Ridden: Aprilia’s RS660 – a new contender for the Lightweight TT crown

| | TT and Roads
Picture: Milagro

As a big fan of the TT Lightweight class (the RS660 will be eligible for the 2021 TT), which consists of racy parallel twins, the RS660 got my attention when it was unveiled two years ago. I’m also old enough to remember Aprilia’s legendary two-stroke RS250. The RS600 was a bike I’ve been so looking forward to riding.

The RS660 is powered by a parallel twin with a 260-degree crank, which is essentially the front half of the RSV4. But although the RS660 is an ‘entry-level’ bike for Aprilia, and is designed for a young and inexperienced audience, it’s neither plain nor boring – the opposite in fact – and even uses more rider aids than Aprilia’s flagship superbike RSV4. Cornering ABS, multiple track and rider modes, traction and wheel control, an up-and-down quick-shifter, even cruise control.

In the bends

It has a short wheelbase (1370mm, 69mm shorter than Aprilia’s own RSV4 Factory); at just 169kg dry or 183kg with fuel it is light, there’s adjustable suspension, a wide 180-section rear Pirelli Diablo Rosso Corsa 2 tyre, and in the purple and red colour scheme reminiscent of the legendary RS250. But is far more relaxed than a wannabee track bike. The seat has some padding, the bars are relatively high and wide, the ergonomics are comfortable, with low pegs.

The parallel twin is a road bike first and foremost, but one that can also be taken on the track.
The steering is light, which is exaggerated by the wide bars. It’s flickable yet stable. Despite its lightness and willingness to steer, it’s predictable. It is user friendly and welcoming, you just jump on and ride fast, safe in the knowledge you have brilliant rider aids at hand, like cornering ABS.

The front 43mm Kayaba forks are fully adjustable and were faultless on the road only test, while the rear unit is also adjustable (aside from compression) and even at a brisk road pace is hard to fault. I’m sure you’ll need a little more support on track with race tyres. But, overall, it’s an easy handling road bike, which can cut it and delivers safe, light positive handling.

Brakes

The standard radial Brembo stoppers, with braided lines and radial master cylinder are more than up for the job, especially when you consider the bike’s lack of weight and comparatively low top speed. When stopping 183kg from a top speed of 140mph, you don’t need the most expensive race-spec Brembo stoppers. The feel is excellent, even the back brake, and the ABS isn’t intrusive on the road.

You have three levels of ABS. The most intrusive is cornering ABS front and rear, mode two is similar but less intrusive, and mode one is conventional ABS on the front, not cornering ABS and not ABS on the rear, which in experienced hands with the standard slipper clutch allows you back into corners for fun.

How fast mister?

What Aprilia have done is essentially use their RSV4 as a base, chopping the V4 engine in half to produce a parallel twin. The bore size is the same as the RSV4 1100, but now stroke is 63.93, not 52.3mm. The twin-cylinder DOHC engine produces a respectable 73.5kw/100hp @10,500rpm and 67Nm/49.42lbft @8500rpm, that is more peak torque than a Yamaha R6.

The little twin will bounce off the rev limiter at 11,500rpm but with a race kit will rev on for another 1000rpm. Interestingly the rev limit for the TT Lightweight class for 2021 will be 11,000rpm. But this isn’t a race engine; 80 per cent of the torque is at just 4000rpm and 90 per cent is at 6250rpm. There will also be an A2 version for restricted licence holders with 95hp, which can then be restricted further.

It’s not just a V4 in half. There’s a new clutch, a new intake system, a new cylinder head, new 48mm throttle bodies… this is a completely new engine, albeit one that leans on the experience and knowledge gained from the V4. Aprilia has cleverly reduced vibration and allowed the engine to run smoother, with 270-degree counterweights on the new 270-degree crankshafts. The completely engine is a structural part of the bike, too, with the swing-arm bolts directly to the rear of the engine.

It doesn’t sound like a Kawasaki Z650 (with a 180-degree crank), with each cylinder balancing each other – this is much smoother. The light, one-piece, 6.2kg exhaust consists of one silencer per cylinder plus a cat’ exhaust/collector box, which then exits on either side of the rear 180 tyre. The race exhaust is more conventional one exiting exhaust. A tickle of the ride-by-wire throttle allows the revs to dart up the full colour TFT digital dash. The revs build smoothly, quicker than I was expecting, and for a standard exhaust, the system adds a little soul to the RS660 experience.

