How should you store tires/wheels?

[ScottN]

I have kept my stock wheels/tires so I can have a backup set. How should I store them? Lay them flat or stand them up?

Thanks.

[Wah]

Doesn't matter really. The only problem of storing them standing up (on the thread) is that they can roll away if they are not chocked or they tend to fall down sideways when bumped.

Otherwise, it doesn't matter.

[Luke@tirerack]

they should be stored on their sides and kept away from chemicals, sunlight and electric motors. Standing them up will create flat spots on the tires

[ScottN]

Thanks for the replies.

[landho]

They should also not be in direct contact with concrete floor

[cire96]

One more caveat. Let the air out. Rubber ages by several avenues. One is the vaporization (evaporation) of the more volatile components of the rubber. That's why you can smell new tires.

By keeping them aired up, there is added pressure, hastening the loss of the more volative ingredients in the rubber compound, leading to premature hardening.
Cire