Kumho tire delamination

[altiain]

If either of you saw what was left of my right rear tire, you'd understand why I hit a few cones on Saturday.

[tailchaser]

If either of you saw what was left of my right rear tire, you'd understand why I hit a few cones on Saturday.

Didja take a picture of that tire for us yet, Sparky?

[altiain]

Don't call me Sparky. :P




I'm going to email Kumho in the morning and see what they have to say about it. I've corded plenty of R compounds over the last half a decade, and I've never had one come apart on me like that one did.

[sammm]

I'm going to email Kumho in the morning and see what they have to say about it. I've corded plenty of R compounds over the last half a decade, and I've never had one come apart on me like that one did.

Check with JRW. I know he finally heard back from Kumho a few days ago, but I don't know what the outcome was.

[JRW]

Hey Sparky, did that separation start at the tread belt splice?

[sammm]

Hey Sparky,

He shoots, he scores!

[altiain]

Hey Sparky, did that separation start at the tread belt splice?

I don't really think so, but I haven't examined it that closely to see if that's where it started. It honestly looks like about 1/3rd of the outer circumference just peeled itself right off the belt casing.

I went back and worked out how many runs I got out of that tire, and it came to 41. They were sent to me shaved and heat cycled from Tire Rack, and I flipped them about 14 runs ago to prolong their life. What really chaps my hide is that I had 36 runs on the V710s when they went back, and they weren't even half worn yet!

Kumho is definitely not filling me with confidence so far this year. I was impressed by how they chose to handle the V710 problem, but now I feel like every set of tires they've shipped me so far this year has been defective. I'll take the V710s I've got coming to me, but I'm starting to wonder if the time has finally come to take my R compound business elsewhere.

[TurboDuane]

In all fairness Iain, I don't know what Kumo's going to say about the separation. I mean when you've got cords showing, you are already beyond the time to replace them. Now as far as the longevity of the tire, that’s a different story.

[altiain]

No offense Duane, but I've corded my fair share of R compounds. This was not a "normal" failure. Besides, those tires had a good 2/32nds of tread on them when the day began - there wasn't cord showing (or even close, for that matter) anywhere on those tires. The two main circumferential grooves were still both readily visible, and the outside edge still had readily visible tread scallops.

I know what a tire looks like when you cord it through normal use, and that generally doesn't include edges peeling back and chunks of tread hanging off. I've never spun the car on these tires, nor had I ever flatspotted them. Yeah, I've driven them hard, but no harder than the other 5 sets of Kumho R compounds I've run down to cord on the Miata (including two previous sets of Ecsta V700s), and none of them failed like this.

Maybe it is a "normal" failure, as far as Kumho is concerned. However, one of the primary reasons I've run Kumhos for years was because they lasted longer than Hoosiers. If I'm only going to get ~40 runs out of a set of tires these days, I might as well buy the fastest ones out there.

[TurboDuane]

No offense Duane

None taken, just throwing out another angle. You know playing devils advocate. I personally have never run to cords, so your experiance far out-weighs mine . Of course all my experiance with tire replacement, so far, have been on daily driven tires. And I don't pretend to know anything about "R" compound tires as I've never owned a set, or even driven on a set. And while I am inclined to agree that it should't separate, I'm just saying they may just look at you and go

.....................So I'll just shut up and stand in the corner now.

[altiain]

Well, their products have been a bit questionable this season, but I'll give them an A+ for customer service. I guess it helps when you track down the email addy for the North American Motorsports Director at Kumho...

Subj: RE: Kumho Ecsta V700 tire delamination
Date: 7/19/2004 2:59:25 PM Central Daylight Time
From: [email protected]
To: [email protected]
Sent from the Internet (Details)




Iain,
Thank you for your message. It's good to hear from our customers. I am sorry that you experienced a problem with our product. I can have the Tire Rack send you a replacement tire. Do you still have the invoice number from your purchase or your Tire Rack customer number?

Thanks for your continued support for our company and our products.

Sincerely,
Rudy Consolacion
Motorsports
Kumho Tires



--------------------------------------------------------------------------------
From: [email protected] [mailto:[email protected]]
Sent: Sunday, July 18, 2004 11:15 PM
To: Rudy Consolacion
Subject: Kumho Ecsta V700 tire delamination


Mr. Consolacion,

I'm writing this email to discuss a problem with one of your products. This past Saturday the 17th, I had the tread on one of your 205/50-15 Kumho Ecsta V700s severely delaminate. I've attached some pictures of the tire in question. The tire had been inflated to a (cold) temp of 36psi, had never been flat-spotted or spun upon, and was received from Tire Rack shaved and heat-cycled. The tire in question had been used for nothing but autocrossing (no track time), had 41 runs on it at the time of failure, had recently been flipped and remounted to preserve its life, and at the beginning of the event it showed absolutely no signs of impending failure. The tires were originally shipped to me as replacements for a set of the recalled V710s, and were used on a C Stock '99 Mazda Miata.

I've been using Kumho tires exclusively for autocrossing and lapping days for almost half a decade now. I'm not a National level driver, and my tire budget is minute compared to many, but I'm very active with a number of different organizations that run both autocross and track events in North Texas, and I've never hesitated to recommend Kumho tires when asked. I've also corded my fair share of tires, and I've never had one let go like this. I understand that you don't offer a warranty per se on competition tires, but I've used enough sets of Ecsta V700s on this car to know that they should not have failed - especially in such a spectacular manner - after a mere 41 runs.

I would like to arrange to have this tire (or set of tires) returned to Kumho and replaced, or to be given some sort of credit towards a future set of tires form your company.

Thank you,

Iain A. Peebles

[TurboDuane]

Cool, and congrats.

[joe.MIATA]

Mr. Consolation?, how fitting....

Good job.

[tailchaser]

I still think you should have sent this letter

[Majik]

I didnt see you call him sparky once!!! WTF man?? Also, I know Khumo has sort of a proven rep now, but have you ever thought of using hancooks new r-compound? I dont really follow all of the news on tires, does anyone use these? What do they think?

[EvilSpeeder]

The Hankooks are very similar to the Toyo RA-1s in my experience. Not quite as sticky as the Kumho and nowhere near the Hossier.

[altiain]

Yeah, the Hankooks are definitely more of a road racing compound similar to the RA-1s or Hoosier R3S03/4s.

Honestly, I don't know what I'll be running next season. Hopefully the V710s will last for a few months before self-destructing, and I can finish out the season on the mismatched Ecsta V700 remains.