When BOTH my trainers told me horse and I were both ready we started introducing the double.
My pat answer is:
1.) When rider uses LITTLE rein and more seat to influence horse
2.) When rider can use X without inadvertantly using Z - in other words when you have an independent seat and hands.
3.) When horse/rider combination score above 60% at Third Level in a recognized show.
Thank you very much for such a quick reply to my thread the main reason I am asking this is because my friend uses a pelham and she says she is using it for refinement but I didn't think she was ready for it when she first put it on her horse and now her horse is in a false head set all the time and that added with this information has made me believe that she is diffenately not ready to be ready in this bit.