Dunlop's tire woes

[DRU2]

Was wondering what other people think about this exploding tire thing.Some people have said that its the bikes, they have too much power, to much tork.But in the same respects the Moto Gp bikes have alot more power & tork then the super bikes and they don't seem to have this problem.Other have said that its time to stop running the Nascar tracks, that they are to fast. But here again the
Gp bikes run at speeds over 200 miles a hour and it seems that some of there tracks are just as fast.although I don't think that they have a track that they go onto the banks like in the Nascar tracks.  Are the AMA riders getting different tires? I have never ridden Daytona,in Europe or have I been on a bike that is that powerful.So I really don't have anything that I can base a opinion on. so i ask you  whats the problem with the Dunlops that are given to the riders in th AMA?

[Jeff]

You're not riding on the same tires that the AMA guys use.  The compounds and construction are different.  Additionally, I'm led to believe that the factory supported guys get different 'test' tires which may be a complete one-off from what is sold/used/distributed/available to the general public.

Let me ask you this...  How many CCS/WERA/CRA/CMRA (non-AMA) guys have you seen disintegrate a tire?  None...

Would the same thing have happened on a different tire? who knows.  

[Super Dave]

AMA Superbikes are heavier.  That is key.  We are talking about load.  My bus has what 250HP but it needs 10 ply tires because it weighs 9100# empty.  A 250HP car doesn't need the same tire as my bus.

That make sense out of it?

I haven't been a Dunlop racer for a while, regardless, I think Dunlop is a good manufacturer.  I don't know what to say about it all.  The tires that are blowing are definitely the better race tires, but they are certainly not unobtainable as was our experience in AMA Superbike in 2003 with Safety First Racing.

At the AMA level, Dunlop has purchased most of the field.  So, they certainly have more tires out there.  

I myself do use Michelins.  

[Mark Bernard]

I use Dunlop exclusively and I have never had a problem with them.... I over cooked a set once but that was my fault, not the tires. (Live and learn!) Seeing how I am going to do a full season in 04, I am going to try others (Michilins/Perelli) to see for myself what I really like and what i dont. But overall, I am really happy w/ the Dunlops! (my $0.02)

[MudDawg]

Let me ask you this...  How many CCS/WERA/CRA/CMRA (non-AMA) guys have you seen disintegrate a tire?  None...

Privateer Brian Livengood popped a tire at Road Atlanta the day before Mladin did it in the race.

Sorry...but last I knew Road Atlanta wasn't a Nascrap track.  

Basically we are looking at the tires not keeping up with the bikes they are being put on.  Yeah...MotoGP bikes put out more hp.  But US riders don't have access to those tires. Plus the AMA bikes are heavier putting more heat and load on the tires.

Either way....time ti try a different manufacturer until Dunlop figures this out.  Either that or put more chicanes out there to slow the bikes down.  People haven't said it...but the new chicane at daytona has allowed even faster speeds throught Nascar turns 3 & 4 at DIS.  Not good on the bigger bikes.

[DRU2]

So how much lighter are the Gp bikes compared to the Super bikes? And what are the differences in the tires that they use. And if there so different why the hell arnt they used in the here!

[unlss29]

Not to be tire brand bashing or anything but I don't remember anyinstances of steel belted radials coming apart at high speeds in the last few years. Think about how few tire failures you heard about in Moto GP from all the brands. What's up in the U.S.?

[KevinC]

MotoGP bikes have different minimum weights, depending on the engine config. Three cylinders can be 135 kg (297 lbs.), 4 or more 145 kg (319 lbs.). That can't be that much lighter than an AMA Superbike, given that the street versions of those bikes weigh 365 or something.

WSB must make the same or more hp, and weigh about the same as the AMA Superbikes.

I don't think the weight or the HP are the real factors here. Either Daytona shouldn't be used anymore, or Dunlop have a problem. Given the two Dunlop tire failures at Atlanta, it seems it might be a Dunlop issue.

[Eric Kelcher]

Kevin the AMA superbike rule is 370#s the street versions of these bikes are in the 420# range

Seems to be a DUnlop issue Pirelli, Bridestone, and Michelin have not problems with their tires there.

[Zac]

Maybe Dunlop hired some ex-Firestone engineers...

[Nate R]

If you read the articles an amasuperbike.com it will make more sense.

The MotoGP guys: What track are they doing THAT much speed THAT long? sure they've hit over 200, but do they do over 180 for anything close to the length of the banking used at Daytona?  Also, the loading from the banking creates more heat, as does the ripples in the pavement from cars. That, and the extra 50 lbs. together will create a TON of heat.

[r6_philly]

and the Ducati and Vaveline guys don't go that fast on Michelins? Michelin hasn't raced at the top level in America for how long? They bring a bunch of tires that are unknown also for "testing" and no issues that we are aware of?

