Anatomy of Ycc-S

ANATOMY OF YCC-S

Shifting by wire while coming through in the clutch

How? And perhaps more important, why?

Those are the first two questions people ask the moment they learn that the FJR1300AE is equipped with electric shifting. How does it work, and why did Yamaha equip that bike with such a feature in the first place?

Wouldn’t electric shifting be better suited for an entry-level bike or a workaday commuter instead of a high-end, high-performance sport-tourer?

As logical as the latter question seems, that isn’t how Yamaha

views YCC-S. “It’s not intended for new or lazy riders,” said Brad Banister, Yamaha’s Media Relations Manager. “Its purpose is to eliminate the fatigue of having to use a clutch in heavy traffic or at the end of a long day but not be obtrusive when the bike is ridden aggressively. We hope it will broaden the FJR’s appeal and introduce more riders to the fun of sport-touring.”

There’s also the matter of cost. Entry-level and economy bikes have very sensitive price points, and the premium that YCC-S tacks onto the MSRP ($1800 on the FJR) would turn buyers away in droves.

Whether or not Yamaha’s marketing strategy with YCC-S

works as planned, the system itself certainly does. For one thing, it retains the very same transmission and clutch components as the standard FJR1300A.

YCC-S uses a slightly modified shift pattern (Neutral is at the bottom rather than between First and Second), so it requires a different shift drum, but all the gears, shafts, forks and ratios are the same.

What differentiates YCC-S are the actuating devices for the gearbox and clutch. Instead of the usual shafts, arms, pawls, pushrods, et al, YCC-S uses two electric actuators-one connected to the shift drum and the other to the clutch pressure plate-that operate in response to commands from the ECU. When the rider initiates a gearchange by moving the foot or handlebar shift lever, it sends an electrical signal to the ECU, which then tells the actuators to sequentially disengage the clutch, execute the shift and re-engage the clutch.

Here’s the cool part. In managing the fuel-injection and ignition systems, the ECU receives all sorts of data from sensors on or around the engine; so it simply employs some of that same information (engine rpm, throttle position, road speed, etc.) to regulate the engagement characteristics of the clutch. If the situation calls for rapid engagement, like when making quick upshifts at higher rpm, that’s how the clutch behaves; if slower action is appropriate, such as when downshifting without blipping the throttle, the clutch engages more gradually. The gearchanges

themselves always take place in milliseconds, but the speed of clutch engagement is regulated according to the need perceived by the ECU.

Other tasks vital to the operation of YCC-S also are managed by the ECU. The engine will not start in gear; the transmission must be in neutral with the front brake applied before the starter will operate. Any time engine rpm drops below 1300, the clutch automatically disengages; it does the opposite when pulling away from a dead stop, beginning the engagement point at 1300 rpm and slipping as needed for a smooth, normal-feeling takeoff. Although Neutral is at the bottom of the shift pattern, there’s no

danger of accidentally ending up there by inadvertently downshifting from First; the transmission will not go into Neutral until the bike is at a complete stop. If the ECU senses that you’re lugging the engine, the digital gear-position indicator on the instrument panel flashes until you make the necessary downshift; conversely, it won’t allow you to make a downshift that would cause the engine to overrev.

You also have to learn the three-second rule when parking the FJR-AE. If you want to leave the bike in gear so it won’t roll on a hill, you turn off the ignition and wait three seconds, after which the clutch-which was disengaged while the ignition was on-will engage.

There are a few other eccentricities inherent in the YCC-S, but the point is this: It works. And damned well, too. Upon their arrival, everyone attending the press introduction of the FJR-AE was a bit skeptical about the electric shifting; upon their departure, they all gave it a thumbs-up. -Paul Dean