Vee4 is back

Roland whacks the throttle on the latest generartion of V4 litre class power available for the street. Behold the Aprilia RSV4!
Photography: Milagro

The first session had been horrible, but this was fantastic fun. The rain was coming down quite hard now, and the slippery Misano track had already seen three crashes this morning. But as the RSV4 tipped smoothly into the turns, drove through with a guttural V4 growl, and then catapulted towards the next bend with a stirring howl, the speed and poise of Aprilia’s new challenger was thrilling despite the conditions.

This was the upmarket Factory version of the Italian firm’s new super-sports flagship, and the name was well deserved. The production RSV4 was managing — with its looks, its agility, its suspension control and sheer power — to give a flavour of the works V4 on which Max Biaggi has shaken up the established players in the first weeks of the World Superbike season.

It shouldn’t really have been a surprise to anyone that Aprilia would be so competitive so quickly on the track, or that the 183PS production RSV4 would be mighty good to ride. After all, the Noale firm is part of the Piaggio Group that is Europe’s biggest bike firm. More than three years and 25 million euros have been invested in this project, after starting with a blank sheet of paper.

“Our goal was clear,” Piaggio’s director of motorcycle engineering Romano Albesiano had said last night. “We wanted to build the fastest motorcycle on the racetrack, for use on track and road. There were no limitations; no constraints. We were free to choose the engine layout and the chassis. We wanted to make the most compact super-sports bike ever built, and we did it in a unique way: by combining the work of two teams, the engineers of the R&D department and the race department.”

Aprilia’s history also pointed to the RSV4 making an immediate impact. Back in 1998 the original RSV Mille V-twin, the firm’s first ever superbike, was a fine roadster although it never turned World Superbike race wins into a championship victory. This new bike’s links to the V-twin include its trio of headlights and aluminium beam frame layout. But this all-new V4 is very different; lower and more compact, as well as more stylish.

The dozen RSV4s poking from Misano pit garages had cut through the early morning gloom. Miguel Galluzzi, creator of Ducati’s Monster and now head of Piaggio’s design team, has given the V4 a unique and aggressive look. The sharp lines of the cut-down fairing and sculpted tailpiece are reflected in the upswept black silencer. The aluminium frame spars are smooth and polished. Classy, typical Factory-spec touches include Öhlins suspension, Brembo radial Monoblocs and forged Marchesini wheels.

There’s nothing particularly unusual about the view from the rider’s seat, which is quite low and slim (although luxurious compared to the razor-blade that a pillion gets to sit on). Clip-on bars bolt to 43mm forks whose gold-and-blue tops jut through the cast top yoke. A low screen gives a view of the digital display. But there was definitely something special about the way the motor came to life with a raw, raspy V4 sound through the four-into-one exhaust, revving urgently as I blipped the throttle.

Being tall I was glad to find that despite the bike’s compact dimensions it didn’t feel cramped. But I wasn’t glad about the weather. Aprilia had gambled by holding the launch in north-eastern Italy, and had been rewarded by rain. The standard Pirelli Diablo Supercorsa SP tyres had been replaced by softer still racing wets, but I still didn’t enjoy relearning the slippery circuit, especially after one guy had crashed on the opening lap.

The bike was not to blame for that. To suit the conditions Aprilia’s technicians had suggested setting the three-way injection map to the S for Sports position, the middle of the three. This is easily done, using the starter button while the motor is running. The T for Track setting gives max power in all gears; S smooths delivery and cuts max output in the lower three ratios; and R for Road flattens the torque curve and limits output to 142PS at all times.

With the Sport setting selected the V4 was fabulously flexible and sweet-revving. The close-ratio box’s first gear is tall, so I was splashing round the tighter bends with the revs dropping below 5000rpm. Yet the Aprilia picked up sweetly as I cautiously opened the ride-by-wire throttle. The engine note was initially gravelly; a touch of vibration briefly came through the footrests… then the sound rose in pitch and the motor smoothed as the bike stormed down the straight, kicking harder at about 8000rpm and hurtling towards the next turn.

On the wet track I was happy to leave the engine in S mode for almost all my three sessions. A brief test of the Road setting was enough to suggest that its gentler delivery might be useful occasionally. There was certainly not enough grip to allow any advantage from the Track setting’s full power in the lower gears, so I left that for another day.

Even in the dry there would have been no room at Misano to get close to the Aprilia’s near-300km/h top speed, but the bike was into fifth in the generally sweet-shifting box, and still pulling hard (no time to glance down at the digital speedo) on the main straight. That’s despite it having to cut through the wind and rain with my unaerodynamic body increasing the bike’s tiny frontal area despite my efforts to hide behind the low screen. The RSV4 certainly felt seriously fast; just how fast it is remains to be seen.

Full analysis of its handling ability will also have to wait, because the track didn’t dry out. It’s ironic that the RSV4 has the most comprehensively adjustable chassis ever seen on a production streetbike — giving the option to change steering geometry, ride height, swing-arm pivot point and even engine position — but the weather meant that I didn’t adjust even its suspension.

