When the Henry was released in 2007, I was told there was not enough room for a breguet overcoil, seems like that may have changed now. Maybe I was not listening properly. To answer your question, the double hairspring oscillates in opposite direction and hence negates the effects of gravity acting on any single hairspring. BTW, there's a video of the double hairspring in action a few thread down. This message has been edited by Wylie194 on 2009-05-18 06:25:52