No other tire has experienced a total blown out/failure in AMA as far as I can remember (albeit not that far)

I have never seen seam seperation on any other brand but Dunlop? Quite a lot I might add. Go look at 10 dunlop DOT race tires I bet you more than 1 has seam seperation? They can claim its safe all they want, I don't want to see cracks in my race tire contact surface.

[WebCrush]

Take a look at this tire:



This MICHELIN is from Tom Fournier's Ducati.  It blistered and the came apart on the 3rd lap during the SuperTwins race at Daytona.  It cost him the race and he crashed mid way through turn 1.  One second earlier and that would have been a highspeed banking blowout.  The subsequent leader also had his Michelin chunk out on him crashing him as well.

I don't think any tire manuf. is going to handle the pressures of Daytona very well.  I mean, lets be realistic--do you know any other tracks where the REAR tire pressue is 36psi and they fill em with nitrogen to keep them cooler?  The only reason the Dunlop gets so much attention is that 90% of the SB riders (and almost ALL of the factory teams) are using them.  It comes down to statistics.  

How many Michelins were tested at Daytona?
How many Dunlops were tested at Daytona?

Quadrulpe the number of Michelins tested and I'm sure you'll see a blowout or two also.

Also, were the tires being tested by Michelin 'daytona' tires?  Dual compound?  I've heard a lot of complaints about the Michelin Daytona tire (wobbly and vibrations).

[r6_philly]

actually I eat my own words.

I was pitted right next to (the other side of the table)that ducati and had a good look at it. Funny you guys took pictures of it.

Front tire blow up was weird, because all the tires I have seen, rear is worse than front. There was something wrong wtih that tire, but maybe just THAT tire.

Still, some body answer me on the seam seperation and why dunlop don't care to listen about it?

that was the sole reason I stopped using dunlops by the way. and I influrence quite a few people, believe it or not.

[WebCrush]

you were on the other side?  damn, we prolly met and don't even know it.  Tom (Ducati rider) and I shared the same garage that weekend.  Were you the guy that kept borrowing my air compressor?

[r6_philly]

no, but we kept borrowing funnels and pump cuz we bought a drum of VP and forgot the pump haha

2 chinese guys, hard to forget  ;D

[harb990]

Not to mention it does happen in MotoGP - I think I remember Rossi's rear chunking last year during the 2002 race season and costing him a finish - don't remember which round, he noticed it and came into the pits before he had bigger problems.

[Super Dave]

Yes, it happens, tire failures.  Again, I use Michelins, and I have nothing bad to say about Dunlops.  As for that seam that opens up on Dunlops, that's been happening ever since I started racing, and using Dunlops at the time, in 1987.

Recognize that the bikes that have had serious failures were high HP bikes.  Livengood wasn't riding a factory bike, but it certainly was a well prepared bike ridden by a very good rider.  

Anyway, even a production based 1000cc bike produces some really serious loads now that we didn't see in 750's, and we won't see in 600's.  The weight above a GP bike has to be a factor in comparison.  These things are at the limit.  You've got to draw a line somewhere.

[thetireguy]

This MICHELIN is from Tom Fournier's Ducati.  It blistered and the came apart on the 3rd lap during the SuperTwins race at Daytona.

Hey Folks Tom Mason here aka: The Tire Guy for the Midwest region.  Mr Fournier was not using tires approved by Michelin for use at Daytona. Mr Founier was told NOT to use that tire and we (the Michelin garage) refused to mount the tires he bought with him to Daytona.  He has been using non Daytona rubber for a while and gotten away with it.

 Non Daytona tires are not recomended on any big bike and you can see from the photo what could happen.

Good news is the tire was holding air pressure!!!

[Super Dave]

Bingo, there usually is an explaination. 8)

[KevinC]

Maybe Daytona could be cancelled, and a real road race at an interesting track substituted?

If I wasn't so desparate to watch a motorcycle race by that time of year, I'd never watch Daytona anyway. It's a terrible track for a road race race, too much like watching Nascar.

[r6_philly]

As for that seam that opens up on Dunlops, that's been happening ever since I started racing, and using Dunlops at the time, in 1987.

And that is a good thing? in my eye that is a design flaw. would you still race a bike if the frame had a hairline crack but they keep telling you it wouldn't matter?

If that had happened to 1000's DOT tires designated for road use, I think Dunlop would have to address that issue don't you?

I know we had to trust our equipment, but is it really a good thing that we trust a tire with seam seperation.

again I am not saying that dunlops are bad tires. I am saying I would not patronize a company who does not fix what they could fix. Maybe the tires are exloding because an accepted design flaw is finally biting them? I don't expect to ever hear the truth because no third party is investigating.

Lets see that happen to a road tire. The gov would be all over it and dunlop would be forced to recall all tires made from the same facility.

