A while back I noticed my headset kept loosening up. I eventually had it almost as tight as the bolt would/should go to get it right. Took it apart and the top cup had cracked all the way around near where it goes into the frame. It was an FSA Pig DH Pro, not cheap or light...took it in to get fixed and the mechanic noticed the frame was cracked too (Tomac 204). No idea how that happened.How the hell do you break a headset?
I've pretty much broken all the stuff listed except a fork and crankset (bent one a bit, but I still use it). Broke handlebars this year. That was cool.