Hi Lewis,
The threads for the rear sprocket are left hand. The locking ring is right hand as you already found out. I would suggest that you heat the sprocket around the thread area before you start hitting it with a sledgehammer. If Locktite has been used by an earlier owner (as on mine) – heating to at least 150 degrees Celsius will be necessary.
I wish you luck! 🙂
Kind regards, Carl
