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Body Positioning (hanging Off)


CHAOS

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1 N = .224 lb

 

 

1 kg of mass weighs ~ 1.63 N or 0.36 lbs on the Moon.

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Personally, i think you could have gotten your point across without showing 1/2 of a guy's naked ass.

 

lol

 

 

 

I agree that the most mass is in the upper body and the upper body should be off the bike. Leaving your head over the tank or even almost to the point of "kissing" the outside mirror doesn't do much (if anything) for lowering the CoG.

 

But, the question about being more upright or laying flat/low is a good one.

 

One of the guys i showed on the first page (the guy who has sparks flying behind him) is a co-member of a different forum and a school that he attended actually taught them to stay more upright instead of being low and against the tank. They taught him that while being low may "look" faster, you are better off being a little more upright.

 

He said it works. Obviously "works" is a relative term and what he probably meant was that it works for him. But this guy is no squid or noob, he is a WERA "Expert" racer and has been for years.

 

Note that he also agrees the upper body should be off the bike and to the inside to reduce lean angle of the bike, but he feels that being off the bike but being more upright is better.

 

So what is yall's take on it? Low with upper body against/beside the tank or upright.

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Ok, so we have established that it is better to have your body to the inside to reduce lean angle on the bike. So from reading the last few posts (sorry, i made my post without seeing page 3) i have gathered that it is better to be back in the seat which will allow one to be more parallel with the bike.

 

So in summation:

 

Butt back in the seat a little bit.......

 

Upper body off the bike, low and to the inside.

 

What else did i miss?

 

(i want to take something from this thread and i dont want the good points and suggestions to get lost in everything else....)

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Personally, i think you could have gotten your point across without showing 1/2 of a guy's naked ass.

 

lol

 

Er...sorry. I was playing with the BBCode and got a little carried away. It's like a front, back, side view of the human body thing going on.

 

 

 

I agree that the most mass is in the upper body and the upper body should be off the bike. Leaving your head over the tank or even almost to the point of "kissing" the outside mirror doesn't do much (if anything) for lowering the CoG.

 

But, the question about being more upright or laying flat/low is a good one.

 

One of the guys i showed on the first page (the guy who has sparks flying behind him) is a co-member of a different forum and a school that he attended actually taught them to stay more upright instead of being low and against the tank. They taught him that while being low may "look" faster, you are better off being a little more upright.

 

He said it works. Obviously "works" is a relative term and what he probably meant was that it works for him. But this guy is no squid or noob, he is a WERA "Expert" racer and has been for years.

 

Note that he also agrees the upper body should be off the bike and to the inside to reduce lean angle of the bike, but he feels that being off the bike but being more upright is better.

 

So what is yall's take on it? Low with upper body against/beside the tank or upright.

 

IIRC, when the body is held upright and/or butt close to the tank, you can end up in a more "rotated" position with less actual mass off the bike. Just by being upright, you raise the mass and bring the upper torso/shoulders closer.

 

Bottom line, the more upright you are, the higher your Center of Mass. And, from my point of view, lowering the mass is the main priority to be able to carry more speed at a given lean angle. Make sense?

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Ok, so we have established that it is better to have your body to the inside to reduce lean angle on the bike. So from reading the last few posts (sorry, i made my post without seeing page 3) i have gathered that it is better to be back in the seat which will allow one to be more parallel with the bike.

 

So in summation:

 

Butt back in the seat a little bit.......

 

Upper body off the bike, low and to the inside.

 

Yeah, that's my take on what the school is teaching.

 

Thinking about why is the fun part now.

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Hey Racer,

 

Regarding your points above, if we could get some photos of guys that do put their upper body over the top of the bike, and compare that to guys that don't. Bayliss and Abe used to be really noticable examples, and Abe was famous in GP's for leaning the bike over further than anyone else (there used to be pictures of him scraping fairings).

 

C

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Here is another example. Nicky is straight up and down with the bike...he isn't hanging off at all. His bike and obviously his tires are different than mine.

 

Is that the major difference? If your tires are good for 60+ degrees of lean angle do you not have to get off the bike as much...and you can simply lean over?

 

Nicky_Hayden_Valencia_02.JPG

 

Honestly, I think Nicky has finished the corner at this point and its heading down the straight... ...look how far his knee is from the tarmac and the rear tire is clearly tracking to the rider's right. But there is something to your point where, with MotoGP level equipment, there comes a point where the lean angle causes the edge of the bike and the rider coincide with a single plane defined by the road's surface! It starts to look very much like the rider isn't hanging off anymore! Ah, this is a domain reserved for Keith's private sessions!

