Storing tires

[BlkBird]

What is the best way to store tires?

I just received a nice new set of Yokohama's, but still have lots of tread left on the Bridgestone's. Probably won't need the Yoko's for a year or so...

1) Store them flat on the basement concrete?
2) Upright on their treads on the basement concrete?
3) Hang 'em from the rafters?

Having a spare set of tires is a luxury I am not used to, but Tirerack was having such a good sale even my wife was convinced buying a new set was a wise idea.

Thanks in advance,

[cstreit]

Ozone and sunlight are the killers...

Basement is good temperature controlled env. Seal them in platic garbage bags... Better if the are on sides or hanging to prevent flat spots...