Using throttle to control cornering arc?
 

One of the key missed steps in advancing rider skill is getting comfortable using throttle application to control cornering arc while leaned over in a turn.

How are you doing in grasping/mastering this?

Wait, wut? How so?

I use my body to control the arc--go a little wide and dip the shoulder down to tighten it--but I don't know that I'm consciously controlling the arc with the throttle.

Grossly exaggerated here, but need to tighten up arc, carefully chop/reduce throttle input, need to widen arc, give it more throttle, with more throttle the bike wants to come/straighten up.

I try to set up the corner before entry but if necessary, I will use more brake on corner entry... is this a trick question? You're not on the throttle on corner entry which basically determines your arc. Obviously, you can make adjustments with the throttle on corner exit... I don't know, it just seems like an awkward question....

Pretty much my answer too, but I'm also not sure I understand the original question

Interesting question. I don't use it to define my line (arc) through a turn. That is done with visualizing the line, hitting your turn in mark and rolling through on steady to increasing throttle. I use it some on the street if needed and used it extensively when I raced to make quick direction modifications while at high speed with a lot of lean angle. It is (for me) a good way to make corrections or changes when you have too little available traction for brakes or steering input. It is also a way to modify your direction when hanging off without moving your body or putting unwanted input into the bars. For me, it is just another tool to put the bike where I want when other inputs might be inappropriate. The few time I've brought this up with friends they either get a vague look in their eyes or look at me like I have 2 heads, so I figured it was just something that worked for me and STFU on that.
I would imagine that dirt riders use something like this more than pavement guys, but IDK since I don't ride dirt.

Chapter 9 in Lee Parks' Total Control is all about Throttle Control. Basically, he says that you know that you are using the throttle correctly in a turn when the suspension barely moves. That's smooth.

One of the many reasons I like my old GS1000 is that my throttle connects directly with the carbs. When I open the throttle, the piston/needle rises exactly the same as my throttle, letting in as much fuel as my right hand says.

There are no vacuum operated pistons that rise up due to air pressure like the constant velocity carbs on my old CBR1000. And there are no fuel injectors that have a dozen sensors that let in exactly as much fuel as the computer tells it to.

Is my right hand better than a computer? Hell no. I've bogged the engine many times, opening the throttle too fast or being in the wrong gear. One place I think I'm better than a computer is going into and coming out of a downhill corner. I feel that I can transition between the brake and throttle so smoothly that there is little suspension movement.

Strange you should ask. I actually consciously did this while riding this afternoon.

I think in limited traction situations the benefits/application options are diminished.


I find, though, that cornering arc decreases with the input of throttle and increases with throttle reduction.

I must be doing it wrong.

Hmmm... so you are on the throttle entering a corner? I'm on the brakes, sometimes right up to the apex and then I apply the throttle... I don't know, I must be missing something. I'm going to bed, goodnight all!

lol

I use it in everyday riding..especially on long open sweepers. Keeps me at a constant lean without making scalloped turns. High speed twisties...not so much..

try it, you'll like it...

Someone else understands!!!!!

I've tried to explain this to people about the KZ, but they don't get it.

It was something I really enjoyed on the 1977 350 4 barrel Pontiac, too.

I also prefer the slides to be a mechanical connection, but you have to have ridden a bike with those type carbs enough to know the difference. Most folks on here haven't.

Your 77 Pauncho had vacuum operated secondaries unless it had an after market mechanical linkage carb on it. Back in prehistoric days, we used to use screws and such to force the secondaries to open with the linkage instead of waiting for the diaphragm to ease them open on carbs that we could rig it on, like a Holley.

You aren't doing it wrong but you aren't at the threshold of traction.

It should be even more obvious in low traction situations (think ice).

Here is an extreme example but it shows it well.

If he used less throttle, he could hold a tighter line, more throttle pulls him toward the outside of the turn.

http://www.youtube.com/watch?v=mRHoAKn4KnY

In everyday riding i sometimes modulate throttle in long corners at normal highway speeds to keep my line. Its a lazy way to maintain your arc. In high speed situations like racing I am applying all the throttle the rear tire and corner radius will stand. Backing it off at any point will just kill your drive down the next straight. Pause if you must, but dont lift.

