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Discussion Starter #121 (Edited)
andyf said:
I'm glad I posted the question in the original thread, this has turned out to be quite a read ..
Andyf, a question for you?

As the original poster of the question, tell us which side of this debate are you on, little ol' me or our good friend Simon and the multifarious cast of trolls projecting him forward as The Great White Hope?

[Just a time out for us to draw breath, breathe in... hold... and ... relax.]


[Edit... breathe out.]
 

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Hi Theo

But wouldn't lowering the pressures (on the big tyres) mean you would lose some stiffness / make the tyre too compliant ? Or would you indeed fix that with a different tyre design ?
Absolutely. A tyre is designed to run at an ideal deformation. Run them too low a pressure (for the load) and the sidewalls take too much of the load, inflate them too high and the contact patch becomes smaller, and the entire width of the tyre is no longer used.

So the main part of a tyre's characteristics (this isn't important stuff to worry about, just possibly of interest) is how the tyre deforms under different loads. The load is changing all the time, so therefore so is the contact patch, and the load on the sidewalls (on radial tyres that is, bias ply is a different story), how the sidewalls skew and stretch under sideload, etc, etc. There are a number of parameters involved that not even the designers could possibly take them all (in-fact any more than a fraction of) in to account. This is the reason for extensive tyre testing.

Cheers

Simon
 

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'
SDB[/i] It is unquestionable that doubling the load on a tyre less than doubles the grip it produces. [/QUOTE] [QUOTE][i]Originally posted by Mycroft said:
That is not correct! That only applies after the tyre has reached its' optimum load/adhesion break point!

Until that point the exact opposite is the case!
Originally posted by Black_Bird_Blue
V Load = 900 lbs - coefficient of friction = 1.1
V Load = 1350 lbs - coefficient of friction = 1.05
V Load = 1800 lbs - coefficient of friction = 0.95

i.e. more load = less friction.
Originally posted by Mycroft
And many here see that confirmation of Simons assertion that 'double the weight and you get less than double the grip'
Originally posted by Mycroft
Claudius, staggeringly these fools actually do think that co-efficient of friction = grip.
Originally by Lewis Carroll, "Alice's Adventures in Wonderland"
"When I use a word", said Humpty Dumpty scornfully, "it means exactly what I choose it to mean, neither more nor less."
"The question is", said Alice, "whether or not you can make a word mean so many things."
Mycroft, what are you talking about?

What is the difference between coefficient of friction and grip? And how can the numbers I gave (from your link) be made to show the opposite effect as you describe? Why am I a fool for just not knowing something I've never been told?

Please tell me, I think I'm on the verge of understanding something here that is really interesting.


BBB
 

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Mycroft said:
Hi Claudius... damn it man in your first post you start to spoil my game. :D
(Sadly) Oh I see, it's not about telling us stuff at all, it's just a game you're playing?

That's a shame because often I come across who think they know about this stuff and they turn out to just be game-players.

There must be lots of people who really want to know, but they must get really disillusioned by players, I guess. I so wish I knew someone who could explain it in plain english and without playing games.

Sigh.

BBB
 

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Discussion Starter #125
Try to see the co-eff figure you have given as being like giving someone just giving out the Cd of a car, it is useful to compare, but only tells part of the story.
 

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Discussion Starter #126
To make it even plainer, if Simon posted 'As the weight doubles on the contact patch of the tyre the co-efficient of friction less than doubles''

This thread would have moved along without demurr from me, 'cos that is right, but grip is not and never will be as far as any 'rubber' material is concerned the same thing as co-eff/friction

:D
 

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OK...

Let's just sort cut this dead.

Mycroft. Either tell us the whole story or don't it's up to you. Otherwise you're adding nothing to the thread and spoiling it for everyone, so I'll simply ignore you.
 

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Mycroft said:
To make it even plainer, if Simon posted 'As the weight doubles on the contact patch of the tyre the co-efficient of friction less than doubles''

This thread would have moved along without demurr from me, 'cos that is right, but grip is not and never will be as far as any 'rubber' material is concerned the same thing as co-eff/friction

:D
Mycroft

(You're going to love this)

Please see page two of this thread, go to my first post (which is the second on the page)..

There is some hidden text. Highlight the post with your mouse and you will see it.

It is a code, which makes up the first letters of the following :

"As can be seen from this code, I am not in the slightest bit surprised that you have simply chosen to twist my words by suggesting a different definition for the word grip. None of this thread is important unless it is discussing the performance of the car, and it's ability to corner (and brake and accelerate). By grip, anyone with any inteligence would be able to deduce that I meant the cornering forces produced by the tyres."

