You'll need a business plan;
What about an environmental impact statement?
Various licenses / permits / fees?
Insurance responsibilites?
Dump / disposal fees? (most places have to pay to have chemicals and tires taken away- around here, anyway)
After all that, just Google around using words like "state aucions", "insurance auctions", etc
Also, put ads around offering to dispose of old bikes. People clean old buildings and don't know what to do with junk like that.