Thoughts On Tread Feathering
 

While it's a street car I'd like to see what the setup pro's have to say about the following as it doesn't seem to be a typical issue.

On the right rear tire, the second tread block from the inside has a feathered (raised) front sipe edge, the corresponding rear edge is unaffected. The entire circumference of the tire is affected. All other tread blocks on both rear tires have zero issues. I've attached a picture and a screenshot of my alignment which was done at the time the tires were installed, 1,400 miles ago.

From my motorcycle road racing days I've found this to be a rebound issue; however, I realize cars are a different animal. Any insight you can lend would be much appreciated. :tiphat:

In my experience (not a lot and most of it is with older cars), nearly all uneven wear problems are caused by misalignment or improper inflation. If inflation is right, I'd take it to another shop to verify alignment.

I've gotten this on all four corners - inflation and alignment seems to be within spec (as much as it can be, anyway, without adjustable parts. I'll get it aligned again and report back as well...

Looks like you have too much toe in. It should be dead in the middle of spec or a little less toe in. Your camber is also off from spec in the rear.

Please keep us updated as to what the tech’s suggested changes are from existing settings. Thanks.

Thanks now I’m confused as the toe comment contradicts what I’ve read from multiple members posts here.

I’ve read on this forum before that to prevent these cars from unsafe oversteer on the street & best stability rear total toe should be double that of the front setting which is within 0.02* of middle spec. That’s exactly what I have, still within spec and only 0.04* from the middle on the affected side. The unaffected side is within 0.02* and isn’t exhibiting the problem.

As far as camber goes that was done purposefully to stop the heavy inside wear that I saw on the OE size tires which would have been even worse on the 325 series I’m running now. I’ve seen owners on the forum running as little as a half or 0° camber without issue.

Feathering? Nahh, you're fine.

Post when it starts to look like this -->

https://s15.postimg.cc/4hkqw0jtn/20150501_163919.jpg

http://www.the370z.com/members/2011-...910-183103.jpg

It happens on a track where you have a lot more high g turns in one direction and only a few in the other. A bit more camber helps (2.5deg on mine all around), also a square setup where you can rotate tires helps minimize the effects. Even with the staggered setup I switch left to right even though the rotation is backwards its fine but I don't do that if the track is wet.

Oh ya the racetrack can be a harsh and expensive place. After a seven lap sprint motorcycle race a set of $550+ tires are no longer usable in a race, practice if you're lucky.

Four people missed the fact that the tire was mounted (sidewall) inside out. Dammit!!! :shakes head: