Maybe kind of a newb question but how dead is too dead to spur climb, say on a crane removal, where you wouldn't have to worry about the top swaying the tree as much? Are there any general rules or basically just if your spurs stick? Maybe like using the claw of a hammer to see how far it is rotted through? I have heard of that, and i know different trees are different, like locusts are hard to tell since they rot inside out, but any advice would be appreciated