Originally Posted by
AlanO
It's not a spring. It's mainly hysteric damping, the frame is its own damper. The same reason a steel beam returns to its original shape after the load is removed. You don't need a viscous damper to experience damping.
I am skeptical of the highlighted claim.
Something returning to its original shape has it not an indication of it being damped (internal or otherwise). In fact, if you deflect a steel beam and let it go with no external damping, (not a common situation, as what it is bolted to may be damped) it will keep moving back and forth (vibrating) because steel itself has low hysteric damping (some, but little). And eventually return to its original shape.
The fact that steel has such low hysteric loss is the reason it makes a good spring for uses like a trampoline and pogo stick. Why would it suddenly have higher hysteric losses when you change the shape to a bike frame?
All a steel spring is is a long piece of steel that gets deflected when you compress the spring. The coil shape just makes it practical to work with. How is a steel bike frame fundamentally different?