ChrisC Posted January 2, 2003 Share Posted January 2, 2003 Hi All The car I bought 4 months ago has ACB10 tyres on 13”, the fronts 6.0/21.0 – 13 rears 7.0/21.0 – 13. I want to change the tyres to a more road focused tyre i.e. Yokohama A021R for the road, with a set of either A048R or A032R for track days. There are two things I hope you can help me with 1, The size of the Yokos I need, because I assume they are not the same size as the ACB10 2, The car was Flat Floored with the ACB10’s, if I change the De Dion End Plates back to standard, is there any more setup required on the rear or front suspension. Chris... H15 SVN Get It! PS are the ACB’s worth selling? They all have at least 4mm of tread, and the spare (front) has not been used. Link to comment Share on other sites More sharing options...
Peter Griffiths Posted January 2, 2003 Share Posted January 2, 2003 Chris Have just ordered a set of AO48's following inputs from a number of sources that they will provide excellent performance under both dry & wet conditions thus a combination of the characteristics of the 21 & 32. George Polley has no stock at the moment, but (on GP's advice) I managed to get them from John Cross at X-Sport. The AO48 has been nominated as the control tyre for the rally cross folks and as such Yoko have sold the current UK stock to X-Sports. Price is the same as GP and DT (also no stock). Trust this helps - in part Peter 7 Rosina C7 PRG XFlow + Clams The 24 carat Solution Edited by - Peter Griffiths on 2 Jan 2003 11:48:14 Link to comment Share on other sites More sharing options...
murph7355 Posted January 2, 2003 Share Posted January 2, 2003 What sort of car have you got? Something with SL type power levels (arbitrary finger in the air of up to 160ish bhp) go with 185s all round. Over that go with 185s front and 205s rear. R500 levels might warrant 215s at the back but no more is necessary and they work well enough with 205s on the back too. Profile depends on preference but I run 60s. 70s are cheaper and give a bit more "comfort" trading off "control", but for road use it's probably going to be tough to tell the difference. For the wider tyres, 70s may not (a) be available and (b) fit under the arches properly. Link to comment Share on other sites More sharing options...
F355GTS Posted January 2, 2003 Share Posted January 2, 2003 Chris these are approximations Changing to 185/60 13 on the front will result in an increase in ride height of around 10mm changing to 205/60 13 on the rear will increase ride height by 23mm. Therefore you would need to have the ride heights reset to keep the rake angles correct. Important note, ACB10's are crossplys and generally run with no camber, 32's and 48's are Radials and therefore would normally have camber front and rear I would think the ACB10's with 4mm are worth something, they only start off with around 5 to 6mm anyway. They're around £100 each new and many of the race teams sell them off for around £15 but with less tread, reckon you'll get some interest at around £125 for the 5. Mark Link to comment Share on other sites More sharing options...
ChrisC Posted January 2, 2003 Author Share Posted January 2, 2003 Thanks Boys! The car is 97 HPC (or not HPC). So I think I will go with 185/60 on the front and 205/60 on the rear. Looks like I will need to have the flat floor done again 🙆🏻, but should be OK for light duties until the weather gets better. I am not sure the 048 are as good in the wet as the 021, so two sets of wheels are on the cards. Next job will be a check on prices of the 021, but expect a posting in the For Sale section soon. Chris.... Hope to make an Essex meeting one day (when I am not working in Denmark ) Link to comment Share on other sites More sharing options...
scooby dooby doo Posted January 2, 2003 Share Posted January 2, 2003 following on from Mark's post - the camber at the front will therefore need adjusting, which will mean the tracking will have to be checked again. just changing the ears will do the rear. also - i agree with andy - i currently have about 150 bhp and 205s on the back - its a bit too stuck down for fun at the rear. another 50 bhp shold help HOOPY 500 kg R706KGU Link to comment Share on other sites More sharing options...
Peter Griffiths Posted January 2, 2003 Share Posted January 2, 2003 BTW the AO48's are 58:64 + vat Peter 7 Rosina C7 PRG XFlow + Clams The 24 carat Solution Link to comment Share on other sites More sharing options...
murph7355 Posted January 2, 2003 Share Posted January 2, 2003 21Rs are around the 55 quid mark (incl VAT if memory serves) for the 13" sizes... and are, IME, exceptionally good tyres for mixed use. Jury's out on the 48Rs as I don't believe anyone's yet tried them on a 7 in the same sizes as are usually used on 7s...but the people in the know (Polley for example) do say they're meant to be very good. Link to comment Share on other sites More sharing options...
Miraz Posted January 2, 2003 Share Posted January 2, 2003 Consider using the CR500's - they are happy to run with the same camber as ACB10's, and provide very good road performance, especially in the wet. Miraz Link to comment Share on other sites More sharing options...
robmar Posted January 2, 2003 Share Posted January 2, 2003 and that is my plan for the year cr500's for the road slicks for track days acb10's for sprinting just need to get the third set of wheels for the acb10's into the garage b4 the missus finds out 😬 rob Link to comment Share on other sites More sharing options...
murph7355 Posted January 2, 2003 Share Posted January 2, 2003 All subjective of course, but: - CR500s cost twice as much as the Yokos. - they aren't as good in the wet, though aren'#t too far behind 21Rs it has to be said. - they wear out faster (new "green bad" compound might be better, but still unlikely to wear as well). On the plus side - they're lighter than Yokos - you don't need to make suspension adjustments. - they look funkier than 21Rs (but not 48Rs). Having tried both, the cost aspect alone would prevent me from buying CR500s. They simply are not worth the extra money. Link to comment Share on other sites More sharing options...
