Dunlop's tire woes

[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...