After reading about the issues several people have had recently with Nitto NT01s delaminating or opening up along the tread, I decided to investigate other options for track tires for the approaching season.
In researching the new spec racing Toyo Proxes RR, I came across posts on other message boards from a couple months ago complaining of opening up of the tread splice on the new Toyos--it sounds potentially similar to the issue people have been having with the Nittos.
After receiving reports of the tread splice issue, Toyo issued a consumer advisory giving specific details on mounting orientation of the tires, based on the side of the tire that has the DOT date code. Why they didn't include this information with the initial release of the tire is beyond me, but apparently the high stresses and forces encountered by an R-comp tire on the track can open up the tread splice from manufacturing if the tire is rotating in the wrong direction. The front tires see mainly the forces of braking and turning, and the rears the forces of acceleration, so the correct direction of rotation is opposite for fronts and rears.
Who knew this was an issue with tires that by appearance seem to be perfectly symmetric and non-directional? I've learned that this is an issue with almost all R-comps and race slicks, from the Toyos to Hoosiers. So it may explain what's happening with the Nittos as well.
I sent an email to Ben@TireRack for his input. His response was very informative and appreciated. Below is our email communication:
__________
Hi Ben--
I've ordered from you before and I see your posts on m3post frequently.
I have a couple of questions about the new Toyo Proxes RR. I'm looking for a track tire for my 2011 M3 to replace the Nitto NT01s that I had previously been using for track duty.
I was about to order a set of 275/35-18s all around when I came across a post describing delamination or tread splice separation on the new Proxes RR. Some early users of the tire came across this issue in December. Apparently Toyo's response was to issue a consumer alert describing a particular mounting strategy for the tires that suggests they're not truly symmetric afterall, even though it's a semi-slick with two straight tread grooves. You've probably seen the alert--DOT stamps on the sidewalls to point in the same direction (to the left) on both tires on the front, and DOT stamps to point together to the right on the rear. Tire rotation can then occur diagonally to compensate for wear.
This concerns me--why didn't Toyo describe the need to do this from the outset, prior to people having tread separation? Is this considered a defect, or just the nature of the tire's construction? I noticed on your website that the Hankook Ventus 214 semi-slicks have a directional arrow molded into their sidewalls, and they cannot be run backwards, despite appearing to be symmetric in design. Is this because of the same potential tread separation issue?
What about the BFG R1s? They appear to be of a very similar design to the Toyo RR and Hankook 214. Do the R1s also have a certain mounting orientation?
Thanks for your help
Ben's response:
Very good question. I did some research, as this did sound like a familiar thing. It is not uncommon on competition tires for the splice to become visible under hard driving.
We actually have an article about it here:
http://www.tirerack.com/tires/tirete...jsp?techid=160
and Toyo's specific bulletin here:
http://www.tirerack.com/images/pdf/p...mendations.pdf
BF Goodrich, states in their documentation of the R1 that the tire can be mounted either way without issue. It is possible that there will be some future modification to this advice, but they currently think it should be fine.
If any competition tire exhibits a visible tread splice that has not torn or separated, it is normal procedure to reverse the direction of rotation and keep using it.
If you order online, please reference "Ben" on the order as a previous contact. Thank you.
Ben Rooney | Sales Specialist
__________
Here is page 1 of the Toyo Consumer Advisory:
Click on the link to the bulletin in Ben's email above to see the second page, with specific mounting directions.
Hope this info helps.
