Did anybody see the TWT with dunlop

Uncompetitive to the other two tire companies.

Eboz being number one on that list, but there are several other people that I could think of that could win the race if all the factory teams are on uncompetitive Dunlops.

Rapp
Vincent
Acree
Pridmore
etc........

Roger, there future as a company might depend on whether they can fix this problem. I bet they get it done.

It might not be the best solution. You might have every factory rider out there compaining about the lack of grip from the Dunlops, but they will make damn sure that a tire does not expload during the 200. Even if the rear tires have to weigh 10 pounds......

 

Do you feel smart or what.

Funny how you come in, talk shit...then hide behind some else's shadow to prove "your" point.

Priceless.

 

Hey, I'd just like to refute the implication that a set of Pirellis would be at significant risk of that kind of terminal failure, as you suggest. I see these tires being made every day, to the highest specifications. I see them tested to destruction in the R&D labs. They run them up to 200mph and take the load up to 88% of max (88% of 805lbs) and I see them just sit there all day long. Eventually they fail - and thats just good fun to watch, unless you're on the bike that is.

So how much load is on one of these "heavy" superbikes? What do they weight? Well an R1 with fuel weights about 425lbs, plus rider of say 200lbs is 625lbs. Divide by 2 for 2 wheels is 312lbs. So how much G is created on these banked walls. Well, its definatly not 1G, lets be generous and say 0.5 G. SO total weight is about 1.5 * 312 = 468lbs.

We run them up to 200mph with708lbs, and they all pass.

I'm so confident, that I would happily send my mother out on Mladins suzuki, with you and your family perched on the pillion seat, around Daytona.


....she doesn't go over 55mph, so I think I'm on safe ground here....


To be honest Pirelli doesnt pay me anything to mindlessly cheerlead about their product - so I'm off to demand a raise. Basically, I beleive Dunlop make excellent tires, that are probably the best race tires you can buy. They are faster than the Pirellis in all probablity. But they do have a safety issue.


Finally, will any street riders change brands as a result of Dunlops failures?? - I doubt many will, they dont pay that much attention.
Will many privateer Dunlop racers switch brands? - nah
Will many factory teams switch brands? - probably not.

So, apart from rider safety, whats the issue? None. Thats why, the ONLY issue is rider safety.

 

Dunlop told me the banking at Daytona puts 1.5 Gs on the tire

 

Street riders do pay attention, and most of them are uninformed and make tire decisions based off irrelevant info.

If a Dunlop fails during the 200 and it becomes widespread news that they are having safety problems then I won't be able to give a set of D208's away. Promise.

 

I don't work in retail, so I can accept your point of view. I guess I'm just thinking back to when I rode my R1 on the streets. I didn't follow racing, and would not have even heard about the Daytona 200.
I guess, that when I buy something, I assume its going to be ok. If I hear that a Bridgestone blew up on a F1 car, I don't make any connection to the 'stones on the family SUV.

But, I do take your point. The average sportbike rider is probably into racing too.

 

1.5G total (excluding the effect of nominal gravity)? I would imagine to Dunlop techs, that they are quoting an engineer that recorded the force being applied in the perpendicular direction to the plane of the banking and divided it by the force of gravity - hence 1.5 times the weight of the bike. So, the thoughts above by the Pirelli employee is actually correct.

 

...I knew I shoulda been an engineer ....must be that Holiday Inn I stayed at once....

 

Ya...you gotta watch engineers, they will play with words and bullcrap (like G forces) to come up with some really exciting junk. The point is on this...Dunlop is out of control with their tires. They have an inherent construction problem that simply effects their ability to construct a tire. Every tire is different (rubber, material of the belts, orientation of the belts, etc.). And Dunlop's preferred method is just not being designed or manufactured to accept the forces applied to them.

 

Maybe I missed this and it has already been posted, but have all the catastrophic failures (tire explodes-will not hold air) been on rear tires?

Just curious.

 

I have a hard time believing that Dunlop has not failure tested their tires in the lab at more than twice the predicted loads. I bet none of their tires blew in the lab after only 11 simulated laps. The problem is that they have not identified enough of the real world variables to make an accurate simulation. This makes the situation much more scary. When they thought they had the problem solved, they obviously didn't, and they probably can't figure out why. The only thing left is real world failure testing, which I don't think any of the pro riders anticipated. When they test, they are prepared for things not to work correctly, but there is usually some warning.

 

Yes, all rears.

