Jack, the RA1 is a very well built and durable tire. I and other people I know have run them completely bald and reached cord several times during races. While nobody recommends running tires with cords, it has been done and the tires stayed together. I race in NASA which uses RA1s as a spec tire and everybody loves them. I do not know of one incident of tire failure due to Toyo construction. They last a long time (at least 2x Kumhos) and seem consistent throughout their life. I've got RA1 tires on my Capri that are very old and hard and I plan to test at Thunderhill this weekend. I want to compare them to my new Kumho Victoracers.

BTW, the RA1s work well at higher pressures as compared to the Kumhos. During a long and hot race, I'd come in and 40 to 43psi wasn't uncommon and the tires stuck well. I find that the Kumho Victoracers start to lose their grip after 35psi.

One other thing I should mention is that the RA1s seem to start losing their grip just before getting cord. I suspect that Toyo puts on a interface layer between the cords and final rubber.

Good luck.