Blatman Posted March 19, 2003 Share Posted March 19, 2003 But all other things aren't equal as far as List 1As are concerned. No-one has made performance cars with 13" wheels for what must be nearly 10 years now. Tyre technology and performance has come on in leaps and bounds since then and, suprise suprise, this hasn't been applied to 13" sizes because there is no market.It's not just about compounds (though modern compounds are not on 13" tyres), it not just about the static contact patch, there's the casing construction to consider as well, then how all these thing's change and behave under load, at temperature, and interact with and suit the car/ suspension behaviour. That's an interesting point. I thought that all tyres sold in the EU had to conform to EU regulations regarding their construction, and the materials used in the construction of the carcass. Surely all the tyre companies would want to do that as cheaply as possible, which I reckon means that compound and carcass construction are much of a muchness. That would make their behaviour under load (again, an EU specified set of regs is applied, I'm sure, to ensure road/consumer safety and product consistency, so that Joe Bloggs can have 4 radials from different manufacturers on his car without becoming a danger) similar enough that the vast majority of drivers wouldn't be able to tell the difference. I realise that Guy is far from an average driver, and may well be able to tell the difference. Most of us can't though. I'm sorry Guy regrets imparting his widom, but I'm afraid I need more than just "it works, 'cos I say it does". Science would never get anywhere with that sort of attitude. That said, I have the greatest respect for Guy and his many ahcievements in sprinting and hillclimbing, and I have some sympathy as I'm sure he doesn't want to give away for free what was no doubt hard won information into the intracacies of the art. I don't want chapter and verse, though, just an answer to a question......so why would for example 15" Bridgestone SO2, be "better" than a 13" Bridgestone RE720. As far as I know, they are identical compound, from the same manufacturer, and both made to modern construction techniques. Which one's best? No opinions please, just an answer. Thanks. Quote Link to comment Share on other sites More sharing options...
ACW Posted March 19, 2003 Share Posted March 19, 2003 IMHO, and this has absolutely no technical merit, I believe that the 539 in a 15" would be most suitable, unless you have sufficient power to require more grip, the wider tyres only really been availiable in 16" (M3's et al) 13" List 1A's are AFAIK all naff compound, also the higher profile tends to allow the tyre to move around too much IMHO. 539 has small tall tread blocks and so therefore will give better grip and less wandery feel when these are shaved down, although I believe unlike the SO2's you will not be releasing a softer rubber at the centre. As I say thats what I think, I'm probably wrong so be nice in flaming me...... Quote Link to comment Share on other sites More sharing options...
guy g Posted March 19, 2003 Share Posted March 19, 2003 That's an interesting point. I thought that all tyres sold in the EU had to conform to EU regulations regarding their construction, and the materials used in the construction of the carcass. Surely all the tyre companies would want to do that as cheaply as possible, which I reckon means that compound and carcass construction are much of a muchness. That would make their behaviour under load (again, an EU specified set of regs is applied, I'm sure, to ensure road/consumer safety and product consistency, so that Joe Bloggs can have 4 radials from different manufacturers on his car without becoming a danger) similar enough that the vast majority of drivers wouldn't be able to tell the difference. Like most regulations primarily concerned with safety, these are designed to promote a minimum standard. As you say Joe Bloggs can then have his 4 radials and they won't throw him off the road or fall to pieces, and it's all about cost of course in the budget/mass market. At the high performance end though it's different. Of course they meet the minimum standards but they're designed up from there, so that's not the end of the story. I don't believe they are all the same - sorry to quote experience again (I haven't cut any up to have a look) - they certainly don't drive all the same -not on my road car, and they didn't on my Westfield. It's quite insulting to have it implied that I have more between my legs than between my ears (but there again maybe not). Still I've never had any complaints in either department before!! It's a bit like the driving really - it's not the size of your tyres, it's what you do with them that counts!! suppose that what Ferrari, Williams, BMW, Mclaren and Mercedes spend on basic research (materials, aerodynamics, wind tunnels, electronics etc.) and the hundreds of people they employ in these fields are just there to use up the sponsors money and don't explain why they are consistently better. Yes, and guess what they spend a lot of the rest on - testing. Why, because despite the greatest theories in the world - real experience is still one of the keys. But all other things aren't equal as far as List 1As are concerned. No-one has made performance cars with 13" wheels for what must be nearly 10 years now. Tyre technology and performance has come on in leaps and bounds since then and, suprise suprise, this hasn't been applied to 13" sizes because there is no market. It's not just about compounds (though modern compounds are not on 13" tyres), it not just about the static contact patch, there's the casing construction to consider as well, then how all these thing's change and behave under load, at temperature, and interact with and suit the car/ suspension behaviour. Sorry but I thought the explanation was there. The last bit is all about maintaining the contact patch under extremes of load during cornering, braking and acceleration. Which is down to tyre construction and geometry, and how well the suspension works. It's awfully nice too if when it lets go it does so in progressive and consistent fashion - construction again I think. The key to lots of things here is to look round and find out what works best, copy most of it - that'll get you most of the way. The focus effort on the areas where you can find most time. If you're on list 1As it isn't the tyres BTW. Quote Link to comment Share on other sites More sharing options...
