racer
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Two thoughts:
I don't think this will be very popular discussing other teacher's techniques on this website, but I seem to recall hearing Freddie Spencer mentioning on TV that since trail braking steepens the bike's steering geometry, it allows the rider to change direction more effectively (i.e., run a tighter line to change direction quicker) and, hence, get on the gas sooner.
Another thought is: perhaps a reason why fast guys trail brake is to carry their speed from the previous straight longer by compressing the braking area into the shortest possible distance (at a later point) as close as possible to the optimum point where re-accelerating should begin.
Hey HRC-E.B.,
I think there are different ways to approach trailbraking. It doesn't necessarily have to be used in conjunction with late braking. And it certainly is useful in specific circumstances like decreasing radius turns or outbraking an opponent. However, at the end of the day, I agree with Keith that until one is very solid in the basic fundamentals without it, trailbraking will complicate and slow the learning process.
The bottom line is that while being on the brake may steepen the steering angle, it also increases stress on the contact patch reducing traction and, by defnition, dictates a slower entry speed and slower, not quicker, turn-in in with a more shallow entry line. And, in most circumstances, I believe the goal you describe can be accomplished with more efficient techniques that have been discussed at some length here.
racer
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Hi Avih!
Welcome to the forum! It's great to meet you!
I really enjoy the international "flavor" here, being able to connect with riders from around the world to share riding experiences, discuss riding techniques and especially Keith Code's teachings.
I first learned to ride on a Yamaha TY 80 (trials) and DT 100 (enduro) thirty years ago and bought my first street bike, a Kawasaki LTD 440 in 1983. In 1985 I was given a Kawasaki 600 Ninja as a perquisite "company car" and bought a GPz 750 for road trips a year later. One of my first trips was spectating the AMA Superbike event at Mid-Ohio where I had an epiphany and realized that my life would not be complete without going racing. A year later I signed up for Keith Code's California Superbike School and the rest, as they say, is history.
I attended Keith's schools about half a dozen times or so, bought my first race bike, a Yamaha FZR 400, in 1990 and devoted myself to racing. Soon, I put a 600 engine in the 400 frame and a couple of years later I bought a 125 GP bike, fell in love with two-stroke GP's and attended Keith Code's 125 GP school. After a decade of racing, I used my experience to tune GP bikes for several national championships. I currently work for a motorcycle dealership here in Pittsburgh, PA and am looking forward to attending the new and improved Keith Code schools this summer.
Keith Code's books and schools have not only enriched my riding life, they have saved my life countless times and I am commited to paying it forward, so, please let me know if there is anything I can do to be of assistance.
Cheers,
racer
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For starters, Keith shows students how to use the body to maximize their ability to turn the bike using the least amount of energy. You learn the pivot turn, the hook turn, the knee to knee...among other things.
I'm familiar with those terms and concepts that are published in Keith's books and available for free at the public library. In fact, the copy of Twist II I've been referring to for the past several months belongs to my local library. If and when somebody requests it, I'll need to return it, however, I suppose my point is that I find something mildly disingenuous about hosting a public forum where the only participation by those "in the know" consists of undefined "buzz words" or vague references to secrets that can only be obtained by attending the school session which is simply not affordable or even possible for most people. Which is why the books (and I would think this forum) are out there in the first place.
The bottom line is that it, our "sport", is a matter of life and death and I have a hard time witholding information that will save someone's life for a few sheckles (or pieces of silver), especially if that information is availble to the common man for free. I'm not looking to be a guru or profit.
At the end of the day, perhaps those who do attend a school session could be given a password for a "members only" forum where only those who were able to afford the school session might speak in private thereby protecting the secrets of the inner sanctum... ?
Or would it be better to have open discussion of their experiences as there really is no substitute for the real thing and having students show up already versed in the concepts might greatly improve their results and the stats of the school in general and... what a pleasure for the coaches that experience would be, eh? Personally, I think reading the books should be a pre-requisite for attending the schools.
You should try Level III Racer...Indeed. Although I attended the school many times between 1988 and 1995, there are certainly new aspects I look forward to experiencing and soon will be unless Mid-Ohio is already full this summer... now that I can afford it.
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You mention skis. Now that makes sense. The lead edge followed by the trailing edge because it's a solid piece. Turn that leading edge and the rear edge must pivot around the lead edge, thus pushing snow away from it.
I'm not sure I am following you here.
Snow skis have a curved edge or sidecut (when viewed from above) that allows the ski to bend when leaned over on edge creating a curved edge that carves the snow. The more you lean the ski, the more the ski bends and the sharper the curve of the edge in contact with the snow, hence, the tighter the ski turns.