Shame to think top level racers are not as important as joe public. Good company I say

[fourandsix]

I can't help myself and i have to reply , It is with great entertainment that i read the posts about the seam line opening up on the dunlops. I have used a large amount of Dunlops over the years , if i had to guess i would say maybe i have seen 5 tires that seperated a little bit and that was after the race .Actually the tire that won the 600 race at road america with todd riding was one with a seperation.I have never had any other major problems with a dunlop but then i never raced in a big bike class when the lap times were that fast at daytona or the bike had that much horsepower.
Someone also touched on a very valid point , How many tires did the riders try at the dunlop test versus the michelin test? You also have to remember that this was a test , the tires aren't neccessarily ever going to be a production tire.The reason all those factories use dunlops is that they want to win championships. Why did most all of the Factory teams in world Superbike back out? They don't think they can win on the Spec tire. We can speculate all we want what went wrong , but i'm sure Dunlop is working very hard to correct it.

[OmniGLH]

Shallcross (AM#43)  had 3 Dunlop rears fall apart on him at ROC this year on his GSX-R750.

[r6_philly]

I am not relating the seam seperation thing with the tire test woes.

I am merely saying that I don't like how dunlop approach QA and how they assess their product.  I will not accept sean seperation as a "normal product behavior" as you want me to think.

So if I write a letter to NHTSB with 5 samples of seam seperation under normal usage, you think they are going to tell me "oh it didn't fail so keep using it"?

Product fails when it exhibits abnormal behaviors. Unless you want to have me believe it is normal. So tire tread surface coming apart is normal? Lets see if DOT thinks so?

And you tell me its been happening for 20 years? Well what a case this is? At the very least, a cut in the tread surface will increase wear that will reduce the product life of dunlops. That would be a DEFECT.

Oh its rare? I saw 5 samples walking down 1 aisle of paddock at VIR the last track day there. Maybe you just dont look at tires too closely, or you really don't care.

well some people care, just not the people who makes the darn tires. go figure, they care about you the rider?

[fourandsix]

It's a race tire! not a street tire.i have also in the past raced on other brands and those had some failures. You say you saw a bunch a VIR at a track day , i am sure they were on properly set up bikes and had very low mileage , track day guys hardly ever use the tires more than 5 or 6 trackdays and then ride on the street between track days. I'm sure Shallcross might have had some problems in his case was the bike set up correct for Daytona and he was also riding the wheels off the thing. How many laps did the tires have on it ? There are a lot of factors that go into a tire having a problem and i am sure that Dunlop is working very hard on it , as all of the Tire Companies.I read somewhere Bostrom Chunked a Michelin and he was even running as fast as the hondas. Maybe it is a set up problem with the Suzuki or yamaha , Did the Kawasaki's blow up one?In Racing there are many unknowns!

[fourandsix]

R6 I can sympathize with your concern but you probably don't use Dunlop tires anyway , and as for not looking much at tires, i have probably checked tires more closely than you ever will.Some years i have checked more tires at a race such as the daytona spring races than you would use in a year, and i don't care? I care very much as i build quite of few bikes for racers , racers who use other tires than Dunlops.I would never want to endanger a rider at anytime.Apology accepted!

[r6_philly]

I know what a great job you do, I just being sarcastic.

DOT race tires are NOT race tires, they are street tires. They have to pass DOT specs and be certified to be street safe. So I wonder what DOT would say about seam seperation? If a DOT race tire will seperate at the seam on a stock bike with factory settings, then the tire is a DEFECT. sorry, that just has to be the case

Oh and I am not doing a plug for whatever tire I use. I didn't mention it did I? I stopped using dunlops when they didn't show any concerns to my concerns. And just because it happens to alot of people doesn't mean squat other than they should look at their tire and make an improvement. I may not be a tire engineer, but seperation on the tread surface can't be good can it?

And it does not matter how the bike is set up unless is not within factory specs. So if you put the recommended pressure in the tire and ride it normally (it is certified to go 149mhp for a Z rating isnt it) and the seam still seperate, then something is wrong.

what do I have to apologize for? I can only perceive what you express. I didn't say you endanger racers, I say dunlop potentially is.

look past the status quo, just because it is "normal" doesn't make it right. I say it again

[r6_philly]

by the way I am not talking about slicks, or the daytona problem. Just seam seperation on DOT's. Just to clarify.

The blow up at Daytona could be one of many reasons. But the overall attitudes of dunlop, its support personel have toward my concerns with seam seperation leads me to questions the real culpit behind dunlops tire problems. But I have no facts, so I am not talking about that.

[WebCrush]

on a lighter note:

I've used nothing but Dunlop since I started racing (5 years ago) and have never had one chunk, seperate, blowout, etc.  Not a single failure ever.

One time while in the trailer some metal rubbed a raw spot on a rer and I still rode the shit out of it and it didn't have a problem.

