'Homemade' heatcycling and shaving for Rcomps

[SergioK]

So I bought a brand new set of the Dunlop SP Super Sport Race tires. I didn't have Tirerack shave or heat cycle them because I plan on driving them on the street for a while before taking them to the track. They come with 7/32" of tread new... I'll drive them on the streets to about 4/32" before taking them on track.

Since I've never driven brand spankin new Rcomps on the track before (the previous set was already shaved/ heatcycled) what are the downsides to driving new R comps on track. I've heard that the extra rubber simply adds to their faster demise because they retain more heat. Is this accurate?

Also, since they'll be 'heat cycled' by me via daily driving... would the toll of daily driving prove to harden the rubber moreso than the 'shop method' of heatcycling??

[Desertnate]

Please don't take this to be a sarcastic question...I really don't know...

If you buy R rated tires and have them shaved (I have heard of this being done many time) why don't they just make the tires with a more shallow tread? Since you say it is a heat issue that causes them to fail earlier, I would have thought they would be made with an optimal tread depth. Do they do that so everyone can shave to their own desired depth?

Seems pretty silly to me if you have to buy a tire and then shave off almost have the tread. :dunno:

[·clyde·]

Please don't take this to be a sarcastic question...I really don't know...

If you buy R rated tires and have them shaved (I have heard of this being done many time) why don't they just make the tires with a more shallow tread? Since you say it is a heat issue that causes them to fail earlier, I would have thought they would be made with an optimal tread depth. Do they do that so everyone can shave to their own desired depth?

Seems pretty silly to me if you have to buy a tire and then shave off almost have the tread. :dunno:

Because sometimes it's really wet out there and full tread is better. Sometimes it's dry or not too wet and shaved tires work better.

[SergioK]

What Clyde said.

Although, I have asked myself that same question too! Seems kinda silly that you buy with full tread then shave it down! (That's also the reason I want to drive these on the street... get my full 100% use out of them and break them in a bit as well) :)

[·clyde·]

Also, since they'll be 'heat cycled' by me via daily driving... would the toll of daily driving prove to harden the rubber moreso than the 'shop method' of heatcycling??

People that know more than me should chime in, but...

In many R tires, the first heat cycle is most important. Heating the tire changes the molecular structure of the rubber. If the first heat cycle is well controlled and the tire is given ample time to cool down and "set" (depending on who you listen to and the tire in question, it can be anywhere from 24 hours to a week) the tires should provide the longest life with the most grip they are capable of.

Each time the tires are used (heated and subsequently cooled) is a heat cycle. Most competition tires can only be heat cycled so many times before they turn to rocks and lose their grip. Some are very tolerant of heat cycling and can realistically be used as street tires. Others can only go through a very limited number of heat cycles before they become useless. Toyo RA-1s hold up well enough to be used full time in the summer on the street AND track/autox while my Hoosier A3S04s have gone off after 8 heat cycles in autox competition. I have no idea where the Dunlops fall on that scale, but I would be reulctant about using them on the street until more is known about them (from both heat cycling and durabillity standpoints).

[Desertnate]

Because sometimes it's really wet out there and full tread is better. Sometimes it's dry or not too wet and shaved tires work better.

If conditions make you that concerned about water, will the extra few 32nds really do that much for evacuation? The tread patterns of the R rated tires I have seen don't looks like they would be that good in water no matter how deep the tread.

[SergioK]

People that know more than me should chime in, but...

In many R tires, the first heat cycle is most important. Heating the tire changes the molecular structure of the rubber. If the first heat cycle is well controlled and the tire is given ample time to cool down and "set" (depending on who you listen to and the tire in question, it can be anywhere from 24 hours to a week) the tires should provide the longest life with the most grip they are capable of.

Each time the tires are used (heated and subsequently cooled) is a heat cycle. Most competition tires can only be heat cycled so many times before they turn to rocks and lose their grip. Some are very tolerant of heat cycling and can realistically be used as street tires. Others can only go through a very limited number of heat cycles before they become useless. Toyo RA-1s hold up well enough to be used full time in the summer on the street AND track/autox while my Hoosier A3S04s have gone off after 8 heat cycles in autox competition. I have no idea where the Dunlops fall on that scale, but I would be reulctant about using them on the street until more is known about them (from both heat cycling and durabillity standpoints).

