lomoto Posted September 8, 2006 Share Posted September 8, 2006 Thanks Val siete un aiuto grande.... non arrestate la vostra occupazione Quote Link to comment Share on other sites More sharing options...
Removed Posted September 8, 2006 Share Posted September 8, 2006 ffs give me time, I'm translating it on the fly! Quote Link to comment Share on other sites More sharing options...
Guest prescience Posted September 8, 2006 Share Posted September 8, 2006 If you truly believe that proves you are correct - best of luck Quote Link to comment Share on other sites More sharing options...
Removed Posted September 8, 2006 Share Posted September 8, 2006 just acknowledge you 2 were wrong in not even considering that a tyre is a deformable object and act graciously for once will you Quote Link to comment Share on other sites More sharing options...
Dash Posted September 8, 2006 Share Posted September 8, 2006 back on topic.... I learnt that I was right: wider tyres makes for more grip, fact. I had a first gut feeling that F1 cars could not be that wrong to choose as wide a tyre as possible and here's the reason, translated into english from Italian, courtesy of an Italian member of the 350Z club, race engineer I'll surely use wrong terminology in English, but hope you will still understand the goings on... "there are 2 reasons why wider tyres produce more grip, due to the laws of physics : 1) from a physics point of view if you consider non-deformable objects, the resistance generated (= energy trasmitted by the tyre) is proportional only to the energy that lies on top of it, multiplied by the grip coefficient. So if I increase the width area that touches the ground, the energy doesn't change. I simply have more surface, on which there is less specific energy (kg/ sq. cm) and I have no improvements to the " tangent strenght" (no idea on that term I'm afraid) transmitted. This is only valid for non deformable objects, though A tyre is NOT a non-deformable object and the wider is the contact area to the ground the less is the specific pressure for every sq. cm of tyre, and less is the deformation of the tyre. Deformation causes a loss of grip (adherence) 2) da un punto di vista statistico, non tutto l'asfalto ha il medesimo coefficiente di aderenza. Ampliando la sezione, si aumenta la possibilitàdi trovare punti di asfalto a coefficiente di attrito più elevato, e si riduce il rischio di perdere momentaneamente trazione perchè magari il 30% della gomma sta toccando con un asfalto corrugato. Considera che, una volta persa trazione, si passa dal coefficiente di attrito statico (moto di puro rotolamento) al coefficiente dinamico (moto di strisciamento) e che quest'ultimo è sempre minore del primo. Morale, se "rompi la trazione", poi dovrai togliere potenza per tornare al puro rotolamento. Ecco che statisticamente conviene avere gomme grandi; 2) from a statistical point of view, not all tarmac has the same grip coefficient. Witha wider tyre, you increase the chance of finding points on the tarmac that have a higher grip coefficient, and you reduce the risk of temporarily lose traction because say 30% of the tyre is touching a different type of tarmac. Consider that, once traction is lost, you go from a static friction coefficient (can't find the translation of this "moto di puro rotolamento" ) to a dynamic coefficient (again "moto di strisciamento) and the latter is always smaller than the former. In other words, if you break traction, you will have to take the foot off the gas to get back to the "puro rotolamento". hence another reason why it's better to have wider tyres. So, unless there is excessive air pressure in the tyres which penalise traction, wider tyres give more grip." phew, that was hard Its a shame you went to all that trouble when the subject we were referring to was a WET roundabout and we CLEARLY stated that in the WET or on surface of low adhesion due to the PSI being spread over a wider area a wider tyre is more prone to aquaplaning. As I mentioned earlier why do you think ice racing uses such skinny tyres? If the unsprung weight doesnt change (scientific fact) and the surface area is greater (another fact) and the pressure placed on a fixed parameter (PSI) is less due to the larger area, How on earth can your arguement work. The Non deformable object is prone to EXACTLY THE Same level of deformity as the narrower tyre! therefore the quation remains the same! Its simple science my friend. Otherwise you need to contact Pirelli and notify them that you have altered the rules on compound adhesion based on a fixed pressure because those poor bastards have been doing it all wrong for the last 50 years! Quote Link to comment Share on other sites More sharing options...
Removed Posted September 8, 2006 Share Posted September 8, 2006 Ok - i was cross with Valerio in fact for just calling me a bragger as it goes Bigger is better for grip overall though due to the rot. dynamics and moment of inertia increasing due to mass primarily (the radius is also larger but that is probably nullifed by a different weight distribution) Bit quiet on the OC recently hasn't it been nope as the above was said by Dorian and it is not correct. wider is better for grip full stop. the fact that in the wet there's other variables to take into consideration is another matter Quote Link to comment Share on other sites More sharing options...
Guest prescience Posted September 8, 2006 Share Posted September 8, 2006 from a physics point of view if you consider non-deformable objects, the resistance generated (= energy trasmitted by the tyre) is proportional only to the energy that lies on top of it, multiplied by the grip coefficient. I got to here, and noted that 'resistance' is a force and 'energy' is work which is force over a distance (trying to relate it to force) - how can you equate the two? Quote Link to comment Share on other sites More sharing options...
Removed Posted September 8, 2006 Share Posted September 8, 2006 Dash you'll have to contact all F1 team then and suggest them according to your science knowledge they should all go with bicycle tyres as they will give you more grip Quote Link to comment Share on other sites More sharing options...
Guest prescience Posted September 8, 2006 Share Posted September 8, 2006 It must be lost in translation mate - but it does not make any sense does it? Quote Link to comment Share on other sites More sharing options...