Instead I was happy that the front and rear Öhlins units were reasonably soft and very well damped, and gave good feedback in conjunction with the super-soft Pirellis. Misano’s relatively recent change to run anti-clockwise has resulted in a couple of tricky, decreasing-radius right-hand turns that put emphasis on front-end grip. So it was just as well that the RSV4 steered with a light and neutral feel that made direction changes easy.

I hadn’t expected to enjoy splashing round in the wet, even so. But during my second session the bike felt so precise, controllable and sweet-handling that I was having a great time despite the rain. I was cornering faster, leaving my braking later — glad that the Brembo Monoblocs gave plenty of feel, as well as stopping power — and winding on the gas earlier and harder out of the turns.

Then I had a biggish rear-end slide exiting the same second-gear left-hander that had seen a Greek rider high-side in the previous session. Clearly even this most rider-friendly and poised of bikes could easily exceed its limits. By mid-afternoon seven riders had crashed. Our final session was cancelled amid fears that Aprilia would run out of bikes for the following day.

So the RSVR Factory’s debut ended inconclusively, and the V4 still has work to do to show that it can be as competitive a production bike as its works-racer variant has shown it can be in World Superbikes. Perhaps Aprilia will give the Factory traction control, to compete with Ducati’s similarly priced 1198S, after introducing the cheaper RSV4-R model (with Showa springs, cast wheels and probably a simpler, non-adjustable frame) that is expected in about six months’ time.

Despite the weather and the crashes, though, the Factory had done enough to suggest that Aprilia’s second major assault on the open-class superbike market will be even more successful than the first. The competition is hotter than ever this year. But the RSV4 was mighty good in the rain, and will surely be better still in the dry. The superbike world has a very serious new challenger.

RSV4 Tech
This bike represents the start of an important new family for Aprilia, who threw huge resources into developing an engine that will eventually power naked and sports-touring models, as well as a base-model R version of the RSV4. The firm’s aim to create the “missing link between track and road” led them to use engineers from both R&D and race teams, and to run sophisticated computer programmes to analyse potential lap times of numerous engine layouts — including V-twin, triple and transverse four — before opting for a dohc V4.

An eight-valve V4 with cylinders at 65 degrees was eventually chosen as the best compromise between engine power — for which a larger angle allows more space for intakes — size and vibration level. “We chose the configuration with optimum performance and mass distribution,” said Piaggio’s bike engineering chief Romano Albesiano. “We wanted to keep the same weight distribution as the RSV V-twin, but make it smaller. The V4 is narrower and produces less vibration than an in-line four, so the higher development and manufacturing costs were worthwhile.”

The 999cc engine’s dimensions of 78 x 52.3mm match those of Yamaha’s latest R1, the most oversquare of Japan’s inline fours. Camshaft drive is by lateral chain to the intake cam, then gear to the exhaust cam, allowing very compact cylinder heads. Titanium is used for the valves; magnesium for the engine covers. A single balancer shaft minimises vibration. The transmission incorporates a six-speed cassette gearbox and wet, mechanical slipper clutch.

Breathing is highly sophisticated, featuring variable length intake ducts and ride-by-wire throttle control. The Weber-Marelli injection system incorporates two injectors per cylinder: one located downstream of the throttle valve for optimum low-rev response; the other in the airbox to boost fuel atomisation for maximum high-rev power. Peak output is a claimed 183PS at 12,500rpm. Pressing the starter button toggles between the maximum output T (Track) mode; S (Sport) which smooths output and limits torque in the first three gears; and R (Road) which gives a 142PS limit in all gears.

Aprilia’s road and race heritage demanded a polished, twin-spar aluminium frame. The RSV4’s is welded from cast and pressed sections, weighs 10.1kg, and is fine-tuned for optimum stiffness, giving 39 per cent more torsional rigidity than the RSV V-twin’s equivalent, but less rigidity elsewhere. The matching aluminium swing-arm weighs 5.1kg and is stiffer than its predecessor in every respect. Most of the 17 litres of fuel lives under the seat, for improved weight distribution.

The RSV4’s key chassis feature is a level of adjustability unprecedented in a production bike. Removable steering head inserts can alter the headstock position and alter rake and trail from the standard settings of 24.5 degrees and 105mm. Rear end height can be adjusted via the swing-arm pivot as well as shock length. Even the engine has alternative mounting points.

This adjustability is largely for the benefit of Aprilia’s Superbike race team, and springs from the race department’s close collaboration in the RSV4’s design. “Some targets such as power, weight and handling were clear to both the R&D department and the racing engineers, but the potential for chassis adjustment was a demand of the racing department,” says veteran RSV engineer Mariano Fioravanzo. “The adjustable frame was more complicated and expensive, and we discussed it a lot. But in the end the racing department got what they wanted.”

The Factory model’s cycle parts match the frame’s quality. The 43mm usd forks, piggy-back shock and steering damper are all by Öhlins. Forged wheels are a kilogramme lighter than those of the Factory V-twin, let alone cast alternatives. Brembo’s radial Monobloc calipers bite purpose-designed 320mm discs. Carbon-fibre mudguards and sidepanels contribute to a claimed weight of 179kg without oil or battery.