Interesting. My 1st and only set of Rcomps (Trampio R1-R... really a Toyo) lasted an amazingly long time. I think they were heat cycled so much that they got a bit too hard for an Rcomp but as per my not so scientific evaluation of their performance, they were still better than running on street tires.

I guess the only way to see what theses Dunlops will do is to go out and try. I have a school coming up in three weekends... I don't think I have enough time in three weeks to get rid of 2/32" of tread unless these tires are really soft. :dunno:

[·clyde·]

If conditions make you that concerned about water, will the extra few 32nds really do that much for evacuation? The tread patterns of the R rated tires I have seen don't looks like they would be that good in water no matter how deep the tread.

On most of them, yes, it does make that much difference. On some it wouldn't make difference...but they usually come molded to 4/32 anyway.

[scottn2retro]

On the Yokos I've picked up from trackside that were already shaved, I've taken them out for a spin on the street to heat cycle them. Never heard of anybody trying to wear off 3/32" in the process.

The risk is if they can only take so many heat cycles before degrading. You may want to ask the people at SASCO tire near VIR. They may know more about how these tires wear/last.

[SergioK]

On the Yokos I've picked up from trackside that were already shaved, I've taken them out for a spin on the street to heat cycle them. Never heard of anybody trying to wear off 3/32" in the process.

The risk is if they can only take so many heat cycles before degrading. You may want to ask the people at SASCO tire near VIR. They may know more about how these tires wear/last.


The wear that I'd try to incurr on the tires would be over several weeks or months of regular daily driving. I daily drove my previous set of Rcomps before tossing them out. :thumbup:

[rennfahrer]

just for your info about the dunlops.
i tried them out this weekend at pahrump, NV
i had all shaved and heat cycled by tirerack before i mounted them on.
a couple of nights before the track day, i've also driven them on the street for about 30 minutes, and doin circles at auto-x speeds.

first time out, i didn't really push the car, since i was still learning the new track. i went at about street tire speeds.
second time out, i didn't heat up the tires properly, and at the end of the session, the front right tire is cording (only right front, everything else was okay)
third time out, i took 1 full lap to warm up the tires, going left and right as much as i could.
at the end of that session, my front left tire was cording as well.
both the fronts continue to get peeled off for the rest of the day
rears were okay.
tire pressures were set to 39 hot, all around.
maybe i'm a bit inexperienced in driving r-comps, these are my first r-comps.
on the front right tire, i admit that was my fault. but the left front tire...i don't think i've done the wrong thing. unless these tires do require more time to heat up.
i do notice that the tires were "predictable"
i've been told by my friends that r-comps are going to be differet then street tires, when they let go, they're gonna snap. he's using victoracers(UTOQ 50 vs Dunlop UTOQ 60)
during my drives, i was still able to feel the limits of the tires. a little bit more then the street tires, but not as good as when i rode with my friend with the victoracers.
just my 2cents.

[scottn2retro]

The wear that I'd try to incurr on the tires would be over several weeks or months of regular daily driving. I daily drove my previous set of Rcomps before tossing them out. :thumbup:

Right, but that was a different tire. Over several weeks, depending on how warm they got on each cycle, the question is how will these tires react to lots of heat cycles.

[SergioK]

That's some pretty remarkable wear for only one weekend. :wow: :yikes:

just for your info about the dunlops.
i tried them out this weekend at pahrump, NV
i had all shaved and heat cycled by tirerack before i mounted them on.
a couple of nights before the track day, i've also driven them on the street for about 30 minutes, and doin circles at auto-x speeds.

first time out, i didn't really push the car, since i was still learning the new track. i went at about street tire speeds.
second time out, i didn't heat up the tires properly, and at the end of the session, the front right tire is cording (only right front, everything else was okay)
third time out, i took 1 full lap to warm up the tires, going left and right as much as i could.
at the end of that session, my front left tire was cording as well.
both the fronts continue to get peeled off for the rest of the day
rears were okay.
tire pressures were set to 39 hot, all around.
maybe i'm a bit inexperienced in driving r-comps, these are my first r-comps.
on the front right tire, i admit that was my fault. but the left front tire...i don't think i've done the wrong thing. unless these tires do require more time to heat up.
i do notice that the tires were "predictable"
i've been told by my friends that r-comps are going to be differet then street tires, when they let go, they're gonna snap. he's using victoracers(UTOQ 50 vs Dunlop UTOQ 60)
during my drives, i was still able to feel the limits of the tires. a little bit more then the street tires, but not as good as when i rode with my friend with the victoracers.
just my 2cents.