You are predictable and boring.

Now...

Let's assume that you really DID mean that all along (which you didn't).. it is still irrelevant anyway...

Could you explain to me why you stated that grip DOES more than double when doubling the load.

Best regards

Simon
 

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PS. You can see by the time it was edited that this code was popped in there prior to me posting my "in the main part, yes" post.
 

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SDB said:
Mycroft. Either tell us the whole story or don't it's up to you. Otherwise you're adding nothing to the thread and spoiling it for everyone, so I'll simply ignore you.
Excuse me, but why are you coming here to tell Mycroft what he has to say and what not? And that about threatening him to ignore him is just plain ridiculous: you banned him from your forum and now join him in another forum (where he's been for a while and posted hundreds of messages) to pick on him in one of HIS threads! :rolleyes:
 

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PS...

It would also be useful if you could explain how this ties in with your last few comments :D

It is only as you add weight that the static friction nearly doubles.

This is the EXACT opposite to what Simon has outlined
 

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Claudius

I'm not getting in to this with you. Please email me, or (with Cem's permission) post a new thread.

I was asked to come and comment on the previous thread, that is why I'm here.

I can chose to ignore who I like. The questions were posed by mycroft to me personally, so it is my choice how I respond to them. If you can see one other bit of negativity towards this board, any other members, or the topic in question, please point it out to me.

Regards

Simon
 

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Discussion Starter #133 (Edited)
SDB said:
Mycroft

(You're going to love this) etc. etc

I don't understand this post at all!

If you are implying I have changed my standpoint then you are wrong, i have repeatedly asked you to confirm your assertion... :D

You have obliged... very very regularly.
-------


Claudius, I see Simons presence here as a compliment to me and the GTR, his own forum is a mess and he is here to get a decent debate.

There is another possible explanation but that would mean he was shallow and sad, so that can't be right can it!

[simon, just ignore the 2 sentences above :D, they are meant for Claudius :D]
 

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:rolleyes:

OK..

Off home now. Unlikely to get a chance to log on this evening, but if there are any questions I'll be happy to do my best in the morning.

All the best

Simon
 

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What a good thread. :)

Some very good points made.

Not wanting to start a slanging match but I suppose it boils down to who do you think has got it right.

The guy who's a circuit instructor, car tester to some of the top name companies, world record holder, works as part of the World Rally Championship, mixes with top chassis designers and has a website dedicated to driving dynamics as well as Scoobynet.

Or

The guy who's read a book.
 

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SDB said:
Claudius

I'm not getting in to this with you. Please email me, or (with Cem's permission) post a new thread.
It is not of much importance to me, just saying how weird the situation is...

I have always had trouble understanding the way you think. Do I need a special permission to post a thread here? What are you on about? :confused:


SDB said:
I can chose to ignore who I like.
Absolutely. It's a free country! :)


SDB said:
The questions were posed by mycroft to me personally, so it is my choice how I respond to them.
Of course. My point was this: since you thought Mycroft is not worth talking to, you banned him from your forum but join him here a few weeks later. After having been asked or not is another matter. I'm just saying that that's inconsistent, not that you're wrong about what you say. I have no way of knowing if you are right or wrong about what you say because I do not understand what you say.


SDB said:
If you can see one other bit of negativity towards this board, any other members, or the topic in question, please point it out to me.
I dont see any negativity here? Just a good thread about tyres, grip, cornering, loads, etc., all these things I am interested in and appreciate reading from knowledgeable people like Mycroft and yourself :)

I dont dislike you, I dont think you should leave, I am just saying that I dont understand what you say. It looks like you sometimes twist things a little and make them more complicated than they are, or look at them from a different perspective than lesser gifted people like myself would.

No offence, but your friend Damian Harty was much easier to understand and everything he said made perfect sense to me; you mentioned him reading this thread earlier. I think it would be great to read his thoughts about the subject if he can point out where the misunderstandings come from (if he can spare the time of course). :)
 

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logiclee said:
What a good thread. :)

Some very good points made.

Not wanting to start a slanging match but I suppose it boils down to who do you think has got it right.

The guy who's a circuit instructor, car tester to some of the top name companies, world record holder, works as part of the World Rally Championship, mixes with top chassis designers and has a website dedicated to driving dynamics as well as Scoobynet.

Or

The guy who's read a book.
Sounds like a fair point to me :)
 
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