Bowchickawowow

Hoping for some analytical guidance here...I have been using the same set of Nitto NT05's for both the track and street for 5 track days (road course) and about 6000 street miles. I've taken them off for brake work before and after each track weekend, but just noticed this issue after taking them off to install tow hooks. My last track event was fairly hot (~90ish) and I ran 26psi cold all around (worked up to 31psi hot). Any ideas why on the center tread strip, one the inside edge is near 3/32" and the outside of the center strip completely flat? (stock alignment specs by the way) Thanks!

hklvette

Mine do the same thing at auto-x. I just flip them when they do that, and don't think its anything abnormal. I think its mostly due to tires' tendency to "round-off" sharp edges during cornering, which is why the edges facing the outside are round and the ones facing the inside are squared.

bluemagoo

I'd say that's typical for the NT05s. I had the same wear pattern with two sets that saw track time.

froggy47

Yep, if the track was laid out straight it would never happen.

Bill Dearborn

Mine did the same thing. Sort of reminds me of the old BFG R1s from the 90s and their groove of doom. They asymmetrical tires that worked well on camber challenged cars and if you ran too low of an air pressure the tread would buckle on hard cornering cause a very similar wear groove near the center of the tire. It might be time to rethink the proper hot pressures for these tires. Instead of aiming for the low 30s maybe they should be in the high 30s.

Bill

avizandum

. Flip 'em before you cord them...

Bowchickawowow

Looks like I'm flipping them and trying a little higher pressure. Thanks for the responses!

froggy47

Not nt05's but here is a data point re: tire wear:


A6 tire wear, pretty even eh?

AU N EGL

Higher ? NOOO

lower pressure

Balding in the center is too much pressure hot.

Bowchickawowow

Since the center is not wearing uniformly, the thought is that the tires may not be inflated enough, causing the outside to buckle when cornering. I think if they were inflated too much the center stripe would be worn more than the outsides, but would be more uniform in the wear pattern than what I'm seeing. I also noticed that the wear triangles on the sidewalls are almost gone on my fronts, again hinting to too low pressures. Disagree?

blkbrd69

If the photo from your avitar is an indication you are running a roval? Dont drop pressure to much, the odd thing is I always gained 8-10 psi with NT-05's front and 6 psi rear.

I looked for 33 hot and had the same wear. They turned to rocks at about that point.

Hi Volts Z06

Check your pressure gauge. Those tires look overinflated.

Also verify your alignment again. I've seen that same wear pattern occur on a vehicle with too much toe in. In my case the alignment machine said 1/16" of toe in....it was actually 1 1/16".

SunnydayDILYSI

Totally agree that the wear is from cornering. Mine did the same thing with 28 PSI cold.

Bill Dearborn

Not always. That is what led people astray with the R1s. The groove on them occurred off center and once people thought about things it became obvious BFG was right and the pressures were being set too low. The NT05 wear is off center toward the outside of the center line of the tire. Only way overpressure would cause that kind of wear is if the wheel had a fair amount of positive camber. Another thing to think about is the wear is beveled from outside to inside with the most wear on the outside of the center section and least on the inside of the center section. In my mind I have a picture of a tire sliding sideways with the outside of the tire leading thus the outside edge of the center strip is being abused. That is understeer and which can sometimes be corrected by increasing tire pressure.

I bet if we were able to take tire temp measurements on the 05s pictured we would find very high temps on the outside followed by almost as high temps on the center outside edge and getting less as we check going across the tire from outside to inside.

Bill

FASTFATBOY

I have run many sets of these tires and this is normal. Do not flip the tire on the rim until the outside edge is worn enough to do so.

I start the session at 31F/26R in a 3800lb Camaro with 385 to the wheels.

Nothing to be concerned about.

hklvette

To add more info to this discussion, I have a pair that are the same size worn down to the bottom of the wear bars and the still have some tread on the shoulders. They were flipped once. I'm going to be getting a fresh pair soon, and when I get them will measure the tread depth across the face. I'm curious if they are shallower in the center than the edges when new. If so, even wear could look like over-inflation even though it isn't.

ZedO6

Add pressure The tire carcass is flexing on turn in and the center tread bar wear is the proof. When I had factory support years ago running BFG's the engineers blamed too low pressure on the "groove of doom" and damnit if they weren't right! I'd also call it somewhat normal from what I've seen. Adding pressure may reduce it, but doubt it will eliminate it.

FASTFATBOY

You run too much air in these tires and they slip/slide and get greasy and the problem compounds itself as the session goes on.

These tires get a bad name because of it.

hklvette

I'd be curious to see what tire temps look like with higher pressures. For auto-x, I can only get them to really work when the ambient is 90+ and bright sunshine. Higher pressures may cause them to run cooler, preventing them from reaching their operating temperature.

FASTFATBOY

Not when I gain 7-9 PSI over the course of a 20 minute session.

Starting with 31F/26R I gain 3-4 PSI and the grip is like a totally different tire.

I started with these tires at 35F/30R and wondered WTF?! As I was all over the place, I wasn't any faster than I was on my junk $99 each Maxxis street tires.

I kept dropping starting pressure until the tires came around.