Just read "Flat Free Tires" in Countryside Mag, Vol 94, No 4. These tires (by Marathon, Carefree Tires, andTricam) are made of light polyurethane and are easy to change. They will save lots of energy that the average tire might require of you being patched.
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girl power ... turns out to be about a hundred watts. But they seriously don't like being connected to the grid. Tiny ad: