As we see individual experiences vary from one extreme to the other, so we can only talk from our own personal experience. So FWIW here is my PERSONAL assessment of the past and present tire situation and I am NOT talking on behalf of SMAC
In my case, I have raced approx 17 weekends a year for the past 10 years, and in many cases I have doubled up racing my Spec Miata in other classes. I always run the test day so in reality I get an average of more than 10 sessions per weekend so race around 170 race sessions per annum. I change out my cars every 2 years.
During this time I have raced on RA-1's, R888, RR. SM6 and SM7's. Under the OPM tent, with their approach to maintenance, I have not experienced an increase in bearing, hub and sub-frame failures.
My personal tire summary
TOYO RA-1
I think the RA-1's were the hardest wearing tire, and gave the most heat cycles, but we all shaved the tires down and had a spreadsheet for every track and had a shave that worked for that track, and we also had to do tests to determine what the best shave and cure was. So while they exhibited great wear characteristics, we were still getting similar life to the current SM7 tire. The RA-1 "rain tire" was phenomenal - no grip, scary as all get out, but it could easily last more than a year with many wet sessions. For me the perfect rain tire!!!!!
TOYO R888
Total disaster as a Spec Miata Race Tire
TOYO RR
Actually a very good race tire, but still benefits from shaving and those that are experimenting are finding different shaves suit different tracks - For this reason I am happy that it is not our tire of choice for SCCA
HOOSIER SM6
Total disaster as a Spec Miata Race Tire. This exceptional tire had one or two hero laps, was always best as a sticker tire and was by far the most expensive tire we have ever had. It more than tripled my annual tire budget.
HOOSIER SM7
Great tire, much cheaper to run than the SM6. Shaving does not improve the competitiveness of the tire, most front runners typically get 3-4 very competitive heat cycles at most tracks, more at some and less at others. The tire has helped make the racing very close. Predictable break away characteristics, with decent slip angle and no surprises. The current H20 is a phenomenal tire in terms of wet weather grip, but it is having a negative affect on peoples rain driving skills as no one goes out in a wet weather session (unless its a rain session) as it costs you $700 per session as the tire has only one competitive HC as a wet tire. So drivers are not practicing their wet weather skills.
MY GENERAL OBSERVATIONS AND DESIRES
- We all want the unicorn tire that is competitive at all tracks under all conditions, and gives us the most possible heat cycles. This tire does not exist and will not exist
- We want a durable tire that works for a good number of HC at most tracks, but some tracks will always need stickers and some tracks will always prefer high HC tires - this will not change no matter what tire we use
- The current rain tires is too expensive to use, and needs to be of a harder compound. Lots of drivers will not agree with this as they love the H20 because it feels safe and predictable.
CONSIDERATIONS and CONSEQUENCES
- Going to a smaller tire does have some merit. It will reduce the grip, potentially lower the stresses on the car components, but with less grip comes more wear and potentially less HC.
- Going to a harder compound also has some merit. Once again it will reduce the grip, potentially lower the stresses on the car components, but with less grip comes more wear and potentially less HC.
- Both of the above or even a combination of the above, while attractive on the surface, will also come with some unforeseen penalties. The time gaps between drivers will increase with less grip, just in the same way going to a harder rain tire will exacerbate time gaps between drivers. The more grip that a tire provides, the closer the fields are. There will always be those that have good car control and that are more comfortable on the ragged edge of disaster.
- And with less grip, more sliding, the competitive HC lifespan might not actually improve,and so the annual tire budget might not decrease and many even increase.
Personally, with my limited component failure experience, the number of competitive HC I get, the zero competitive advantage from shaving, and the great support we get at the track from Hoosier, I personally believe that the SM7 is the best tire that the class has ever raced on.
However I am definitely open to trying out smaller / harder compound tires. and I would ABSOLUTELY like to see a longer lasting rain tire.