DD only started using grips after her L8 season last year. She could have gone longer as she wasn't peeling off or anything but because release moves were in her near future, they decided it was time. It took her 2 weeks and she was doing everything like she had always done. It was a really easy transition and I'm glad that we waited so long because she is small. Most girls have them by the time they are in optionals at our gym, but some get them before and some get them late like my DD. I do think it should be based on the individual's needs and not a set thing.