What brand of tire was Maladin running in the AMA Superbike race at Road Atlanta today? Holy smokes! That had to be a truly "Oh Crap, help me God, moment" :o
Dawn
QuoteWhat brand of tire was Maladin running in the AMA Superbike race at Road Atlanta today? Holy smokes! That had to be a truly "Oh Crap, help me God, moment" :o
Dawn
I think all factory guys runs Dunlops?
Another thing : Brian Livengood crashed at high speed (same corner?) on Friday with a suspected tire failure too. It was reported that his rear tire smoked right before he crashed in the turn and getting air lifted. He was on Dunlops as well... hmmmmmmm
Mlading sure had a good enough save though. sucks to be mladin. Maybe he is riding that thing too hard ;D
Mladin was on Dunlop and just FYI Brian is OK
Yes, Dunlop buys the factory teams and additional other front runners. I believe that both tires lost air and then the results happened. We'll never really know the exact cause, but those things can happen. It's a rough track and the 1000's are still putting out 170HP in really easy privateer trim.
I heard they thought Livengood might have ran over some debris shortly before the incident. I'm just glad he's okay. Anybody hear anything about Deatherage (Sp?), the guy that caused the red flag in the other race in the esses? Couldn't see him and he was right by a wall. Scary stuff...maybe they need to move some more walls there.
Remember when Ben Bostrom's Dunlop let go at Daytona tire testing when he was riding for Ducati in the US. How come it is only the Dunlops that fail?
QuoteRemember when Ben Bostrom's Dunlop let go at Daytona tire testing when he was riding for Ducati in the US. How come it is only the Dunlops that fail?
Maybe the privateer bikes that uses other brands are not as hard on tires? I don't use dunlops, so I don't care as much, but it does raise a question or two.
anyone in club racing had similar experiences I wonder?
I had a bridgestone tread come apart once, but thats cuz the tire guy mounted it the wrong way.
I had a 207GP develop a cut across the tread last year, but the dunlop guy told me it was probably a saftwire cut :-/
QuoteHow come it is only the Dunlops that fail?
Not true - remember last year when Rossi's michelin threw a chunk out it - can't remember the race
QuoteRemember when Ben Bostrom's Dunlop let go at Daytona tire testing when he was riding for Ducati in the US. How come it is only the Dunlops that fail?
The vast majority of the field is running Dunlops (in AMA). Your sample size is much greater than other brands, so the chances of something bad happening are greater than they are for other brands.
Tire failures can happen with any brand of tire. I was looking at the tread pattern and trying to figure out what it was. It was really scarry to see.
Dawn
Don't they run slicks in Superbike? Anyhow, believe me, the tire manufacturers do not want this happening at the national level. Bad press. They will have it analyzed and fixed pronto.
I have personally seen 4 Dunlop 208GP's develop what looked to be a cut/crack perpendicular to the rotation of the tire on my friend's bikes from a trackday. The worse of which split open enough to see the belts under the tread. They were running proper air pressure and overall the tires looked good with the exception of the cut/crack. None of the other brands of tires at the track on those days showed any abnormal features so I'm assuming it was a deffective batch. I hadn't run Dunlop's up to that point and after seeing that I'm pretty sure I won't.
I was mounting up a race castoff (dunlops) on my street bike and saw the same thing...we had to scrap the tire...interesting....
QuoteI have personally seen 4 Dunlop 208GP's develop what looked to be a cut/crack perpendicular to the rotation of the tire on my friend's bikes from a trackday. The worse of which split open enough to see the belts under the tread. They were running proper air pressure and overall the tires looked good with the exception of the cut/crack. None of the other brands of tires at the track on those days showed any abnormal features so I'm assuming it was a deffective batch. I hadn't run Dunlop's up to that point and after seeing that I'm pretty sure I won't.
I had that happen to a set of 208s last season. The response I got from the tire guy was, oh that happens and it will be fine. I was at Brainerd and with the speeds of T1 I didn't feel comfortable running that tire.
QuoteI had that happen to a set of 208s last season. The response I got from the tire guy was, oh that happens and it will be fine.
Ask him if he'd be willing to run the tire himself. Unacceptable. Completely unacceptable. We want tires we can be confident on. Yeah, Turn 1. Brainerd. Didn't duhamel have his "skirt fly up over his head" there? No need for good tires at all. Jack, you just ask too much I tell ya.
