Digsy Posted March 4, 2002 Share Posted March 4, 2002 Hi all. A bit p*ssed off at the moment because I have to replace my front two perfectly good (in terms of tread depth) Yoko AVID306s because the sidewalls are cracking like hell. The cracks are developing circumferentially around the tyre wall about 20mm outside of the rim. They appear to have started where the makers' lettering is embossed in the tyre wall. I measured the depth of one of the worst looking cracks by inserting a peice of paper. Looks like about 2.5mm deep - eek! Had a quick chat about it to friends and family, all of whom came to the same conclusion: my tyre is or has been run under-inflated. A check of the tyre pressure showed that all four of were down by 2psi (from 36 to 34 - I am running UK sized wheels and I believe this to be correct) but surely a small drop like that wouldn't cause that much damage? What do you think? The two rears are fine, so has someone previously given my front tyres some abuse, or could there be another explaination like incorrect geometry? Opinions please. Meanwhile i'm off to get some quotes from Mr. Frisbee. Quote Link to comment Share on other sites More sharing options...
AJI Posted March 4, 2002 Share Posted March 4, 2002 I don't think that running your tyres at 34 psi would be a problem, to damage your tyres you would have to be nearer 28 psi or below. Sometimes extreme cold or heat can damage tyres and cause them to crack. Have you kerbed your tyres recently or ran over something at high speed?? This could also be a reason. I have been told that you can run down to 30-32 psi without any problems. With high tyre pressures you will find that the middle of the tyre wears away quicker than the outside. With lower pressure in your tyres you will find that the edges of the tyre will wear away quicker. On my last set of tyres I took the pressure down to 32psi because the middle tread of my tyres was worn more than the outside. I didn't have any problems with cracked tyre walls and there wasn't that much of a difference with road handling, (well not for everyday driving type of handling, would have notinced a difference if I was on the track). You're unlucky that its cracked on the tyre wall as this can not even be fixed at a tyre specialist, it does sound like you are needing new tyres. Quote Link to comment Share on other sites More sharing options...
Digsy Posted March 4, 2002 Author Share Posted March 4, 2002 Hi AJI. Thanks for the reply. No, no kerbing that I can think of. The damage is almost symmetrical left to right so I'm thinking it must be somehow down to the general use of the car. It can't be mileage because the tyres have about 4mm tread left on them but I suppose it could be down to physical age because the car had only done 26000 miles in 7 years. The roads around here are a bit bumpy, but not enough to make you think you might be damaging your car when you drive over them. I'm having them changed on Friday so I'll be able to see if the inside walls are damaged too. Hopefully the new ones won't go the same way, and if they do at least I'll be able to take them back to someone! Quote Link to comment Share on other sites More sharing options...
Guest Mycroft Posted March 4, 2002 Share Posted March 4, 2002 I have never heard of AVID306's. The only thing I can think of is these are the Japanese 'winter' tyres. It would adequately explain the cracking, they can't cope with long runs on hot days and they expand too much and the compound will crack radially or concentrically. If you have been running around on 'imports' then your insurance has been invalid, these tyres are not approved and fall outside the C&U guidelines, all 4 bad'uns means loss of licence if caught. If the cracks were just in one spot then that would be lack of use, all the weight on one small part of the tyre construction for months on end in the sun would do that. (Edited by Mycroft at 3:24 pm on Mar. 4, 2002) Quote Link to comment Share on other sites More sharing options...
Digsy Posted March 4, 2002 Author Share Posted March 4, 2002 Well they certainly are the tyres that came with the car when it was imported. Insurance issues aside there is no evidence of cracking (touch wood) on the rears, and I'm getting the fronts changed to providing I'm not spot checked bwtween now and Friday I should be OK. The car has recently been stood for four weeks, but used each weekend in between, but I would be hard pressed to use more than both hands and one foot to count all the "hot" days since I got it in September 2001! :-) Interesting info about the J-spec tyres. I assume this is a different compound. There must be loads of us with Jap spec tyres out there. What are the C&U guidelines? Are they published anywhere so that we can check them through ourselves? Quote Link to comment Share on other sites More sharing options...
Guest Mycroft Posted March 4, 2002 Share Posted March 4, 2002 Construction and Use, the filf use it to nail you as you leave Southampton Docks with your nice newly imported Skyline etc. It is an offence to SELL any car with these Japanese tyres, all cars must be sold with correct footwear! They are designed for different roads and although not that different to our own tyre spec they do have different heat tolerances and therefore they can be dangerous (only in extremes though it must be said) The Winter tyres are bloody dangerous though, they do need to be kept cool and not run fast on hot tarmac, they will de-laminate and kill you! The limit on hopt tarmac can be as low as 50mph, even if they are 'V' rated!!! Quote Link to comment Share on other sites More sharing options...
Digsy Posted March 4, 2002 Author Share Posted March 4, 2002 Thanks for the info Mycroft. I have been doing some digging on the net, and I don't think they are winter spec tyres. They seem to fall under the low-price low-spec end of the performance market. However I did find this on www.miata.net, which might explain a lot... "A low performance, soft sided tire with good grip and a comfortable, quiet ride." "I had these tires installed when I hit an object in the road and destroyed one of my tires. The others were pretty far gone and I didn't want to buy just one. This is not a tire I would have selected, it was what Discount Tire had in stock at the time." "A very smooth and quite tire [sic] with a lot of side wall flex. They really limit the handling of the car but they give it an incredible ride. I take a lot of long trips and although I would prefer a performance tire, the excellent ride is certainly appreciated on the highway. In spite of the soft side walls, they actually have pretty good grip and are very predictable. I would recommend them to anyone looking for a comfortable tire and a low price who is willing to sacrifice handling for comfort." My car has been SVA'd (possibly even ESVA'd) so hopefully they are approved tyres, albeit not teriffic ones by a long shot. Quote Link to comment Share on other sites More sharing options...
