Scott McCrea wrote:NZcaver wrote:Scott McCrea wrote:A properly configured and used rack will stop or slow down when you let go.
Or, more likely, cause you to plummet just like most other non-autostop descenders. Have you tried letting go completely while descending on a rack? (Why would you?) And (like Hank was saying) a nice clean flexible 10mm rope is likely to perform differently, as a micro or other U rack might versus a J rack.
Yep, I tried it. It works on any variable friction device. Racks are configurable on the fly so it can be adapted to preform differently.
Scott, some day I'd like you to show me how to configure one of my micro racks to stop me when I let go of the rope completely (with both hands, feet, and other appendages) while rappelling with no additional rappel safety. It seems to me the amount of friction to make this possible would mean I would need to painstakingly "feed the micro rack" just to rappel somewhat normally. And we know that's a no-no.
To keep this on-topic, basically I'm a little skeptical when I hear racks being promoted as self-locking descenders (the title of this topic). There are many reasons to prefer a rack design over other descender choices, but without an external hitch or shunt I don't see a "let-go-safely" feature as being one of them. Of course I could be wrong.