I have used Duralast Gold in several of my bikes over the years and have had no issues with them. I currently have lithium batteries, but would buy a Duralast in a heartbeat if needed. I am 68 and I too would like to have a Royal Enfield 650 in my stable. Unfortunately we recently downsized and most of my stable was sold because of garage space. I have my RT and my Suzuki which were the ones I rode the most.