Originally Posted by
BobH
In theory the spine and edge wear together, spine thins and blade narrows, maintaining the geometry of the blade. Like RezDog says if you put more pressure on the spine and little on the edge the spine wears faster, as is the case with beginners, and the geometry can get out of whack pretty quickly.
The 17 degree angle of bevel still allows for a few degrees + or - to be still within tolerance.
Bob