2012 Yamaha YZF-R1 vs. 2011 Aprilia RSV4 R APRC [Video]
Microprocessors take on horsepower in this battle over traction control supremacy
Aprilia RSV4 R APRC - Track
Starting with the Aprilia, its 65-degree V-Four engine is the centerpiece of an overall design that focuses on mass centralization and is placed as forward as possible within the lithe chassis. The fuel tank’s smallish exterior appearance is because the rest of it is hidden underneath the seat. This gives the rider a very close relationship with the bars, and the extremely tiny tail section further exemplifies this compact feel.
Ironically, the Aprilia has a slightly longer wheelbase than the Yamaha, coming in at 55.9 inches, 0.2-inch longer than the R1. Power was not the RSV4’s strong suit last year as our test bike made 149.5 hp to the wheel at 12,800 rpm and 70.2 ft.-lbs of torque at 10,100 rpm. Both numbers at or near the bottom of our 2010 literbike combatants. This dyno deficit was largely forgiven once in motion, as its supremely agile chassis allowed the rider to choose lines with complete precision, and the standard Brembo monobloc brakes and 320mm discs were rated highly.
For 2011, Aprilia made a few tweaks to the RSV4 R. Sachs suspension now adorns both ends of the bike, replacing the split Showa/Sachs combination from last year. Additionally, two extra teeth on the rear sprocket balance a taller primary drive ratio. Cylinder heads get improved lubrication and a new cam-chain tensioner, and now the exhaust valve in the muffler doesn’t open until certain speeds and rpm are reached — a change from last year when it would open solely based on gear selection. Lastly, mapping has been revised to provide better fuel economy.
None of these changes act to better horsepower ratings, but our 2011 test bike nevertheless clocked 155.0 hp at 12,500 rpm – an improvement of 5.5 horses over our 2010 model.
On the track, power delivery isn’t as telepathic on the RSV4 as it is on the crossplane-crankshaft R1, though it’s still very tractable thanks to the nature of the V-engine configuration. Its supremely agile and precise chassis allows it to create a gap between its Japanese counterpart in the more technical sections of the track. Where the Yamaha is a sword in the handling department, the Aprilia is a scalpel, capable of carving whatever arc the rider chooses.
“The Aprilia RSV4 APRC is a sharp weapon,” says Content Editor Tom Roderick. “The bike turns in faster than the Yamaha and you have to adjust to its quick handling.” Jumping on the RSV4 after spinning laps on the R1, we needed a few laps to reacquaint ourselves with the handling differences as, on more than one occasion, we had to adjust our lines from those we took on the Yamaha as the turn-in points were too early on the Aprilia.
“The RSV4 feels heavy when pushing it around, but its mass seems well centralized once in motion and feels agile,” says E-i-C Duke. Its curb weight of 464 lbs is 10 more than the R1, though six pounds lighter than our 2010 RSV4 R test bike without APRC. Credit there goes to the lighter wheels and exhaust. Still, its heft is odd considering its diminutive stature and compact ergos. Get it rolling, however, and you’re struggling to figure out where all that weight went.
At five-foot, eight inches, I didn’t have a problem with the Aprilia’s seating position. The Yamaha definitely offers more space, but the only time I wished for more on the RSV4 was in a full tuck, as I couldn’t scoot back as far as I’d like before hitting the tail section.
Aprilia’s arguably at the forefront of rider aids with APRC. Of all the acronyms the system includes, the most important is ATC (Aprilia Traction Control). On the surface it acts like any other TC system in preventing unwanted wheelspin, but the method Aprilia has chosen to achieve this is among the most sophisticated in the industry.
Along with the wheel-speed and gear-position sensors seen on the Yamaha, the ‘Priller’s system also employs a dual-axis gyroscope and accelerometers that measure both longitudinal (front to back) and lateral (side to side) movement rates. Further, the system also utilizes a yaw angle change rate that monitors the amount and the speed at which the rear steps out of line with the front — to date, Aprilia is the only manufacturer utilizing this technology.
All of this information is then sent to a Marelli ECU that computes this data and, like all other TC systems, references it to the set parameters within the system. If it needs to intervene, ATC, like the Yamaha’s TC, reacts by closing the throttle butterflies, then retarding the spark or fuel.
