No surprise, everything is elastic. Some are profoundly like natural rubber, others microscopically like rock salt. These elasticities define the world around us. Even if unnoticeable, they create limits and rhythms that affect our every moment. The fun of bicycles seems always to return us to the basics because our machine is so lean. A great place to observe and marvel at properties like elasticity.
Remember, every force change (tension, weight) causes a change in length. If the length returns when the force is removed, the change is called elastic. If the change is permanent, then the material’s modulus has been exceeded and we have a plastic deformation.
For a wheel, the interesting topic is everyday performance, not plastic deformation like accidents. And when it comes to elasticity the wheel is a busy place. How do bicycle wheels manage all of this without exotic solutions? Some folks don’t quite get it.