BobM Posted March 19, 2003 Share Posted March 19, 2003 I freely admit I know b******* all about tyres, but remember some discussion about different carcass material etc. over in the MLR Forum some time ago. The postings by V-Bird are the relevant ones, he has posted extensively in there with some highly technical stuff about tyre construction (and different fuels, Optimax v Toluene etc but that's a different matter ...) Seems to me some of this stuff is relevant to Westies, although probably in the opposite sense to that applied to Evo's! Quote Link to comment Share on other sites More sharing options...
Blatman Posted March 19, 2003 Share Posted March 19, 2003 Thanks for the link Bob. I've learnt something new that I can look out for already......... Quote Link to comment Share on other sites More sharing options...
Turbo Tommo Posted March 19, 2003 Share Posted March 19, 2003 Guy, Still I've never had any complaints in either department before!! It's a bit like the driving really - it's not the size of your tyres, it's what you do with them that counts!! Yo am de man!!!!! Quote Link to comment Share on other sites More sharing options...
Fat Albert Posted March 20, 2003 Share Posted March 20, 2003 Hmmm You all might, especially Guy, like to read this One of the maxims that I follow is 'with knowledge comes success, without knowledge comes Eddie Irvine' so to speak Pompous preach over Quote Link to comment Share on other sites More sharing options...
Gazza Posted March 20, 2003 Share Posted March 20, 2003 When will I ever learn? I always regret responding to anything on here. Someone asks for the benefit of experience, you give it, then get innundated with misguided and simplistic theories proving that black is white. Guy, It's a shame that the vociferous minority put you off posting replies here. But trust me, there's the usual silent majority who appreciate what you've achieved and therefore value your experience/knowledge. All power to you amigo! Quote Link to comment Share on other sites More sharing options...
guy g Posted March 20, 2003 Share Posted March 20, 2003 List 1A tyres are hardly "performance" tyres, so I just can't see why manufacturers would spend any money on "developing them up" Oh yes they are. The list contains pretty much every high performance tyre on the market - standard equipment on Porsche, Ferrari, M3/5 etc etc. List 1B are not really road tyres. And the list contains the flagship tyre in almost every range, and this is where the development takes place that eventually filters down into the mass/budget market. You all might, especially Guy, like to read this Simplistic physics applied to the static situation. If you follow this logic as it stands I would expect to see F1 cars with 3" wide 40" diameter tyres running at 300psi!!! Bet I don't. One of the maxims that I follow is 'with knowledge comes success, without knowledge comes Eddie Irvine' And I bet you're many times more successful than Eddie Irvine, but shun fame and publicity to such an extent that I've never heard of you!! Sorry I couldn't resist. Pompous preach over Shame. Quote Link to comment Share on other sites More sharing options...
ACW Posted March 20, 2003 Share Posted March 20, 2003 What a great thread.... Loads of tech info and discussion and a healty mix of humourous handbagin to boot.... (Oh Blatman pls can call me.....) Quote Link to comment Share on other sites More sharing options...
