[WetShrub]

So, I had a VERY windy track day at T-hill yesterday. Boy was it tough. The front was wiggling out of tons of turns as the wind got under the bike. Everyone was running pretty slow. To make it worse the 35 mph wind gusts were pushing down the front straight so a buddy of mine was the first victim of the wind as he went in too hot into turn 1 at 100 mph. He is okay, bruised behind and needs a new clip on some plastic but for the most part he came out okay. Bike just swept out from under him as the tail wind turned to cross wind.

Aside from that, I got home and looked at my rear tire. I am running Pirelli Dragon Supercorsa SC1 (front) and SC2 (rear). Supersoft rear. On the left side of the tire it looked like there were small divets periodically over the tire. It's not possible for me to have run something over because then it wouldn't create this effect. Let me know what you think it could be. I don't really know unless there is a defect in the tire? They are pretty new. I did the shortened practice day on them at Sears when it was cold out (15 laps totally maybe) and one race at Buttonwillow. Then this track day. I had more miles on my last set of Pirelli's and they didn't look at all like this.... Think I should trash these?

If you look just where the tread stops you will see what I'm talking about.

-Shrub

[stegen]

I have to give you credit on that arrow, its quite nice

[WetShrub]

Originally Posted by stegen

I have to give you credit on that arrow, its quite nice

Thank you. It's actually my 3rd one. The others weren't as pretty so I had to re-do it. Microsoft Paint is good for something you know.

-Shrub

[luvtolean]

Looks pretty normal to me. If you keep riding it the tire will look the same all the way around.

[WetShrub]

Originally Posted by luvtolean

Looks pretty normal to me. If you keep riding it the tire will look the same all the way around.

Could that be considered "blistering"? I just haven't seen other tires with those periodic chunks taken out of it.

[Trackho]

Originally Posted by WetShrub

Could that be considered "blistering"? I just haven't seen other tires with those periodic chunks taken out of it.

Its called cold tear, every single tire made has this issue at T-Hill until temps are above 85F, only happens on the left side. The tire isnt getting hot enough to flow so it tears. In general Dunlops tear less, some folks think less rebound dampening helps, others think softer compounds tires help, for me the Persmellis/Metzlers seemed to be the worst--changed over to Dunlops, mo better, but you need to choose your compounds wisely.

Hers more info up the butt on it

warning: there is NO easy answer, gets noticably worse until 2:05s

But I hear if you leave your cell phone in the trunk it might help

[luvtolean]

Originally Posted by 929Boomer

But I hear if you leave your cell phone in the trunk it might help

Dude, if you did your job better the phones wouldn't get so hot...go get your thermo book out and study.

[abtech]

That doesn't look like any cold tearing I have ever seen. Cold tearing is usually an angled shearing of the top 2 layers of the compound running against the direction of rotation. The tire is essentially useless once this has happened. I have only seen this happen to tires manufactured in Germany.

What I see in the pics is just notching at the end of the groove that happens when the groove edge gets raised while hot and torn under off-corner acceleration. Just about every DOT race tire I have ever seen does this to some extent and it really isn't indicative of any serious problem.

[WetShrub]

Originally Posted by abtech

That doesn't look like any cold tearing I have ever seen. Cold tearing is usually an angled shearing of the top 2 layers of the compound running against the direction of rotation. The tire is essentially useless once this has happened. I have only seen this happen to tires manufactured in Germany.

What I see in the pics is just notching at the end of the groove that happens when the groove edge gets raised while hot and torn under off-corner acceleration. Just about every DOT race tire I have ever seen does this to some extent and it really isn't indicative of any serious problem.

So you think the tire was cupping and then the raised edge was high enough to be torn off?

[Trackho]

Originally Posted by abtech

That doesn't look like any cold tearing I have ever seen. Cold tearing is usually an angled shearing of the top 2 layers of the compound running against the direction of rotation. The tire is essentially useless once this has happened. I have only seen this happen to tires manufactured in Germany.

What I see in the pics is just notching at the end of the groove that happens when the groove edge gets raised while hot and torn under off-corner acceleration. Just about every DOT race tire I have ever seen does this to some extent and it really isn't indicative of any serious problem.

