I have a Dura-Ace sprocket and lock ring and I wondered if anyone can help me figure out how they have been plated. You can see from the pictures that they are coated in some kind of special golden material. I don't think it is titanium nitride like the EAI Gold Medal cog. I thought it may be just nickel coated / electro plated but is that possible in gold colour? I am also not sure if the coating functions to reduce friction or if it is just for show? Anyone who is knowledgeable about these things - I appreciate your help.