Are we discussing drifting in a street thread? Everyone makes corrections in a corner whether they are body position, counter-steer, braking or throttle... I typically enter a corner off the throttle completely and on the brakes then I let off the brakes as I increase the throttle at the apex/exit of the corner. I don't think that I input throttle while entering a corner personally. I realize that I could be doing it wrong.

Throttle on corner entry means you are either going very slow (slower than you could be) or are very skilled. Generally speaking (except for adv riders) you should be done braking before the apex. Then you should pick up the throttle to what is referred to as maintenance throttle. It helps keep the bike and the suspension working properly. If you turn the bike in and simply shut the throttle off and leave it that way you will probably run wide and run the risk of losing the front via low side because of the added weight transferred to the front off throttle. This is of course very dependent on speed. As you continue through the corner toward exit you should be continually and gradually opening the throttle.

Interesting thread. My line doesn't really tighten when I roll off the throttle, but it's because if I'm rolling off the throttle mid-corner it's because I've fugged up and my ass-puckerage is making the thing stand up :lol:

My god.........................
 

...you guys crack me up!

Read the first bloody post, for God's sake!

It is a skill, a technique, just another trick you SHOULD have in your kitbag.

Some of you do it without thinking about it, some of you follow a rote formula....brakes on, slowing, brakes off, initiate turn-in, hit apex, begin acceleration, exit turn........ which is fine on trackdays and the twisties......

BUT....usually I gotta put a lot of miles on to do either.... this is a technique for day-to-day riding when I'm not WFO, to smooth out my arc through less-than-smooth bends at less than max speeds. Like the freeway, the roads leading to the freeway, ect.

Depending on the bike, when I'm droning down the road from point A to B, I rest my throttle-hand index finger on the throttle housing; I can then use the support to fine-tune both my speed and arc through turns without making gross changes.....the name of the game is SMOOOOTH.......

Remember, it's just another little technique to throw in your repertoire.

Thats bass-ackwards from what I've ever heard/experienced.

If I've overshot a corner, I lean harder and give it gas to tighten it up.

BRAKING makes a bike stand up and want to go straight


Unless I'm totally misunderstanding the original statement

:sign: Yes, grabbing brakes will stand the bike up; but we're not talking about braking; we're talking about decreasing or increasing throttle (speed) mid-turn. You don't believe me? Next time you go for a ride find a nice, long constant radius turn, pick a constant speed, and then roll off the throttle without changing anything else; the bike will tighten up it's turning radius; and the converse is also true.

Don't take my word for it...go try it out.....

For the doubting Thomas
 

http://www.msgroup.org/forums/mtt/to...p?TOPIC_ID=311

And a little more math for high-speed turns:

http://www.physicsforums.com/showthread.php?t=88999

And this paper, which is primarily concerns itself with the role of yaw inputs, but explains and models the 6 forces (not including rider position, which is actually a seventh parameter) in the complex role of turning a motorcycle.

http://www.dinamoto.it/DINAMOTO/8_on...ringtorque.htm

:lala: Look.....I paid this Asian enough to buy himself high for a month so I could pass physics III, and struggled enough with dynamics and earned a degree in Architectural Engineering to NEVER make provisions in life to EVER revisit complex dynamics/math

As long as YOU have it all figured out, I’m golden :rockwoot:

Your theory is speed dependent. If you are going to call people out for making posts that are relevent to the track, then you need to clarify wtf you are talking about. Me, I don't do much street riding and don't care to. But I can assure you as I approach T1 at my home track from a terminal velocity of over 170mph and intiate turn in at over 100 if I roll off the throttle and leave it off the last thing that is gonna happen is that my turn will magically tighten. The bike won't like that at all.

How come none of that takes into account weight transfer and suspension movement? It's always been my understanding that letting off the throttle upsets the suspension and loads the front wheel. The weight transfer and centrifugal force is what causes the bike to go wider.