Blatman Posted March 20, 2003 Share Posted March 20, 2003 ACW. You have voicemail at home, and I'll be following up soon........ It's a shame that the vociferous minority put you off posting replies here.But trust me, there's the usual silent majority who appreciate what you've achieved and therefore value your experience/knowledge. All power to you amigo! Er, nothing wrong with asking for an explaination. Isn't that what bulletin boards are for? It'd be a dull place if the silent majority were left to it.......... And as I have stated, I have the greatest respect for Guy, his achievements, and his knowledge. I just need to see more of it, and I won't if I don't ask........ Now....... Oh yes they are. The list contains pretty much every high performance tyre on the market - standard equipment on Porsche, Ferrari, M3/5 etc etc. List 1B are not really road tyres. I obviously need to re-evaluate my interpretation of performance tyres........but that will be juxtaposed with you're comment that the tyres are less important than other areas. If they were that much less important, would we be spending so much time talking about them. I'm still waiting for an asnwer to my first question...... Why would a 13" tyre with a wear rating number of, say, 200 have less grip than a 15" tyre with the same wear rating? I'm assuming similar widths, but not necessarilly similar profiles, ie a "real world" scenario where 15's are probably a 50 aspect ratio, and 13's would almost certainly be 60 or even 70. I asked because Guy said No-one ever wins on 13" List 1A tyres anymore. It's not about handling it's about GRIP. The emphasis was most definitely on GRIP So which has more grip? A 13" tyre, or a 15" tyre, assuming identical carcass construction, compound, and width, but appropriate aspect ratio IE a 60 for the 13, and a 50 for the 15. And I expect to be told why the choice has more grip, too......just "'cos it does" doesn't answer anything........ Quote Link to comment Share on other sites More sharing options...
Fat Albert Posted March 20, 2003 Share Posted March 20, 2003 Guy I apologise but as I don't know you from Adam it was just an opportunity to use my Eddie lines, just a bit of fun. But then you don't know me from Eddie or what I might have done in an earlier incarnation. As I've never driven a Westy (not even mine, yet) I can't comment on the correct rim/tyre combo, as you'll note from my posts all I seek is enlightenment on the principle Finally much as I admire what Eddie has achieved, how much more could he have achieved if he'd :- 1. Kept his mouth shut more often 2. Really flattened Senna instead of that pansy push Quote Link to comment Share on other sites More sharing options...
guy g Posted March 20, 2003 Share Posted March 20, 2003 I'm still waiting for an asnwer to my first question...... Quote Why would a 13" tyre with a wear rating number of, say, 200 have less grip than a 15" tyre with the same wear rating? I'm assuming similar widths, but not necessarilly similar profiles, ie a "real world" scenario where 15's are probably a 50 aspect ratio, and 13's would almost certainly be 60 or even 70. I asked because Guy said Quote No-one ever wins on 13" List 1A tyres anymore. It's not about handling it's about GRIP. The emphasis was most definitely on GRIP So which has more grip? A 13" tyre, or a 15" tyre, assuming identical carcass construction, compound, and width, but appropriate aspect ratio IE a 60 for the 13, and a 50 for the 15. And I expect to be told why the choice has more grip, too......just "'cos it does" doesn't answer anything........ I'm not sure I understand why the question hasn't already been answered. Again - IT'S NOT THAT SIMPLE. Maybe, if we all parked our cars in the paddock, attached a rope and pulled the car sideways with a Landrover. The prize going to the owner of the car that took the most pulling. It dosen't though - it goes to the chap with the lowest number on the clock after we've actually driven the cars, so you have to consider the whole equation. My experience has been hard won and expensive BTW so don't expect it to be given away. The initial advice was an attempt to simplify the issue for someone who was new to the game - to provide some genuine help before the whole thing got too complicated. I hope whoever asked the initial question hasn't been put off by what followed. How do you learn - by experience - your own and by listening to and learning from people who have more than you. That's how I learned. Funny thing is though, the natural reaction here seems to be: 1. Ask for advice 2. Immediately attempt to prove it's wrong 3. Do something different 4. Then go slower than the person you ask for the advice from Dosen't seem to be me that's silly does it? Quote Link to comment Share on other sites More sharing options...
steve wilson Posted March 20, 2003 Share Posted March 20, 2003 After reading all that my brain hurts and i still dont no what size wheel/tyre combo to put on the bird Quote Link to comment Share on other sites More sharing options...
SteveD Posted March 20, 2003 Share Posted March 20, 2003 steve what the hells the bird Quote Link to comment Share on other sites More sharing options...
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