 

Here's a shot of a guy at Summit Point showing what can be done on street tires:

 

IMG_0754.jpg

 

Does he need to hang off that far? Maybe not, doesn't look like the bike is in any danger of dragging. Nevertheless, you have to be impressed! I guess the real measure of success is lap times...

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So, just out of curiosity, what metric would you use to express the weight of 1 kg of mass on the Moon up there in TO?

 

Newtons (N)

 

Would you tell a grade school student that weighs 100 lbs on Earth that they would feel like they only weighed 16 lbs on the Moon? Or would you only express weight on the Moon in terms of a force/acceleration formula for the child? ;)

 

A 100 lbf student on earth has a mass of 3.10809 slugs(mass in SAE) That same student exerts a force of 444.822 N on earth (force ISO) If a 100 lbf student weights 16 lbf force on the moon he/she still has a mass of 3.10809 slugs.

 

Our earth bound perception of mass is actually the force of that mass due to the gravitational attraction of the Earth's mass. This is a major cluster f*ck of our understanding of mass/weight. Truly a mess! I just convert to metric for my calculations even though I am used to pounds.

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I think the idea behind getting the butt back in the seat is mostly about being able to get more mass off and down low. If a rider is hunched or scrunched up against the tank, by definition, the angle of the body that is hung off is like maybe 45° or something. That alone means less mass off the bike and less room to get the mass down. It practically forces a rider, especially a tall rider, to sit more upright. There just isn't room to get down. It seems to me that pushing back creates a more acute angle, closer to parallel, and creates more room to fit all of the torso down low.

 

As for the CoM forward... after the first priority of lowering the CoM, I suppose it is a good idea to be aware of what else is going on and what that means. I could be wrong, but, whether the butt is back or not, I think we are probably going to end up essentially moving the mass forward in the process of hanging off...assuming the body is off and low.

 

So, what does that mean?

 

Can we still acheive a 40/60 weight distribution by cracking on the throttle?

 

Will it take more throttle to reach 40/60 if the mass is further forward than it would if the mass was back? Would that be a good thing? Does more throttle mean that you go faster?

 

So, what about the idea of breaking the rear loose easier if the mass is forward? Is that a bad thing?

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Apologies to the thread/topic...last word:

 

 

From Wiki:

 

"A pound or pound-force (abbreviations: lb, lbf, or lbf) is a unit of force. Pound is also the name of a unit of mass."

 

http://en.wikipedia.org/wiki/Pound-force

 

Some folks also use a capitalized "Lb" to distinguish, as well. But, "lb" is perfectly acceptable and, in fact, the most common usage outside the physics lab here in the United States. Probably because we are still on the Imperial system. D'oh. The fact that bathroom scales, grocery scales and torque wrenches are labeled with "lb" here in North America should also give a hint to that reality.

 

For the record, had I been addressing a group of engineers at my shop or physics students at the university, I probably wouldn't have jumped from metric to Imp in the middle of a sentence; but, then, I wouldn't have needed to explain the difference between mass and weight (force) to them either.

 

And THAT is the point. My words were first and foremost tailored for the ear of the person who asked the question (and were perfectly accurate in any case). As it was, that person perfectly understood because I used the common usage that he and most anyone here would most readily understand. The widest understanding by the largest possible percentage of your audience. Communications 101.

 

"Speaking out" to ring one's own egotistical bell and say "Look at me, I am smarter than you" without consideration for the person being addressed or the subject being addressed (or the thread topic) risks undercutting the trust and confidence in the source of the information; and, by extension, the confidence in their understanding of the principle. Especially when the person "speaking out" is, in fact, completely wrong. And THAT is the only reason I responded to the pedantic trolling in this thread: the accuracy of the information in this motorcycle forum and the benefit of the person (people) who needed to understand. I couldn't care less about "winning" anything here.

 

http://en.wikipedia.org/wiki/Internet_troll

 

 

ETA: In hindsight, I suppose that I should have simply posted the quote and link from the top of this page and ignored the trolling. Live and learn. Sorry for all the noise.

 

ETA: I'm watching the International Space Staion crew spacewalk to prep the ESA Columbia Module live on NASA TV. And one of the spacewalkers is from Europe, too, if I'm not mistaken. Just now, they were calling out fastener torque readings from the European module to the controllers (in Munich)... in... wait for it... foot-pounds (ft-lb). Not Newton-metres (N-m). Huh. Go figure. I guess European engineers and scientists are familiar with the "pound" as a measure of force after all.

