This video helps me a lot! The headset of my bike had produced "tak tak tak" sound (not coming from the upper/lower bearing of the headset) during driving vibration, after cleaning and re-installation with the tricky tips by K2, now my bike is running smoothly and the "tak tak tak" sound disappear. Frank Sinatra once said that, Success is combined by Technique, Experience and Wisdom. K2, your technique and experience are golden! Your own success will surely be coming!