[imslow]

I just want to start a new thread to get Branson and Zack started. Though you'll think this is lame.

this is what I know about leaning the bike over going into a corner, and I want to know more.

I've read seomwhere that the reason to hang as far off the bike as you can is to change the center of gravity of the bike to a point that is outside (inside?) the bike so the bike can go faster around a corner as the bike will be in a more upright position. And the reason the knee "drags" s simply to have a reference point as to how far over you think the bike can go based on your position on the bike.

Putting more weight on the front end going into a corner loads the front tire? But then you're taking weight stress off of the back tire? If you're taking weight off of the back, and trying to accelerate (lifting the rear more) isn't that couterintuitive?

wanna know more, I've been through books and mags and noone makes it as clear as you guys can.

Post you lamos!!! Has anyone else noticed caffeeracer is really slow lately?

evil

 

[UngaWunga]

quote:I've read seomwhere that the reason to hang as far off the bike as you can is to change the center of gravity of the bike to a point that is outside (inside?) the bike so the bike can go faster around a corner as the bike will be in a more upright position. And the reason the knee "drags" s simply to have a reference point as to how far over you think the bike can go based on your position on the bike.

Putting more weight on the front end going into a corner loads the front tire? But then you're taking weight stress off of the back tire? If you're taking weight off of the back, and trying to accelerate (lifting the rear more) isn't that couterintuitive?

you really need to read "Twist of the Wrist".
And no, its not a masturbation manual. Keith Code's book. Good stuff.

 

[jbranson]

Scott,
I've read both of Code's books. Good info, although I think the same info can be found in most other books without the mumbo jumbo. Code gets a little too philosophical for me.

Leaning does a whole crap load of things when done right (which I can't do yet). Keeping the bike more upright is only needed if your corner speed is so high that you can't physically lean the bike over far enough otherwise without dragging something.... also with high hp bikes it keep the bike on the center of the tire more in preparation for hard accleration out of a corner.
Aside from that it also lowers the center of gravity making it more stable in the corner.... AND it moves the center of gravity of the bike/rider package closer to the inside radius of the turn...which means the bike tends to swing around the corner likes it's on a string to a very small degree.... I think the technical term is it decreases the moment of arc inertia through the corner... ( like moving flyweights closer to the center of rotation).

Knee dragging is for exactly what you descibe.

You said
"Putting more weight on the front end going into a corner loads the front tire? But then you're taking weight stress off of the back tire? If you're taking weight off of the back, and trying to accelerate (lifting the rear more) isn't that couterintuitive?"

Depends on the bike and traction conditions how much this would be necessary. Typically under hard braking enough weight is already on the front that you don't have to load it.... however...as you get to be a faster rider you will find that each corner is not necessarily a braking situation and that loading the front end keeps it planted and prevents it from pushing (running wide)..again depends on the bike and it's natural weight bias. You also don't want to over weight the front and cause it to lose traction. For the most part at my level of skill I only find myself feeling the need to load the front during rapid turn-in.. keeps the front wheel on the ground and the bike responding to input quicker. Good examples are the "tight ten" and chicane at Loudon.
I'll load the front some coming into turn 3 because our 175's are light in the front and because of my height it's very tempting to keep my butt way far back, the bumps coming into three can cause the front tire to skip off the surface and lock up if it's not loaded nicely..proper braking technique makes this unlikely too.

Coming into the tight left at the bottom of the hill at Frontier land was the hardest braking I've ever done on a vintage bike...I was skipping the rear wheel on downshifts and right on the border of the front suspension ceasing to work..and you can feel it when that starts to happen.

This was the first year of vintage racing that I've felt a lot of these issues that I'm more used to noticing on late model sport bikes.
JohnnyB

 

[aaron]

My front end was not dampening at all this season until frontier land. So I found that if I kept the bike vertical and my body paralel with the ground I could make my body counter what the bike was doing wrong. Some of that is a joke and most of that is true. But it did indeed allow me to keep more corner speed. I do find on high speed corners that when you plant more weight on your knee and pull the bike around a corner I have more control at speed. I've been told this wrong to do and also have heard other people with good lap times doing this as well.

Aaron

 

[jbranson]

I guess a whole lot of it is what works for you and what doesn't. There are numerous ways of accomplishing a task..as long as you don't do something really goofy.

Bear in mind that the reasons the pro's are leaning off is because they are at corner speeds that require a lean angle that would be impossible without hanging off the bike and or they want to get the bike as upright as possible as soon as possible to apply their 200hp to the ground. A bike can only lean so far to counteract the cornering forces...when you run out of bike lean you have to use body lean and move the center of gravity to a point were it counters cornering effects.

