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Sunday, June 8, 2008

Part 87 - Riding Skills Series - Clutchless Upshifting

Riding Skills Series - Clutchless Upshifting

Upshifting Without A Clutch

gauge view
Slightly lifting up (preloading) the shifter with around two to four pounds of pressure a moment before your desired upshift allows the shift to happen virtually instantaneously when you slightly let off the throttle. Open the throttle as quickly as you let off, and you'll find yourself magically in the next gear. Immediately release pressure on the shifter, allowing it to ratchet back and index the next gear before your next shift.

Once its fundamental theory is understood, the skill of clutchless upshifting is typically mastered in a matter of minutes. For first-timers, snicking slickly through the gears without the clutch brings a smile of wonderment, as if they just learned a new magic trick.

Surprisingly, the last time this shifting trick was discussed in these pages it brought about a storm of controversy that continues through Sport Rider correspondence to this day. It's actually a time-honored technique that I first read about in a Motorcyclist story about Eddie Lawson more than two decades ago. After that story was published, Lawson earned four Grand Prix world championships, all before the rider-aid wizardry of electric shifters, which, by the way, use the same basic principles discussed here. Anyone who still doubts the advantages of clutchless upshifting is welcome argue with Mr. Lawson, though last time I checked he still isn't one to lose at anything.

Though it's difficult for many to initially accept, upshifting without a clutch is in many ways simpler than the conventional pull-the-clutch-in-while-rolling-off-the-gas, shift-up,let-the-clutch-out-smoothly-while-rolling-back-on-the-gas method most of us grew up using. Instead, simply preload the shifter lightly, then quickly let off the throttle slightly and then back on and-presto-you're in the next gear. Done correctly, a clutchless upshift sounds and feels like that of an electric shifter, and no, it's not abusive to the transmission; countless years of the SR staff racing their personal bikes stand witness to this. The key qualifier here is the phrase "done correctly." Fortunately this is as easy to feel as it is to learn.

First, understand that while accelerating, even mildly, you're able to lightly lift (preload) the shift lever with your toe without causing the transmission to shift or pop out of gear. By lightly, we mean perhaps two to four pounds of upward pressure for a moment before your desired shift point. Then, as the tach sweeps past the desired rpm, simply crack the throttle slightly off, then instantly back on, as quick as a blink of an eye. Don't fully shut the throttle; only close it enough to momentarily reverse the acceleration load on the transmission before returning the twist grip to its original position. Remember to release the pressure on the shift lever after the shift to allow the mechanism to ratchet back and index the next gear.

As Kevin Schwantz teaches at his school, clutchless upshifting doesn't have to be under full-throttle acceleration and, in fact, is best learned under moderate acceleration at partial throttle. Once mastered, however, you'll find that it works at any speed and any rpm. Initially, it takes a bit of trial and error to get the timing and feel for it, and different bikes may require slightly different amounts of throttle change or quickness of movement, but you'll know when you hit the right combination. The shifter should snick into gear with a smooth movement and no notchiness. The bike's acceleration between gears should be virtually seamless.

All this clutch-free shifting business isn't just to impress your friends or passenger, however; there are several tangible advantages as well. As a man who earned his living (and the '93 world championship) wrestling savagely unsophisticated two-stroke GP bikes before the days of engine-management software, Schwantz is able to demonstrate that a well-executed clutchless upshift upsets the bike less than a conventional shift. In my 26 years of experience, I miss fewer shifts when I shift without using the lever on my left handlebar. Exiting right-hand corners with my body hung off to the inside (I'm talking track riding here, since, for several reasons, I do not hang off on the street), it's far easier to just snap back the throttle for an upshift than to make sure my left forearm is in position to allow my fingers to properly manipulate the clutch as well. It's simply one less thing to do, one less thing to think about and one less thing to go wrong.

We're not saying you should forget about using the clutch entirely; there are plenty of situations where it's likely to be to your advantage. But at the same time, clutchless upshifting is a skill worth learning. Don't get discouraged if it doesn't come to you on your first, second or 16th time. Practice it in a parking lot, or on a remote stretch of straight road, at moderate speed in an environment that allows you to give this novel technique your full attention and, by trial and error, varying the quickness and amount of throttle movement, it will come to you. When the situations warrant it, using your new shifting skill should give you all the satisfaction of pulling a rabbit out of a hat.

Experiment with varied quickness and amounts of throttle movement-and remember we're talking a small fraction of the total throttle travel here, so if you've got, say, a quarter-turn throttle, it's going to be perhaps a 16th of a turn or less. Think of it as Kevin Schwantz describes, "as almost just a thought, really," and you'll have the right idea. The satisfying feeling of finally getting it right is well worth the effort.

Get more tips here --> http://www.sportrider.com/

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