As well, while decelerating, you're still carrying forward velocity which causes the bike to want to go to the outside of the corner. How would you transfer that force by decelerating ?

A. I'm not "calling out" anybody....and this is a street thread....last time I checked....

B. Read what a number of us here said about application (YES, it IS speed dependent...that's what we said...)....it's for the smooth coping with minor corrections on the STREET.......NOT WFO trackstuff. (Although the physics are still the same...but don't tell anybody I said so)

When i want to tighten my line I simply hang my balls off the inside of the bike. My scrotum acts as a sail and....OOOO shuthefuckup!

Really guys why get heated. Lets just discuss. dont assume street or track. We all know you want a smooth increase in throttle from apex to exit on track. But we can all share without shouting down anyone elses ideals.

Re: weight transfer. Remember what I said: using SMALL inputs...."Depending on the bike, when I'm droning down the road from point A to B, I rest my throttle-hand index finger on the throttle housing; I can then use the support to fine-tune both my speed and arc through turns without making gross changes.....the name of the game is SMOOOOTH......."

Slamming shut the throttle will definitely upset things, no doubt about it....we're talking FINE THROTTLE CONTROL... for fine adjustments. Not hobby-horsing down the road.

Argue with me if you want, but it is what it is....go TRY IT.

Cheeze. Same crap happened in the clutchless downshifting thread.....

Now I remember why I shut up here for so long..............

I'll leave you all to debating how many angels on the head of a pin...see ya..........

I still love ya OTB. Got to point out platoniclly cause some on here dont know the difference.

I use my index finger on the brake lever bracket as a brace to keep my throttle smooth. But what we are discussing does work and way better than a major change like a countersteering input.

Don't worry about these guys OTB. If they really knew it all they'd be MotoGP champions.

In your example (which I think was not where this thread was really going) You will tighten up, except at that point you have exceeded the front tires ability to maintain grip and you will start pushing in a straight line. Since the road turns and you are going straight, if you can't gather it back, you will "run wide" as you pass through that part of the track on your way to auguring into the dirt.

But I can tell you that it is a heady rush to push the front all the way through a turn while riding your knee trying to find some traction. Finding it about 6in from the dirt, snapping it up straight and pinning the throttle on a good line out.
Um, that memory is making my fingers get all tingly. LOL

Damn I need to go do a track day.

No you don't. The delicate egos of these younguns couldn't take the blow.


Some of these guys parents weren't even dating when you were ripping up Deal's Gap.

I know exactly what you're talking about OTB. Try it on a 750lb cruiser and you'll see how fast it falls into and tightens up the turn if you back off the throttle a bit and opposite for adding throttle. This is very minor throttle adjustments mind you. And it's really noticable because it's hard to shift your weight and body on a wide cruiser seat so that's the best way to adjust your line. I did a LOT of this trying to keep up with Kerry and Kathy going across the Cherohala Skyway back in May. I finally had to give up when they picked up their pace and quit playing around :lol:

It's incredible how many people on here, frequent riders, are arguing against one of the basic principles of riding. Increasing speed decreases turning radius?!?! That must be why we all slow down for turns, right?:wtfru:

The arguments about weight transfer to the front causing loss of traction only applies if you don't have good throttle control, which the technique assumes you have figured out. Tached posted up a technique everybody on this board should know. If you don't, you should learn it.

Oh well it works for me, I basically wanted to get a good discussion going. I'm not the fastest rider or most skilled rider on this forum BUT I'm always willing to look at ways to improve my skills, add different ones to my toolbox and generally "not limit my self or my thinking"

A. Lee Parks is a dipshit.

B. What works for a twin, doesn't always work the same with an inline four, or a thumper.

C. Did I mention that Lee Parks is a dipshit?

<<<<Backs away, watches heads explode. :lol:

JC

Why do you say that? I've met him twice and he's a real motorcyclist. He may look like a dipshit, but his book is way more simple and easy to understand than Code's two books. And Parks' Total Control class was terrific.

