What type of bar mount? 3005, 3003 or 3002? ES replaceable tip or E bar with just the sprocket wheel in the nose? Either one can be replaced by punching the rivets out and spinning a new tip, But the E bars are pretty much cost prohibitive. By the the time you buy the sprocket wheel for the E bar and spend too long messing with disassembly and replacing it, you're better off buying a new bar.