Mogul skis are softer with a deeper sidecut to allow really sharp turns between the bumps.
It's a less precise process in powder than on hardpack, but, still the same basic action.
If the ski does not track precisely, say on ice, in powder or during less aggressive or lazy skiing, or with "beginner" skis with less sidecut performing a "snow plow" into a "step turn" or "christie" or simply more of a sliding style, the rear may tend to slide and "rotate" around until it catches and the ski begins to carve. This sliding technique is useful in many situations, but, I guess I am thinking of really good skiers (like racing in good conditions) who utilize the sidecut to really carve the ski.
Anyway... if one is sliding more than carving the ski, then more velocity will cetainly increase the radius of a turn. But if the ski is carving, then the lean angle determines the radius. And the faster you go, the more you lean and the sharper the ski turns... until you slide.
Is this what you are thinking of?
Anyway, the rear tire may be tracking "off radius" or off center on a tangent so to speak that might account for the increased turn radius or maybe the tire is squishing or rolling the carcass away from the edge effectively creating a larger rolling radius... these seem to be the best two ideas I can come up with. I'm about ready to throw in the towel and do some research on Google.
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Either the tire is "creeping" or semi-sliding and tracking less precisely or the contact patch is effectively a larger radius. If the front does not affect the direction at a stable lean angle, I don't know what else it could be.
Does nobody else have any thoughts on this?
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If you take Level III (which I would highly recommend that you do) you will learn how to maximize your connection to the bike and by extension help you appreciate the reason why the bars and rear sets are where they are.
Ah, come on young Kevin! It's not nice to tease your friends!
DISH!!
How did Level III help you appreciate why the bars and rear sets are where they are?
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OMG - I started a monster.
But a fun monster to be sure!
from experiments in the labratory I can tell you that the impact of hanging it out is huge. The whole hook turn thing has a dramatic effect on the bike. It was fun to enter turns with my shoulders and head 'high' and then as I passed the apex to drop them down low. the change in my line was dramatic.You mean you keep your head and shoulders higher to quicken your turn-in (hook) while establishing lean angle... then lower them to reduce the lean angle (maintaining radius) enabling more throttle application? Is this a technique taught by the coaches/classroom?
Have fun modeling this.We will, we will!
BTW - Lean Angle != turn radious...for a given velocity.
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My real test is if I'm able to roll off the throttle to maintain my line.
Roll off to maintain your line? Huh?
Again, I know this isn't good practice or technique, but it seems to be something which happens to me at one point or another during a track day.Actually, it's called a survival reaction, not a technique. And it's a bad deal because it makes the bike run wide.
I know that its correct that rolling off the throttle will not tighten the line but at a recent track day I was running wide on a very tight turn, rolled off the throttle (unthinking survival reaction) and the bike tightened its line. It did, I know it shouldn't but it did and no I didn't adjust the steering, not conciously anyway. How is this explained.Consciously or unconsciously, actively or passively, you probably leaned in further when you rolled off. If you had been at maximum lean angle when you did that, you would have ridden off the edge of the tire... or run wide.
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I'll have to devote more time to work it through, but, it sounds good to me.
Not to be a piddly pedant, but... would it be better to label rider and bike mass rather than weight?
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An instructor at a local riding school recently told me that a rider must apply slight pressure to the bars to maintain lean angle under acceleration (to prevent the bike from standing up?) and that hanging off with your upper body just the right amount will create equilibrium without applying pressure to the bars. I have not had the opportunity to play with this. And I don't know if it has any bearing on the question at hand.
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Alright, even though there is more cornering force applied to the suspension and at the contact patch, if the bike is accelerating, the suspension actually extends rather than compressing as the chain pulls the swingarm down like a lever forcing the rear to rise. And the front gets light and tries to rise under acceleration as well (the beginning of the wheelie process).
So, the front fork does not compress under acceleration in a corner, even at relatively low acceleration of 60/40 and higher relative cornering forces.
So... the wheelbase gets a tad longer and the fork gets longer so maybe the front wheel turns out due to the geometry ... but the front is still merely trailing under acceleration. The rear wheel is in control.
Could it be gyroscopic precessional forces? The rear wheel will try to turn opposite the direction of the lean if it is lifted... or merely torque attempting to lift the lean angle is applied at the rear axle. Nah.
The rocker, the sidecut... it has to be a physical matter of the effective radius of the rear tire. Has to be. Or it is slightly sliding, ie. not tracking precisely.