Some riders still believe that the bike is more important than the rider's skill. On steep, downhill, twisty roads, I have caught up with bikes that had twice as much horsepower and a third of the weigh of my thirty-year-old bike with steel frame, bias-ply tube-tires, 35mm air-forks, dual shocks, and an air-cooled engine with built-up crank, mechanical ignition advance, two-valves per cylinder, 26mm carbs, and a centerstand. You don't see any of those things on new bikes, because they've all been improved (except for the centerstand). The best thing I improved was my skills by reading Parks' book, taking his class, and practicing.

By the way, where are these 100MPH sweepers? The highways near me are so crowded and patrolled, it's rare to go 90 on straights.

Asshole owes me money, and no, I'm not kidding.

Code is a Scientologist. I can't make heads or tails out of what he says either. As for Parks' book...meh. I didn't find it to be anymore insightful from what you could learn at an advanced MSF course.

If it works for you, cool. I just don't like the guy because he's a lying cocksucker that owes me money, so I'm biased. :lol:

JC

Come on down! Once you get away from the main highways, the cops pretty much leave you alone around here. Lots of sweepers!

Up here too. 120-150 on Leonard all the way to Grand Haven which I am sure you are very familiar with.

Yep, I used to live about one mile off Leonard on Collindale down the street from Shawmutt Hills... In the Summer, I'd ride Leonard to Grand Haven 3 or 4 times a week.

:ladysman:

Please post pics of that GS if you have them.

And thanks for giving me hope in riding the KZ up to potential. I get so tired of people looking at my bike and thinking it's a slow POS.

It tightens up because when reducing speed you have now given much more time to complete the radius granted you have the same lean angle and the same force to the center.

Well, here's my GS. It was my first new bike, and my first four-stroke. It's lightly modified. The biggest improvement was the Works Performance shocks. Thirteen and a half inches. Half inch over stock, and probably another half inch over the old sagging shocks. That quickened the steering and keeps the skinny tire on the ground. A Telefix brace and Progressive Suspension springs help the forks.

It's got the original calipers with Russel lines and Ferodo GG pads. Unfortunately, they don't make HH pads for it. Stock carbs. I added a jet kit, but at this altitude, it ran worse, so I went back to stock. The original ignition was points, but I installed a Dyna electronic. Also has Dyna coils and solid copper wires.

For your KZ, new shocks would be nice, but they're expensive. Not to lower your hopes for your KZ, but when I ride with my friend on his Gixxer1000, I have to ride like a maniac, just to try and keep him in sight. But that's going uphill. Coming back down, the bike does much better. I've done all the maintenance myself, and it's been a hoot to ride. As Suzuki's first superbike, they way overbuilt the engine. Wish they would have done the same to the frame. Anyway, I couldn't care less what people say about me or the bike. Most are amazed that I'm the original owner.

http://img43.imageshack.us/img43/8729/suzukigs1000.jpg

I put a new set of Progressives on it, 11 and a 1/2, LOWERED it enough so I could touch the ground. LOL

:lol

at where this went

I believe you succeeded, as usual, in one hell of a debate. Way to go! :dthumb:

We have some here too!

It depends on how in control and how near the limit you are.
Rolling on or off the throttle can have either effect.

Wow. So in a discussion, someone has a different opinion than you, so you take a suck and leave? You must be a hoot in real life.

Where are your and OTBs MotoGP champ trophies then?:gofurslf:

I read and have applied the techniques from twist of the wrist, and I find they work for me. A constant or increasing throttle through the turn will keep the suspension compressed, allowing it to keep the bike on a tight arc. Letting off the throttle, even in small amounts, allows the suspension to decompress, making the bike run a wider arc through the turn.

Karl, don't take this personally, but the sooner you realize that ONE BOOK isn't the be-all-end-all of motorcycle riding, the better off you'll be. I'm sure you realize this already, but you seem to be stuck in that mode.

See my prior post. Increasing or decreasing your speed can have EITHER EFFECT... there are far too many variables involved to discuss them effectively on a message board, but I will say this...

Done properly, decreasing speed will decrease your turning radius, all other things being equal and you don't upset the chassis.
Done IMPROPERLY, decreasing speed will increase your turning radius by standing the bike up, making you run wide.

