Flipping Tires (NT-01s): Grassroots Motorsports forum: Grassroots Motorsports Magazine

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July 3, 2009 4:40 p.m. Salanis UltraDork

I have Nitto NT-01s for the track. I figure they're about halfway worn down (pretty much all the tread gone, and just the circumferential grooves and depth holes). They don't quite have uniform wear, and I'm thinking of flipping them on the wheels, to even things out.

Only thing is, I'm not sure if they can be safely flipped or not. The NT-01 is non-directional, but the sidewalls have "inside" and "outside" marked on them. The tire has circumferential grooves that are a bit one the inside of the tire from center.

Would it cause problems to take them to a tire shop? Or should I not even bother? The wear inconsistencies aren't too bad. The biggest issue is the outside edge (on the right in the photo below) got a fair bit of scrubbing at an auto-x.
July 3, 2009 5:30 p.m. iceracer HalfDork

I know Hoosiers can be flipped, don't know about Nitto's but I don't see why not.
July 3, 2009 7:12 p.m. Salanis UltraDork

Seems like you should be able to. Only thing I can think of, is maybe the grooves help evacuate water, or something. But I am not using those tires in the wet, and this is Cali anyway, so we only hear about this mystical "water from the sky" thing in stories.
July 3, 2009 7:59 p.m. laz New Reader

It's fine. It's pretty common to run directional RA1's or R888's in the "wrong" direction in the dry, I can't see how the NT01 would be any different.
July 3, 2009 8:23 p.m. walterj Dork

Unless the outside wall were made stiffer to improve turn-in I cannot think of a single reason except tread pattern and that is mostly irrelevant once you get that far down.
July 4, 2009 9:21 a.m. wbjones New Reader

you would tend to loose a small amount of grip at the ultimate .... the large rubber blocks on the outside of the tire would now be on the inside... the only way to tell how much is to go ahead a flip
July 4, 2009 9:22 a.m. wbjones New Reader

iceracer wrote:

I know Hoosiers can be flipped, don't know about Nitto's but I don't see why not.

forgot this one... the grooves on the Hoosiers are centered on the tire... no advantage running them in either direction
July 4, 2009 7:01 p.m. mw Reader

I have heard that with 710's, they don't work nearly as well when flipped. I would guess it has to do with the sidewall construction.
July 5, 2009 7:45 a.m. wbjones New Reader

mw wrote:

I have heard that with 710's, they don't work nearly as well when flipped. I would guess it has to do with the sidewall construction.

maybe... but could still be the positioning of the grooves...
July 5, 2009 8:42 p.m. Salanis UltraDork

I e-mailed a message off to Nitto. I'm going to see what the people who made the tires have to say about them. Aside from just the thickness of the tread blocks, I think the surface of the tire might actually taper a bit towards the outside edge.

Given my tread wear, it almost looks like I just need to run a bit higher pressure. The wear that concerns me the most all happened at an auto-x where a friend was sharing my car, and he lowered the pressure 9lbs below where I keep it on the track. He did hustle the car well enough to take 4th at a competitive PCA event.
July 6, 2009 6:29 a.m. Dashpot New Reader

I've run NT-01's for the last couple of years, and don't bother with the expense of flipping them on the rims. I do however rotate them around to even the wear. While this works for visual tread wear purposes, my last set really went nuts before any visible cording. I spent most of the braking zones trying to keep from backing into the turns, felt like sombody loosened up all the suspension bolts.

So be careful if your tread's all gone and you rotate at random.
July 7, 2009 11:31 a.m. Salanis UltraDork

I got a response from Nitto. It just said, "We can not recommend flipping the NT01". No other details. I like to know why things work the way they do, but I'll just defer to their expertise.

Dashpot wrote:

So be careful if your tread's all gone and you rotate at random.

When the tread is gone, aren't these tires still supposed to have half of their life left? They become slicks at 3/32", and are meant to be able to get shaved that low.
July 7, 2009 11:59 a.m. Dashpot New Reader

Salanis wrote:

When the tread is gone, aren't these tires still supposed to have half of their life left? They become slicks at 3/32", and are meant to be able to get shaved that low.

