Originally Posted by
cryptid01
Is it really the "stretch" that adds strength? If so, why don't they make spokes out of rubber bands? Or is it in fact the tensile strength (aka resistance to "stretch") of the spokes that gives the wheel its strength?
Well, that's a matter of semantics, I think.
Any material will stretch when placed under tension, it's just a matter of how much. You could very easily make a wheel out of rubber bands, if you could find any that wouldn't exceed their elastic limit under the required tension.
And aluminum actually has a lot
less resistance to stretch than steel: aluminum has a
Young's modulus of 60, and steel has a Young's modulus of 200. That means that you have to make aluminum spokes thicker to achieve the same spring constant as a steel spoke. Steel also has a much higher
ultimate tensile strength (860 Mpa) than aluminum (483 Mpa).
So I guess I don't see your point.