Originally Posted by
bikingshearer
I have never been a paid mechanic nor did I ever play one on TV, but I always thought that was the way you were supposed to do it regardless. It's what I do with or without a key and my headsets stay put. Now my Italian threaded drive-side bottom bracket cups are a different story . . . .
Drive side bottom bracket cups have precessional force that works to loosen the drive side cup pretty much continuously whenever you're pedalling. Precessional forces on headsets are essentially nonexistent.