Hmm... I ran 208GPs at VIR for two trackdays, and I have a little slit perpendicular to the tread pattern too. WTF?! I liked the tires a lot but that's really weird. :o
Funny, mine was at VIR too. I bought the brand new 207GP, had them mounted it. Ran 2 races, and there is 3 inch long crack across the tire. About 1/2 inch deep. they tried to tell me that it was a cut from debri. Also said, if it gets any worse I can always 'get' another one. I wasn't going to buy a new tire because it cracked within 14 laps.
that was the last time I ran dunlops. So far I have used over 10 sets of Pirellis, no abnormal wear/tear whatsoever.
QuoteI had that happen to a set of 208s last season. The response I got from the tire guy was, oh that happens and it will be fine. I was at Brainerd and with the speeds of T1 I didn't feel comfortable running that tire.
I had the same thing happen to me on last years GP208's. I had one session and came back in to the pits to think I ran over something. I took it over to the tire guy and he kept reassuring me that it was ok and they see it often; another expert racer confirming in front of the tire guy that it was ok. I came back later and stated again that I was uncomfortable running something with a big slit from wall to wall. He changed my tire, but stated he wouldn't do it again if it happened because it was totally safe??? If it happens again, i'll be looking for another brand of tire. He also stated I should be using the GP208A's and should upgrade.
-brent
I have a small slit on my rear tire. it's not beyond the depth of the wear bars, but it's there. Probably about 2" wide. I have little problems with that, mentally. This may be happening on the Dunlops, but at the club level, who's shredding tires because of it? I don't see the tires failing, and I'll continue to use the tire.
Interesting. In fact, this Reassures me, because I thought I might've ran over something, and have a slow leak. But, in fact, it's a normal thing. BTW, this is on my new 207GP 160 rear.
If it were down to the belt, or edge to edge, well, that might be a different issue.
I had a new set of Dunlop 207 GPs develop an inch long slit in the SIDE WALL tangential to the rim...very scary and the Manufacturer replaced it at their cost. I have never had these kind of problems with Michelins, and chunking and failure (explosive) aren't in the same ballpark. :o
The 'crack' you are seeing is the end of the rubber. Rubber is wound onto the tire. You are seeing the end of the winding. Also the tread of the tire does not hold the air, there is a layer of rubber on the inside that retains the air. I have had it happen on a few bike tires and on many kart tires with no problems.
QuoteThe 'crack' you are seeing is the end of the rubber. Rubber is wound onto the tire. You are seeing the end of the winding. Also the tread of the tire does not hold the air, there is a layer of rubber on the inside that retains the air. I have had it happen on a few bike tires and on many kart tires with no problems.
This is the case. However, it does not inspire confidence that the tread rubber won't just disintegrate and fly off as a whole, such as the Firestone fame. I presume the end of the rubber unwound because of the wear and high operating temperature. Common physics would dictate that more wear and tearing between the body of the tire and compound will develop with continue usage. No it does not retain air, but if the tread does fall off, I think you are going to crash. If the adhesive thats bonding the end of tread rubber can deteriate and fail, why wouldn't the adhesive that bonds the tread to the body fail in the same manner.
If I walk to your pits and use a utility knife to cut a 4 inch long, 1/4 inch deep gash on your rear tire, would you not mind and go out and race on it?
I was only trying to explain what was happening. It is up to the rider to decide if they want to ride on the tire. I have used such tires. As log as no cord is showing, i used the tires. What is happening is not tread seperation (what happened to firestone). The rubber is supposed to join with the other layers during vulcanization, no adhesives are used. Cold tearing can look similar, but happens in more than one spot.
QuoteAdhesive does not hold the tire together, the vulcanization of the rubber does. Also the showing of the end of the wrap is not the same as what happened to Firestones (problems with cords/belts did not allow the tread to adhere during vulcanization). I have used tires with a fairly wide gap showing. It is up to you. I have seen it happen to more than one brand of tire. Some tires are more prone to it than others. The wrapping of the tire is determined by the rotstion direction of the tire. The first time you see it, it can be quite un-nerving. Virtually every kart tire I used (spec tire class) showed the end of the wrap, some worse than others.
The end of the wrap showing is not the same as cutting a tire with a knife.
