I have been running DUNLOP race tires since 2002, and have not had any trouble out of them until last year at the GNF. The tires are coming apart on me, and I don't understand why. Dunlop replaced my rear tire that split at the GNF last year with no questions asked. Since then, a friend of mine who runs Dunlop tires began having the same problem. The rear tire was coming apart. The Dunlop representative said that it was okay to run the tire with the 2 in. split because he said it was only cosmetic. He said he would not replace it. I continued to run the tire, DUMB ON MY PART, and mounted a new set for a practice at Roebling Road. These tires split too, as you see in the picture. I called Dunlop and told them the tire was splitting, and they told me to calm down and not to use big words like "splitting" and "coming apart". You can be the judge on what you call it, I call it splitting and coming apart! I told them I would meet them in Daytona, and show them the tire. I took the defective tire to the Dunlop trailer. They only wanted to replace the rear tire. I asked them to give me a SET of the same tires because you should never mismatch tires. I would have been satisfied with a new set or a refund for the set, but they refused. It is unprofessional of such a well-established company to not back their product. I ended up having to miss 2 sessions of my track day, and the 1st practice session at Daytona because tech would not pass my bike with the defective Dunlop tire. Because Dunlop refuses to help a long time paying customer, there is only one other option. That option is to show everyone who runs Dunlop 208 GPA tires to watch out for this defect. I know that I am not the only one that is having this problem. I have now switched to a new brand of tires, and I am satisfied. If you don't trust your tires then you should stay home and save your money.
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i'm not a tire guy...but i am a quality manager in a die casting plant, so i understand quality problems in a mfg environment...
i also think there are some similarities between the die casting process and the tire making process.
i strongly agree with you that this appears to be a serious problem. got a couple comments:
- don't let anyone tell you that 'there musta just been a bad batch....here's a new tire for ya'. a motorcycle tire would be considered a safety critical item which would mean that extraordinary measures are taken in the mfg process to ensure that no bad ones are made. i would expect less than 5 tires per million would be defective.
- my experience is that the tire guy at the track don't know chit. call dunlop, speak to brubaker or whoever is in charge now, and find out how to know where this tire was made. call the mfg plant and ask to speak to the quality mgr. don't be an alarmist with him, just try to hand him the facts. he's the main guy that can prevent this from happening.
- realize that, in my opinion, they owe you nothing more than a replacement tire. woulda, shoulda, coulda....someone made a mistake. they don't owe you the world. your motivation should be to prevent others from getting hurt.
- don't give up the tire unless the person receiving it assures you that you will get an answer on what was wrong with it.
good luck.
QuoteThe Dunlop representative said that it was okay to run the tire with the 2 in. split because he said it was only cosmetic. I called Dunlop and told them the tire was splitting, and they told me to calm down and not to use big words like "splitting" and "coming apart".
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Well, the tire IS coming apart. Specifically, the tread layer. What you see there is the tread seam separating. (Tires are built in several layers) When the tread is wrapped around the carcass it has a cross seam that should adhere (via stitching) and basically disolve during the curing (vulcanization) process. If any of the rubber compounding, green product, build, stitching, & curing processes are wrong, that's what you can end up with; as well as running tires at incorrect (either too high or low) pressures. All of these are even more critical with high speed rated tires.
IMHO, they owe you a new rear.
and if they made one bad one....they made many more.
Quoteand if they made one bad one....they made many more.
Yup. If I was a factory guy, I'd be checking the tire ID code and run the stats on a few thousand before-and-after builds.
That`s scary....real scary!!! :o
I had the same exact problem last year. I have been running the Dunlops since 99. After "every tire I got form Dunlop" last season split after one session. I even had one split in the rain. Just had the tire replaced and in 5 laps on a semi wet track it split. I have dumped dunlop for Perilli's. I should have done that a long time ago. I really like the Perilli tires. Dunlop lost my business for good in the beginning of last season. I have enough to worry about. I Dont need tire issues. . . and now I dont. Dunlop really screwed them selfs last year and its not any better this season from what I have heard. "Dunlop sucks... Perilli rules! IMHO!
Bernie!
Quotei'm not a tire guy...but i am a quality manager in a die casting plant, so i understand quality problems in a mfg environment...
i also think there are some similarities between the die casting process and the tire making process.
i strongly agree with you that this appears to be a serious problem. got a couple comments:
- don't let anyone tell you that 'there musta just been a bad batch....here's a new tire for ya'. a motorcycle tire would be considered a safety critical item which would mean that extraordinary measures are taken in the mfg process to ensure that no bad ones are made. i would expect less than 5 tires per million would be defective.
- my experience is that the tire guy at the track don't know chit. call dunlop, speak to brubaker or whoever is in charge now, and find out how to know where this tire was made. call the mfg plant and ask to speak to the quality mgr. don't be an alarmist with him, just try to hand him the facts. he's the main guy that can prevent this from happening.