There are five riding modes to choose from: three for the road – Commute, Dynamic and Individual – and two for the track – Challenge and Track Attack. Each mode changes the engine character, feeling and the multiple rider aids, including traction and wheelie control, cornering ABS, engine brake assist, while the-up-and-down quick-shifter which comes as standard is the same in all modes. Again, you can change and personalise each mode if you wish. It may sound a little complicated for a 10k ‘entry-level’ 100hp middleweight but, in reality, it isn’t. It’s simple and intuitive.

Like every other Aprilia I’ve ridden recently the fuelling was perfect. Aprilia has a world-class fuelling team, throttle response is always perfect, which is particularly impressive for a parallel twin. Again, like the premium RSV4 1100, the quick-shifter is perfect too, both up and down.

As we headed into the Alps it was time to flick from Commute mode to the Dynamic mode, which automatically changes the engine character and response, and reduces the intrusion of rider aids. You can feel the difference, the response is a little sharper, especially from a closed to an open throttle. It’s not snatchy, the fuelling is again excellent, there is simply more urgency.

Power is relatively linear (90 per cent of torque is in by 6250rpm), and you can short-shift on the fast quick-shifter and still make progress, but thrill-seekers will head above 7000rpm. It’s so much fun to thrash, tapping up and down the quick-shifter with the clutch redundant, excellent rider aids and cornering ABS on hand if the road surface should unexpectedly change… I really felt I could attack the Alpine mountain passes as if they were my local roads.

It’s a brilliant engine to thrash, it sounds good, is responsive and fun, and blessed with excellent fuelling and a synchronized quick-shifter. And thankfully, when you look down at the full colour TFT dash, you’re not doubling the speed limit and facing a jail sentence should you get caught. I’d estimate top speed is around 140mph, but unlike a RSV4 it’s not scary on the road.

More tech than the RSV4

At your disposal are multiple rider modes, eight-stage traction control, wheelie control, engine brake assist plus cornering ABS and conventional ABS. Additionally, you have cruise control and an up-and-down quick-shifter. The modes are easy to change on the move, and you can even de-active the traction and wheelie control on the go, too.

As you’d expect there are the usual accessories from Akrapovic, including a full race and road exhaust. There is also additional software available which means you can flick over to a race shift, and have access to a pit lane limiter.

2020 Aprilia RS660 Verdict

It appears Aprilia has produced a usable, friendly, road-going sports bike laden with rider aids. It’s not extreme; instead it is comfortable with a versatile engine that shouldn’t get you into too much trouble, this is not a modern RS250 Aprilia. It sounds good, has character, looks great, and is more desirable than the competition – but at a price. The suspension may need an upgrade for some serious racing/track action, but with more power and better chassis than the competition, this could be the new king of the Lightweight class.

2020 Aprilia RS660 Tech Spec

New price £10,149
Capacity 659cc
Bore x Stroke 81 x 63.93mm
Engine layout parallel twin, DOHC, 8v
Engine details water-cooled
Power 73.5kw/100hp @10,500rpm
Torque 67Nm/49.42lbft @8500rpm
Top speed 145mph (estimated)
Transmission 6 speed chain
Average fuel consumption 4.9l 100km
Tank size 15 litres
Rider aids Five rider modes, three road two track. APRC System (Aprilia Performance Ride Control), which includes Traction Control (ATC), Wheelie, Control (AWC), Engine brake (AEB), Engine map (AEM) cruise control (ACC) up and down quick-shifter.
Frame Aluminium duel beam
Front suspension Kayaba inverted 41mm forks.
Front suspension fully-adjustable
Rear suspension Kayaba single shock
Rear suspension rebound and preload
Front brake 2 x 330mm discs, Brembo radial 4-piston callipers with cornering ABS
Rear brake 220mm single disc, Brembo 2-piston calliper with ABS
Front tyre 120/70 ZR17
Rear tyre 180/55 ZR17
Rake/Trail 24.1°/104.6mm
Wheelbase 1370mm
Seat height 820mm
Dry weight 183kg (169kg dry)

Picture: Milagro
Picture: Milagro