RT660s weird tire wear

[The_Ryan]

I noticed the odd wear on the RT660s after a day of auto-x and I wanted to double check to see if anyone else experienced this on their car, or if it’s just a freak thing on my end. I’ve e-mailed Falken and Tirerack already to hopefully get some technical insight.

The course ran a clockwise loop, so this wear is only on the driver side, but almost entirely on the front and a little on the back.

The wear on the main tread blocks looks like a lot of little horizontal cuttings/splits. That mostly went away with normal driving afterwards, however there are areas on the shoulder wear that looks like tearing/pitting and then in one instance it looks like a split in the rubber a bit. Images below. The day started out cold and rainy and I noticed this wear occurring on the last two runs of the day which happened when the tires were warmest and the course was dry. No one else I spoke with had similar wear

Tire size: 215/45R16
Pressures run at the time of this photo: F38 R30
Camber is about -1.5 each side

 

[m3kerry]

Interesting. I have not autox my 15/205/40 but have driven 100 miles on them.

I put about 24 passes on mine on the mustang and will look later this week.


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[foodtruck]

Pitted surface looks like a pretty normal melty autocross tire to me, but not the vertical splits... I'm guessing it's the outer side of the tire? I run stock camber so I definitely went through many a tire shoulder but I've never seen one split like that.

 

[The_Ryan]

Pitted surface looks like a pretty normal melty autocross tire to me, but not the vertical splits... I'm guessing it's the outer side of the tire? I run stock camber so I definitely went through many a tire shoulder but I've never seen one split like that.

yeah the pitting on the main tread is normal to me as well, what was weird was the vertical splits and weird shoulder pitting that kind of looked like little chunks tearing out.

And yeah you’re right, only outer side of the tire. I’m interested in seeing what Falken says. Thankfully it’s was only my first time out with them so if I do end up replacing it, I can get away with just buying one tire.

 

[Pablo Pistoffo]

Yeah, I haven't seen anything like that split on mine. Was the split tire on the front or rear end? I run 225/45R15, but run waaaay different pressures than you. I was running 34F/ 33R, and seemed to do ok.


edit: corrected tire size

 

[The_Ryan]

Yeah, I haven't seen anything like that split on mine. Was the split tire on the front or rear end? I run 225/45R16, but run waaaay different pressures than you. I was running 34F/ 33R, and seemed to do ok.
View attachment 39774

Front driver side which makes sense because the course ran clockwise and had several large sweeping right turns

 

[Rexracer]

Front driver side which makes sense because the course ran clockwise and had several large sweeping right turns

Whats the condition of the surface? If a fairly worn surface I could see the front pushing a bit across a sharp aggregate and causing the vertical cut, like if this was Packwood I wouldn't give it a 2nd thought.

Also, on the RT660s, I was running 39 in Vegas 2 weeks ago, and burned triangles completely gone. Day 2 I went to 41 to try and save the shoulders a bit. On RE71s I run 38.

 

[faust]

here's my front after around 20 runs at yesterday's test n tune (35 & 45 second courses). Stock camber, and I did let the pressure get up to 44-45. I was chalking as I went, and it seemed like even at that pressure, there was some wear at & past the triangles.

what's the date code on your tires? These are august '20.

 

[FORZDA 2]

I noticed the odd wear on the RT660s after a day of auto-x and I wanted to double check to see if anyone else experienced this on their car, or if it’s just a freak thing on my end. I’ve e-mailed Falken and Tirerack already to hopefully get some technical insight.

The course ran a clockwise loop, so this wear is only on the driver side, but almost entirely on the front and a little on the back.

The wear on the main tread blocks looks like a lot of little horizontal cuttings/splits. That mostly went away with normal driving afterwards, however there are areas on the shoulder wear that looks like tearing/pitting and then in one instance it looks like a split in the rubber a bit. Images below. The day started out cold and rainy and I noticed this wear occurring on the last two runs of the day which happened when the tires were warmest and the course was dry. No one else I spoke with had similar wear

Tire size: 215/45R16
Pressures run at the time of this photo: F38 R30
Camber is about -1.5 each side

Those are cuts from debris on the track when the tire is pushed sideways due to lots(too much?) of steering input. Slow in - fast out works best.

 

[ktronic]

Those are cuts from debris on the track when the tire is pushed sideways due to lots(too much?) of steering input. Slow in - fast out works best.

I agree.. I remember seeing sideways marks that look like that at autocross events with really abrasive surfaces. I wouldn't worry about that, BUT, I do think the peeling is of concern. I'd be interested to see what Falken says. It *could* just be a side effect of really abrasive surface plus lots of sliding, and that the RT660's and other top 200tw tires have gotten so soft that this kind of thing is unfortunate but may be expected if the conditions are just right.

 

[The_Ryan]

Those are cuts from debris on the track when the tire is pushed sideways due to lots(too much?) of steering input. Slow in - fast out works best.

This was my assumption, especially since my driving was hot garbage that day. I just never had seen it before. First time out with 200TW tires though so I wasn't entirely sure. Like @ktronic said, I'm mostly concerned with that what looks to be a huge split, but I think that might just be an unfortunate situation of catching some gravel at the wrong angle.

 

[ktronic]

Also, just today I saw someone on a FB autocross group share pics of their RT660s with some similar sideways marks and some peeling as well. Seems to be normal-ish.

I'll have a new set of 215/45-16 RT660's in about a month and will definitely keep an eye on the wear.

 

[The_Ryan]

Falken/Sumimoto Tire said it appears to be superficial and to keep an eye on it. Will send and hopefully I will suck less next time

Also, just today I saw someone on a FB autocross group share pics of their RT660s with some similar sideways marks and some peeling as well. Seems to be normal-ish.

I'll have a new set of 215/45-16 RT660's in about a month and will definitely keep an eye on the wear.

Glad to know I'm not alone at least. Falken got back to me and said it appears to be superficial but to keep an eye on it. Full send next event, will update then.

 

[johnny5]

Does anyone know what Falken recommends for tire temps across the face (measured with a tire pyrometer)?

 

[CSM]

Haven't seen this before....

That one big horizontal line across the tire looks like what a lot of SSC folks are reporting from some batches of tires. I believe TR has said its the point where the tire is laminated, or something....and that it was cosmetic and not a worry.

The other issue that seems to be sorted is the center rib delaminating. I haven't had that on any of the sets I've ran so far.