Stock Bridgestone RE050A Tire Chunking

[MSMS3]

I failed to see anything about this with our search engine. My '08 MS3 has just over 20,000 miles on the stock Bridgestone RE050A's.

Yesterday I rotated the tires again and noticed for the first time that there is tread chunking on the inside edges of both front tires. This was not present at last rotation and is slight but noticable.

There is good tread life left. The chunking is uniform, about every three inches or so along the inside edge of each front tire. None on the rear.

I rotated them to the rear but am a little concerned that this will (1) continue on those tires which are now on the rear and (2) begin on the rotated tires now on the front.

Has anyone had a similar experience? Is it just the relatively soft compound and a lot of aggressive driving with heat build up, including many hard launches and quarter mile runs, or do I have some type of alignment issue?

Let's not go blaming Bridgestone as I'm at 20,000 hard, fast miles. I'm just trying to figure out the chunking. Wear is otherwise uniform.

If you're not sure what chunking looks like, I'll try to take some pix and post later.

Advice and recommendations please.

 

[Kain]

Alignment...?

 

[MSMS3]

Thanks, Kain. That's what I'm thinking, but I hope to hear from others.

Autox'ers and guys the road course sometimes chunk the outside edges from aggressive cornering at high speed, but this is the opposite. Both front inside tread edges.

I'm just wondering if I overheated them somewhere along the line with maybe way too many hard launches and several Interstate bursts in 6th gear at higher speeds than I care to admit. 20,000 miles may be the limit for the any "spirited" driving on these tires. Dunno.

 

[Stotrupp]

All I know is my stockers were long gone at 10k

 

[MSMS3]

Here are some pix. Yeah, they are close to shot but not quite down to the wear strip. Soon to be replaced.

But I don't want new tires to have the same problem, so I seek advice on what may be going on with those inside edges.

 

[GoFast]

That typically is going to be caused by overheating. Since it is on the inside of the tire, I would guess too much negative camber.

 

[Nliiitend1]

It's quite doubtful that you have "too much negative camber" in the front. If anything, I'd say this car needs MORE negative camber in the front...

That being said, it looks to me like old, nearly worn out tires that have perhaps been heat-cycled a few too many times. I would worry about it.

 

[bluelion]

excuse my ignorance or noobnes, but what is "overheating" or "heat-cycled"? is that from doin burnouts or something??? my stockers look similar to that and now i'm gonna go look at them to see if i have chunks also....

"All I know is my stockers were long gone at 10k "

damn...you must burn out at every red light! i'm close to 30k....

 

[JamesCH]

That typically is going to be caused by overheating. Since it is on the inside of the tire, I would guess too much negative camber.

I agree.

Have you been doing lots of hard accelerations out of sharp turns? (naughty)

As an aside, I don't see why people get all worked up about adding tons of camber... I haven't seen a single shred of test data that says that radials like anything greater than -1deg of camber.

 

[mr_mazda329]

Chunking is cause by certain rubber compounds being heated up past their limits and cooling changing the compounds. In your case, too many heat cycles. (yes i know its a street tire) Some tires do it..some dont. I can roast my old ass RS-2's and they dont even chunk but they are hard as rocks cuz of the Heatcycles.


As far as the alignment is concerned,you got 20k out of the orignal tires, thats really good.

I haven't seen a single shred of test data that says that radials like anything greater than -1deg of camber.

It depends on the car.

 

[MSMS3]

Thanks guys. I'm gonna replace all four soon, even though the rears (now rotated to the front, have not started chunking and are probably good for another 5,000 miles. I look to see them start chunking soon.

I do keep them on the high side of pressure range, typically 40 psi in front, about 38 in the rear.

Truth be told, these tires have amazed me that they lasted this long, given my driving habits. My guess is that I have probably done over 100 very hard launchs for practicing 60 foot times working on launch techniques, not counting 9 trips down the strip and maybe 50 quarter mile practice runs with a G-Tech accelerometer.

