Tire Dry Rot?
 

I have a small collection of C&V bikes, some with odd-sized (Schwinn) tires. Would like to buy some spare tires while I can still get them, but dry rot is a concern. Will a brand-new tire dry rot in storage? If so, there should be something I can coat them with to keep ozone away?

Buy blackwalls instead of gumwalls.

Store them in a cool, dry place away from sunlight and electrical devices.