase.

But, the quickshifter issue feels like a larger concern. Aprilia needs to generate goodwill with customers right now in the United States, and this add-on-package-extra-fee non-sense does the opposite of that.

As enticing – and it is very enticing – as the Aprilia RS 660 is as a motorcycle, how a brand treats its customers and supports them post-purchase is a critical component to my purchase-making decision.

Aprilia hasn’t made me a believer in that regard so far with the RS 660. I hope I am proven wrong, however…I’ve got that track record to break, after all.

Photos: Kevin Wing Photography