woodslinger
TreeHouser
My concern on hinges is how far they flex before they let go.  Therefore I usually set a high pull line, and usually angle it 45 deg off the lay, opposed to the lean (the deg is not my main concern, I just find a bomber anchor in that general direction).  Head leaners are really the only trees I don't pull.  My other concern wedging a tree, especially a back leaner, is the upward force on the hinge before it comes over center.  I am quite afraid of the sudden snap of a failed hinge and a free falling trunk, so I don't do it.  When I find one in the woods that I can experiment with (with no consequences) I'll tinker with it, none of the trees I need to thin out of my woods are large enough.
Good tip on the broken off wedge.
				
			Good tip on the broken off wedge.
	
		