Originally Posted by
merlinextraligh
. . . you can use a tire that's worn past the point you would trust it on the road.
+1
My "trainer" tires are tires that are well past their prime for the road but are still functional. I usually go through about a set of tires a summer on my road bike. Since only the rear tire gets wear on a trainer, the pair usually has enough left in them to last all winter. Never had a blowout yet on the trainer despite letting them get awfully thin.