Shaving tires? [Archive] - MX-5 Miata Forum (2024)

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EyeMaster

18th January 2007, 11:49

Ok, so I'm decided. I'm going to get the Toyo RA-1's.

Thinking I was all done with the decisions for tires, the vendor asks me: Do you want them shaved?

Then I see from Toyo's site that shaving them gives diffrent thread patterns! (up to almost slicks). What do I do? Do I get them shaved???

The use of the tires will be track and solo2.

Lance Schall

18th January 2007, 12:06

If they are race only and you don't mind doubling your tire costs, shave them.

EyeMaster

18th January 2007, 12:40

Isn't it like 30$ a tire?

Icehawk

18th January 2007, 12:54

$15per. The RA-1 does not need shaving.

STS2

18th January 2007, 13:01

For your use, don't shave them, unless moola is falling off trees for you :).....

Custom2M4

18th January 2007, 14:00

Put them on the back and do some burnouts. That will shave them for free, and you'll have a crap load of fun doing it :D

crocair

18th January 2007, 15:51

If it is for daily driving and track days do not shave them. If your racing then do it

EyeMaster

18th January 2007, 16:13

It's only for racing. I don't want to run 225/45 r15 on the streets

Icehawk

18th January 2007, 17:08

Again, you do NOT need to shave them if you are doing track days. If you are actually racing on track then these are not the correct tires to begin with and you should look at a Hoosier R6 or the like (or whatever is class spec). If you are serious about autocross these are again not the correct tire and the Hoosier A6 or Kumho V710 are the optimal choices. To me it sounds like you are doing HPDE and some autocross in which case the RA1 makes a decent dual-use tire - long wear, don't overheat, and offer good grip.

The RA1 lasts a long time so shaving can have some advantage IF you are not using all of the rubber on the tire before it heat cycles to death. With the RA1 this isn't very likely so I don't see the point.

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Pennsylvania Bulletin

So today I talked to a Toyo distributer, and he said that if you are driving hard on-track on a 90+ degree day with 125+ degree track temperatures on a 8/32nds unshaved RA-1, chunking is more of a probability than a possibility. As you reduce tire temperature through less aggressive driving, shorter sessions, and/or lower ambient & track temps, the chunking risk reduces accordingly. When it comes to racing, he said that some teams had found that 3/32nds tires outlasted 4/32nds tires due to the lower running temperature, dependent of course on driver and conditions. He said he had sold a handful of tires shaved to 5 or 6 32nds, but had never received any feedback about them. Sounds like the key to protecting taller-treaded RA-1s is to pay close attention to temps.

Bender-san

20th January 2007, 12:38

I was always under the impression that the RA-1 was nearly impervious to death by heat-cycling. Should I be staying away from these tires as a street/autocross tire (CSP or SM2 car, so 615s are out)?

emilio700

20th January 2007, 15:16

Any tire will have a finite number of heat cycles before they "die". As track tires go, the RA-1 will tolerate more heat cycles than most. Generally, they like heat, especially when the tread is below 4/32nds.

miata_racer

20th January 2007, 20:07

I beg to differ. I had a set of Tech RA Avons and they were pretty impossible to overheat and wore wonderfully. Better than I got with Victoracers for sure. And they were only about 0.3-0.5 slower on a 60sec course than my 710s were. Plus they have a kicka$$ stiff sidewall that has a huge cantilever sidewall (makes bigger tires fit smaller wheels) that makes it quite responsive. Also communicates well and fits the stock wheels well.

One other tire to consider (and I know I'll get flamed by people who have never run them and have no track experience on them) is the Michelin Pilot Sport Cup. They will work in autocross and are absolutely awesome on the track. Wear like iron and are dang fast.

I have run a set of RA1s on our Boxster and about 4 sets of Michelins. The Michelins were in a narrower size than the Toyo and were about 2-4 sec a lap faster on a 2 min course. AND... the toyos lasted about 500 track miles while the Michelins went about 750 miles.

