Can o' worms time. Most of you say just buy a new one. But there must be some test once they are on the bench to see if there is any service life left in them. By analogy, if I have a drive chain and when you hold it out sideways, if it just curves down to the ground, then it's done. Look at the chains in the pic. The top and bottom ones are loose and sloppy, but the centre ones still resist bending the wrong way. I think they could be reused. Let's have some opinions, please.