First it was Ducati with its 1098R introducing the company’s DTC (Ducati Traction Control) to the masses. The (now) somewhat rudimentary system basically measured the difference in front and rear wheel speeds to determine how much power to pull back. Then BMW took it a step further with its own internally branded version of DTC (Dynamic Traction Control) on its groundbreaking S 1000 RR, which took lean angle into the equation via a gyro sensor. Kawasaki was the first of the Japanese manufacturers to counter with its own S-KTRC system on its latest ZX-10R, utilizing complex algorithms to crunch the information from various sensors to actually predict wheelspin before it occurs, and continually adapt when it does. Needless to say, the level of sophistication with electronic riders aids is growing at an astronomical rate.
We were very impressed with the performance of Aprilia’s RSV4 Factory model last year, with the all-new compact V-four handily beating all comers in our annual Bike of the Year comparison test. The engine’s broad spread of power combines with an ultra-quick-revving character to launch the Aprilia out of corners with unmatched authority — but we couldn’t help wondering what the RSV4 would be like with a refined TC system to assist the rider’s efforts at getting the maximum performance out of the new Italian steed.
Well, the wait wasn’t very long. And not only did Aprilia add adjustable traction control for 2011, but also a slew of other electronic rider aids aimed at providing useful tools for the rider to get around the racetrack (and twisty road) as quickly as possible. Interestingly, there are two models in Aprilia’s USA lineup that are equipped with the company’s latest rider aid technology: the top-of-the-line RSV4 Factory APRC SE (the lengthy acronym representing “Aprilia Performance Ride Control Special Edition”, which we tested here), and the RSV4 APRC, which is the standard R model (sans variable-length intake stacks, Öhlins suspension, forged aluminum wheels of the Factory version) with the APRC electronics.
ATC, AWC, ALC, AQS…WTF?
Last year’s RSV4 Factory was equipped with three different riding modes (Road, Sport, Track) that consisted of different engine maps for various conditions. The new Factory APRC SE model includes that same system, but adds an impressive electronics package that is stunning in its breadth and adjustability.
Chief among the numerous rider aids in the APRC package is the ATC (Aprilia Traction Control). Utilizing a two-axis gyroscope as well as accelerometers to measure both longitudinal (front to rear) and lateral (side to side) movement rates, the Aprilia’s powerful Marelli IAW 7SM ECU takes that data along with relative speed between front and rear wheels, gear selected, and — unlike any previous system — the yaw angle change rate (indicating how much and how quickly the rear end is kicked out during a slide) to determine how much wheelspin is acceptable. And unlike most other TC systems, the ATC manipulates the throttle plates — there are no secondary throttle plates, only primaries controlled via the ECU — for initial power reduction, and only resorts to ignition advance reduction as a last resort.
Another innovation with the Aprilia TC system is that it can be adjusted to any one of eight positions (or turned off) on the fly at any time via two small, easily accessible paddles on the left clip-on bar. This means that instead of having to come to a stop (or at least closing the throttle and pulling in the clutch as with the BMW DTC) and then scrolling through the dash menu to get to the TC settings in order to make adjustments, a simple tap with either your index finger or thumb is all that’s required to change the setting.
The RSV4 dash with analog...
The RSV4 dash with analog tach and LCD panel is well-designed and easy to read at a glance. The LCD panel can also be switched to a “Race” mode that displays information more pertinent to track riding, such as ATC and AWC levels, lap time, etc.
The two paddles on the left...
The two paddles on the left clip-on bar allow you to change the traction control levels on the fly at any time with your thumb or forefinger. No coming to a stop and scrolling through menus, or shutting the throttle or pulling in the clutch.
The AQS (Aprilia Quick Shifter)...
The AQS (Aprilia Quick Shifter) worked well at racetrack speeds and aggression levels, but the kill time in the lower gears at average street speeds was overly long, making for jerky shifts.
Brembo monobloc calipers and...
Brembo monobloc calipers and 320mm discs provide excellent power and feel, but were a little more high-effort than we’d like on the track. Öhlins fork’s performance was excellent as usual.
While other TC systems have some form of wheelie control to help optimize acceleration, the AWC (Aprilia Wheelie Control) system is unique in that it is separately adjustable to one of three settings, or switched off. By measuring forward acceleration and comparing the front/rear wheel speeds, the system determines when a “wheelie condition” is present, and reduces engine torque primarily by controlling ignition advance. Of note is that even if the AWC is turned off, the ATC will only allow a wheelie for a maximum of 30 seconds (sorry stunters), and it will inhibit wheelying if it determines that the lean angle has exceeded 25 degrees.
The new Aprilia is also the first sportbike to be equipped with a launch control function to enable easier race starts. The ALC (Aprilia Launch Control) allows the rider to launch at either 10,000 rpm (in Level 1 or 2) or 9500 rpm (Level 3) by limiting rpm to those levels before the clutch is engaged; just hold the throttle wide open, and concentrate on feeding out the clutch for your start. The ALC also limits wheelspin and wheelying while the clutch is being fed out, and then allows a slight amount of wheel lift for maximum acceleration. The ALC automatically disables itself when the rider either shifts into second gear or exceeds 93 mph. The dashboard also features a new “Race” display that features information more important to a track rider more prominently on the LCD panel.
Another rider aid increasingly making its way onto production sportbikes is the quickshifter, and Aprilia has joined the club with its own AQS (Aprilia Quickshift System). Like most quickshifter systems, the AQS adapts its “power cut” time to how fast the bike is accelerating; both ignition advance and injector timing are pulled back to allow the transmission to accomplish the upshift without allowing excess unburnt fuel to damage the catalyzer.