Rear wheel rubs against frame?

I have a Specialized Hardrock bike that is probably 6 yrs old. Right when I get on the bike and peddle a few feet the rear tire rubs against the frame and completely stops the bike. Both tires have spokes. I don't believe I have over tightened the bolts holding the wheel. If I have the bike upside down and... show more I have a Specialized Hardrock bike that is probably 6 yrs old. Right when I get on the bike and peddle a few feet the rear tire rubs against the frame and completely stops the bike. Both tires have spokes.

I don't believe I have over tightened the bolts holding the wheel. If I have the bike upside down and spin the rear wheel it spins fine.
I have tried having the bolts really tight and a little loose and same thing.

What would be causing this and how do I fix it?
Thanks
7 answers 7