Kumho Tire Blew Out

[darrahc]

My tires have a little more than 2K on them and when I took the car out and was accelerating from a stop sign, the right front tire blew out. Odd thing is that I checked and adjusted all the tire pressures (35 front, 29 rear) right before I left and had about 2 easy miles driving through a neighborhood before it happened. So the tires were still cold.

The tire did have a slow leak from a nail that I plugged about a week prior. The plug was pretty much in the center of the tire - not near the side wall. This was the first time I drove it since I plugged it. I wouldn't think that would have had anything to do with this since it seemed to be holding air.

I'm going to swing by a Kumho dealer to see if they'll warranty but not very hopeful since it does have the plug in it.

IMG_7646.JPG

[texasram]

up to 2/32'' tred depth kumho will replace it for free, regardless of plug

[Pappy]

I guess my questions regarding the recent repair would be: who mounted the tire, what equipment did they use, and how much pressure did they put on it to get it to seat? Based on where and how the tire failed, I would also be curious if it was driven at low air pressure back when it had the nail in it.

Pappy

[catwood]

35 front and 29 rear????

[bluesrt]

35 front and 29 rear????

that's correct for the acr tire

[labtec]

Is that a clip-on wheel weight at the point of failure? Could that have had something to do with it?

[mjorgensen]

Driving on it under inflated would possibly weaken and do this, and yes the mounting and dismounting could have damaged the sidewall, I would look for other damage inside the tires sidewall.

[FRANKVR4]

On tire industries they call tire zipper rupture ,cause by operating underinflated .

[LightningKray]

If the tire were compromised at all from being driven underinflated it would be evident by a quick inspection of the inner tubeless lining. But if this were the case and the tire was run in an underinflated condition, I would have hoped the shop performing the repair would have brought it to your attention.

[texasram]

On tire industries they call tire zipper rupture ,cause by operating underinflated .

The tpms would warn of under-inflation

[bluesrt]

Is that a clip-on wheel weight at the point of failure? Could that have had something to do with it?

not hardly

[TrackAire]

Was the tire removed from the rim to "plug it"???

That is a key bit of info that is missing here (or at least I don't see it).

[darrahc]

Was the tire removed from the rim to "plug it"???

That is a key bit of info that is missing here (or at least I don't see it).

No, the tire wasn't removed to plug it. The tire was installed at the factory so I don't think that had anything to do with it. The under inflation theory has some merit. I noticed the leak when the warning came on when it was under 30 and it probably got down to around 24 before I was able to plug it.

In any case, I took the wheel to a Kumho dealer and he called them to see if it was covered under warranty. Apparently the rep couldn't answer the question and is going to have to call back but the guy I was talking to said he didn't think they were covered. I told him I thought they were so we'll see...

[TrackAire]

No, the tire wasn't removed to plug it. The tire was installed at the factory so I don't think that had anything to do with it. The under inflation theory has some merit. I noticed the leak when the warning came on when it was under 30 and it probably got down to around 24 before I was able to plug it.

In any case, I took the wheel to a Kumho dealer and he called them to see if it was covered under warranty. Apparently the rep couldn't answer the question and is going to have to call back but the guy I was talking to said he didn't think they were covered. I told him I thought they were so we'll see...

Ok, thanks for the clarification. I'm 100% sure that the plug had nothing to do with causing this blowout.

My guess would then be that the tire was slightly under inflated before it was plugged and you drove over something like a bump or driveway entrance and the rim pinched against the sidewall where the major split is causing a very weak spot. Seems to make sense since it matches the radius and size of the rim pinching the sidewall if the tire didn't have enough air and the wheel made contact with something hard enough to momentarily collapse the sidewall due to lower than normal internal air pressure.

Then again, it could have been a dozen other causes too, lol.

Glad no damage was caused to the rim or your bodywork.

[bluesrt]

That tire is so low profile it cannot take low pressure abuse. Was there rubber dust in the tire upon removal?

[GTS Dean]

tire was slightly under inflated before it was plugged and you drove over something like a bump or driveway entrance and the rim pinched against the sidewall where the major split is causing a very weak spot. Seems to make sense since it matches the radius and size of the rim pinching the sidewall if the tire didn't have enough air and the wheel made contact with something hard enough to momentarily collapse the sidewall due to lower than normal internal air pressure.

^^^^^^^This.^^^^^^^

[Darius]

Those tires are the reason the ACR set records. They are ultra soft. Only good for maybe 1 session at race pace. You have to baby them to even make it 1 track day. I've had 1 come off the rim, and blistered a brand new one in 1 session, whole day ruined. I was at Laguna a day after they set the record. The Kumho big rig was still there. I could only imagine how many fronts they went through. I guarantee they put new fronts on every session. Rears are fine. Adjust your ride height accordingly and put some R7's on the front.