Just be sure to figure your tires in $$$ per mile for track use and $$$ per run in autocross. Makes it clear which tires are really cheeper.

Just some food for thought...

emilio700

20th January 2007, 20:42

I beg to differ. I had a set of Tech RA Avons and they were pretty impossible to overheat and wore wonderfully.

I think you might be confusing overheating with heat cycles. Two different variables. One can overheat any race tire in 10 minutes if enough load is put into it. Heat cycles refers to complete heating and cooling cycles.

miata_racer

20th January 2007, 21:02

Heat cycles are a way of live in Houston ;) Azenis are good track tires once here and that's it for that reason. it's over 90 about 9 months out of the year and near 100 for 2-3. :)

I'm just saying the avon is not as prone to slowing down from heat cycling or overheating as most R comps. As I said, I ran Tech Ra's for about 50-60 runs in the dead heat of the summer months in Houston and never had to water them and heat cycled them about 10 times and they still stuck well. My 710s fall off after about 6-8 heat cycles of 35 autocross runs. However on the track they come up to temp more gradually and seem to do well.

P.S. - I'd still stick with my Michelin recommendation. Even at $199 a tire. They can be driven to and from the track and are fast all the way to cord.

Icehawk

22nd January 2007, 11:01

Have you used the Michelins on the Miata? I haven't looked recently but as I recall those only come in larger sizes and are meant for significantly heavier cars (your Boxster is +500lbs over the typical Miata).

emilio700

22nd January 2007, 11:57

Ice,

Never used the Pilot Sport Cup but I've heard (FWIW) that they are very impressive. Faster than an RA-1n and possibly even longer lasting / heat cycle tolerant. For $200 in a 205/50/15, they should be.

gsr20det

22nd January 2007, 14:04

I'm not saying this to be a contrarian (and I hope you don't consider this a flame!), but I tested a set of the Pilot Sport Cups and destroyed them in less than one day. Granted, it was a hot day at Willow Springs, but they were no where near as fast as the Toyos we used on the same day. At best, I'd say the Michelins can not take heat like a Toyo and while they are better than street tires, they are not as fast as other R compound tires.

On the other hand, I was testing them on the recommendation of a friend of mine who loves them on his street car (but is on a track at least one time a week for work). Most Porsche and some BMW guys I know love them also.

Then again, I don't think my Yoko A048s are sticky on my street car...

miata_racer

22nd January 2007, 16:36

Interesting :) Sorry to hear your luck wasn't so good :\

EyeMaster

23rd January 2007, 13:34

Well then, I won't shave them. I didn't plan on driving them on the street either.

I'll have to learn about checking tire temperature and cycles and all that, for now, I know nothing. Once I've learned that, I'll figure out if I need to shave them or not, as I beleive they go hand in hand.

Last question. Can you shave a tire that's been on the track already once or twice?

Icehawk

23rd January 2007, 16:53

Absolutely not. It is both dangerous and damaging to the equipment - remember these are very sticky tires that can literally pick up rocks just by rolling over them.

chuckerants

23rd January 2007, 17:59

It sounds like heat cycling diminishes the life of the RA1s on the track. How about using heat cycled tires on the STREET? Would they be stickier than say, the new Azenis?

97montego

23rd January 2007, 20:12

It sounds like heat cycling diminishes the life of the RA1s on the track. How about using heat cycled tires on the STREET? Would they be stickier than say, the new Azenis?

If your talking about race tires that are "cycled out" and would they be faster than Azenis, they might be if they were not overheated. Some racers will discard or sell a tire as soon as the initial stickiness is gone, others run them till they're hard as wood blocks and still try to sell them.

So, it depends.

chuckerants

23rd January 2007, 21:59

I found the following by searching here.

It addresses heat "cycles", but doesn't define what "overheating" is and what its affects are.

