124Spider

I've been following the threads on shaving the RA-1 with interest, since I'm about to buy tires for the track (I'm planning to continue using RE050 tires for street use). Being entirely ignorant on the subject, however, I have some questions:

1. What exactly is shaving? Is it merely taking a bunch of the tread off?

2. I infer that the reason for shaving is that the tire is too loose unshaved; is that correct?

3. I am learning that our local track likely will be unusable for the duration of the winter and early spring, since moss, algae and the like growing on the track make it too interesting for me. Would there be anything wrong with using the RA-1s as street tires for several months (I drive about 2,000 miles per month) to wear the tires down, rather than shaving them, thereby getting some extra use out of the tire? If so, how far down does one want to shave/wear the tread before dedicating it to track use?

4. What exactly is heat cycling?

5. How many track miles can I expect to get on a set of shaved/properly worn RA-1s?

Thanks.

cthree

1. Yes. The tire is put on a lathe and rubber is removed to the specified depth, usually between 4/32 and 6/32 of an inch (the wear bars are at 2/32).

2. The tread block flexes if it's too thick on a dry track. Also the tires will "chunk" as big bits of the tread are ripped off. Removing the tread prevents chunking and flexing. Additionally the flexing of the tread block can overheat the tires. If you drive the snot out of a full tread tire on a dry track you will completely destroy it in about 4 30 minute sessions on-track. That applies to both DOT-R and normal DOT tires. The only exception are slicks and Hoosiers. RA1s, PSCs, V700s or any other street tire don't come designed to accept the punishment of track use.

3. You aren't going to wear them down fast enough. If you drove maybe 8-10K maybe but otherwise get them shaved to 6/32 and wear them down to 4/32.

4. Heat cycling is simply heating and cooling the tires. Some rubber compounds start out less than optimal and become stickiest after they have been cycled a few times. Every tire has a given number of heat cycles before the molecular structure of the rubber breaks down. This is generally not a problem for track use because you'll wear them out faster than they can over cycle. Autocross drivers are more likely to have this problem and the tires become hard and glazed. RA1s come ready to run. No cycling is required before use and they will remain excellent for 6-8 track days no problem. Heat has a major impact on the rubber of the tire. There is an operating range where you need to stay to get the most out of them. If the tires overheat (a problem with lots of tread) they will get greasy. The RA offers the widest range of operating temp in my experience. They heat up after just one lap and generally wont overheat and get greasy unless you have a major understeer problem or are drifting a lot.

5. 6-8 track days and probably 6K street miles. If you did one track day a month plan on a set each year.

Ludedude

1) Yes.

2) The real reason for shaving these or any tire is to eliminate chunking due to overheating the tread blocks. A side benefit is that you get more good rubber on the road so it gives more grip. RA-1s are loose unshaved due to excessive movement from the tread blocks at full tread.

3) Full-tread RA-1s make great rain/street tires. In your neck of the woods that's probably an important consideration. Track performance starts to get "good" at around 4/32" tread depth, or right about where they're shaved to if you buy them that way.

4) Heat cycling: http://www.insideracingtechnology.com/tirebkexerpt3.htm

5) There are many many variables here. Alignment plays a huge part in this as does swapping tires side to side and flipping them on the rims to keep wear even. You probably don't want to swap side to side with treaded tires if you expect to see wet weather as the desired effect of the uni-directional tread will be compromised It's accepted that you can get 7-8 track days plus street miles to/from the events with no trouble. That probably equates to about 8,000 miles or so total but I start with 4/32" shaved tread.

For more, read the thread Mike Garrison has going in this forum. it also has a link to another excellent older thread on the subject as well.

cthree

These are slicks we are talking about here so street driving in the PacNW over the winter is not recommended. These are dry track tires which you can get away with on the street if you are very sure it's not going rain (like in SoCal most of the time). I wouldn't use these as street tires at all in the PacNW.

other experiences I had:

PSC - Never quite seem to heat up even under severe track use and don't quite get into their own. Last for f-ing ever, longer than you want them to.

V700 - Heat fast and go off quickly. Good for 7-8 laps and them need to be cooled off. If you continue to push them they will cord. IMHO they don't have the heat range we need and wear out too quickly.

Ludedude

Shaved yes, full tread would be fine.

cthree

One last point then I'll shutup.

Track and autocross are NOT the same. These are two vastly different environments and as a result a good auto-x tire like the V700/710 is exactly what you don't want for the track and vise versa. The RA1 is not a winning autox tire because it doesn't heat quick enough. Autox requires the tire start cold and hit ideal temps immediately on a very tight course with a car heavily weighted toward understeer and for only 60 seconds or so. The track requires a tire that reaches optimal temps later and lasts for a lot longer on a high speed course with the balance weighted toward neutral or oversteer.

Different tires are targeted towards one or the other or in the case of Hoosier they have different models for each use. RA1s are squarely more track oriented and the V700 more autox specific. There is a middle range but not much of one.

Just FYI as you are talking to different people about their tire recommendations. How they use the tires has a lot to do with their preferences.

cthree

Unshaven RA1 =

When pigs fly then there will be such a thing.

Ludedude

That's a case of animal abuse right there.

jerrypeterson

I can recall driving through the passenger window on a straight section of freeway... at 30mph in the rain.

Yeah, couldn't agree more. With the local Northwest weather you have little choice but to own two sets of tires.

Triple-H

And other variables are the tracks themselves and how hard you push the car. Something like a Watkins Glen compared to a Mid-Ohio are going to give different wear rates because the condition of the pavement/concrete is so different.