ChrisC Posted January 2, 2003 Author Share Posted January 2, 2003 OK here is the deal, since you are all so helpful I want two tyre recommendations, one for Road, and one for Track. I assume (since I am still new to 7’s) that the best would be A021 Road ACB10 Track – (or slicks, but cant drive with them on to the track) But because the car will need different setups for each tyre this is impractical. So compromise time. I was thinking A021 road and A032 track, keeping the setup the same. I love track days, but don’t get the time the do them that often. This is the reason I sold an Exige, the car was fantastic on tack, but I only found time to do 2 track days in 18 months of ownership. So the main focus is Road use. I like the idea of the A048 and only one set of wheels, but until a large number of BlatChaters recommend them for the road (and wet, it is England after all) I can only go with Exige/Lotus drivers comments that they appear to be faster wearing A039’s, with similar characteristics. So I think they are out at the moment, however I await Peters comments. So I suppose my options are 1, Stick with the ACB10’s, and drive very slowly if I am caught out in the rain. – Cost £0 2, Change to A021 and sell the ACB’s – aprox cost £ 275 – ACB (£125 ish) + Flat Floor (£175 ish) total £325 ish + another set of Wheels and tyres later. 3, Change to A048, still £350 ish, and take a chance. (but still better on wet that ACB10) 4, CR500 , need to know cost, lifespan and Road charateristics Please add your 2p’s worth, so I can make a decision Thanks Chris. H15 EXG -> H15 SVN Get It! Link to comment Share on other sites More sharing options...
robmar Posted January 2, 2003 Share Posted January 2, 2003 but Andy - chris already has the acb10 setup so going with cr500's would negate the need for a flat floor session I cannot commet on 12's never used them, but I have used cr500's in the wet and ont he road they where fantastic even in standing water, on a wet/damp track they where way better than 32's, although I did have my little accident in the wet using cr500's but I think that was more indicative of the poor driving than the tyres.... I have never used them int he dry so cannot comment on dry performance yet... rob Link to comment Share on other sites More sharing options...
robmar Posted January 2, 2003 Share Posted January 2, 2003 my vote ( as that is what I am doing would be) cr500's road and acb10 for track - if costs is not an issue otherwise 21s road and second hand slicks/acb10's for track days - you can pick up 2nd hand tyres relatively cheaply and then it doesn't really matter if they do not wear evenly, of course you will not get maximum performance but you will have fun the other can of worms you will open with very sticky tyres and trackdays is engine protection (i.e dry sump or apollo) rob Link to comment Share on other sites More sharing options...
robmar Posted January 2, 2003 Share Posted January 2, 2003 cr500 cost direct from avon last time i bought where 90 quid for 175 * 55 100 quid for 205 * 50? rob Link to comment Share on other sites More sharing options...
murph7355 Posted January 2, 2003 Share Posted January 2, 2003 Do you really *need* a change in suspension set up? And if so, do you *have* to have it done now? The answer in both cases is no. I've driven my car (usually set up for Yokos) on slicks and there was still a suitable performance improvement over the road tyres. OK, suspension tweaks may well have made it even quicker and, possibly more progressive (though my feeling that the slicks weren't could just be how slicks are), but there was still an improvement and the car was still safe to drive (though some spectating at the time might have felt differently - then again, they do when I'm on Yokos). You could opt for some Yokos and leave the suspension. You could even have a bash at fiddling with the suspension yourself (I believe Peter Carmichael [i seem to be refering to PC often these days, but he does write a lot about tech stuff] has posted in the past on his DIY flat flooring technique which is easy enough to follow), tough the rears do ideally require new ears. 21Rs are way better than CR500s in the wet and in my opinion ("feel" is always subjective remember). CR500s are good, but Yokos cut through standing water better than anything I've tried. It's one of the main reasons I use them as I'm not partial to cacking my pants (though in winter there are warmth advanatges) and aquaplaning at speed is one of the things in life guaranteed to give me a better bowel movement than a grannie on sennakot. And with the difference in cost of these tyres, your flat floor session will have been paid for with 6 tyres anyway. The ideal combo has to be a road tyre (21R/CR500, whichever suits) and slicks for track use. Then buy a wheel rack from Peter Carr to allow you to transport the wheels on the 7. Note, however, that Richard Ince doesn't believe there's a quantum leap between ACBs and slicks so you coul djust as easily go ACBs (both are available "scrubbed in" for not much per corner... Of course this is far from the cheapest solution, but it's a good one. Incidentally, it's possible to rip both CR500s and 21Rs to pieces on track in the dry. I got through a set of 21Rs in about 1k road miles and three track days on Le Sept. The rears, however, were a bit too narrow for the car and they were getting pushed at times. Biggest reason for Caterham flogging CR500s is their tyre deal with Avon...IMO of course. Link to comment Share on other sites More sharing options...
