What do you do with an Olympic ski jump in the off-season?
You roll tires down it and see how far they fly.
Of course, to give this event a little more credibility, make sure all your jackass friends are wearing lab coats and white gloves. People are more accepting of crazy science stuff they don't understand.
The other thing I love about this video is the fact that its a Japanese video, posted by a German fan.
"Japanischer Reifentest auf der Sprungschanze! "