RA-1 Care and Feeding
--------------------------------------------------------------------------------
1) Toyo Proxes RA-1's may be "flopped". That is, the tires can be rotated on the rim so as to move the inside shoulder to the outside shoulder position. This is actually a good way to increase the life of the tire if you are experiencing excessive outside or inside shoulder wear. If you are experiencing excessive inside or outside shoulder wear, you should flip the tires on the rim at or a little before the tires are half worn to maximize tire life. There is no difference in construction of the inside sidewall vs. the outside sidewall like the old BFGoodrich Comp T/A R1 tires, so doing this is not a problem. Also, if you are running in dry conditions, the tire can be run rotating in the opposite direction. This can be handy if for example you want to rotate the left front to the right rear position during a race weekend. Even though the tread pattern is directional, this is mostly for better water drainage. If you are running in wet conditions, they should definitely be run in the proper direction of rotation.

2) The RA-1 does not really require heat cycling. The compounding is formulated to be very stable from the beginning of the tire's life to wear out. This is one of the reasons why many racers love the RA-1 for enduro's. Also, the compound is not very sensitive to the number of heat cycles you put on it. So even if you put a lot of short easy stints on them, they will not turn rock hard. So you CAN race on green tires. But if you are running at a very fast track such as Willow Springs in California, you may experience blistering if running full tread depth.

Here are some tips when running the RA-1. I have to emphasize that these are only recommendations. Setup boils down to making the car comfortable for each individual driver.

1) The optimum operating temperature for the RA-1 compound is about 200 degrees F. A general minimum operating temperature is about 160 F and a maximum of 220 F. Because tires cool off fairly quickly, you should be reading slightly lower temperatures when checking the tires in the hot pits. So, if your pyrometer is reading 200 F or higher in the pits, you're probably running too hot out on the track.

2) Target HOT pressures are the low 40's. For the 205/50R15, if you start around 34-PSI front/31-PSI rear COLD on the Miata, you should be getting up to around 43 PSI HOT. Hot pressures in the low 40's may be a lot higher than what you are used to, but (cautiously) give it a try and see how it feels to you. A lot of times people run the RA-1 too low. Hot pressures tell you how the tires are working. Adjust cold pressures to reach the optimum hot pressure.

3) As a general rule of thumb for camber setting on the Miata, max out negative camber on the front and use about 1 degree less in the rear (-3 degrees front, -2 degrees rear for example).

4) If you are running at a high speed track with high ambient temperature (again, using Willow Springs for example), you should run shaved tires in dry conditions. Having full tread depth may lead to excessive heat retention causing the tires to overheat, performance to drop off, and then eventually blister.

5) The RA-1 has slightly softer construction then some of the other competition tires out there. One comment I hear from a lot of guys is that you can push them a lot harder than you initially think. As you get used to the tire and how it feels, you may find that the limits are higher than you initially thought. Of course, please be careful when exploring those limits!

6) Just as a side note, one misconception that a lot of beginning racers have is that even tire wear reflects optimum tire setup. That's not necessarily the case. You usually make up the most time on the high speed sections of the circuit. Therefore, you should adjust your setup to optimize tire performance in those high speed areas. This often means more negative camber to optimize the tire contact patch when the suspension is heavily loaded. What you may find is that this leads to greater inside shoulder wear vs. what you are seeing on the outside shoulder since most of your heavy braking is done in a straight line.

I hope this information helps. If you feel this information is worth wile, please feel free to post it on any of the Spec. Miata bulletin boards. Let me know if you have any other questions. Thank you for trying out the RA-1. We'll be doing our best to support you guys. Good luck, and good racing!

Thomas Okihisa
Staff Engineer
Technical Service Department
Toyo Tire (U.S.A.) Corporation

Icehawk

24th January 2007, 11:39

IME a worn out race tire is much worse than a decent street tire.

Shaving tires? [Archive] - MX-5 Miata Forum (2024)

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