At the preseason MotoGP tests this year, and at the first round in Qatar, the Honda RC212Vs were showing a serious turn of speed. In some sessions, the Repsol Honda trio of Casey Stoner, Dani Pedrosa and Andrea Dovisioso topped the charts, while satellite rider Marco Simoncelli (on a factory bike) was often not far behind. Only some gritty riding by current MotoGP champ Jorge Lorenzo prevented the quartet from total domination in the race at Qatar. Rumors of a special transmission in the Hondas began spreading, and although DCT as we know it from the VFR1200 is illegal in the class, there are other quick-shifting gearbox options floating around. Kent asked me if I knew of any developments, and as I usually do when some new technology surfaces, I started looking at what patents Honda had recently applied for.
The United States Patent Office (www.uspto.gov) and Google (www.google.com/patents) both offer some powerful search tools for hunting down patents, but even then it can be a difficult task. Quite often manufacturers utilize the shotgun approach when it comes to securing some intellectual property, at least applying for a patent for seemingly every obscure development. And finding what a particular patent covers is not as simple as reading the title; pages of legalese include statements such as "The invention includes a part A, which is attached to part B, and a part B, which is attached to part A." The topper is this: search for a patent using the term "motorcycle" and you’ll find that many applicants—perhaps intentionally—don’t use that word even for motorcycle-related applications.
While I didn’t find a transmission patent in my search for something to explain the Hondas’ speed, I did stumble upon a couple of interesting—and maybe related—items. The first is an Electronic Clutch Control Apparatus For Vehicle, which details how a sensor and electronic actuator replace the cable or hydraulic actuation of a motorcycle’s clutch. Multiple springs in the lever system are used to mimic the feel of a conventional clutch, while feel and feedback would be considerably more consistent as the clutch changes temperature and wears.
Perhaps more interesting is a patent that is titled simply "Vehicle" that Honda applied for late last year. This patent covers KERS (Kinetic Energy Recovery System; refer to the Electric Superbike story elsewhere in this issue for a full explanation) used on a vehicle for several benefits, many of which apply to MotoGP. To reduce fuel consumption and emissions, the fuel injection on a car or motorcycle is turned off under deceleration. On a bike, this results in excessive engine braking, and a slipper clutch is usually the cure. On the bikes in the patent (actually a dirt bike or scooter, according to the diagrams), the clutch has a one-way bearing that lets the motor go to idle when the bike slows down while a small electric motor/generator provides a modest amount of engine braking. The benefits are two-fold: Fuel economy is increased as it is when the fuel injection is cut, and the energy stored by the KERS under braking can be released into the motor under acceleration, further increasing fuel economy.
How does this relate to MotoGP? Fuel consumption is just as important as power in the class, so any improvement in that area gives a corresponding boost in power. Perhaps more importantly, consistent, controllable engine braking would be a benefit to the rider entering corners. Combine the KERS with the electronically actuated clutch, and you’ve got an engine-braking system that is infinitely more tunable than a standard setup with a slipper clutch.
On the RC212V, however, the most likely performance advantage is said to be a gearbox based on or similar to the Xtrac Seamless Transmission unveiled late last year. Xtrac, a UK-based company that provides transmissions and driveline components to Formula 1 and other automobile racing teams, developed the Instantaneous Gearchange System (IGS) transmission using a ratchet-and-pawl system between each gear hub and the main shaft that allows two gears to be engaged at once but with only one set of gears driving. The IGS transmission is claimed to be lighter, more compact and shift gears quicker than a dual clutch transmission, and has been used in racing—although the company does not state the exact application. That said, Xtrac is the exclusive supplier of transmissions to the Indy Racing League, for which Honda supplies the engines.
Until the next big technological leap comes along—whether it is some space-age material or electronic widgetit appears the question for the time being is not What is the latest and greatest? but rather How can I best use the current technology available? The small advantage eked out by a manufacturer at any given time can be due to the engineers’ imaginations as much as the riders’ abilities or any perceived technology edge. Whatever Honda has done with the RC for this year, it appears the company has that advantage at least for the time being. SR