OK... the rear wants to stand up, is trying to stand up more at higher speed. Newton's laws and all. So, as the bike is accelerating, we have to apply pressure at the bars to maintain the same lean angle. But when we are merely carrying more speed to start with and maintaining the same rate of acceleration (60/40) at the same lean angle, what is different?
Either the tire is "creeping" or semi-sliding and tracking less precisely or the contact patch is effectively a larger radius. If the front does not affect the direction at a stable lean angle, I don't know what else it could be.
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Hi fastlane,
Back in the olden times of the original Keith Code school v.1.2 (circa 1986 or so), when the 600 Ninja was first introduced, Keith elected to install aftermarket handlebar kits called "Storz Superbike Bars" on the 600 Ninja school bikes. These bars were higher and wider (like a dirt bike) and provided more leverage due to the wider grip position and were easier to get "behind" (instead of "over") providing still more leverage from a more natural riding position. Many of the most famous fast superbike racers at the time (Bubba Shobert, et al) were using Storz bars and, after getting comfortable with what felt like a motocross handlebar on a cafe racer, I found them to be an amazing advantage. In fact, after getting used to the Storz bars, going back to the stock clip-ons on my street 600 Ninja was really uncomfortable and made fast riding (quick flicking) physically more demanding and difficult from a practical standpoint.
I suppose in the end it is a matter of personal preference. If you are looking to gain that last second of laptime due to aerodynamics (can't get behind the bubble) or can't get your body position long and low when hanging off, then maybe the lower clip-ons will be better for you eventually or in the long run. But, frankly, for now, for your size and strength, I think wider/higher bars might provide a significant performance advantage with the increased leverage.
Just my nickel,
racer
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OK, it's quite late and I am fading fast, but... to review...
I have been attempting to isolate downward force at the front to use as an analogy for increased downward force on the suspension in general due to increased cornering force when carrying more speed through a corner. And also attempting to define and isolate a state of equilibrium (from the forces of forward acceleration), ie we are not increasing speed or acceleration through the corner. We are still at 60/40 r/f weight distribution... just at a higher speed. 60/40 at 75 mph compared to 60/40 at 60 mph. (60/40 @ 75 mph should carve a wider arc than 60 mph.)
We have a given from tweek that lean angle remain the same as velocity and radius increase. The bike is not standing up with less lean angle to describe a wider radius arc.
With ice skates and snow skis, this lean angle vs radius is mechanically determined and tweek's original idea (the title of the thread) holds true. Lean angle determines radius. Whether discussing the ice skate's "rocker" or the side cut of the ski, the radius is predominantly pre-determined by lean angle and the relationship between lean and radius is directly proportional for all speeds. The faster you go, the more you must lean to balance and the tighter your line will be. Not so with a motorcycle. While lean angle and radius are mechanically related, that relationship is affected by speed. You can go faster at the same lean angle and vary the radius of your turning arc.
So... the question is why does the bike run wide merely from a higher speed and consistent lean angle?
If we start with the fact that the rear is responsible for stabilizing the bike and/or the direction of travel while leaned over... then we probably should not ignore this as a source for what causes the bike to run wide under increased cornering force.
So, when the tire is leaned over, the contact patch is not symmetrical. It is conical (cone shaped) like a styrofoam cup rolling on its side. The base is smaller than the top lip hence it rolls in a circle. So, does a styrofoam cup roll in a wider radius circle the faster you roll it? I don't think so.
The bike is not standing up but what could make it act as if it were? Might the tire deform more under the increased cornering force... the faster you go the conical shape of the contact patch changes thereby altering the path? How would the contact patch change? Bigger? Would the tire carcass actually set or roll further up toward the center of the tread creating the same effect as if at less lean angle?
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I cant wait for saturday. all my stuff is packed and the plane leaves tomorrow morning. I plan to spend some quality time in Mr. Barber's museum and watch my friends who are doing the two day camp.
anyway - I'll get to work on the stuff this thread has been about from the beginning: turning the bike like a wild man.
Have a safe journey and great time, tweek! We'll be expecting an Earth shattering Ka-Boom of riding epiphanies upon your return!
I really envy you getting to ride Barber, dude. It looks like an AWESOME track on the AMA race tape I've been watching. I suppose I'll just have to settle for being patient while waiting for my birthday... at Mid-Ohio in August.
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The funny thing about this link is Keith did all this for YEARS to research his books. (And still does) I'm sure he could easily shed some light on the question we're trying to answer. But that would take all the fun out of it.
Exactly!