Done properly, (ie, assuming the chassis is stable throughout the turn) increasing speed will increase your turning radius.
However if your chassis is for some reason a little unstable, increasing throttle position will stabilize it which can tighten up the turn.

So in reality, you're all right.... but you're also all stubbornly ignoring the other side of the argument... THUS brings me to why I believe OTB (and others) often give up trying to waste their time arguing on internet message boards, NOT because someone don't like their opinion, but because the other person is too damn ignorant of all the variables that can change the outcome of a given situation.

Wouldn't that same theory imply trail braking causes you to take a wider arc through a turn?

no, because it is still compressing the suspension, not releasing it.

good point Oreo.:yes:

Good point, but you're still arguing only one side of the story.

You said that letting off the throttle allows the suspension to decompress which makes the bike run wide.... but done smoothly, it can decompress the REAR more than the front as the weight transitions forward. This reduces rake and trail, makes the bike inherently less stable, thus more maneuverable and you can lean the bike easier as long as you keep your arms loose and don't transmit all that force onto the front end.

Turning radius is a function of lean angle and speed... reduce speed and as long as you can maintain chassis stability & lean angle, you're reducing the arc of the turn.

So again... it can have EITHER effect. It all depends on whether or not your inputs destabilize the bike & make it stand up & go wide.

One of the things I love a motorcycles and motorcycling is that even the most skilled rider doesn't really, with absolute certainty, understand WHY a motorcycle does what it does. Just the description behind the physics of turning a motorcycle provides enough engineering fodder to fill a book of debate.

Riding really is a mysterious art.

All curves aren't the same either. Going up Golden Gate Canyon, the first curve is a broad, 50 mph sweeper. Less than a hundred feet later is a blind, decreasing-radius, 15 mph curve in the opposite direction. Guess how many cars and bikes cross the double yellow there? There was another one further up the canyon, but they blasted away the canyon walls to make it a 20 or 25 mph curve.

I don't know about curves where everyone else rides, but most of the curves on my roads only last three or four seconds. Then I'm setting up for the next curve. A second or two to downshift and apply the brakes before the curve, one second to lean and keep the brakes on until the apex, and one second to apply throttle out of the curve. Going uphill might be earlier throttle, and going downhill might be longer brake. But except for leaning off the bike and pushing on the inner handlebar, my brakes are what I use to control the cornering arc.

I agree... that is, until you reach the apex, right?

and in this case, my definition of apex is the point at which you stop turning IN and start turning OUT.

How do you figure light braking would affect the suspension differently than decreasing the throttle? Doesn't each transfer weight forward, loading the front forks and decompressing the rear (albeit a small amount)? Mind you, we're not talking about slamming the throttle closed, but subtle changes.

Wouldn't closing the throttle be characterized by decreasing the fast and braking be classified as increasing the slow?

Wouldn't braking have a more cumulative, greater impact on front suspension compression than just closing the throttle?

No, if you want to get technical. There is only acceleration. Some of it just happens to be negative acceleration.


Kinda how cold is just classified as a lack of heat.

Wow this is deep! Considering that most riders only use the front brakes, decreasing throttle would inherently have a greater effect on the rear of the bike, while braking has a greater effect on the front, right? I mean, all things being otherwise equal, wouldn't a 5 mph reduction in speed accomplished by decreasing the throttle have a lesser effect on the front suspension that a similar decrease in speed brought on by the brakes? Obviously ASSuming that you would use the front exclusively. I actually use my rear brakes quite a bit...

Woldn't you agree, though, that there is a difference between just turning off the heat and shoving it in the fridge?

This technique is used once lean angle has been set. We are talking anywhere from a few thousandths of a second to a full few seconds. In terms of throttle, movement is very subtle not abrupt at all to minimize upsetting the suspension.

yup... just as there's a difference between steering with the front wheel & steering with the rear... which is kinda what this thread was originally supposed to be about.

Two things that seem irrationally difficult for some people to grasp.

