astock165

About a week ago I found one of my V710s had a cut on the corner of the tread. I figured that during the winter one of the snow shovels or a garden spade or some other deadly yard implement had fallen against my stack of tires and cut it. All the tires have a lot of tread left so I was irritated but it's not the end of the world.

Well since then I've found two more tires have the same thing! And one of those tires was on the car and should never have tangled with said deadly yard implement.

I bought the tires in late 08 and ran a couple of track sessions on them. Used them for only 3 track sessions in '09.

Below are some pics of the first tire I found but the other two look quite similar but vary in length. Two have them on the inside edge and one one the outside edge.

Has anyone ever seen or heard of anything like this?

gkmccready

http://forums.corvetteforum.com/1546965665-post7.html

Search for "v710 splice" or "v710 seam" or "v710 has anybody seen this?" :-)

RX7 KLR

Search kumho butt splice seam.

In most cases if you run the tire in the other direction - change them side to side - it will not get any worse, and it does not effect the tires performance.

astock165

Was just pointed to the section below from the Tirerack website.

Tire Inspections Between Sessions

Tire inspections between sessions should be used to remove all rubber pickup from the wheels and tire treads, as well as offer an opportunity to examine the tires for punctures or cuts that might lead to compound tearing or air pressure loss. The inspection should also confirm if each tire's tread compound splice (that runs perpendicular to the direction of travel across the tread area) has become visible.

A visible tread splice is caused by tearing open the tread compound junction at the tread splice. Visible tread splices are caused by the torque of the engine spinning the tires during acceleration or the stopping power of the brakes briefly sliding the tires when slowing from high speeds. Front-wheel drive and most all-wheel drive vehicles place extreme stress on the front tires from both acceleration and braking forces, and are therefore more likely to see these visible signs of use than more balanced rear wheel drive vehicles.

If a visible tread splice is detected during tire inspections, the tire should be rotated side-to-side on the same axle. This will then use the vehicle's wheel spin to "close" the splice rather than continuing to "open" it. While this may cause the tread splice to become visible on the other tire used on the same axle, the inspections and side-to-side rotations should be repeated until the tire has worn out.

NOTE: Continued use of a tire with a visible tread splice in the same wheel position will cause the tread compound to tear downstream from the splice, forcing the tire to be removed from service.

The tires on very high horsepower cars should be rotated side-to-side between every session as preventative maintenance.

Armycop

You aren't alone, my Khumo's are doing it too. I rotated the tires per the tirerack instructions prior to my last outing and the split hasn't worsened. Tires are still sticky too!

Bill Dearborn

I agree with all that has been said about swapping the tires from side to side. However, some times that tread comes apart quicker than you would think. I purchased 4 V710s in August 2007 and used them at an autocross within a week of getting the tires. During the autocross one of the tires split at the tread splice and actually peeled off a section of tread. That was on a Sunday and the next day I was on the phone with Tire Rack. They warrantied the tire and sent me a replacement.

Bill

Wayne O

I've run Kumho 710s for quite-a-while and have not experienced anything like that.

longdaddy

this is nuts. i would not buy a tire that does this - how common is this issue? is this unique to kumhos?

astock165

I don't know if it's unique to Kumho but it does seem to be a known issue. Most of the feedback I've gotten (here and on the forums of two clubs that I run with) are that the side to side or diagonal rotation of the tires between sessions helps keep it from worsening.

I'll check into a warranty but won't hold my breath for that one. I've been a huge Kumho fan but this may change my mind.

autox_vette

There was an issue with cracking on newish tires a couple of years ago (I think it was Kumho). The excuse I heard from Tire Rack was that the tires hadn't been stored properly and had been subjected to too many freeze/thaw cycles during storage. I don't under stand the physics behind it, but that's what I heard (and TR warrantied them). Could be

mashinter

I had heard not to let competition tires freeze; maybe this is why.

CHJ In Virginia

I have the same splice showing on a brand new set of V710 Kumho's that have been used only at one event. Nothing to worry about, run the snot out of the tire. I have had splices that have shown 3-5 inches long across the flat tire surface and run them without problem. Just watch it between sessions and if it starts growing dramatically, rotate the tires. I usually just rotate side to side after every event. This is a known occurrence with Kumhos.

drivinhard

My V700's used to do the same thing, regardless of how/if you heat cycled them, abused them, took it easy, etc.

VetteDrmr

I've seen it on 2 V700s. I didn't panic, just ran the tire in the other direction, watched it close up, swapped sides again (to keep wear even), maybe it would open back up, maybe it wouldn't. Ran the tires until they corded.

Don't enjoy dealing with it, but it's not a big issue.

HTH, and have a good one,
Mike

TS Motorsport

That's intense!

froggy47

Almost every 710 I have run does this, often all the way across. I rotate & flip a LOT and I only had one that really opened up and peeled. Did not get any warranty satisfaction on it (Discount Tire).

longdaddy

i wanted to try these after my current set of hoosiers is done due to slight price advantage but I am not so sure now

astock165

The price advantage is getting to be less & less and the difference may be worth the piece of mind.

fatbillybob

Maybe if you get enough giant gaps on the Kumho's you can use them as rain tires.

rustyguns

you better not use that tire. sell it to me for 10 bucks and you won't have to worry about it