Sorry, I ain't no hi-lee edu-macated enjuneer or nuthin... But won't ch'all just try and bear with me fer a secund....

The tire tests are performed at a static load. And it is estimated that Daytona puts 1.5 Gs on a bike.

There are dynamic factors nobody (but weirdos like me) think about.

The primary dynamic variable that ruins all of this esteemed panel of experts analysis, is that the track is not flat. It is very very wavy as a matter of fact. The bike is constantly undulating all the way around the banking.

When you first get up on the banking, you are on the right side of the tire, and as you accelerate, you get the bike to vertical, and then eventually, you get past vertical and onto the left side of the tire.

The G-load is constantly varied. It is varied so much that the riders cannot support their own upper body weight, and most run chest pads and chin pads on the gas tanks to help hold their head and bodies up.

That means the tire is taking the same variations in load. Seriously, not being a tire engineer, I cannot say for sure, but I do know that with most metals, and woods and rubbers, you can apply constant pressure of a great amount to anything without it failing, while cyclical pressure, or "working" the test piece will result in failure with much less pressure.

Secondly, in the lab, the tire gets a constant, fat footprint. The more tire that touches the ground, the cooler it will run. The ground acts as a heat sink for the tire.

When a tire is being compressed, and then released, it makes the contact patch get very small, and this is when wheelspin in a straight line occurs. Obviously less tire touching the ground makes it get hotter, and making it spin makes it way hotter.

I don't know, but I doubt seriously the dynamic conditions are being duplicated in a lab.

But I guess they could ask Michelin for advice...

 

If the dynamic forces on the latest fighter jets (which are unflyable without a computer) can be simulated, then so can the forces on a race tire. It may be expensive, but this has become a real safety issue and potentially a public relations issue. Besides, all you really need is some brilliant guy to derive all the mathematical formulas and put them in a powerful computer.

 

I just wanted to say the AMA is not the only motorcycle race held at daytona.

Out of respect for WERA I will just say there is another "group" that runs there twice a year with some pretty fast bikes and they don't all use dunlops.

I have no idea if there have been tire problem at these races but it would be worth checking into for this subject as there will be a larger group of non-dunlop riders.

I betting pirelli was raced at these races so they are not untested.

 

It isn't as simple as that. The machine testing the tires needs to be capable of dynamically simulating track conditions at Daytona.


BTW, running on the apron is an even WORSE idea. That means you are on the SIDE of the tire with it loaded and slipping and spinning for about a mile at a time. That is MUCH worse than what they have now. They have trouble at Willow and that is a much shorter distance than at DIS.


FUSA has had HP restricted (well, they are restricted when tested on the dyno anyway...) for a long time. The limit is 145HP and DOT tires.

 

I think he was referring to the Ducati, not the tires.
Ducatis have made it to the checkers and onto the podium.
Damn, they could have even won in 1992 if only Chuck Graves was around to sucker Ru$$ell into flipping him off!

 

Ain't hiding behind anyone's shadow there Jr. And the only point I was attempting to make was the fact that you weren't arguing from a position of strength. A point I think has escaped you thus far.

 

Most of this talk is pure BS. Who cares? The fact of the matter is that Dunlop tires have experienced a mired of catastrophic tire failures. In my opinion debating physics, discussing horsepower, arguing load factors, spouting theory and talking about this in terms of statistics is FN retarded. At this point does it really matter why a tire fails? Who gives a shit?

The bottom line is reality. Dunlop has serious production/quality control issues. Anyone who thinks otherwise and chooses to debate the facts is just plain retarded. G

You know who you are: S.T.F.U. retards.

 

Plus this year they did away with the 750's in the premier superbike class - now run only 600 IL4's restricted to 660 cc's and 145 HP.

Unlimited GP is the only class that allows unrestricted 1000 cc IL4's with slicks, so that's the only class that is comparable. The fields are not that deep, but you get some ringers showing up occasionally, especially at Daytona. Barney and Rapp won the 2 races there this year on GSX-R 1000's - Barney in March on his AMA Superbike on Pirellis, Rapp in October on a Valvoline bike of which I don't know the specs on Michelins. Stokes and May were also there in the Spring on Pirellis, but they were one 750's if I remember correctly. No tire disasters either weekend that I'm aware of, but not sure how valid the observation is.

 

F/USA Superbike last year (and for this year) has no HP restrictions, just a 660cc max displacement.

UNGP was won by Eric Wood on a 750.