How Sketchy is a Rope-worn, Sharp-edged Biner?

裂缝

Kolin Powick of Black Diamond tests what happens when catching falls through rope-worn biners.

http://www.bdel.com/scene/beta/qc_kp.php#rope

It’s not the ultimate strength of a rope-worn biner that makes me the most nervous; it’s the risk of cutting a rope. As the biners get grooved or “trenched” from rope wear, a sharp edge begins to form on the sides—and the rope runs directly over it. This edge would seem to be especially dangerous to your rope during a fall, lowering or winching/dogging up. I’ve had several friends whip onto sharp biners with the end result being the “sheathing” (i.e., the sheath gets cut and exposes the core) of the rope and possibly soiling of their shorts.