Originally Posted by
79pmooney
And after you've spun that nut a few times, it will have polished/enlarged the hole in the crankset and your replacement nut is unlikely to lock itself into place. (I love cranksets where the nut seats simply tightening the bolt. Need to get it out? Back off the bolt slightly and give it a gentle tap with a hammer.)
Might be a reason to avoid the impact wrench.