THis is the way the cold tearing always starts, at the end of the sipes, then the dots grow, and eventually connect and trench all the way around the tire, Trust me I have seen it many, many, many times at T-Hill

[abtech]

Originally Posted by WetShrub

So you think the tire was cupping and then the raised edge was high enough to be torn off?

Yep . . .

[abtech]

Originally Posted by 929Boomer

THis is the way the cold tearing always starts, at the end of the sipes, then the dots grow, and eventually connect and trench all the way around the tire, Trust me I have seen it many, many, many times at T-Hill

If it was cold tearing (according to Metzeler's Knowledgebase), then the tires are toast. Every tire I have seen that has been diagnosed (by the ontrack tire reps) with cold tearing looks nothing like that. I think we actually are talking about 2 different things here, as I am certain the track temps in California never even approach (under the worst conditions) an average spring or fall day in Michigan where track temps of 20 degrees F. aren't unusual. I think the term "cold tearing" or "cold shearing" is Metzeler/Pirelli's way of burying QC issues. I had to run (against my better judgement) a set of their slicks a couple of years ago (long story). I spent a full hour talking to the Metzeler/Pirelli tech about setup and after mucho adjustment, put on the warmers for nearly an hour before going out for practice. Within 6 laps on a ninety degree track surface both front and rear tires started sliding all over the place, so I came back in and the tires looked like someone had taken a chainsaw to them. I went and got the tire guy and he looked at them and said: "hmmm looks like you're tearing em up, maybe you ought to think about changing your "riding style" . . . We don't normally get cold tearing on a warm track (I didn't even mention the tire warmers).

That was the last set of German tires I will ever purchase (They hit the dumpster at Grattan 15 minutes later).

[WetShrub]

Originally Posted by abtech

If it was cold tearing (according to Metzeler's Knowledgebase), then the tires are toast. Every tire I have seen that has been diagnosed (by the ontrack tire reps) with cold tearing looks nothing like that. I think we actually are talking about 2 different things here, as I am certain the track temps in California never even approach (under the worst conditions) an average spring or fall day in Michigan where track temps of 20 degrees F. aren't unusual. I think the term "cold tearing" or "cold shearing" is Metzeler/Pirelli's way of burying QC issues. I had to run (against my better judgement) a set of their slicks a couple of years ago (long story). I spent a full hour talking to the Metzeler/Pirelli tech about setup and after mucho adjustment, put on the warmers for nearly an hour before going out for practice. Within 6 laps on a ninety degree track surface both front and rear tires started sliding all over the place, so I came back in and the tires looked like someone had taken a chainsaw to them. I went and got the tire guy and he looked at them and said: "hmmm looks like you're tearing em up, maybe you ought to think about changing your "riding style" . . . We don't normally get cold tearing on a warm track (I didn't even mention the tire warmers).

That was the last set of German tires I will ever purchase (They hit the dumpster at Grattan 15 minutes later).

It was about 85 degrees yesterday....I didn't feel any sliding but then again I don't ride anywhere near the pace that you guys do. I wonder if backing off the rebound would help?

Back to one of my original questions. Is the tire okay to ride on? Is it going to get worse? Should I trash them and get some Dunlop GPA's?

-Shrub

[luvtolean]

Yes, it's going to get worse.

You can decide if you want to run it or not. I prefer GP-A's, you'll just have to try them and see what you like better.

[Trackho]

T-Hill SV Tearing


Nother

If you do a search youll find many more.

I spoke with the Metzler rep, first he blamed it on suspension, then made some calls, then he said that it was T-Hill and that all brands were tearing(which was actually true)---he reommended using the RS3/SC3 rear, but I have seen those tear too.

Just about everyone agrees that reducing rebound helps, othere argue about a softer/harder compound fixing things. All I know is that the problem totally goes away with temps above 85F. Many blame it on the length of T2. Who knows, havent experienced this at any other track besides T--Hill

[WetShrub]

Originally Posted by 929Boomer

T-Hill SV Tearing


Nother

If you do a search youll find many more.

I spoke with the Metzler rep, first he blamed it on suspension, then made some calls, then he said that it was T-Hill and that all brands were tearing(which was actually true)---he reommended using the RS3/SC3 rear, but I have seen those tear too.

