So, I've got Nitto NT-01s on my car now. They're getting towards the end of their life, but I'm planning to just run them until they cord, since I know they'll be good that long. Then, I have a set of RA-1s to mount up.
My question is though, what will happen when a set of R compounds cords on the track? Does handling get progressively worse? Will I be able to tell? Or will they just suddenly fall apart, let go, and send me off the track requiring a tow back into the paddock?
ckquote>Salanis wrote:
My question is though, what will happen when a set of R compounds cords on the track? Possible blow-out
Does handling get progressively worse? Absolutely
Will I be able to tell? Yes
Or will they just suddenly fall apart, let go, and send me off the track requiring a tow back into the paddock? Very good chance.
Just put on the new tires and don't take the chance of wrecking your car and causing yourself a lot of pain. Even worse, you might take someone else out with you. A bit of common sense would be prudent.
Dayam- This newby likes his Loti!! Welcome to our madness.
If you inspect them after each session you will see them start to go. Usually you can see a few threads starting to show in one area or some blisters indicating they are really close.
What I typically do is mount up a new set and on other wheels and swap them in as each tire wears out. I have actually had a tire explode on track (not because it was old or worn... just because) and it isn't really pleasant. I have also driven a tire pastr the threads and into the wire without issue except it was like ice to turn left 
. Don't push it - if you know you are close... better to throw away 10 min of tire life than a whole quarter panel or worse.
The thing with NT-01s and RA-1s is that they never give up grip until you finally run out of rubber so... you can only tell they corded on track because that corner feels like it hasless grip all of a sudden. Visually inspect before each session as you get close and don't panic if you cord one on track - just back it down and bring it in.
I guess the other operative question is, how to tell when the tires are almost done. They've got plenty of meat left on the inside, but a lot less towards the outside. Even still, there is plenty of rubber above the wear triangles on the sides.
Giant Purple Snorklewacker wrote:If you inspect them after each session you will see them start to go. Usually you can see a few threads starting to show in one area or some blisters indicating they are really close.
What sort of blisters? The outside shoulders on the rear look a little spotted, like there are a couple of spots that have flaked off a bit or something.
Edit: Here are pics of the current shape of the worst looking tire. Please excuse the poor quality cell-phone pics:
Yes, the handling will get progressivrly worse, as in "no grip". Steel on asphalt doesn't equal rubber on asphalt. Rather than run them at a track event use them at an autocross (or 2-3) until they're gone.
Years ago I ran a BFG exhibition event where drivers used Comp T/A R's on Mazda MX6's. We all ran the same course on the same tires; my runs were last in the group and the tires were already showing cord.
I received the "most aggressive" driver award, but it was due to a friction co-efficient at nearly zero and that I love driving other people's cars really fast.
YMMV
Those pics are a little too grainy but from the look of the divot in the last pic and the edge line compared to the arrows you have a way to go before you throw sparks. Take the worst tire and place it on the most unloaded wheel.
Those look like you could do with a little more camber in the car if that wear pattern is as it looks to be in the pic (lots of outer edge and plenty of rubber elsewhere).
Giant Purple Snorklewacker wrote:Those pics are a little too grainy but from the look of the divot in the last pic and the edge line compared to the arrows you have a way to go before you throw sparks. Take the worst tire and place it on the most unloaded wheel.
Those look like you could do with a little more camber in the car if that wear pattern is as it looks to be in the pic (lots of outer edge and plenty of rubber elsewhere).
Yeah, I know the car doesn't have enough camber. I've maxed out the front camber, and I don't want to screw with the front/rear balance. I'd need some offset bushings or something up front to fix it. I'm planning to get another track car soon enough to not be too worried about it.
I have put them on based on how quickly I think they'll get used.
I once corded a street tire so bad that it actually corded a hole in the tire.
it wasn't one of my proudest moments....
If they're radials, I would expect sparks at some point.
Even before they cord you'll probably notice the grip going away. When things go all greasy then it's time to give them to your autocross buddies.
Salanis wrote:They've got plenty of meat left on the inside, but a lot less towards the outside. Even still, there is plenty of rubber above the wear triangles on the sides.
So take them off, and remount them on the rims on the opposite side of the car. Then you've got thicker tread to the outside, and the tires are still spinning in the same direction.
In reply to foxtrapper: Note the word "OUTSIDE" molded into the sidewall on the first photo.
erohslc said:In reply to foxtrapper: Note the word "OUTSIDE" molded into the sidewall on the first photo.
So? Those markings are simply for directionality. Since it is practically a slick tire with no tread, they can be flipped with little performance loss.
erohslc wrote:In reply to foxtrapper: Note the word "OUTSIDE" molded into the sidewall on the first photo.
Its a somewhat common practice and I have seen it done without ill effect. If I recall correctly the manufacturers have even given it the go ahead.
maroon92 wrote:So? Those markings are simply for directionality.
Is that even a word? 
I believe it is a perfectly promulent word...
Giant Purple Snorklewacker wrote:maroon92 wrote:So? Those markings are simply for directionality.
Is that even a word?
I'm afraid so. But promulent is not. Maybe cromulent. Proper grammar embiggens us all.
Apexcarver wrote:erohslc wrote:In reply to foxtrapper: Note the word "OUTSIDE" molded into the sidewall on the first photo.
Its a somewhat common practice and I have seen it done without ill effect. If I recall correctly the manufacturers have even given it the go ahead.
What tires did you do it on?
The NT-01 is not directional; it is asymetrical. I checked with Nitto about it, and they said they could not recommend flipping them, but didn't elaborate as to why. I know they space tread blocks unevenly (widest block on the outside) to improve characteristics, but I suspect they may also construct the sidewalls differently, too.
Otherwise, that would have been the obvious answer a while ago.
Dude, you're talking about running down to the cords. Asymetrical tread design advantages have long worn off.
foxtrapper wrote:Dude, you're talking about running down to the cords. Asymetrical tread design advantages have long worn off.
LOL! Good point. I'm still not sure if they maybe construct the sidewalls differently.
Still, it's not like I'm using these to race or anything, and it will stretch my dollar.
foxtrapper wrote:Dude, you're talking about running down to the cords. Asymetrical tread design advantages have long worn off.
+1. I would flip them. On a somewhat related note, I had a classic moment a while ago at school. We were showing off an old FSAE car to bunch of future students. Of coarse the car was on slicks and one of the mothers asked how the car gripped without any trend on the tire. 
Sell em to someone building a challenge car and get some money bake now that they are almost dead.