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Apologies to the thread/topic...last word:

.......................

For the record, had I been addressing a group of engineers at my shop or physics students at the university, I probably wouldn't have jumped from metric to Imp in the middle of a sentence; but, then, I wouldn't have needed to explain the difference between mass and weight (force) to them either.

.......................

"Speaking out" to ring one's own egotistical bell and say "Look at me, I am smarter than you" without consideration for the person being addressed or the subject being addressed (or the thread topic) risks undercutting his trust and confidence in the source of the information; and, by extension, his confidence in his own understanding of the principle. Especially when the person "speaking out" is, in fact, completely wrong. And THAT is the only reason I responded to the pedantic trolling in this thread: the accuracy of the information in this motorcycle forum and the benefit of the person (people) who needed to understand. I couldn't care less about "winning" anything here.

................

As for the idea of "getting weight over the bike to put more weight on the tires" ... first, scientifically speaking, we need to separate the concepts of mass and weight. Mass is a measure of matter, weight is an effect due to a force like gravity. On Earth, 1 kg of mass weighs 2.2 lbs due to gravity. Being that gravity on Earth is constant (at 1g), this relationship is consistent all over the planet, hence, one may express weight in kilograms without confusion ... here on Earth. However, if we travel to the Moon, 1 kg weighs ~ 0.36 lbs as the force of gravity is only 1/6 what it is on Earth (or about 0.166g). So, mass remains consistent regardless of forces applied. Weight does not.

 

Well then, my apologies too. This is where racer is right. This has been going on for too long.

 

It's my mistake that being new to this forum I didn't know what I'm getting into by contradicting such a great scientist who's taking his information from Wikipedia and considers an audience on a motorcycle riding forum less intelligent than a group of students, or engineers. For the future I promise I will not reply to any of Mr. racer's posts, only to avoid causing to all of you nice people the inconvenience of reading his incoherent 'scientific' dissertations.

 

In the mean time, no matter how much he insults me, publicly, or in my private inbox, I refuse to lose my confidence in my own understanding of the matter and therefore I still maintain that 1kg = 2.205lbs everywhere in the known universe, Earth and Moon included.

 

Have a good weekend all of you (racer too).

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I guess looking at all the pictures of other riders/Pros threw me off because I thought I was doing it "right" and then I see all of these people with more experience and more skill than I have not hanging off the bike.

 

I never even thought about the fact that they might have never been taught or learned anything different.

 

I recently watched the "2007 MotoGP Review" and "The Doctor, the Tornado, and the Kentucky Kid." That's like 6 hrs of motoGP related stuff. Thankfully they are available from netflix. From watching this stuff it is very obvious the guys at the front, Rossi, Hayden, Edwards, etc, they are all hanging off in pretty much classic superbikeschool style, butt and shoulders off the bike equally, shoulders really low, and sometimes they are hanging off quite a lot. It's better to watch videos, you can see it more clearly. It's like the other poster said, Hayden is powering out of a turn in the picture you posted. And the rider in the chicane could easily still be at some point in his transition from left lean to right lean.

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Thanks for the heads up about the 2007 MotoGP Review available on Netflix, harnois. (I just added it to my queue, so hurry up and send it back so I can get it next...lol.)

 

As a matter of fact, Netflix also have the 2001-2006 MotoGP Reviews and other selections like "MotoGP:Head to Head, The Great Battles" and "Faster" about the sport of MotoGP in general.

 

For anyone interested... a two-week trial subscription is available from Netflix for free and can be cancelled without penalty before any charges are made. Anyway, I've been a member of Netflix now for sometime and it never occured to me to search for motorcycle racing.

 

Thanks again!

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I finally got a copy of Twst of the Wrist II from the library last night and randomly skimmed through it before reading Chapters 1 & 13... and now I think I see where Cobie is/was going with the front end and body position in this thread. Hook turn?

 

I also have to say that much of what I read so far really clarifies stuff I have learned the hard way or the long way over many years and many dollars of racing experience.

 

Man, I wish I had read this book when it first came out. I can't wait to read the rest.

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I finally got a copy of Twst of the Wrist II from the library last night... ...I wish I had read this book when it first came out.

 

 

I've got the package deal with both Twist books and audio CDs, Soft Science book, an interactive CD and a DVD. Believe it or not, the best of it is audio CDs! I haven't finished reading Twist II but I've heard it almost every work day since I got it. Just let it loop in the background. There's a ton of info to digest; hope it comes to me while I'm riding like a Led Zepline tune!