- realize that, in my opinion, they owe you nothing more than a replacement tire. woulda, shoulda, coulda....someone made a mistake. they don't owe you the world. your motivation should be to prevent others from getting hurt.
- don't give up the tire unless the person receiving it assures you that you will get an answer on what was wrong with it.
good luck.
I agree they don't owe me the world but all I asked for was a set of tire to replace the set I purchased. If you bought a car and 5 hours later the engine blow up would want a new car or you money back or just fix the engine? Enough is Enough. If you check the WERA board you will see that this becoming a common problem around our racing circut. Thanks for the advice I will look into it.
What bikes are you riding?
Anyone having these problems on SVs?
QuoteWhat bikes are you riding?
Anyone having these problems on SVs?
I am riding a 05 GSXR 600. I don't know if anyone is having the same problem on the SV's but alot of people are having the same problem around the race circut. Check the wera board. Thanks
I race and ride on Michelins.
However, over the course of years and years of doing this, I have raced on quite few Dunlop tires, among others.
This is something that happens to some Dunlop tires on the race track. It never affected the performance, and it never self destructed. It is common.
QuoteI race and ride on Michelins.
However, over the course of years and years of doing this, I have raced on quite few Dunlop tires, among others.
This is something that happens to some Dunlop tires on the race track. It never affected the performance, and it never self destructed. It is common.
So you would ride the tire for a race ?
We always did before because that's what the Dunlop tires always did. Especially if you were more budget concious like myself. It was never a problem.
Happens because of the way the tread is laid over the carcass and it meets in a place imperfectly.
Regardless, I've got great service from my Michelin tire guy locally, and at the national events. There are good people at Dunlop. I know them too. I don't see that they are trying to screw you, but the Dunlops just do that.
If that brings you to ride on something like a neat Michelin, well, I like the Michelin's, and I hope you do too.
QuoteSo you would ride the tire for a race ?
abso-friggin-lutely not!!!! and that comes from a person who has no problem plugging a hole in a race tire (with a plug patch).
i know too much about flow lines and stress risers and the rotational stresses on tires to even consider riding on that thing.
don't listen to the guys that said they rode on them and they were fine. it would be the same as saying 'i drove with my eyes closed for a mile and i was fine....'
Quoteabso-friggin-lutely not!!!! and that comes from a person who has no problem plugging a hole in a race tire (with a plug patch).
i know too much about flow lines and stress risers and the rotational stresses on tires to even consider riding on that thing.
don't listen to the guys that said they rode on them and they were fine. it would be the same as saying 'i drove with my eyes closed for a mile and i was fine....'
I am with you. I would not ride on it either and do not want anyone else to ride beside me on one, budget or not. Thanks for all the input. I do agree with him on something. There are good people at Dunlop I eat dinner with some of them at the races. That is not what I am saying. Just informing the race community of the problem. Thanks my wife said you had the best reply yet.
And so we see why we NOW have a 200 run with 600s!! :P
QuoteAnd so we see why we NOW have a 200 run with 600s!! :P
True
QuoteTrue
i'm guessing mladin new about this long before we did.
QuoteThere are good people at Dunlop I eat dinner with some of them at the races.
i am guessing after you have been granstanding like this you wont be getting an invite to the Dunlop table any more ;D
Quotei am guessing after you have been granstanding like this you wont be getting an invite to the Dunlop table any more ;D
Who cares.........
oh and don't buy the story that this is ok to have on a street tire...but won't happen on a track tire.
it's a long story to go into, but in their documentation they assess what might go wrong in a tire in what's called an fmea (failure mode element analysis). they list everything that could go wrong in the process and assign 3 numbers to each potential failure mode.
severity 1-10 how bad is it if it happens
occurance 1-10 how often is it going to happen
detection 1-10 how likely will i catch it if it happens
you multiply these three numbers together and get an rpn (risk priority number) for each potential failure mode. the idea is to try to minimize the risk (lower the rpn) on your highest rpn's.
a race tire that seperates and causes a crash - would probably be a 10 for severity (maybe a 9 since we have leathers and good runoff....but i am sure it is a 10) and the occurance would be higher (more likely to occur) on a race tire.
the street tire would still have a 10 for severity, but may have a lower occurance since it sees lower stress by the average street rider.
but, i believe they are both z-rated...and both could make you lose control. street/race tire....don't matter.
QuoteWho cares.........
well you made a point of bringing it up....
Quotewell you made a point of bringing it up....
I know I was just saying if this makes them mad enough to not invite me to dinner then I will eat an MRE by myslef. ;D
Had the same problem with a Dunlop in 2002.
QuoteAnd so we see why we NOW have a 200 run with 600s!!
Isn't this also why they took out the T2 banking section?
QuoteIsn't this also why they took out the T2 banking section?
This tire did not split at Daytona it split at roebling Road on a track day. But this is why they did take out the banking in turn 2 at daytona but it mainly was happening on the 1000 cc not the 600's