Nonetheless, you would race with a tire that has a gash in it, then its your decision. Just because the synptom is common doesn't necessarily mean the cause is the same. If we are all to presume all is ok, I wouldn't safety wire my bike because the nut should be able to stay on the bike... being cautious saves lives, and if one brand of tire tend to causes more concern, I probably not going to use it.
QuoteNonetheless, you would race with a tire that has a gash in it, then its your decision. Just because the synptom is common doesn't necessarily mean the cause is the same. If we are all to presume all is ok, I wouldn't safety wire my bike because the nut should be able to stay on the bike... being cautious saves lives, and if one brand of tire tend to causes more concern, I probably not going to use it.
It depends what the tire looks like, is it a gash or the end of the wrap? Is cord showing? As long as it is just the wrap line, I have used them. Sometimes it gets worse, sometimes it does not. If cord gets close to showing I would replace the tire. I am not defending anyone, only trying to explain what is happening.
Brian, the cracks that are developing are deep and in my case you could see the cord. I thought it was a symptom of a tire that had been mounted and then remounted. This thread shows that it is an endemic problem with Dunlops. I agree that it is up to the individual rider to choose a comfort level with the equipment, but this is something that Dunlop ought to look at on a serious level. If there is a problem with the compound, they can and should solve the issue. Will this keep me and Roger from mounting Dunlops on our machines? Until the problem is solved, that is a definite yes. I'm not a really good risk taker in this type of situation.
I really haven't used a Dunlop to race on in quite a while, however, I can make this statement. Dunlop tires seemed to have this "split" happen forever. As I remember, it was just a spot that where the exterior of the tire was overlapped when being placed on the carcass. Wasn't a problem then. And that was in the days of bias ply tires when tires would get really hot just from rolling in a straight line.
QuoteI really haven't used a Dunlop to race on in quite a while, however, I can make this statement. Dunlop tires seemed to have this "split" happen forever. As I remember, it was just a spot that where the exterior of the tire was overlapped when being placed on the carcass. Wasn't a problem then. And that was in the days of bias ply tires when tires would get really hot just from rolling in a straight line.
I understand the reason why it happens. But if it has been happening for years, wouldn't think they would try to come up with a solution? I liked dunlops, but just haven't had the comfort level and the confidence since that happened. It seems to be a slight flaw in the manufacturing process, maybe they ought to proper address it instead of just saying "its harmless"
I can't give a good answer, I use Michelin tires from Mason Racin' Tires with Chicken Hawk way cool warmers. I think I have it made. ;D
I have used Dunlops since 1991. I have never had the wrap line appear. Most of that time I was on slicks, but have been using 208GPs starting last year on my RC51.
When I raced karts, the tires I used always showed the wrap line (Goodyear tires).
QuoteBrian, the cracks that are developing are deep and in my case you could see the cord. I thought it was a symptom of a tire that had been mounted and then remounted. This thread shows that it is an endemic problem with Dunlops. I agree that it is up to the individual rider to choose a comfort level with the equipment, but this is something that Dunlop ought to look at on a serious level. If there is a problem with the compound, they can and should solve the issue. Will this keep me and Roger from mounting Dunlops on our machines? Until the problem is solved, that is a definite yes. I'm not a really good risk taker in this type of situation.
I would not call the situation endemic. Is there really a problem? Were all the tires purchased from a track vendor or from a dealer or mail order? Is it just 208s? How many tires? More so than other brands? The same or different lots of tires? What percentage of tires does it happen to? It would take a study of all the evidence.
If it makes you feel better, use different tires, but at this point I think it is a bit of a stretch to call it a problem with Dunlop tires. I have used about 8 sets of 208s starting last year, I have had no problems.
QuoteI would not call the situation endemic. Is there really a problem? Were all the tires purchased from a track vendor or from a dealer or mail order? Is it just 208s? How many tires? More so than other brands? The same or different lots of tires? What percentage of tires does it happen to? It would take a study of all the evidence.
If it makes you feel better, use different tires, but at this point I think it is a bit of a stretch to call it a problem with Dunlop tires. I have used about 8 sets of 208s starting last year, I have had no problems.
its also kind of a stretch for you to give one explanation to a seemingly common symptom without examine each of the tire mentioned in this thread.
So just to go on a generalization based on insufficient evidence... there are a slew of people chiming in with what seemingly to be the same problem with 207GP and 208GP's. But no one mentioned another brand of tire with the same problem
Lets leave the sketchy conclusion alone