murph7355 Posted January 2, 2003 Share Posted January 2, 2003 If you have slicks/Avons and are getting the most from them, you want a dry sump. The Vx may be a bit better than a K in this respect but I'd still say it'd be advisable. That makes the Avons slightly less than twice the price of Yokos, but not much. And as you chew these up in 6k miles (or less) that works out at a not insignificant sum if you're swapping the tyres every 9mths. Link to comment Share on other sites More sharing options...
murph7355 Posted January 2, 2003 Share Posted January 2, 2003 PS I've only ever heard of one person saying they hated 21Rs and that was V7. I'm not indicating that he's wrong (even though he is ), but it does highlight that this is all subjective. If you're in London I could possibly lend you a set of 21Rs to try out if you have some axle stands (my spare set are bald and will be getting 48Rs when they're on stream). Link to comment Share on other sites More sharing options...
F355GTS Posted January 2, 2003 Share Posted January 2, 2003 Andy I ran mine with 1.5 ears using both ACB10's and slicks and after one track day on each they were knackered with a heavy wear on the inside edge measuring about 40mm from the tyre wall, I've now changed to .25 ears and the problems gone away. don't know the effect of doing it the other way ie running radials with no camber but presumably the problem will be reversed Mark Link to comment Share on other sites More sharing options...
robmar Posted January 2, 2003 Share Posted January 2, 2003 Mark - I ran a set of 2nd hand slicks for about 6 very hard track days last year on the 1.5 ears and although I got un even wear as you described it was nothing as bad, maybe I wasn't going fast enough 😬 rob Link to comment Share on other sites More sharing options...
Miraz Posted January 2, 2003 Share Posted January 2, 2003 I prefer the CR500 in the wet over the A021 - it feels a little more progressive, and clears water very well - add me to the list of people not liking the 21R. The new compound CR500 (with the green stripe) seems to last longer the Yoko 21's - I'm getting around 6-7000 road/wet track miles from the rears and 11-12000 road/wet track miles from the fronts. My suspension is setup for ACB10's, but the CR500's wear evenly across the tread - suspension setup is a key factor in the life of the tyres, Rob Grigsby managed to trash a set of 4 cr500's in a week of road miles (admittedly a 2,500 mile week...) but his suspension was carrying a lot of camber front and rear. Link to comment Share on other sites More sharing options...
ChrisC Posted January 2, 2003 Author Share Posted January 2, 2003 Fantastic Info, Please Keep it Coming I have both sets of ears (original and the ACB10) and since I have removed the DeDion tube, ready for a bit of powder coating by Arch that is what got be started. Andy, thanks for the offer, but it looks like my 7 has a few bits missing at the moment and I need the axle stands So in order Road / Wet use A021, CR500, A032, ACB10, slicks (not sure where to put A048) Track Days use Slicks, ACB10, A032, CR500, A021 (still not sure where to put A048) I think then a set of CR500 for the Road (cos no setup change) and use my ACB10 on the track days. I should be able to get that past the wife because the Exige used a set of A039 in 5K miles + 1 track day, cost just short of £1K. Yep that’s right £1K, £250 rears and £230 fronts. Just need to know how long the CR500 last road miles only, based on normal 7 driving. Chris. Link to comment Share on other sites More sharing options...
Miraz Posted January 2, 2003 Share Posted January 2, 2003 My experience is that CR500's last well on the road, or even on a wet track - but if you use them on a dry track then they overheat and fall apart fairly quickly. Slicks, ACB10's and CR500's are all happy using the same suspension setup, so they can be juggled at will. All the Yoko tyres are similarly interchangeable, but if you try to mix them with the Avon's then you will not be getting the best out of the setup. Miraz Link to comment Share on other sites More sharing options...
rgrigsby Posted January 2, 2003 Share Posted January 2, 2003 I'd definetly go for CR500's for the road, having used 021r's, 032r's, ACB10's and slicks on my car the CR500's provided the best compromise for road use in terms of wet weather ability and longetivty (as long as you get the camber right ie the same as ACB10's and also check the pressures!!!). Track wise stick to ACB10's/Slicks and then bring out the CR500's when the heavens open 😬 021r's were ok but didn't seem to be quite as grippy or friendly in the wet as CR500's. As Miraz says if you mix Yoko/Avon's you will get wear problems, I've been running ACB10's/CR500's with a radial set-up during 2002 and the tyre wear is all over the place! that's one of the things that's going to be sorted out this christmas!! Cheers Rob G Rob G www.SpeedySeven.com Edited by - rgrigsby on 2 Jan 2003 14:52:38 Edited by - rgrigsby on 2 Jan 2003 14:54:48 Link to comment Share on other sites More sharing options...
ChrisC Posted January 2, 2003 Author Share Posted January 2, 2003 CR500 it is then Thanks All Chris... Link to comment Share on other sites More sharing options...
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