and what they were called?
They would ruin a bicycle inner tube, among the neighborhood boys this was one of the worst things that could happen aside from having the pedal "spike" in one's calf. (That is when all of the pedal is gone and the center or round metal part is remaining). Then, there was always the rumor of a kid riding his bicycle with no seat and only the metal part sticking up and he rams himself on the seat stob-never seen it but it has to be fearful.
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