Hi I was just wondering how do you know when a frame is shot/done for? (This is for visibly undamaged racquets...because ofcourse a racquet is gone if there are cracks or it is broken) Some people have been playing with the same racquets for 10/ 15+ years just replacing bumpers and grommets when/if needed. Some people find/collect vintage racquets that are 30+ years old and still play with them. And then other people change racquets after a few months or a year- claiming the racquet has lost responsiveness. How can you tell if you racquet has come near the end of its lifespan?