Removed Posted September 8, 2006 Share Posted September 8, 2006 PS I'll get the engineer guy to come over, he does speak english... I'm sure he'll be happy to answer all your queries, as will be all the F1 teams engineers Quote Link to comment Share on other sites More sharing options...
Removed Posted September 8, 2006 Share Posted September 8, 2006 It must be lost in translation mate - but it does not make any sense does it? I just tried to translate it from his post... he'll explain you better surely... Quote Link to comment Share on other sites More sharing options...
Guest prescience Posted September 8, 2006 Share Posted September 8, 2006 I mean at best it seems to be confusing the following 3 concepts.. - static friction - dynamic friction and - stiction ? Quote Link to comment Share on other sites More sharing options...
Removed Posted September 8, 2006 Share Posted September 8, 2006 no point in trying to explain as I sd... will get him on board, and hopefully he'll explain to you 2 why you are wrong Quote Link to comment Share on other sites More sharing options...
Guest prescience Posted September 8, 2006 Share Posted September 8, 2006 well as a tester static friction == stiction i quite accept that it is a translation thing, my italian is cr&p its also all pretty simple stuff Quote Link to comment Share on other sites More sharing options...
Removed Posted September 8, 2006 Share Posted September 8, 2006 as I sd no point in trying to argue with me as I am not qualified enough, but guess what, I'm quite convinced he's more competent that you and Dash put together, again just a gut feeling the translating thing is simply due to the fact that when you interpret (as in are the interpreter of) or translate technical subjects, you need to have a good knowledge of technical terms for that specific subject. (which in this case I haven't got) Quote Link to comment Share on other sites More sharing options...
Dash Posted September 8, 2006 Share Posted September 8, 2006 no point in trying to explain as I sd... will get him on board, and hopefully he'll explain to you 2 why you are wrong You explained to "him' that we are discussing grip in WET conditions? And not the dry? Quote Link to comment Share on other sites More sharing options...
Guest prescience Posted September 8, 2006 Share Posted September 8, 2006 as I sd no point in trying to argue with me as I am not qualified enough, but guess what, I'm quite convinced he's more competent that you and Dash put together, again just a gut feeling i'm sure you're right cos I'm stupid and I sense Dash has no experience of cars and how they behave either Quote Link to comment Share on other sites More sharing options...
Removed Posted September 8, 2006 Share Posted September 8, 2006 I never said that Dorian, don't put words in my mouth. but if you don't mind I'd rather believe an engineer with a 500hp 300zx Wet conditions are a separate issue Dash. When I referred to Dorian's post and he "got cross" was since he discarded the fact that he went from a 245 width to a 275 width, as irrelevant Quote Link to comment Share on other sites More sharing options...
Dash Posted September 8, 2006 Share Posted September 8, 2006 In the words of manuel (falty towers) "I know nothing I learn it from a book" Quote Link to comment Share on other sites More sharing options...
Dash Posted September 8, 2006 Share Posted September 8, 2006 No WET conditions arent irrelevant as I have stated this all along! Quote Link to comment Share on other sites More sharing options...
Removed Posted September 8, 2006 Share Posted September 8, 2006 No WET conditions arent irrelevant as I have stated this all along! so let's recap: in you 2 guys' opinions (let's use 2 widths for examples) a 245 tyre has more or less grip than a 275 tyre? same brand, compound, tread pattern PSi and condition of the road Quote Link to comment Share on other sites More sharing options...
Guest prescience Posted September 8, 2006 Share Posted September 8, 2006 A tyre is NOT a non-deformable object and the wider is the contact area to the ground the less is the specific pressure for every sq. cm of tyre, and less is the deformation of the tyre Again how can that be correct, what dash and I are saying is that the contact area (as supported by carbibles) is almost independent of tyre because you are trying to put the same sprung weight onto the ground and thus the contact area for rubber will be very similar. The text 'appears to be' confusing width (a one dimension phenomenon) with contact area which clear is 2D? No substance is non-deformable BTW Quote Link to comment Share on other sites More sharing options...
Removed Posted September 8, 2006 Share Posted September 8, 2006 A tyre is NOT a non-deformable object and the wider is the contact area to the ground the less is the specific pressure for every sq. cm of tyre, and less is the deformation of the tyre Again how can that be correct, what dash and I are saying is that the contact area (as supported by carbibles) is almost independent of tyre because you are trying to put the same sprung weight onto the ground and thus the contact area for rubber will be bery similar. The text 'apperas to be' confusing width (a one dimension phenomenon) with contact area which clear is 2D? No substance is non-deformable BTW keep asking ME? Quote Link to comment Share on other sites More sharing options...
Dash Posted September 8, 2006 Share Posted September 8, 2006 No WET conditions arent irrelevant as I have stated this all along! so let's recap: in you 2 guys' opinions (let's use 2 widths for examples) a 245 tyre has more or less grip than a 275 tyre? same brand, compound, tread pattern PSi and condition of the road 2 tyres same brand different widths same conditons (WET)) the 275 will be more prone to aquaplaning (ergo less grip) than the 245. Predominetly due to the difference in the shape of the contact patch the spreading of the pressuere placed upon that tyre by its vehicles weight over a different shaped contact patch and the fact that the capilary action with in the thread of that tyre is not the same due to the reduced contact pressure at any singal point. Quote Link to comment Share on other sites More sharing options...
Dash Posted September 8, 2006 Share Posted September 8, 2006 No substance is non-deformable BTW Carbon atoms? They cant be deformed. Quote Link to comment Share on other sites More sharing options...
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