Should You Reverse Your Shift Pattern? - Riding Skills Series
photographer: Brian J. Nelson, Kevin Wing
Exiting left corners, the advantage of not having to sneak your boot between the shifter and the ever-closer pavement while leaned over is obvious. Just press down on the shifter, and presto-the upshift is executed with less chance of scraping your expensive boot or causing drama.
The names often used to describe it sound exotic, even sexy: "GP-shift" or "race-shift" pattern. The most accurate description-reverse shift-seems ordinary, so it's used the least. Don't, however, fall into the trap of many track-riding newbies who, wanting to look like the experts they aren't, automatically switch their shift linkages for the Cool Factor alone. There are very real positives and negatives to running a reverse shift pattern, so let's examine them in detail.
I've yet to see a need for or advantage to running a reverse shift pattern on the street, though I did so for a short time during my early roadracing career just to reinforce the reverse shifting I was learning on the track. Typical of many riders learning the new technique, my imagination was good at coming up with the horrific consequences of getting it wrong in unforgiving circumstances. In the two and a half decades since, I've made such mistakes and paid the price twice, but we'll discuss that later in this column once we build some perspective. For now, I'm confident in stating that any reasonable rider should agree that aside from deciding to stay consistent with what you do on the track, there's essentially no benefit in reversing your shift pattern on the street.
The biggest benefit to a reverse shift pattern on the track is that upshifts are easier to make while you're still hung off the bike exiting a corner. This applies to both left- and right-hand corners, though for different reasons.
Driving off of a right-hander with a GP-shift pattern allows the rider to stay hung off while on the limit of traction and click down on the shifter for an upshift, rather than having to reach downward awkwardly with the outside foot to lift up on the shift lever and possibly upset the chassis.
It's best not to risk upsetting your motorcycle as long as you're leaned over to the point that traction is still an issue. This means that the combined forces of lean angle and acceleration are still able to spin the rear tire. Obviously this is dependent upon the power of the bike and the aggression level of the rider.
Anytime traction is still an issue, it's not a good idea to make a major shift in body position either entering or exiting a corner. This is why you need to set your body position up hanging off for the corner before you begin your heavy braking. Approaching the turn-in point, all that remains is to balance the braking and cornering forces by gradually releasing the front brake as your lean angle increases. Executing a body-position change at the same moment you turn into a corner often has the unintentional result of affecting your steering input, requiring a correction and upsetting the chassis. In extreme situations it can also overcome front-tire traction and result in a lowside crash.
Exiting corners near the limit of traction is also a delicate balance. Often riders coming off of corners seem in a rush to center their body position back up on the bike, usually to get into an aerodynamic tuck. If you're feeding in as much throttle as the rear tire will allow, leaving the tell-tale arcing dark line off the rear tire as you go, the last thing you need is to put another input into the bars or the pegs. It can upset that delicate balance on either the churning rear tire or the lightly loaded front tire with its nearly fully extended front suspension; the first scenario may result in a spectacular highside, the latter a merely frightening tankslapper.
So what does reversing your shift pattern have to do with the above situations? It makes upshifting while exiting corners much easier, especially if you're hung off to either side of the bike. If you're exiting a left-hand corner and need to upshift while still significantly leaned over, it's far easier to simply press down on the shifter to change up a gear than it is to risk slipping your toe under the shifter, which is now closer to the ground since you're leaned to the left. Former World Champion Kevin Schwantz, who never made the switch to race-shift pattern in all his years of racing and now coaching, rationalized, "There was only one track with a series of lefts that I needed to upshift in where it was an issue, and I figured, 'Well, Alpinestars does give me free boots; I suppose they can afford another pair . . . '??" Aside from the risk of merely dragging a boot toe against the pavement, however, there's also the possibility of initiating an upshift before you intend to. And if you aren't cracking back on the throttle (and clutch, too, if you're not performing a clutchless upshift) when the transmission changes up, that can add a bit of unwanted excitement as well. An electric shifter that momentarily cuts spark when the shifter moves up lessens the risk of a crash but still makes for a tense moment.
Exiting right corners is less perilous, but here the advantage is that it's far easier to toe the shifter downward while hung off to the right than it is to reach under the shifter and toe it upward. This was made quite clear when riding Road Atlanta, where I taught for years at the Kevin Schwantz Suzuki School. The corners leading onto the longest straights at that track were right-handers, and those are the corners most important to get right for a good lap time. Running a GP shift (which we all especially liked to call it to rub in the irony of our GP World Champ boss who ran the lowly street shift) was a definite advantage and far less physical for the rider.
Since most downshifting is done with the bike upright, the fact that lifting up on the shifter to change down gears is a bit more work than on the conventional street shift pattern is offset by the advantages of using a race-shift pattern exiting corners, where more time is made on the track.
If we maintain that pressing down on the shifter is less delicate work than lifting it up, then reversing the shift pattern must make downshifting at least somewhat more difficult. The difference here is that most downshifts are executed with the bike straight up and down rather than leaned over. While the wise rider shifts his weight off to the inside of the corner well in advance, the upright bike makes the downshift maneuver less tricky. And as Editor Kunitsugu pointed out when we discussed this piece, the rider's body is being lifted or rotated forward (the same motion we apply to the shift lever) under braking anyway.
So what are the downsides to it? They are mostly obvious. First, there's the need to remember that not all bikes can be converted to reverse shift, unless you only ride your own bike and don't ride dirt bikes (which due to their lack of a shift linkage, among other reasons, don't run reverse shift patterns). If you're fortunate enough to ride a lot of bikes, like magazine road testers and track-school instructors, you need to always be careful to remember which way the bike under you shifts or risk making The Big Mistake. Take it from me, this is not something you want to learn from firsthand experience. I've made The Big Mistake not once, but twice. (I can be a slow, painful learner at times.) Both crashes were, of course, highsides, and both occurred on the track (thankfully with an ambulance nearby at the ready). Both times I allowed myself to be distracted (once by a new onboard radio system and another time by a fellow SR staffer who was running counter-course direction doing photos while I was performing the test's official timed laps-I know; don't ask what we were thinking), let my brain slip into racetrack mode and executed an unintentional clutchless downshift while exiting a corner hard on the throttle. The results were both predictable and spectacular. The first situation ended with me in the ER for X-rays and a STAR School Suzuki TLR1000 being totaled; the second resulted in the launching of myself and an older Suzuki GSX-R1100 off the crest of Willow Springs' turn 6 hill. Amazingly, we both got back up, brushed ourselves off and carried on-the damaged-on-one-side Suzuki even making the cover minus one mirror.
Occasionally it can make for an entertaining story. One of Schwantz's early attempts at running a reverse shift was when paired with a Japanese teammate for the famed Suzuka 8 Hours endurance race. In the heat of battle Schwantz unintentionally backshifted his priceless GSX-R- based racer on the back straight, triggering immediate and catastrophic damage. "After they brought me and the bike back in the crash truck the mechanics pulled the off valve cover, and valve springs shot out in every direction," he recalls with a mischievous grin. "They looked at me suspiciously and said they'd never seen anything like that before. I told them, 'I don't know what to tell you; it just let go.' That was before data acquisition, so I got away with it."
For those who ride multiple bikes on the street and track, the most common compromise is quite logical; run street shift on the street and race shift on the track. As you can see from the above example, however, there will be times when it can still catch you out. In the end, make your decision on shift pattern carefully, realizing that just as with riding itself, there are very real advantages and risks involved. And only you can decide which risks you are willing to take.
From --> sportrider
No comments:
Post a Comment