At any rate, I'm glad you posted this. Hopefully at least one person got something out of it.

I'd also be willing to bet everyone on this board has, at least once, decreased throttle to get through a turn they over-cooked or had to change their line to avoid an obstacle. And anybody that shot off the road as a result either slammed the throttle closed and/or sat upright on the bike when the decreased throttle.

Exactly.... ALL OTHER THINGS BEING EQUAL, turning radius is dictated by cornering velocity... slow down and it tightens up, speed up and it widens out.

No doubt. Everybody has basically agreed that with no variables, the arc of a corner will change in the way you said. :lol:

You guys seem to be the ones stuck on being right about one small aspect of the equation.

In reality, 99.9% of the time any one of us would just steer a little more into the corner and call it a day.

Would you not agree that it is good to know all possible outcomes of your actions? I think its good to know that you can tighten a corner by getting on the gas, as well as slowly closing the throttle. Just as well, I think its good to know that you can overcome the grip on your front tire if you do this wrong when approaching some serious lean angles.

So, I'm sorry for bringing up other aspects of the technique proposed. I didn't mean to try to run anybody off by bringing up some variables in their scenario.

Merely trying to balance the discussion... most people seemed hellbent on arguing that you can't or shouldn't control the arc with an adjustment in speed.

I dunno about 99.9%, but yeah, no doubt that's the first piece of advice that I'd give to just about any rider that wants to know what they should do if they find themselves entering a corner too hot. "Neutral throttle & keep on leaning!"

The main reason why I was talking more about speed controlling the arc than lean, is because that was the original question... It's also how one would typically change the turning radius if you were already at or near full lean. It's also how you want to control your exit.

But I suppose what it all comes down to is steering with the rear wheel like this is more of a racing technique than a street technique. Not that it can't be used on the street, but it's not used as much due to the circumstances. But having the ability to control the turning radius with an adjustment in speed rather than JUST using lean angle IS a sign (to me at least) of a more proficient rider.

One steering input per turn is the goal.

That would be smooth. I remember a video of an interview with a teenage Nicky Hayden after he beat a bunch of experienced racers, and he said something like "I guess I was just smoother than them."

I'd say that half the curves around here are blind. And about 10 percent of those blind curves are decreasing-radius. What messes up many riders is that they are not prepared to change their steering input for the tighter radius.

To tighten the steering, I just push the handlebar more. I'm usually leaning off at my max, so I can't change that. If I'm off the brakes, I don't want to put them on unless I have to stop. And my simple brain couldn't tell my hand to give more throttle when all my other senses are telling me to slow down or lean more.

By pushing on the handlebar more, instead of giving brake or throttle, a rider behind me might think I looked real smooth going through that decreasing-radius curve. And being smooth is important to me even when nobody's behind me.

I'm no guru but love to make others think, and love to pick other's brains when it comes to riding techniques etc...

Lookout Mountain was clear of ice and snow today, so I tried using the throttle to control the cornering arc. On really tight turns, I could only give throttle when coming out of the corner. But that's because I'm so leaned over. On faster curves, I was able to give throttle while in the corner. What happened? The bike went faster.

This wasn't a very scientific experiment, but opening the throttle on a bunch of curves did not bring the rear around, and didn't make the front go around any faster. With the sun at a low angle, I really had to squint and watch the road. Plus, I didn't really notice what the suspension did when giving throttle in the curve. But I assumed it raised up in the front which would worsen handling. As the bike sped up, I had to lean off the bike more. I'm not sure if that was caused by the suspension or the throttle. But it was fun. More snow coming in tomorrow.

Interesting. Not the technique tached was posting about, but interesting. :lol:

Yep, No Worries, go back to the same set of curves, set your entry speed and lean angle to desired taste, have the rpm somwhere between 60-80% THEN infinitely reduce your throttle ever so slightly as you go through and report back what happens. I am too lazy to look but I'm curious what the trail/rake is on your GS1000? The GS has a 130 rear tire out back right?

Reason you had to lean off further when you added more throttle is to compensate for the bike wanting to pick itself up and run a wider line.