Does anyone know the proper method of heat cycling? What is the purpose of this?

Thanks for any helpful suggestions!

--MAW

 

i dunno haha, but at buttonwillow, by the 4th session my tires kinda slid around some turns that i went fast on...i mean still very safe and controllable, just i'd prefer no squealing.

 

No need to heat cycle Azenis

 

Yup no need for heat cycling street tires Heat cycling causes the molecules in the rubber to line up better, which equals better wear and better stick. The Azenis stick right away.

 

Yeah, tell that to MaddMatt

 

Oh hell yes they do.

http://www.sr20deforum.com/showthrea...threadid=26242

 

thats breaking them in, not heat cycling them. two very different things.

and quite frankly the tires "going away" after 4 maiden laps doesnt sound like a tire issue...


[Modified by Tyson, 5:44 AM 9/25/2002]

 

OK, then what does it sound like?

After talking to a former Michelin tire Engineer (my brother) he absolutely agreed with my assessment. Oh, and my uncle too, who has worked for Uniroyal and Michelin.

 

first, you can run competely new R tires on the track for the first time and they will be fine, just wont last you as long. i dont see why a street tire would be more sensitive as you claim in your case. (yes i know the difference in street rubber and R rubber. still, no reason for it to "suddenly" give out in a turn.)

second, simply breaking in the tire is different than heat cycling. breaking a tire in just gets the smelly release agents out. heat cycling does it in a specific way to get optimal life of the tire. ok, not very different things, but not the same.

thirdly, oil?


[Modified by Tyson, 5:56 AM 9/25/2002]

 

Yeah, agree with Tyson. The Azenis don't really need a heat cycle, just a good scuffing, ie: break-in session. Everybody I spoke to running Azenis, complained that they are pure **** until that first layer is crubbed off... Totally differrent thing from heat-cycling r-tires...

 

Yes, the smelly mould release agent is the culprit. It's in the first 1/32" of tread depth. As the tire heats up, that compound begins to work it's way out. That's what happened to me. Shave your race tires and you'll have NO problem with that, since you've removed that 1'32" layer.

Bottom line, whatever the problem is, you cannot go out on track with Azenis tires with zero miles on them. I would say, however, a drive to the track would take care of this problem. Had I done that instead of towing, I'd never have found myself in the tire wall.

I am not blaming the equiptment here. It performed exactly as it should. I screwed up by not knowing what needed to be done. Now I know.

 

Matt... dude... sorry to hear about that off. I hate to say I know how you feel. Consider yourself very fortunate. The Gods must be smiling on you.

I'm genuinely interested in this perplexing situation. I can't believe your tires just "went away" like that, though I do trust your account implicitly. You've got the experience to back up that statement. But this is STRANGE. What exactly did your brother say about this sort of thing? I can't imagine that ANY tire company would put an agent in a street tire (of all things) that would cause catostrophic sudden tire failure (IMHO, this fits "catastrophic") when new. There would be TONS of accidents due to this, I'd think. How could a tire get a DOT rating on it? Is it a function of the rapid introduction of heat that overwhelms a green tire? I'm really curious cause this raises my eyebrows a good bit.

Tyson - the break in of a street tire and an R-compound tire is more similar than you think. *To my knowledge* (and why I'm questioning this), most tire manufactures recommend a break in of 500 street miles on high performance street tires. This is to give the appropriate amount of heat cycles (determined by an average of some sort I'd assume?) and allows the rubber sufficient time to cure. The time is the critical factor. Then, you can go out and hammer the hell out of them. BUT, if done before this time, you can cause the tire to fail. Remember when Car and Driver tested a Renntech Mercedes on Pirelli P-Zero's? They took the car out on brand new tires and the tread seperated from the tire at 180mph on a test track. The lack of heat cycles caused the tire tread to seperate from the carcass. But, I don't believe they had grip issues.

However... on an R-compound, (again, my understanding) the rubber compounds are more volatile, if you will, and a quick heat cycling will excite the rubber molecules sufficiently enough and will cause them to take a set when they cool. Once they've been heat cycled, you're supposed to lift the tires off the ground, put them in plastic bags, and allow them to cure in a cool dry place for at least 24 hours. However, the cure time is critical. I've heard on Toyo RA1's, for example, that if they cure for 1 month, they'll last nearly forever with plenty of useable life (I'm finding this to be true - still on the orginal 4 tires that I started this season with).

Even with or without these heat cycling processes, I'm curious as to why the tire went away suddenly. I'm offering what I know and want to know more. So I'm posing these questions and NOT flaming as Matt is VERY experienced and knows his chit...