[Pinecone]

I don't worry too much about wear patterns on fronts with a low time R-comp driver. ONE corner entered way to hot resulting in plowing can cord some R-comps. You have to be VERY careful on R-comps to avoid going in too hot. Start with lower entry speeds and work up.

What I don't understand is either a) running or b) any instructor letting you run, corded tires. Once corded, the tires are very subject to coming apart at speed. Any cords, the tires are done and should be tossed.

And yes, those tires that are molded to a deeper tread can normally use that deeper tread for wet conditions. Also in any wet conditions the tires run cooler, so having the extra tread driving up the temps can be good. Others (like Hoosiers) are molded at the proper tread depth.

And even if they are heat cycled, you should give them some running to finish removing the mold release agents.

Running them on the street to "wear them to shaved tread depth" is probably not the best idea.

[SergioK]

Running them on the street to "wear them to shaved tread depth" is probably not the best idea.

Why do you say that? I've known people to buy Rcomps, come spring, and run them the entire summer long simply for fun. I doubt anyone driving on Rcomps for regular daily driving, even spirited driving, would get them anywhere near track hot temps. So what differentiates running Rcomps solely for street use from new to gone to new to half gone then taking them to the track. This is what I do with my street 'track tires'. Why not Rcomps? :dunno:

[TeamM3]

if you're cording the outside corner that quickly then you likely had too little front tire pressure relative to the amount of front camber

[Pinecone]

Why do you say that? I've known people to buy Rcomps, come spring, and run them the entire summer long simply for fun. I doubt anyone driving on Rcomps for regular daily driving, even spirited driving, would get them anywhere near track hot temps. So what differentiates running Rcomps solely for street use from new to gone to new to half gone then taking them to the track. This is what I do with my street 'track tires'. Why not Rcomps? :dunno:

Because of the potential heat cycle problem. It doesn't matter how hot you get them, as long as you get them hot enough to cause the chemical changes related to a cycle. Too many heat cycles and the rubber gets hard and you lose some of the benefits of running Rcomps in teh first place.

You also run the chance of overheating them or chunking them by overstressing the extra rubber.

If you believe that something is all right since someone did it, go for it. Of course nobody has doone something wrong. :)

[rennfahrer]

that's what i've been told recently as well, that the tires still have too much tread, even after it's been shaved by tirerack.
so i'd probably order a new pair for my fronts, and have them shaved a little bit more.

[SergioK]

Too many heat cycles and the rubber gets hard and you lose some of the benefits of running Rcomps in teh first place.

Right. I see how too many heat cycles will cause the rubber to get relatively harder over time.

The way I see it though, the heavily heat cycled Rcomps are still going to be wayyyy softer than my 25,000 mile old street tires that have been downgraded to track use. Plus, I'm not racing, just lapping so I don't need that extra 1/10th of a second.

I figure if I were in a race situation, then yes, I'd want the tires to be optimally conditioned.

[Pinecone]

a) R-comps are more sensitive to heat cycles than street tires are. They may be better, but they could be worse. You can buy a durometer from someone like OG Racing and actually check rubber hardness.

b) Why spend the money for R-comps and they trash them on the street. Especially an new on the market tire. If you wnat R-comps for street and track not worrying about top performance, get Toyo RA-1s that are proven to work in this environment.

But no matter what, have fun. :) I wouldn't do it that way.

[SergioK]

a) R-comps are more sensitive to heat cycles than street tires are. They may be better, but they could be worse. You can buy a durometer from someone like OG Racing and actually check rubber hardness.

b) Why spend the money for R-comps and they trash them on the street. Especially an new on the market tire. If you wnat R-comps for street and track not worrying about top performance, get Toyo RA-1s that are proven to work in this environment.

But no matter what, have fun. :) I wouldn't do it that way.

a) Unless I'm mistaken, and no one has yet to say anthing regarding this, I'm pretty sure an Rcomp will stay much softer than a street tire even if it's been heat cycled 'too much'.

b) I wouldn't necessarily say that driving Rcomps on the street equates trashing them. I drove several thousands of miles on the street with Rcomps and it's quite... fun! :D

c) Tirerack has these Dunlop Rcomps at prices cheaper than my current 'street' tires (Kumho MX). Even if I end up trashing this set in half the time it took me to go through my previous set of Rcomps (at a cost/usage basis comparison, both sets would be about the same actually) :thumbup: