Ulysses
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Posts posted by Ulysses
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I think there would be a difference here in what is a mechanical change to the bike, and what is a rider change. One rider can change bikes, the new bike can be completely different--say going from a modern 600 to a Harley full dresser. That wuold be a pretty big change, one would want to get accustomed to the new machine, no?
What I had in mind when I said machine setup were things like suspension adjustments for instance. One day I had one experienced racer and mechanic take my bike out and give me some feedback on it. He said the rear should be higher. I fully raised (10mm) the rear shock and the turning behavior of the bike changed radically. I loved it and it stayed like that to this day. If on top of that I'd decided to be more aggressive with my steering input, perhaps that would've been a bit too much change. Now a Harley... that's blasphemy...
But how about the rider that tries to change his riding position on the bike, while also trying to learn how to brake and downshift simultaneously? B and D is one of the hardest things we train, the single most complicated action in riding. And body position is one of the biggest issues we see with our riders, and the changes they make often--those can be large changes. Does a body position change affect other things, like your vision?Agreed...B&D is a lot to deal with. Now that you made me thinking about it, I cannot say precisely how/what I'm doing with these two maneuvers, which means it's something to work on until I know exactly how to do it. I'll pull out Keith's books to see if there's something on the subject there. I assume B&D is either level III, or IV. I remember the first two levels were done with virtually no braking at all.
I experienced with body position a lot and indeed it changes many things. Vision is only one of them. How you push on the bars is another, or how easy/difficult is to lock your knee on the tank. If you think too much about all aspects involved, you've spent all your $10.
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That means don’t be too darn greedy for change.
I find that erratic changes, with no plan and no process to evaluate the results, are more wasteful and dangerous than too many changes. Or maybe there is a correlation between these two aspects?
I usually find myself to be greedy for change, in my quest to improvement. Mostly because track time is so expensive and I want to get the most out of it.
My questions:
When is there too much change and how should one manage change in riding technique and/or machine setup?
How do the big companies make so many changes to a motorcycle every two years and come up with, usually, a better machine? I don't think they have the time to do one change at a time and look at the results, or we'd still be riding the 1999 models today.
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Apologies to the thread/topic...last word:
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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.
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"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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The more parallel/level the body is, the more forward and low the combined CoM moves.
The more hunched or upright the body is the more CoM moves rearward and upward.
I agree. But now take that rider, parallel with the bike and move it to the rear. Will that move the combined CoM to the rear too?
What I was saying was that it's easier to be parallel if you're not pushed against the tank, but that offsets a bit the moving forward of the CoM.
Intuitively, I feel that being too far back is bad.Why?
I don't know. That's why I call it intuition. I need to think about it.
The rear raises under acceleration.Right, but it raises more if it's less load on it. That's one reason for assuming it's better to be as far forward as possible while getting parallel with the bike.
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Again with the evasion and weak attempt at a strawman guilt trip.
It was a joke meant to put an end to a discussion that had little to do with the topic.
By no means it was a guilt trip. What I wrote in my first post is correct and I stand by it. It was a reply to your post, where your idea of separating the mass from weight and their effect on the bike was good, but the way it was explained was ...well ..wrong.
What I was evading was asking you if you need to be always right.
I believe the words you are searching for are something like, "Oops, I was wrong."Are you talking to your inner self here? Because otherwise your belief is lapping the track in the wrong direction.
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And you were being a full blown pedant by looking to pick nits
have a nice day
IC... I'm a bad person and you're good... I guess I can live with that.
and split hairs where, in fact, none existed.So... you're bald?
That's ok... the helmet fits better. I know first hand.You have a good day too. And a good night before that...
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I agree...lets get back to that....
OK, here is a thought for you guys---where is the mass of a rider's body, above or below the waist? With that in mind, what's more beneficial to have hung off? What different styles have you guys seen on this?
C
I think that regardless of how the mass of a rider's body is distributed (big legs and small body, or big torso and skinny legs) the more body parts he can put closer to the track the lower the combined CoM will be and this is the intended result. Being parallel with the bike, makes it possible to put more of the upper body lower, as opposed to being crossed on the bike, when the upper body is left high.
But it takes some practice to get used to being parallel with the bike. Sometimes, if my butt is off the bike too much, it's hard to lock my knee against the tank and the result it's disastrous. I end up using my arms to hang on to the bike and at that moment the ability to be smooth with the controls is lost. It happens to me especially in combinations of turns when I have to shift my body quickly from one side to the other.
Also, one needs to consider how he affects the weight distribution between front and rear when the body is parallel with the bike. If the rider is too close to the tank, I think the upper body tends to remain higher, especially for taller people. But going away from the tank loads more the rear and unloads the front. Intuitively, I feel that being too far back is bad. And if I think about it, the more the rear is loaded, the more the rake is changed for the worse. The forks are loaded less and extend a bit more and the rear is also lowered by the added weight.
