Bone Help needed - wierd result- slinky effect

I’m trying to create a slinky walking effect. I created a cylinder parent to a armature. I’ve tried various combinations of IKA solver, track-to etc. But the main problem when key framing is that when the Bottom IKA is going over the Top IKA, the rig becomes unstable for a frame. The whole rig jumps. See the blend file.

Toggle before and after frame 56 and you’ll see what I’m talking about.

Does anyone know how to accomplish this? Maybe a different rigging.

I searched here and found some old references to a Slinky Walk but I was hoping to keep it simple with a bone system.

You might be better off using lattices or curves for this sort of thing. Bones are more suitable for ‘solid’ objects.