Hyper, YOU find me some hard/firm tires on ebay. I searched for 1/8 hard and 1/8 firm and found nothing except one set of firm foam inserts which are useless.

I bet if I put the tires in the oven at 300 degrees for a day or 2 they would come out hard as rocks. They aren't soft because the rubber is soft, they are soft because all the solvents have yet to evaporate out of the rubber. I was just hoping someone had actually tried some way to harden these crappy tires. Rubber gets hard as it ages, all rubber. I just want a way to accelerate the aging process.