I'd say in vintage racing you could limit your hanging off the bike to situation where you will drag something otherwise. I'm at a point now where my lack of skill at hanging off is limiting my speed because I'm limited by how far I can lean the bike over without dragging feet, pegs and pipes.
JohnnyB

 

[aaron]

Wouldn't you say that the pro's are at corner speeds that their suspension and tyres are at the limit, so if you have a shity setup its easy to find its limit?

Aaron

 

[jbranson]

A given corner speed will require a given amount of lean on a given bike in a given corner. If that amount of lean is such that parts drag the ground or the tires run off the "tread" onto the sidewall then you have to do something to reduce lean angle. Hanging off changes the center of gravity so the bike doesn't have to lean as far. However then the pro's tend to use up that corner speed they are allowed due to their hanging and then reach the same point all over again. At that point it's a battle of doing whatever they can to make the bike behave better in the corner...if they can get the suspension to work better then they have more options as far as the line they can take, how deep they can brake, how soon they can get on the gas. Lean angle is pretty much a fixed physical calculation based on your speed, the radius of the corner, the center of gravity of the bike/rider and the camber of the pavement. The battle is to get the tires to adhere to the pavement at the lean angle required to negotiate the corner at the desire speed. Pushing the front...sliding the rear, are all indications that the tires are being pushed beyond their ability to adhere to the pavement. The better the suspension the better the tires follow the surface and the better they adhere, the stickier tire the better it adheres to the pavement. The more you improve suspension, chassis and tires the more lean angle the bike can handle before the tires lose their traction. The more lean angle the bike can tolerate...the higher the corner speed you can maintain.

So yes... I'd say in the case of pro's the limiting factor is the setup/chassis and tires...which limits traction...which limits lean angle...which limits corner speed.

I'd say in most cases the point at which something drags the track on a pro race bike is beyond the point at which the tires have already lost traction.

what was the question again?

JohnnyB

 

[aaron]

You called me a dragon

Aaron

 

[joe c]

i used to have a picture of nicky hayden on his motard with the bars crossed, the back tire smoking, and one knee on the ground. i dont really know that works into your equation of lean angle-vs-corner speed-vs-limits, but i think it might go into another kind of math.


then there is always gary mccoy

jc

 

[jbranson]

Nope...it's all the same math.
Sliding, leaning, hanging are all methods to counter balance the forces of cornering in such a way that you can get around the corner faster.
JohnnyB

 

[paced_haste]

there is simply no way to respond to all of that. but i'm going to try i guess.
much as i love JohnnyB, i think he went about answering one of these questions the wrong way. when talking about "loading up the front or rear in corner entry or exit", there are some things to remember. Scott asked about weighting the front in a corner, and if that was counterintuitive for acceleration. here's the thing; almost no matter how much you try to load that front end up, the weight of the bike is going to transfer to the rear so much that it wont really matter. the most you can do is try to keep some weight forward. on both Pete's bike and my 125 i keep my weight as far forward as i can, for different reasons though. my 125's front end almost wont push, 125s are SO sticky up front that even decel leaned over wont push the front. Pete's bike is ass heavy because it's a vintage street bike, so keeping the weight forward is all i can do. both bikes will spin the rear under acceleration, and it's not from lack of weight on the rear tire.
also, i've got a bone to pick about knee draggin'. it's not just as a reference for how far you're leaned over, it does more than that. placing weight on your knee takes weight off the wheels, which isn't good most of the time, but can come in handy. turn 9 at loudon is an example of a time when you want less weight on the front wheel, but rolling on the throttle is tough because acceleration happens too quickly going downhill. so putting your knee down can relieve some of the stress on the front tire and get away from some of the chatter. i did it on my 125 one time to such an extent that the rear broke loose, which i was NOT expecting...but it was informative to know that that limit existed. also, dragging your knee is fun, i mean come on, that's worth something.
now, professionals and lean angles. yea yea yea, the pros are limited by setup and suspension blah blah blah. tires are what touches the road, so it's all about making/keeping them happy. i think that's a better way to look at it. i'm no pro, but one of the reasons that i lean off, is to keep the bike upright. not to keep footpegs and mufflers from dragging (although i suppose they might), but to keep the suspension upright. when forks are upright, they deal with bumps well, telescoping as they should. when you lean over though, the stress starts to be applied from the side and the forks flex that way, which is bad because there is no damping in effect. so by leaning off and keeping the bike upright, the forks can hit the bumps a little bit more upright. that's the theory i apply anyway. any thoughts?

the pros tend to lean off to the inside, although not always. here's a pic of Mighty Mick doing it his way, which included putting a lot of himself towards the outside of the corner. it's possible that he did it this way one lap, then leaned off the next lap, using a different part of the tire and saving rubber. better? maybe, can't really argue with his results. then check out Tamada.

