To shave or not to shave

So as we all know 140tw tires are no longer legal for SCCA autocross. My local region still allows people to run left over 140tw R1R for this year. I have been driving full thread Toyo R1R (195 wide of course) on my Miata for the last couple of years, probably about 3kmiles street use and 10-ish autocross. It still has a ton of meat left, I haven't measured it for sure but it's definitely more than 4/32, probably more around 7-8/32. I was thinking of shaving the tire to 4/32 since it's going to be worthless anyway next year. My question is since I've been driving it on the road for a while has it been heat cycled out or will I still see the benefit from shaving it to 4/32? Sorry if this sounds like a noob question. Thanks guys.

Oh no! Not another shaving thread!

Just kidding. I couldnt resist....

Cheap at $ shave club!

My guess is that unless you're serious and racing every week, it's just throwing away rubber. Also I'm not sure if many places will shave used tires.

Grow a beard or use a safety razor.

But I would see if you can shave used tires first.

I think it's incorrect to say that they would be 'worthless' they would still have value for the HPDE track day crowd. I'm not sure whether you would benefit from shaving them, or if you could even find a place to shave used tires.

they really aren't very useful as a track day tire … nothing says you can't use them… but they do get greasy pretty quickly .. they don't tolerate heat well at all

that said, I'll keep taking mine with me to the track as they make pretty good rain tires

I'm under the impression that shaving tires will increase performance of a new tire because they need to be worn down some to get the best performance. Since yours are used, there's no point to doing it. I would just run in the Street Prepared class next season until they're worn out, then get 200tw tires to run in Stock or Street Touring.

what shaving does is get rid of much of the tread.

the tall tread (of a new tire especially) squirms under cornering loads (straight away travel also) … squirming causes a slight lose of traction, and produces heat, and can lead to chunking (i.e. tearing of bits of the thread)

by shaving you also get closer to the point where there is little or no tread and the tire then behaves more like a slick … more rubber contact with the road, which equals more traction .. both for accelerating, braking, and cornering ….

depending on how used the tires are, shaving can be very beneficial