Originally Posted by
Doohickie
Spoke nipples are designed only to put the spoke in tension, not compression. The analysis in the OP neglects this; you can't "push on a rope".
Nor can you push anything else. Something always needs to push back. What difference does it make if that something is pretension or microscopic tension or molecular tension? It's all the same.
Even if, as you say:I'm not at all sure the reason for it is If it is true, as you say, that it does not necessarily follow that they haven't been doing any work. The bottom spokes would be the ones to suffer, not because they're doing all the work, but because they're doing nothing or worse: getting in the way. Let's say you tried your experiment many different ways, always with wheel intended for the same number of spokes (16 or 32 would be good), but in each rendition you have different spokes missing. Remove four spokes from the bottom of one wheel, four from the top of another, four from the leading or trailing edge from another; four from each leading and trailing edge of one; all but the bottom four spokes from one, all but the top four spokes from another, and so on. I think we agree that removing the four bottom spokes will wreak the least havoc of all; but I'd argue the reason for this is that they are the most dispensable ones rather than the most essential.
Yeah, but occam's razor says that the simpler explanation is more useful and it's far simpler to say that all forces are the same as a wheel in compression except for adding the constant pretension.