"Mighty Makoto" (sorry) leans off the other way, probably just because he feels like it. and i don't want to hear, "well he's not as good as doohan" or "he's not leaned over as far". Tamada is as good a rider as there is in the world right now (other than Rossi). point being, i think it's got a lot to do with preference.

 

[paced_haste]

by the way, i have that pic that JC is talking about. but it's on my computer, and i don't know how to post pics that are on my comp already. how do i do that?


Z

 

[imslow]

Zack Rules. i knew I'd get some answers ffrom you guys that made more sense than the goddish Twist othe rist guy.

I like the suspension upright concept. It makes sense.

scott

 

[paced_haste]

the thing to remember is...uhhhhhhhhh. well, sometimes you have to, errr, hmmm, lets see. be sure to, ahhhhhhhh, yea i got nothin' on this one.

 

[jbranson]

Here's me doing the Doohan lean.
Sometimes a corner is so tight and in such proximity to another corner than I end up doing a kind of saloom between them...the only way to get the bike turn quick enough is to literally throw it over on the side....when I do that my upper body stays put, the bike and my lower body lean into the corner. When you "throw" the bike over you gotta have some mass to throw it with...ends up being my upper body. Next corner in the saloom comes up and you stand up on the pegs a bit and throw it over the other way. If I had to bring my whole body down and to the inside of the bike I'd never have time to do it before I got into the turn.
I only tend to do it on really really tight tracks like the Nelson circuit at Shannonville.
JohnnyB

 

[aaron]

I start geting to the other side with the bike pitched. I then counter steer (turn in more) and it pitches me to the other side. Sometimes like at the last setup at Loudon where they made turn 10 even tighter I was touching the brake while in the start of transition to flip the bike over faster. I not really sure how trusting I am of the last thing, but I was doing everything I could get the bike to do what I needed to keep up. My general rule of thumb is to get off the bike as much as I can without being uncomfortable, make the apex the way I think it should be done, and change the radius based on what I drag. I use my knee to gauge lots of things... How much further I can lean over before my foot and exhaust hits, unloading the bikes weight in bumpy corners (not sure if thats good either, but feels right) like the transition going back on to the nascar oval in 10 (or what most people call 9) and to air my balls out during a race. I think it comes down to what works for each person. I have a short torsoe and long legs, no matter what I do my legs stick out comparatively to my upper body. I think its mostly in my head and I think that it works so it probably will.

Aaron

Edited by - aaron on Nov 07 2004 8:41:10 PM

 

[joe c]

in the chicane, i push with my feet on the pegs really hard to get my bike turned. ive even come back in from races and have had my footpeck brackets bent down. there i can actually slide the bike under my ass counter steering it. so for a minute, the bike will go one way, while my body begins to pull it the other. i always thought it was cool. when its one smooth motion, its great, when aaron drives up the inside and scares the crap out of me, it sucks. its definitely not something i think would work in fast corners.

jc

 

[paced_haste]

if johnny didn't have mick doohan on his side i'd say he was full of shit. i tend to lean off the inside of the bike quite a bit, but how do i manage to get through the chicane? i think throwing your body around can help in the tight stuff too. if the bike has to go from full-lean right to full-lean left in a hurry, it's going to get unsettled, especially at the end of the transition when traction is becoming limited. but if you use the weight of your body to counter to weight of the bike falling to the left, the transition can be made smoother. essentially i try to throw the bike over to the left, and i follow...then, as it reaches full lean, i pull myself down towards the road by the weight of the bike, taking up it's energy of falling left. know what i mean?

hey aaron, how do i post a picture from my computer onto this site? it doesn't have a URL.

Z

 

[aaron]

You email it to me and I'll put it up... lke this.

Jeremy and I in the paddock. Notice Jeremys big brain at work listening. Jeremy can change his lean angle with just the slightest movement of his head.

 

[jbranson]

Zack...keep in mind that I am at an enhanced level of skill where many of the amazing things I do might not make sense to you beginners. Mick was over having dinner with us the other night, I showed him your NHIS video...we had a good laugh.

Then I slapped him around and did him in the butt...there by robbing him of his riding powers and transferring them to me.

JohnnyB