I'm glad you understand.
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Wow. Thank you for all of that. I'm gonna need some time to digest it all. But all of it is familiar.
What sort of lean angles were you using? Did you ever try letting go at steep(er) lean angles? How tight were you turning at 30 mph? How leaned over?
PS - I am not encouraging you to have an (-other) accident here... lol. I'm sure your ribs are still sore.
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Actually, I think a hook turn done well is a sharp kink. Check out pages 59 and 68 in TOTW II.
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And does this mean that NOT rolling on the throttle while exiting a corner is okay too AS LONG AS I just turn the bars right more?
No. Rolling on the throttle to keep a 60/40 weight balance front to rear stabilizes the bike, establishes and maintains your line (turn radius), and provides maximum traction. And the added advantage of lifting the bike to exit the turn is being able to add MORE throttle to go faster.
Not rolling on the throttle will see the bike run wide, reduce traction and destabilize the entire machine.
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I was reading over some material and I think I might have been mistaken wrt the theory of a bike counter-steering up by simply being off the gas... as opposed to braking while leaned over.
That would fit in better. Still mulling the rear being responsible for steering while leaned over. I get the idea that the front is merely following along... as long as you are on the gas. But I can't get away from the idea of the front taking over off the gas, ie the steering follows the weight. And maybe that is the rub.
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The critical bit is being "on the gas" as you cross the dip more than "having speed" per se. You can be on the gas (60/40 or more) without being "fast". The main point is getting weight off the front.
I do not recall the "vertical as possible" in regards to crested turns in TOTW (and I don't have a copy at hand) but it makes sense from the perspective of "as possible". If the crest is near the exit, get your turning done earlier, if it is right at the entry, you might get your turning done later. If it is in the middle, you might craft your turning before and after so you aren't at max lean as you unload over the crest. I honestly can't think of a turn like that on the circuit but it would be a challenge. If you have enough power on tap to get the front off the ground, you might stay in the gas and carry the front wheel over the crest without losing it, if you follow my meaning...
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Thanks for those links, tweek. They help to see where the track goes and they give a good view of other riders doing it right. Not sure what the guy with the camera was up to. His lines were all wrong. Maybe he was doing that to get cool dramatic footage of passing and being passed perhaps? Anyway, to anyone who watched that: do not use the camera bike as a guide!
My boss brought in a video tape of the AMA races from Barber and Fontana last week. I watched part of it playing in the background at work Saturday and the camera angles at Barber looked great. I can't wait to borrow it! (Yeah, I have a pretty cool job (and boss)!) Anyway, perhaps we can find a torrent of that broadcast before you leave?
Good luck at the school!
racer
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Racer, I have a GSXR750 and I'm 6'1" with a 33 inch inseam. I'm going to install the Stomp Grip this week and see how it goes.
I probably won't be able to find out if I'm doing it correctly until I go to the track in August and September.
Why not? You don't have to be dragging a knee to lock on.
My real test is if I'm able to roll off the throttle to maintain my line.Roll off to maintain your line? Huh?
Again, I know this isn't good practice or technique, but it seems to be something which happens to me at one point or another during a track day.Actually, it's called a survival reaction, not a technique. And it's a bad deal because it makes the bike run wide.
Until then, I have time to practice the [proper] technique on the street.Yes you do.
Thanks...No worries. My pleasure.
Good luck.
Helibars Clip-ons
in School Questions/General Discussion
Posted
Dear Kevin,
Please forgive my "off the cuff" remarks made over morning coffee. In hindsight, perhaps my post was somewhat less than skillful wrt my intended goal(s). I meant no insult.
That said, your remarks addressed to me felt a bit condescending and patronizing and seemed to imply that I lacked the experience to grasp what you were not saying by pointing to the fact that I had not attended "Level III".
I couldn't agree more. In fact, that is one part of my point skillfully reduced to a single sentence.
I am quite familiar with the teaching techniques, style and spirit of Keith Code's school, even if certain techniques have been refined over the years since I last attended. And, after many classrooms and personal coaching sessions with Keith, Dylan, Cobie, et al, I wholeheartedly agree that there is no substitute for attending an actual school session.
However, in my opinion, I think it is quite possible to explain in plain English (your words)... "the reason why the bars and rear sets are where they are."
Or... "how to use the body to maximize [the] ability to turn the bike using the least amount of energy."
And "buzz words" like ... "pivot turn, the hook turn, the knee to knee...among other things."
However, that is only my opinion and I suppose what seems a simple matter to me might not seem so simple to everyone.
Respectfully,
racer