Unlike earlier forms of TC, however, the Aprilia’s system is much more subtle in its operation, at least in the lower settings. Power interruption is gentle, allowing the rider to leave long black lines on the ground if wanted. However, that’s not to say the ATC will prevent a highside; in the lower intervention settings, ham-fisted riders could still launch themselves to the moon if giving it full twist coming out of a slow-speed turn. Intervention in the higher settings is obviously more intrusive than the lower ones, but still quite gentle. Unintentional wheelspin is replaced by the ATC with just enough power to reach the ground without getting the rear end out of line.
Two more features unique to the Aprilia are wheelie control and launch control. On many other motorcycles, the R1 included, the upper levels of intervention also act to limit wheelies. On the Aprilia it’s a separate function. Adjustable to one of three settings (or turned off), the system calculates front and rear wheel speeds, and when a wheelie is detected that goes beyond the set parameters, torque is reduced to the rear wheel by retarding ignition advance. If wheelie control is disabled but ATC is still active, a wheelie can only be carried for 30 seconds before the ECU brings the front tire back to Earth.
Launch control is an entirely new function for production sportbikes and works by limiting revs to 10,000 rpm in the first two levels, or 9500 rpm in level three. All the rider has to do is keep the throttle wide open and worry about clutch engagement. On paper, the system is supposed to provide an optimal launch by limiting wheelspin and excessive wheelies.
In practice, we found that, while it’s still much easier than traditional race starts, the launch control is still jerky upon the first few moments of clutch engagement. If you’re a racer planning to utilize this system, you should probably seek out clutch sponsors. The system disengages when the rider shifts to second gear, reaches 93 mph or turns the ignition key off.
The last rider aid that we wish more bikes came standard with is the AQS (Aprilia Quickshift System). The only nag we have about it, however, is the relatively long kill time in the lower gears, especially the shift from first to second. Otherwise shifting is done quicker and more consistently than any human could achieve. Downshifts are straightforward and mostly drama free, though Duke did notice the slipper clutch “isn’t especially slippery.”
Aprilia’s Traction Control is one of the most fluid and seamless traction control systems we’ve experienced. The interruptions are hardly noticeable and the least bit offensive. For the vast majority of us, the safety net of traction control is one of the few times I’m glad systems are in place to protect us from ourselves. Though it’s important to note that traction control has never claimed to prevent accidents or even highsides. No system can claim that.
Aprilia RSV4 R APRC — Street
Start the Aprilia up in the morning and it settles in to a high idle around 1500 rpm. Further, according to Duke, the V4 engine “rattles around and emits an uneven vibration. From the street riding position the Aprilia’s bars are lower than the Yamaha’s, though none of that matters when trying to see anything from the Aprilia’s mirrors — they’re useless.
With a minimally padded seat, the Aprilia takes no prisoners and makes it known that it’d rather be at the racetrack. Another Aprilia trait, and one which we find rather annoying, is the lack of a turn indicator detent on the thumb switch. This causes confusion as accidental flicks of the switch can trip the indicators.
Both bikes don’t like running when cold, though the Aprilia was the rougher of the two until brought to temp. Tom and I also agreed that the RSV4 required a dedicated rider. As Tom says, “The Aprilia transmits everything that’s going on at both the front and rear of bike directly to the rider.” Simple suspension tweaks make the ride more compliant, but from the onset the Yamaha displayed more civilized road manners.
While the RSV4 didn’t roast our thighs like the R1, cruising through commuter traffic on the Aprilia emits a lot of heat on a rider’s legs. Engine temps go well into the 200-degree range even in mid-60s weather.
The day of our photo shoot in the Malibu hills in southern California followed a rainstorm in the area. Shaded portions of the road provided damp patches perfect for testing traction control on both bikes. And much like they did at the track, the systems prevented wheelspin in their highest intervention settings.
Many of the traits we noticed on the track transfer to the street as well. The Aprilia loves to carve a corner and prefers tight switchbacks over long sweepers. Thankfully front-end stability is great once you find the right suspension settings.
Despite the damp patches on the road, riding in Rain mode wasn’t necessary, as it would take the fun out of the mostly dry pavement. Sport and Track modes only differ in power delivery in the first few degrees of throttle application, but unlike the Yamaha, the most-powerful Track mode isn’t too aggressive for street use.
So far we’ve concluded that the Aprilia is a sharp and focused motorcycle that thrives on cutting up apexes and isn’t for the tall or faint of heart. Its electronic rider aids are incredibly impressive and could set the benchmark for the current crop of liter-class sportbikes.