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I finally got a copy of Twst of the Wrist II from the library last night and randomly skimmed through it before reading Chapters 1 & 13... and now I think I see where Cobie is/was going with the front end and body position in this thread. Hook turn?

 

I also have to say that much of what I read so far really clarifies stuff I have learned the hard way or the long way over many years and many dollars of racing experience.

 

Man, I wish I had read this book when it first came out. I can't wait to read the rest.

 

racer--you got it mate. Keith and Dylan (who are doing the semnars these days) really go over that stuff nicely, and also the next class room, which goes over Pivot Steering.

 

C

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I finally got a copy of Twst of the Wrist II from the library last night and randomly skimmed through it before reading Chapters 1 & 13... and now I think I see where Cobie is/was going with the front end and body position in this thread. Hook turn?

 

I also have to say that much of what I read so far really clarifies stuff I have learned the hard way or the long way over many years and many dollars of racing experience.

 

Man, I wish I had read this book when it first came out. I can't wait to read the rest.

 

racer--you got it mate. Keith and Dylan (who are doing the semnars these days) really go over that stuff nicely, and also the next class room, which goes over Pivot Steering.

 

C

 

Cobie;

 

Keith's presentation of the Hook/Pivot Turn in Level III was one of the most eye opening parts of the whole curriculum. I had it reinforced when I startred up at Loudon and it took me awhile to integrate it into my riding but it's a technique that I use as my speed has increased.

 

I don't have anywhere near Racer's experience but I do think he should consider investing in taking Levels II & III at a minimum...you're never too old or too experienced to "go back to School". I saw that when I watched Roger Lee Hayden on the lean/slide bike with Keith instructing at CodeRACE a few years ago.

 

Kevin

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I don't have anywhere near Racer's experience but I do think he should consider investing in taking Levels II & III at a minimum...you're never too old or too experienced to "go back to School".

 

Er... who you calling 'old'... young Kevin? ;)

 

Point taken. Experiencing the new curriculum is definitely on my "to do" list.

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I don't have anywhere near Racer's experience but I do think he should consider investing in taking Levels II & III at a minimum...you're never too old or too experienced to "go back to School".

 

Er... who you calling 'old'... young Kevin? ;)

 

Point taken. Experiencing the new curriculum is definitely on my "to do" list.

 

Racer;

 

...look at my avitar, do I look young to you? Ask Cobie, he went to School with my grand children.

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...look at my avitar, do I look young to you? Ask Cobie, he went to School with my grand children.

 

Yes, you do look young to me. And, no, I don't believe you have grandchildren as old as Cobie.

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  • 4 weeks later...

Update:

 

I went back to Talladega last month...for the first time since a bad wreck in September which resulted in an aftermarket collarbone etc. (I can't remember if i have mentioned that wreck or not).

 

Anyway, it was my first track day since the wreck...and it was back at Tally so you can imagine how my nerves were. It was also my first track day on my R1. I am having a 750 track bike being built, but it wasnt ready yet so i had to track prep my R1 at the last minute.

 

Here is a pic from the day.

 

Tally.jpg

 

I am sure yall will be able to see plenty of things wrong with my form so feel free to critique.

 

All in all, i can't complain. I had a good time and my lap times were ok. I ran 1:09's which is fairly respectable... considering the above factors and the fact that i was on a stock suspension that was maxed out but still 13mm off because of my 220lbs and on street tires that had 4,500 miles on them when the day began.

 

To be honest, i wasn't really concerned with times. I only looked at my times a few times over the weekend. I never "pushed" myself or the bike. I basically just wanted to get my first TD's out of the way and get back in the groove. I never once even got any chatter out of the rear wheel while braking because i never broke hard enough. It sounds funny, but i was pretty quick in the curves and slow on the straights :). The only people that passed me, did so in the straights...then i re-passed them on the outside of the next curve. When that happened, i would speed up a little on the straights out of courtesy and i wouldnt see them again the rest of the session.

 

But i did get comments from several instructors on how "smooth" i was so that made me happy.

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Chaos,

 

Picture looks pretty good, way more that is right than wrong for sure. Sounds like your approach to the day was also good, cut yourself some slack and not be in too much of a hurry.

 

I don't know what "TD's" are?

 

Was there something in specific that had your attention, or that you have your attention on now about your riding? Also, what levels (if any) have you done at the school?

 

Best,

Cobie

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Cobie, TD's = Track days.

 

Got it, thanks.

 

How about the other question--did something have your attention about your riding (or still does)? And what level(s) have you done.

 

CF

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