At one time shops and lock brands made brackets easily available. These days with the greater variation of frames and posts (let alone lock dimensions) brackets are more of an afterthought. I'm surprised that the shop where you bought the lock doesn't have one in their spares draw. The best lock bracket that is as universal as it gets is a rack. BTW in many locals you'd still be the target with only the "U" lock, consider if you need both locks sometimes. I tell my customers to look around at the other bikes they encounter and gage their locks. Then make sure yours are better. Andy.