In California, automobile tires must be recycled in one of a variety of ways to minimize the effects of the toxic decomposition of rubber in landfills, reduce the risk of tire fires, and give mosquitoes fewer puddles in which to propagate. The State facilitates tire recycling by licensing tire haulers as intermediaries for tire collection and shredding. The resulting mulch is used in asphalt mixes, Astroturf and other paddings, etc.
I've spoken with tire haulers who have refused to take bicycle tires without serious fees (~$4/tire) and I've learned that they don't want to take them because there's so little rubber per the total mass of the tire.
In speaking with CalRecycle, I've found that the law that established the tire hauling and tire recycling business, only "vehicle" tires are required to be collected and re-purposed.
On the other side,
waste management companies throughout California refuse to allow tires
of any sort within their landfills.
Thus, many bike shops are stuck
between a rock and a hard place when it comes to disposing of tubes and
tires. We want to do the best thing possible (recycle), but since it's
not required of tire haulers to take bicycle tires, haulers won't take the tires without major payoff. So what do we do with these tires and tubes? Find an unscrupulous landfill who will take them?
I contacted a guy in charge of British Columbia's tire recycling efforts and he said that they took in 10 metric tons of bike tires and tubes last year for shredding into the same tire mulch that automobiles tires goes into. He couldn't tell me what the blend tolerance is, though. Or, in other words, given the lower rubber content of bike tires, what portion of a mulch blend can come from bike tires without degrading the mulch past utility.
I/we need that information. With the ears of a couple local organizations and legislators, we may be able to change California law so that tire haulers have to accept bicycle tires and tubes, but we need to be able to answer this and similar questions from day one.
So... who do you know in the rubber industry? =)