If you have perfect camber settings and perfectly even tire wear, sure. Not sure about yours but mine are never perfect. Rotating the worst tire to the best corner will make them look better on the surface, but swapping L to R and reversing rotation can't be doing the belts a favor either. I've personally never found flipping tires on the rim to be worth the expense even for RA-1's.
July 8, 2009 9:46 a.m. andrave Reader

I read something about this in an older GRM. I think it was hoosiers they flipped but can't remember. They didn't notice a big difference in laptimes from flipping them. They did note that where the tread is joined, its joined at an angle, and instead of the normal forward rotation of the tires forcing down on the joint, if you flip them backwards, hard braking is actually pulling the joint apart, and on a super soft tire like that, I think they theorized that it could eventually seperate the carcass across the tread joint.
July 8, 2009 9:52 a.m. GameboyRMH SuperDork

Salanis wrote:

this is Cali anyway, so we only hear about this mystical "water from the sky" thing in stories.

I hate you.
Aug. 7, 2009 12:42 p.m. Hydro None

Does anyone here have any experience now with flipping the NT-01.

I've run the shoulders to the cord on a 3 of the 4 tires I have after only 2 events, and was hoping that someone might have flipped them.

If not, I'm going to have to get a new set of tires, and I'll be going with the Hoosier, because I know you can flip them.
Aug. 7, 2009 1:12 p.m. Salanis UltraDork

I did not flip my NT-01s. I contacted Nitto and they said that they could not recommend doing that. They didn't elaborate, but I decided it didn't matter enough to me.

Only two events on those tires though? Geez! What are you doing to them? I have 8 events on mine, several with multiple drivers, and they're only a little more than half worn.

Sounds like you don't have nearly enough camber, or you pressures are too low.
Aug. 7, 2009 1:27 p.m. splitime Reader

Salanis wrote: Only two events on those tires though? Geez! What are you doing to them? I have 8 events on mine, several with multiple drivers, and they're only a little more than half worn.

Sounds like you don't have nearly enough camber, or you pressures are too low.

Yah... how did you only manage that much life? I'm going on 6 full days so far and figure i have at least 2 more full days left.

Shaved and then really abused?
Aug. 7, 2009 5:35 p.m. Salanis UltraDork

splitime wrote:

Yah... how did you only manage that much life? I'm going on 6 full days so far and figure i have at least 2 more full days left.

Base-model NA Miata. Low weight, low power. Never shaved the tires. It hardly uses any rubber at all doing open track.

At this point, I'm thinking the rubber will be crapped out before the tires cord.

I suspect the guy going through tires too quickly needs an alignment. Sounds like maybe bad toe.
Aug. 7, 2009 7:57 p.m. Hydro New Reader

I'm running a 2006 Subaru WRX STI (USDM GD) Car Curb Weight: 3351 lbs Competition weight with driver: 3566 lbs

Alignment (check prior to each event): 0 deg/30min Toe all the way around -1.5 deg/30min Rear Camber -2.5 deg/30 min Front Camber +6.5 Castor

They weren't shaved, and were heat cycled right from Discount Tire Direct.

After thorough research I've discovered that the 06 STI @ 6.5 deg castor and -2.5 camber rolls to positive camber @ 15 degrees of yaw input. I've also discovered that if you change the strut top castor/camber angle with plates or fixed tops (like the Whiteline Com-C strut tops that I just installed) and max out the stock eccentrics, the camber curve will be worse, than if you left the stock top in and just maxed out the stock eccentrics with the same 15 deg of yaw input.

However, if you go with a more than 3.0 deg (steady state) then the camber curve is much more favorable. Thus, I've discovered that with the 06 STI, -2.5 camber is killer on tires. If I would've left the strut tops alone, and ran max camber on the stock eccentrics, I would've saved my tires.