[Modified by Shugg, 7:08 AM 9/25/2002]

 

As with any tire they come with a coating to protect them in shipment. Getting this off is scuffing them.

Heat cycling causes the bonds in the rubber to align to get better grip and life out of the tires.

I didn't do a heat cycle and they have been sticky ever since January and I have 3-4 mm of tread left.

Sounds like someone was over driving the tires or hit a nice oil patch on the track.

 

Eh... just admit you're a shitty driver who had no clue what you were doing. You know I'm right... Any idiot could have kept that car on track. The mould release compound wasn't really the problem.

r2x ~ who when she says "Anyone who does this long enough will hit something" would always add "with the possible exception of Matt".

 

What happened to matt is exactly what he said... the mold release agent made the tires go instantly greasy.

He had just passed me, and we turned into the turn at exactly the same speed, and on the same line...matt in a prepared SE-r taking a conservative warmup, me in a bone stock jetta on crap michelins....when he went off the outside I started wondering what had broken, or if his LF tire had gone down. This was not a function of "overdriving" or "oil on the track" (I would have offed right behind him), this was a tire issue that people should know about.

For street use this isn't an issue, as anyone linking together enough turns on the street to create heat in tires is breaking the law and deserves whatever happens (I speak from experience here, it has happened to me, and cost me a civic) but for track use it is a particularly dangerous issue, as Matt was running at "heat-cycling" speeds at the time of his off.

 

This isn't something they put on the tires for shipping, it the mould release compound they spray onto the rubber to make it not stick to the mould. They generally use it liberally and during the manufacturing process, it does work it's way ~ 1/64"-1/32" into the rubber. Just like a brake pad that green fades, when a tire new starts getting hot, those compounds work their way out, and the grip changes drastically. This is info from my brother (the former Michelin Engineer).

Matt-who learned alot in ~2.8 seconds last weekend....

 

So essentially, your tires "outgassed"... Yikes!

 

Or ... "out oiled" hehe ... "out greased"?
Sorry.

 

Well I guess you learn something new every day. I knew about the "scuffing in" but didn't know about this agent stuff.

I was never doubting you Matt, it just seemed odd. Again, glad to hear you came out of this in perfect condition. Could have been worse. Thanks for cluing us in on this too. Hopefully you'll prevent someone else from similar fate.

 

might i ask why you were using 195/60/14's on a SENTRA???? that things a pig (no offense) and is undertired on 205's.

also, the falken's and most other street tires will heat up to about 125 degrees at highway speeds going straight. (air temp about 75, partly cloudy) "spirited" street driving can get them up to 130-140 pretty easy.

nate

 

The hottest my tires ever got - mind you it was 98 degrees out and 80-90% humidity this year was 133-135 degrees. Way hotter than they should have been.

 

2550 lbs is a pig? My Eclipse is a pig. You realize the stock tire on this car is 185/60/14, right? I've used 195mm wide tires for YEARS with tremendous success. 195/55/14 RE71s for track (when stock), 195/55/14 V700s for track and autocross, and 195/55/15 AVS for autocross. No problems with 195mm rubber on an SE-R.

The 195mm Falkens are a wiiiide 195. Kinda like the 195/55/14 V700. Closer to a 205 than a 195 really.

I wish I had a pyrometer in the car to check tire temps as I waited for them to pull me off the tire wall. 5 minutes after my session was so rudely interrupted, the tires were still extremely warm.

 

the tire temp part of my post was directed to the person who felt street driving wasn't enough to put heat in the tires, which it is. i didn't feel that your tires were still cold nor overheated. i experienced a similar "going away" of the tire at the first autocross i ran them at, but do to the short run time of autocross i did not experience it to the same severity. i say your car is a pig (again, no offense) because it weighs 2550 lbs. my civic only weighs 2300 or so, and i feel that 205 falkens are still too little tire. there is a se-r that autocrosses against me and he's using the 205's and it is definitely not enough tire for him either. just my .02. if 195 is working for you, then by all means.

nate

 

The 205/50/15 Falken Azenis is so wide, it is actually ~1/4" WIDER than a 225mm Kumho. I meassured them back to back at VIR back in July. They're so wide, they wouldn't fit on the back of my Sentra without spacers. My car looks like a steam roller with my 15s on.

205mm and treadwear 200 my ***.

 

i'm not sure of the offset the guy up here is running, but he doesn't have any problems with them rubbing. his is a 91 though, maybe different from yours?

nate