Weird Phenom on Tires After Lapping Day - Anybody Seen This?

Steve Coleman · **Joined:** Sun Nov 13, 2005 9:50 pm **Posts:** 188

Anybody ever seen anything like this? Came to my attention in my thread about tire life on another site. This poster says he'd seen the same thing himself. It was directed at the Kumho SPTs, but from his account I presume has happened to other brands / models.

From Other Site wrote:

I found a post from someone who tracked a car on new SPT's and they seem to have stood up fine other than the reason for the post. The guy's an instructor IIRC.

Link to Thread "Tires After Lapping Day"

From Other Site cont. wrote:

Some of my tires have that on them too and they still drive, perform and feel the same as before. It doesn't seem to go very deep at all, definetely not to the carcass, just in the tread block. It really doesn't seem to me to be of any concequence, and I'm not worrying about it at all.

What say ya'll?

Steve

Marty Howard · **Posted:** Sat Jun 24, 2006 7:42 am

pic added for reference:

Brad Mackey · **Posted:** Sat Jun 24, 2006 9:27 am

Yep, my MX's looked pretty much like that after the first day or two.
I called it "feathering", but maybe I used the wrong term.

Steve Coleman · **Joined:** Sun Nov 13, 2005 9:50 pm **Posts:** 188

Brad Mackey wrote:

Yep, my MX's looked pretty much like that after the first day or two.
I called it "feathering", but maybe I used the wrong term.
:)

Brad,

It's not the feathering that's the issue here it's the real fine 'split' that is in the middle of the continuous center (solid) tread block. It is so uniform that it almost looks like a mold 'seam' that's upset and is the way the tire came from the factory, but it's not, it's a slit that apparently formed after use. Note that the tire to the left doesn't exhibit this.

As for the obvious feathering, I definitley took note of that, and it encouraged me in that it's about what I'd expect and hope wouldn't be any worse in my case. One more reason I decided to give the MXs a try (see other thread on Tires).

Steve

Brad Mackey · **Posted:** Sun Jun 25, 2006 8:23 am

Steve Coleman · **Joined:** Sun Nov 13, 2005 9:50 pm **Posts:** 188

Posted FYI:

From Miata.net we wrote:

A Miata.net Poster Having This Experience wrote:

I Had Asked Them and wrote:

How deep is that slit?

Was there any evidence of it before use. Is there possibly a really thin 'skin' of tread rubber that somehow ends up over it from the mold.

What use have you put yours to, and did it happen to all four corners and if so was it at the same time.

The slit varies but the deepest spot I found was about 3/64".

I never noticed any slit before use. There may very well be a skin as you describe - I think that is likely. It looks like it will wear away after a bit.

I have a ~600 miles on the tire with about 40 - 50 of those miles flat out in the top of 3rd or 4th.

It happened at all four corners at the same time.

Another Miata.net'r wrote:

The SPT's in the picture look perfectly normal other than the shallow "split" along the center rib. My theory is that it has something to do with the manufacturing process as to why it does that.

This is the best explanation and I concur.

Not sure if the MXs (very similar tire, same 'family' IMO) will exhibit this, but I'll be looking.

Hope others find this interesting and food for thought,

Steve

Aaron Buckley · **Posted:** Mon Jun 26, 2006 9:30 am

I saw a brand new set of V710's do the same thing at the DC Pro this weekend on a 350z. The SPT's that Bryan has on his RX-8 doesn't have that though. - AB

Scott Johnson · **Posted:** Mon Jun 26, 2006 10:19 am

Aaron Buckley wrote:

I saw a brand new set of V710's do the same thing at the DC Pro this weekend on a 350z. The SPT's that Bryan has on his RX-8 doesn't have that though. - AB

How are the SPTs to drive on? Thinking about a set for the Celica.

Aaron Buckley · **Posted:** Mon Jun 26, 2006 11:02 am

scottjohnson wrote:

How are the SPTs to drive on? Thinking about a set for the Celica.

They're quiet and good in the rain. Too bad they aren't that good in drying autocross conditions. Danny Popp worked me over in the Super Challenge when it went from pouring rain to drying conditions by the time I ran. - AB

Stacy King · **Posted:** Mon Jun 26, 2006 1:27 pm

Could be worse

:D

Marty Howard · **Posted:** Mon Jun 26, 2006 1:52 pm

Is that from RR??

Stacy King · **Posted:** Mon Jun 26, 2006 1:53 pm

Marty Howard wrote:

Is that from RR??

Yup... saturday afternoon before I rotated them

Marty Howard · **Posted:** Mon Jun 26, 2006 2:04 pm

Stacy King wrote:

Marty Howard wrote:

Is that from RR??

Yup... saturday afternoon before I rotated them

it's amazing what going straight through a sand patch can do to a tire??

:wink:

Steve Coleman · **Joined:** Sun Nov 13, 2005 9:50 pm **Posts:** 188

Stacy King wrote:

Could be worse :D:D

Actually that's not too bad for a 'regular service' type tire especially if you started them at full tread, and at RR. That is an SPT, right?

OCTJMO, ICBW,

Steve

Stacy King · **Posted:** Mon Jun 26, 2006 2:31 pm

Steve Coleman wrote:

Stacy King wrote:

Could be worse

:D

Actually that's not too bad for a 'regular service' type tire especially if you started them at full tread, and at RR. That is an SPT, right?

OCTJMO, ICBW,

Steve

Oh I'm thoroughly please with the tires... they weren't brand new by any measure... AAMOF they saw light duty in Feb on full course in the slush, medium duty on North Course in early April (car wasn't MINE yet, so I wasn't pushing it, and I left early), and heavy duty on South Course in late April.

They are Yokohama AVID V4S all-season sport tires

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Weird Phenom on Tires After Lapping Day - Anybody Seen This?

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