Just about everyone agrees that reducing rebound helps, othere argue about a softer/harder compound fixing things. All I know is that the problem totally goes away with temps above 85F. Many blame it on the length of T2. Who knows, havent experienced this at any other track besides T--Hill

What a strange anomaly that track is. It seems so simple compared to Sears and some others but it has these strange things that happen there. Many mental notes taken. I guess I could try the cheap fix with the rebound damping and if that doesn't work try a softer compound. I would bet though that by the time I head there again for the AFM race it will be in the mid-90's so that problem won't be an issue.

-Shrub

[abtech]

Originally Posted by 929Boomer

T-Hill SV Tearing


Nother

If you do a search youll find many more.

I spoke with the Metzler rep, first he blamed it on suspension, then made some calls, then he said that it was T-Hill and that all brands were tearing(which was actually true)---he reommended using the RS3/SC3 rear, but I have seen those tear too.

Just about everyone agrees that reducing rebound helps, othere argue about a softer/harder compound fixing things. All I know is that the problem totally goes away with temps above 85F. Many blame it on the length of T2. Who knows, havent experienced this at any other track besides T--Hill

The first pic in your first link is tearing and if you'll notice it looks nothing like the pic at the beginning of this thread. Two totally different animals in my opinion.

[ccwilli3]

Originally Posted by 929Boomer

T-Hill SV Tearing


Nother

If you do a search youll find many more.

Good reads, thanks!

[RRWANTR]

Last month at Willow Springs, people were having problems with cold tearing...know for a fact persmellis and dunslops were having problems. I didn't have any problems, but then I didn't ride till later in the day and had my warmers on my persmellis, plus I didn't push it hard in the first lap...

[WetShrub]

Originally Posted by RRWANTR

Last month at Willow Springs, people were having problems with cold tearing...know for a fact persmellis and dunslops were having problems. I didn't have any problems, but then I didn't ride till later in the day and had my warmers on my persmellis, plus I didn't push it hard in the first lap...

I didn't have any problems at BW either but I think part of it was I had never ridden there before and wasn't even close to finding a rhythm after the racer school and practice sessions.

[RacerCutie]

Originally Posted by luvtolean

Yes, it's going to get worse.
You can decide if you want to run it or not. I prefer GP-A's, you'll just have to try them and see what you like better.

Funny you mention this. At Buttonwillow (85 degrees and sunny).
I was also running SC1 on my 929, my hubby 208GP-A (both sets were take-offs in excellent condition from the same rider).

Our riding styles are similar (I'm a little more aggressive in the corners), but toward the end of the day, my tires felt a bit 'squishy'. I didn't slide, but it felt as it the rear wanted to slide. It felt uncertain.
I look at the rear of my tire and the edges of the tires were 'frayed', primarily the rear.
I look at my hubby's 208s and his looked ok, nice wear on the edges, little blueing. Pic isn't sharp, but imagine the fuzzy parts clearer, like you took a wire brush to them.
I'm still debating whether to use these next week or not.

[Trackho]

Originally Posted by abtech

The first pic in your first link is tearing and if you'll notice it looks nothing like the pic at the beginning of this thread. Two totally different animals in my opinion.

Ab---its the exact same thing---on the tread tires it starts like wetshrubs, and ends like the other pic posted, after it trenches the tire, traction is severly compromised on that side (always the left at T-Hill)

[RRWANTR]

Originally Posted by RacerCutie

Funny you mention this. At Buttonwillow (85 degrees and sunny).
I was also running SC1 on my 929, my hubby 208GP-A (both sets were take-offs in excellent condition from the same rider).

Our riding styles are similar (I'm a little more aggressive in the corners), but toward the end of the day, my tires felt a bit 'squishy'. I didn't slide, but it felt as it the rear wanted to slide. It felt uncertain.
I look at the rear of my tire and the edges of the tires were 'frayed', primarily the rear.
I look at my hubby's 208s and his looked ok, nice wear on the edges, little blueing. Pic isn't sharp, but imagine the fuzzy parts clearer, like you took a wire brush to them.
I'm still debating whether to use these next week or not.

That looks like normal wear to me......As talked about in your trackday thread I believe the "squishy" feeling is from running the supersoft rear at those temps. I know at Willow during even the cold months most run a soft rear (supersoft front). During the warm months many run the medium SC3 rear.