I've only done 7 passes and maybe 70 Miles since I bought them a year ago. The last time I used them was in October of last year. They have been sitting on the garage floor since. Do they breakdown like regular tires or are they tougher or weaker? I'm thinking of running them in the back for a while until they are gone or selling them to someone who will use them. I don't want to rot in my garage because of neglect.

 

If you keep them off the concrete floor, such as on a set of wooden 2 x 4, they should be fine for a long time. Reduce the air pressure for storage. I have some road race tires that were mounted in 1996 and they are still in good shape. A little hard perhaps, but they are still solid. Keep them out of the sunlight, and try to keep extreme temperatures away from them. Arizona is probably a good place to store tires, actually due to low humidity.