JohnDThompson 

I was wondering that myself. I suspect the one-piece headlug/head tube frames are probably more susceptible to this type of failure. You'd have to remove the fork and look into the head to determine this: a one-piece head tube will have large openings in which the down and top tubes are visible. The three piece head tubes will only have small vent holes in the head tube to allow the down and top tubes to vent and drain properly.