Doughie Posted March 4, 2002 Share Posted March 4, 2002 Darren those tires sound very dodgy. get them replaced ASAP. you could have a blowout. Tyres DO have a "shelf-life" and if those tyres have been on the cr for up to 7 years then they will *definitely* need replacing. 2.5mm crack in the sidewall !?!?! christ get them changed now. tyres with flexible sidewalls are not suitable on a heavy car like the Supra and it sounds like they are low-budget anyway. put on Goodyear F1's (or maybe beidgestone s03's or Yoko AVS sports) and you will have a much much better and safer tyre. Running tyres under-pressure is not a good idea especially at high speed as under-pressure tyres is the No.1 reason for highway blow-outs. (ask Firestone and Ford .......... they are suffering !). But 33 or 34psi should not do the tyres any harm. it's on;y when you get substantially below recommended pressures that it may get dangerous. they blowout due to overheating of the sidewall due to huge flex. high temperatures (like in the States) aggravates it. i would replace all four tyres straightaway. (not just the fronts). It's your life ! Quote Link to comment Share on other sites More sharing options...
Digsy Posted March 5, 2002 Author Share Posted March 5, 2002 Hey Doughie. I reckon they are the second set of tyres on the car, but judgeing by the tread the fronts are definitely older than the rears (they looked brand new when I bought the car) . I have a pair of Goodyear F1s reserved at Frisbee's for fitting on Friday. I will probably be having all four wheels refurbed next week, so I'll give the rears a going over with a fine tooth comb then. I had planned to change all four rubbers next month anyway. Thanks for all the feedback, guys!! Quote Link to comment Share on other sites More sharing options...
Alex Posted March 5, 2002 Share Posted March 5, 2002 There is a weight rating for all tyres (the amount of weight each one can hold - I think my Yoko AVS's are 93Y (not Y speed rating) which equals 600Kg per corner or something like that - you may hava similar rating...anyway you want 89-99 on a Supra. Are you getting "in-house" tyres??? :biggrin: My mate used to get his elise p-zero's for £6 a tire!! £24 a set! ..... you can bet they didn't last long! Quote Link to comment Share on other sites More sharing options...
Digsy Posted March 5, 2002 Author Share Posted March 5, 2002 Hi Alex, I'll check out the weight thing tonight (if I rememeber). In-house tyres? I wish! :-) We haven't had a tyre and wheel "sale" for ages... Talking of Frisbee's, didn't you meet my chums Julia and Charlie there recently??? He has a black FTO and she has a white MX5. Quote Link to comment Share on other sites More sharing options...
Alex Posted March 5, 2002 Share Posted March 5, 2002 Yep I met them, I knew Julia anyway from work - she'd f*cked her brake discs big time!! I'm waiting for the next Goodyear sale of the century as the Esprit uses the same size of tires that I have on currently! Quote Link to comment Share on other sites More sharing options...
Digsy Posted March 5, 2002 Author Share Posted March 5, 2002 Ah... some major ribbing required next time I see her! Incidentally, the 2002MY Esprit uses Dunlop SPs Sport 9000 tyres: 235/40 R17 front 285/35 R18 rear Don't know if these are the same as the 2000/2001MY car or not... Quote Link to comment Share on other sites More sharing options...
Gareth Davies Posted March 5, 2002 Share Posted March 5, 2002 Darren if I recall you got it from JIC? Both my cars have had their tyres swapped at JIC >after ), they're definatly J-spec tyres as well (i.e. not UK approved). When I first went to JIC the rears were immaculate S-03's but it left with some RE-751 (ironically the same as on the NA). Got a full set of replacements for them friday anyway. I bought 8 tyres from micheldever this morning, and they asked if I wanted a trade account :biggrin: Quote Link to comment Share on other sites More sharing options...
Alex Posted March 5, 2002 Share Posted March 5, 2002 The rears are the most expensive and so I'm glad to see they still fit - could have sworn the last version was 18" at the front too. The tread pattern for the dunlop and goodyear are similar....must be having a blonde moment!! ?? :biggrin: What ever happens they are cheap and therefore I won't feel bad ragging them down a strip! :biggrin: Quote Link to comment Share on other sites More sharing options...
Digsy Posted March 6, 2002 Author Share Posted March 6, 2002 Gareth, Yep, I got mine from JIC at about the same time as you got yours. My tyres were the same each time I saw the car, but I suppose that doesn't mean they couldn't have been swapped specifically for the SVA test. I would previously have thought that would be a lot of trouble, but considering that they practically had to rebuild your car after its SVA, I guess not!! :-) Alex, Hey! My lady's blonde. Hang on...so is yours! :-)) Quote Link to comment Share on other sites More sharing options...
Dipstick Posted March 6, 2002 Share Posted March 6, 2002 A certain importer south of LONDON, sells a lot of cars on part used tires. It is never advisable to drive a high power car on anything you know nothing about. Part worn tyres could have been really abused and could be years old you just don't know. I always wonder why someone would get rid of a tire with 6mm of tread all over. I got rid of my part worns after a week, saw cracks in the side wall not as bad as above. My tire supplier said the manufacture stopped supplying the Yoko's on my car about three years ago. The last time I saw cracks like those mentioned above was on a 5 year old spare on my caravan, it had never touched the road. Get em off now, they are very dangerous, as Stu said it is your life, but might be some one else you take with you. If you get in a smack with that rubber the police will investigate and you could be on your own for mega damages at the very least. Quote Link to comment Share on other sites More sharing options...
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