Is there a "shelf-life", as with many 'high-use' rubber products, before "dry-rot" sets in?
I personally wouldn't drive on a tire over 4 years old. Remember the Firestone tire separations that plagued the Ford Explorers and caused a whole bunch of rollovers? It was largely attributed to tires that were older than 4 years.
But the Sun is not the only enemy of tire rubber.
Believe it or not, air, or really the oxygen in air, is what makes a tire harder over the years as it oxidizes (yep kinda like rust).
Many investigations were done after the whole Ford/Firestone thing and it turns out that it wasn't just Firestone, but all old tires were coming apart at speed (they were fine while sitting still
), researchers came up with several possible contributing factors but it was largely agreed that the biggest was this oxidation. Soon after all the reports came out about tire oxidation, most car tire stores started offering to put Nitrogen in tires, last time I bought some new car tires it was even free (and yet they still asked me if I wanted it). I don't really know if the nitrogen helps, cause the outside is still in contact with air, but I don't see how it could hurt.
So if your gonna store a tire seal it up in plastic real good, and get all the air out you can. That way all the trapped oxygen will get used up in a little while and it will stop oxidizing till you need to install it.
Bear
