You should change the 12mm orings when you lube them. I have had them since they first came out, I can,t rember how manny years. If you ingnore the squeak and do not lube tem then it can be real diffcult to get apart. The O rings can be gotten from McMaster Carr much cheaper than from Fastway. I ride offroad and use the yellow elastomer. As I have said my bars are quite old and the only sign of wear is where the throttle rides.