Re: Spoke wisdom
Posted: Tue Oct 02, 2012 12:43 pm
human909 wrote:Reman wrote:Spokes have almost all the strength in tensile/compressive directions and very little in shear and bending directions
Thats not strictly true. Spokes like any long thin steel wire/rod have very hight tensile strength and negligible axial compression strength and bending stiffness. Shear strength should be approximately similar to tensile strength.
Shear strength of spokes is half that of tensile strength, now this is far more than the resistance to bending but still not the same.
human909 wrote:Reman wrote:Low tension causes these shearing and bending forces, usually around the hub flange where most spoke breakages occur.
Not really. Low tension causes unloading and loading of the spoke which then rubs, bends and fatigues. Its the fatigue that is the problem not the bending or shearing which is SIGNIFICANTLY lower that would cause breakage.
Fatigue caused by the bending and shearing...