In fact, the only tire trouble I ever had was on my trailer coming back from Daytona two months ago:

 I think I shoulda used a harder compound

[r6_philly]

you can hang that on the wall, that looks like a pretty cool art piece  ;D

[DRU2]

Ok, so I understand that at sometime somone is going to have to say enough is enough but what do we do with the bike that are being produced right now. I was hoping that this year with allot of the tire brands dumping alot of money into the ama that we might have a better series in the states here then we have had in the past.Maybe some more teams and new riders.

[r6_philly]

someone was mentioning using restrictor plates to slow down the superbikes. Then you would have to slow down superstock too, then you would have 1000's riding around like 600's. I don't think it would work. And daytona is too big a deal and tradition to eliminate from the schedule. I think the tire companies would just have to sacrifice some performance for reliability and safety, if thats possible. And they have to run 200 miles. The TT has been outgrown by the bikes for how many years now? They still going to keep running it...

[Super Dave]

But the TT is not part of a series.  It is an event all it's own.  I hasn't been in the world championship schedule for decades.

Daytona IS a regular season race.  Certainly it is an event, but without the current factories and riders attending, it won't be the event that it has been.

As for DOT tires...How much does that really mean?  In the days of the Dunlop K591 and my first experiences of that separation thing...we'd get some take offs from Scott Russell or something...There was a period where eventually that the production of the Race 591 was actually a race slick that was put in a different mold so it had the sipes.  The trend of "race" DOT's continues to get more and more race oriented.  It's to the point where companies like Pirelli have Race DOT's, Track Day DOT's, street DOT's.  Race DOT's are race tires.

Regardless, manufacturers design tires to work, function what ever.  Racing is not the normal mode for NHTSB stuff.  "Yeah, I was goin' like 175 and it came apart."  Certainly the Z rating means something, but I'd bet that given the load, etc, we'd be going beyond it's rating.

And this is racing!

Certainly, you do everything you can to be safe.  But things happen.

1990, Eddie Lawson's brake pads fall out of his GP bike...

1971, Yvon DuHammel's H1R ignites at top speed...the engine cases were made out of magnesium and they lit up...Yvon jumped off.

1991, Jaque Guenette (I really can't spell Fr/Can names...) has his clip on break off under braking on his Muzzy Kawasaki.

Didn't Freddie Spencer have his bike catch on fire while he was on it at Daytona in like 1978?

Tire failure?  Barry Sheene.  Laying in a pool of his own blood with his leg laying up over his shoulder.

Kenny Roberts...tire failure...broke his back in testing prior to starting the season to win another world championship.

[G 97]

Regardless, I have more than 10 sets of 208GP's in my garage from this season that are all either out-of-round or have the but joint separating across the tire.   I don't think any of the other tire manufactures have had these types of quality control issues.  I have ran Dunlops exclusively but will switch in 04.  

I really like the feel of the 208's and the ruber compound is great but the build quality somtimes has been suspect.  

I also witnessed Yate's mechanic turn down/reject several sets at RA this year,  while they were spinning them.  I would not classify this as a heated exchange but it was pretty direct and to the point.  

[Photo_Chick]

So is there an explanation between Livengoods tire failure (or should I say explosion) during qualifying and then Mladins that same week-end?  Both on Dunlop tires.  Dunlop says there is no correlation between the two. Seems to me that Dunlop is having major problems with tires lately.  They have caused major injury.  Livengood is very careful with his equipment...

[Super Dave]

I ride on Michelins...but regardless, one has to admit that there are more Dunlop supported riders on the grid of an AMA national than any tire by far.  So, there is more opportunity there.   And the tires are taxed harder by those guys than what you'd get at a FUSA or WERA national...

So...

[Howlin_Mad]

One thing that I have not heard is the comparison of racing surfaces in Europe compared to the US.  The standards for FIM and MotoGP are considerably higher than AMA.  This alone will make a difference in the design of the tire that manufactures put out to there teams.  Most tracks in Europe are repaved completely each season with the best asphalt known.  Only Barber that I am aware of comes close to that type of surface.

[Super Dave]

Good point.  I've been on a lot of different tires.  Sometimes what we got from Europe for the "A" tire was not as good as the "B" tire that followed...on US asphalt.  It can be just different.

Barber...it's using the polymer based stuff.  It's cool but it absolutely blows.  Heartland Park Topeka and Mid-America Motorplex are great examples of what happens to two extremes.  Topeka needs some action on it to make traction, then it works.  Wasn't too abrasive.  But it had no durability.

MAM...extraordinarily abrasive.  I mean, if you were using Pirelli's at one time, you were lucky to get eight laps out of them.  And the durability is aweful.  After about three months, the stuff was crumbling.  

Euro standards are not always the best for every climate, every location.  Look at all the barriers that the FIM made Barber put up.