rgrigsby Posted May 17, 2007 Share Posted May 17, 2007 I've just had a 2nd rear let go on my Duratec engined Caterham. the first time was an oldish CR500 that let go at about 75mph on the m11. the inside tyre wall had a 3-4inch whole in it. the second one that has just happened was a brand new Cr500 that I only just put on the car. i've covered 150miles today mainly on the motorway and it's failed in exactly the way a 2-3 inch whole in the sidewall. i'm a bit concerned now it's happened twice. I can't work out why, there's no rear arb and nothing seems near enough to the tyre to damage it. any ideas as to what might cause it? cheers Rob G www.SpeedySeven.com Edited by - rgrigsby on 4 Jul 2007 22:13:13 Link to comment Share on other sites More sharing options...
k80rum Posted May 17, 2007 Share Posted May 17, 2007 Sorry to hear that Rob, glad that you were okay too - especially after the M11 incident . I'm not near my car at the mo, but I've got to admit I can't think what would be at sidewall height at the rear. Is there anything that could be a culprit, even if it's a fair distance away? The only thing that would seem to fit is something scoring the sidewall under cornering, when it would conceivably flex the most, and then blowing out at speed. If there's nothing at all, I can only surmise you've been extremely unlucky Darren E With an all-new website K80RUM Superlight R #54 Link to comment Share on other sites More sharing options...
Paul McKenzie Posted May 17, 2007 Share Posted May 17, 2007 Something's rubbing obviously - you need to get under the car to see what the problem is Paul Link to comment Share on other sites More sharing options...
Manxseven Posted May 17, 2007 Share Posted May 17, 2007 Is it the same wheel as the first time? Caterham Fireblade here Link to comment Share on other sites More sharing options...
thinfourth Posted May 17, 2007 Share Posted May 17, 2007 Hmmmm I would take springs off the damper and then replace it then with the car up on axle stands move the axle around to see if it touchs or rubs anywhere. Also check everythings is straight and tight The happy handle made me do it here Click here to find 7s in their natural environment Link to comment Share on other sites More sharing options...
philwaters Posted May 17, 2007 Share Posted May 17, 2007 Low tire pressure causing the sidewalls to overheat? Isn't this what happens on a normal car if you get a slow puncture and don't realize the pressure is down. On a 7 we run lower pressures to introduce heat for grip, but on the flip side we rarely sit at a constant high speed which allows too much temperature to build up. Just a thought. Phil Waters Link to comment Share on other sites More sharing options...
Peter T Posted May 17, 2007 Share Posted May 17, 2007 Was the failure in the sidewall in a radial pattern or where they both parralell to the sidewall? R500 260 BHP Mango Madness Link to comment Share on other sites More sharing options...
Graham Perry Posted May 18, 2007 Share Posted May 18, 2007 If it had been rubbing then it would have been obvious on the remainder of the inside sidewall wouldn't it ? Link to comment Share on other sites More sharing options...
dannylt Posted May 18, 2007 Share Posted May 18, 2007 As well as rubber all over the rubbing part. They weren't from the same batch of tyres presumably? Neighbourly sabotage? Link to comment Share on other sites More sharing options...
rgrigsby Posted May 23, 2007 Author Share Posted May 23, 2007 Thanks for all the suggestions, I'm back from the trip now, I've had a good look around and there is no sign of anything rubbing on the tyre sidewall. The only marks on the tyre are where it has actually failed (more holes that marks 😳). I fitted an old spare CR500 rear that I had lying around for the weekend and covered aroudn 1500miles including a 300mile trip back down the same motorway that it failed on during the journey up without any incident at all. The only thing I can think is that some how the tyre lost pressure which lead to the failure, but tbh even this doesn't seem that likely as the rest of the tyre sidewall doesn't look damaged which I would expect it to be after running at low pressure for a while. A bit of mystery, I don't have the tyre to hand at the moment but I should get it back in a few weeks time at which point I'll post some pictures. Then i'm going to take it back to Caterham and see what they say. Cheers Rob G www.SpeedySeven.com Link to comment Share on other sites More sharing options...
Unclefester Posted May 23, 2007 Share Posted May 23, 2007 *eek* Good grief! Do keep us informed.....that sounds really nasty. Lucy in the Sky with Diamonds..ooooh hooo hooo!!... 😬 😬Abbey Road Time-Machine *eek* Link to comment Share on other sites More sharing options...
ruff seven Posted May 24, 2007 Share Posted May 24, 2007 I had a scare on Tuesday night, 110 mph into a fast right hand bend followed by a fast left and right when my left front acb deflated completley mid corner, I was showered in hot rubber as the tyre poured out smoke. changed it last night no puncture just a whole or two in the inner sidewall, I think failure was due to low pressure. scary though. Link to comment Share on other sites More sharing options...
stevefoster Posted May 25, 2007 Share Posted May 25, 2007 The side wall damage is most probably where it let go. Not the cause of the problem i.e. something rubbing. I had the same thing happen on a 205 Yoko rear on the A1(M). The gash in the side was 14" long. I put that down to a puncture letting enough air out to cause it to overheat. What's the wisdom about ideal motorway tyre pressures? On my CR500's I run 17-18 PSI cold, in road blat mode and would raise to 20 PSI cold for Motorways - not sure if that is enough though... Hants (north) / Berkshire club here Area meeting pics here My Racing here Link to comment Share on other sites More sharing options...