And then, there have been several relatively brief but spirited runs on the Interstate without traffic around where the car did run north of 150 mph. I don't know what actual top end was because I came up on traffic before it maxed out due to aerodynamic drag but my GPS registered 153.

So, yes, probably heat cycled a bit too much. lol. I'm not convinced this is an alignment problem, but will have it checked when the new tires go on.

Choice of tires decision are beyond this thread. I'm just curious if chunking is a problem with the RE050A's as they have been great tires otherwise, despite a lot of negative discussion of them in this and other forums.

 

[Stotrupp]

I think the stock potenzas are great, they just don't last long. However, not many ultra high performance summer tires do. 10-12k is the avg for these kind of tires if you don't pussy foot around all day and drive the way they were designed for. Got to pay to play and that's why I don't complain when I'm buying new tires every 10k miles or so, I have a lot of fun

P.S. My tires are rotated at every oil change (3500miles)

 

[mr_mazda329]

FWIW... The Guys on the s2000 forums are raving about the Sumitomo HTRZ III saying performance is comparable, cheaper, and last way far longer at a teadwear rating of 300

 

[Nliiitend1]

I agree.

Have you been doing lots of hard accelerations out of sharp turns? (naughty)

As an aside, I don't see why people get all worked up about adding tons of chamber... I haven't seen a single shred of test data that says that radials like anything greater than -1deg of chamber.

Well I don't really know what chamber is, but I'm pretty sure I don't want to add any to my car...

Static negative camber, on the other hand, is something my car could use a little bit more of in the front, as evidenced by the accelerated wear I see on the outside edges of my front tires after track days.

The MacPherson strut geometry of MS3's front suspension dictates that the camber curve be rather flat, meaning that during cornering the outside front wheels/tires are less equipped to deal with the lateral forces acting upon them (i.e., the camber is more positive than it should be).

 

[JamesCH]

Haha, good catch... I was a little bit hung over when I wrote that.

So if I get what you're saying there is a large amount of camber loss during roll (cornering) that bring the tires to positive camber, which is where they don't want to be. So static camber is set to counteract the camber losses during roll.

Recalling tire test data I have looked at I remember almost every single radial tire performing best between 0 and -0.25 deg of camber, (assuming the Potenzas are similar, which isn't a huge assumption) does anyone know what static camber should be set to? Is there a place to get the camber curve vs roll/bump/pitch etc or suspension geometry for the MS3?

 

[Design]

Here are some pix. Yeah, they are close to shot but not quite down to the wear strip. Soon to be replaced.

But I don't want new tires to have the same problem, so I seek advice on what may be going on with those inside edges.

Ironically, that "looks" like excessive heat/wear from some mild Toe misalignment. Very common with lower profile tires. It's due to the negative camber, stiff sidewall, and probably somewhat from the higher inflated pressure on your car.

Assuming you get your vehicle aligned, it might be helpful to post your alignment before/after specs. Good luck.

 

[MSMS3]

Thanks, Design. Yeah, I'll see what the alignment numbers are against spec and whether any change is indicated. If so, I'll post before and afterward. It took 20k miles for this to show up, so I think it's probably just aggressive driving on a relatively soft tire.

 

[Breezy]

I'm inclined to think it's too much toe .. whether it's toe in or toe out remains to be seen, but too much toe in either direction causes tons of scrub, and therefore heat.

If your car is very darty, you most likely have too much toe out (good for autox). If your seems a bit slow in the steering dept, it could be too much toe in.

 

[mr_mazda329]

People

If it were a toe problem... these tires would not have lasted 10k miles alone. He's got 20k on them and for a tread rated at 140, that's really amazing and almost unheard of. My vote of for old and too many heat cycles

 

[Nliiitend1]

People

If it were a toe problem... these tires would not have lasted 10k miles alone. He's got 20k on them and for a tread rated at 140, that's really amazing and almost unheard of. My vote of for old and too many heat cycles

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