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In any case, whether in Canada or Europe, the point that you continue to not so skillfully avoid addressing is the inherent paradox presented by using the same term to express both mass and weight. THAT is what is illogical. It is understandable that, having grown up (somewhere) in Europe and living in Canada (or whatever country that uses the metric standard), you would not have learned to separate mass and weight by the very logical technique of assigning a unique metric to each. Perhaps then you could answer the simple question for any country on the metric standard:
How much does 1 kg of mass weigh on the Moon?
Ok, I'm not trying to avoid it anymore. :-) I think one would say that a corp that weighs one kilogram (1000 grams) on Earth will weigh only 166 grams on the Moon. Scientifically it's incorrect because the mass it's the same everywhere, but as you mentioned, the units of mass are commonly used to express gravitational force too.
The metric system does separate the mass and weight, One is measured in kg and the other in N (newtons), being a force. The same way in the imperial system. You measure the mass in pounds and the force in pound-force, the latter meaning, of course, the force exerted by the gravity on a corp with one pound of mass.
It still doesn't seem logical to me to use metrics for mass, but from two different systems, to separate mass from weight, but at least now I know where it comes from.
Cheers,
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Ok, in all seriousness...
My initial perception/reaction was that you were in full pedant mode looking to pick nits and split hairs on my head without acknowledging that the principle as I explained it was precisely correct and quite clear. However, in the midst of my reply, I noticed you were in Toronto and I had a wee bit of a mini-epiphany that maybe you didn't understand the somewhat colloquial usage and were sincerely trying to be helpful... and that maybe you were only in half-pedant mode.
Children of my generation who were in grade school during the adoption of the metric system as a standard in the rest of the world, and the partial adoption of it here in the US before those in charge changed their minds, were taught that kg were for mass and lbs were for weight and it wasn't really until high school physics in 12th grade that we learned any different. So, I don't how it is taught to kids today; but, like so many other idiosyncratic habits, I still commonly separate mass and weight with kg and lbs. And, frankly, for the sake of a clear and simple single paragraph pre-amble for why "getting weight on top of the bike" is not only a misnomer, but, not really a good thing, it still seems like a good idea to me.
While I did understand exactly what you were trying to say, the idea that one can use kg and lbs to measure different things seemed totally wrong to me. Never before I've seen them used the way you did and I had no idea why you wrote that way. Here, in Canada, in the grocery store for instance they use both lbs and kg, because not everybody is yet comfortable with the metric system. So for me there was no doubt that everybody used them for measuring the same thing... until now at least. Far from me the idea of picking on you.
At least, that is what went through my head at 4am this morning.Man.. you've got no sleep??? :-)
So, in light of all of that... I really want to know... for the sake of my international communication skills and general enlightenment...How much does 1 kg of mass weigh on the Moon for the common Canadian?
I mean, how do you answer that question in simple terms?
Sorry to disappoint, but I can't answer your question. I'm not a common Canadian (meaning born and raised in Canada). I've done all my studying in Europe, including the university, so I have no clue what they teach in schools here. He, he... 10 years ago I wasn't even speaking good English. In fact I was barely speaking any English.
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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.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?
Cheers, mate.
I don't have a problem with someone telling a 100lbs student that he weighs 16lbs on the moon. But while reading your post I noticed that you stated 'scientifically speaking' that you need to separate mass from force and then you used lbs and kg as they were measuring different things (one mass and another one force), which 'scientifically' is incorrect. I thought I'd clarify that. Sorry if it bothered you.
Cheers,
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Scientifically speaking:
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.
uhmmm.. kg and lbs measure the same thing...mass. It's just that the kg is ISO and lbs is imperial system.
1kg is approximately 2.2 lbs everywhere.
Now, the gravitational force (the weight, or the force pulling a corp towards the center of the Earth) is G=m*g where m is the mass and g is the gravitational acceleration and it is considered a constant (it's almost the same everywhere on Earth) and is about 9.8 meters/square second.
So one kg of mass will be pulled down with a force equals with 9.8m/s^2, or 9.8 N, where N (Newton) is the ISO unit for force.
A given body will have the same mass on the earth and on the moon, but its weight on the moon will be only about 16% of the weight as measured on the earth, because the gravitational acceleration (g) on the moon is lower than on Earth.
Transcendental
in Articles by Keith
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I too work with 'change management', in IT. I'm a programmer. We've got tools to detect what effects a change has in the system overall. But I find there are some differences when it comes to riding.
1. In engineering, IT etc. there are objective ways to measure the effect of a change. In riding, an objective measure would be the lap times and consistency. But there's also a subjective measure, which is rider feel. For instance, when my coach at Keith's school pushed me down on the bike to show me the proper riding position, it didn't feel very comfortable. Judging by feel only, I could have concluded it was a bad change and give up trying to get used to it until it felt 'natural'. Still working on it btw.
2. In riding is much harder to have knowledge beforehand about the effects of a change. You need to try it before you know, especially because of the subjective aspect. And sometimes the leathers will show the result.
The idea of applying the methods of 'change management' from engineering into riding is worth further thinking about if only to filter out obviously bad choices before trying them. Or it may simply be an overkill. I can't say what's the percentage of thinking vs. feel/talent in an accomplished racer. I never had a chance to talk to one.