Dickie Normuss Posted May 25, 2007 Share Posted May 25, 2007 I set mine at 16 cold and have done thousands of miles without incident, it doesn't seem to have been an issue for others either VX HPC - Loud and proud here Watch out, whatever hits the fan will not be distributed evenly Link to comment Share on other sites More sharing options...
Peter T Posted May 25, 2007 Share Posted May 25, 2007 Well this is strange, it is not like we all kerb the wheels like a normal tin top? Tyre pressure could have an effect, although weeping mag rims or any split rim might be a case to answer to? How often do people REALLY CHECK their tyre pressures? Tyre failure is relatively low on good quality brands nowdays. Also how old are some tyres that people use and have the been cared for over winter lay ups? Many variables to collate here to quantify the failures. Just my thoughts. R500 260 BHP Mango Madness Link to comment Share on other sites More sharing options...
ruff seven Posted May 26, 2007 Share Posted May 26, 2007 Mine was down to low pressure, as I had not inflated them after the three hills challenge, new tyres as well. Link to comment Share on other sites More sharing options...
Petrolhead Posted May 26, 2007 Share Posted May 26, 2007 I was the rapid responce vehicle that came to his rescue AKA the shark 😬 R5 no 65 😬 Edited by - Petrolhead on 17 Jul 2007 11:25:43 Link to comment Share on other sites More sharing options...
simonbell Posted May 27, 2007 Share Posted May 27, 2007 Just had a call from one of our local owners this evening to say that he had discovered damage to the sidewalls of his CR500's......small cuts in the sidewall.......he is running 15" tyres. Rob did you have any joy identifying the cause, have you spoken to Avon / Caterham. The local guys tyres would have been supplied with his kit. Simon Bell - Caterham 7 Duratec R I`ve seen the future.....and it`s powered by duratec Check out the website here Link to comment Share on other sites More sharing options...
Mike Biddle Posted May 27, 2007 Share Posted May 27, 2007 I run my 13" CR500's at 13 PSI cold. The current set are now 2 years old and have 6,500 miles on them including driving across the USA on the 2005 tour. Yes I know it sounds low, but most of that time the car has been in UK while I live in Dubai. Yesterday they had a good work out on track at Castle Coombe, 130 being acheived at the end of the straight. After that we had at least an hour (total) of cruising at 100 on the way home. No problems so far except the rears now need replacing. Link to comment Share on other sites More sharing options...
Toonoisy Posted May 27, 2007 Share Posted May 27, 2007 I've recently taken my set of CR500's off (well worn but still very road legal) because two of them have what I can only describe as splits in the sidewall - like the sort of thing you often see on push bike tyres that have been on a few years. Damned pain - I'd have preferred to get them down the the tread wear markers before ditching them but decided that discretion was the best thing. Could these tyres have suffered simlar issues but un-noticed? (mind you, the new tyre sounds unlikely to be the same thing) Paul Link to comment Share on other sites More sharing options...
Mickrick Posted May 28, 2007 Share Posted May 28, 2007 Sounds like a QC issue to me? The older I get, the faster I was! Link to comment Share on other sites More sharing options...
RichardUSA Posted May 29, 2007 Share Posted May 29, 2007 I took my tires off and rotated / inspected this weekend (4,500 miles CR500's / 15") and saw nothing unusual on the sidewall. I do think I must need to hit it harder though as I may get 10,000 at this rate. Thanks for the caution and keep us posted on CC/Avon response please. I drive my kids occasionally and don't fancy a blowout on the freeway. Link to comment Share on other sites More sharing options...
simonbell Posted May 29, 2007 Share Posted May 29, 2007 I had a look at one of these tyres yesterday. As well as the little cuts in the sidewall there was also an obvious band around the edge of the tyre which was a different colour.....sort of bluey brown tinge. This band started at the outside edge, then came in about half an inch all round the tyre then back out to the edge to where it started.....sort of like a circle within a circle but offset so it touched the edge of the tyre at one point. Simon Bell - Caterham 7 Duratec R I`ve seen the future.....and it`s powered by duratec Check out the website here Link to comment Share on other sites More sharing options...
Peter T Posted May 29, 2007 Share Posted May 29, 2007 Took mine off last week and checked for damage, nothing like any splits or tears in the sidwall. Just the usual cracking in the fronts as i am to believe they all do this. R500 260 BHP Mango Madness Link to comment Share on other sites More sharing options...
simonbell Posted May 29, 2007 Share Posted May 29, 2007 Peter Do you have a photo.......I guess what I saw could be described as cracking but it was different to say a tyre that had cracked due to age, it was in a very specific ring around the tyre. Simon Bell - Caterham 7 Duratec R I`ve seen the future.....and it`s powered by duratec Check out the website here Link to comment Share on other sites More sharing options...
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