epic_ed wrote:
Yeah, just to clarify -- the rubber bands used to keep the rope from feeding back through your solo device is a completely different function than re-belaying the rope to protect against a shap edge while jugging; and different still then using something to keep the anchor tensioned in an upward direction to prevent shock-loading the anchor in a fall.
No, I understood that. That's why I asked about a reasonable length of cord, since elastics probably wouldn't cut it in that applications. Materials/techniques used fall into two categories -- ones that you
want to fail in the event of a lead fall, and those you
don't want to fail.
In the case of simply holding the weight of the rope while on lead, you'd prefer something like a rubberband so that it's strong enough to hold the rope, but will break in a lead fall thus keeping your saftey system dynamic.
Agreed. In the case of a re-belay you definitely do NOT want the material/tehnique to fail when loaded.
After my last post, I dug around for a while and found an old post by PTPP, in which he recommends using a Klemheist on a length of cord for all three of these applications; since it slips in one direction, it won't interfere with the dynamic properties of the belay. I can see an elastic being better in this scenario, however, since it will simply break under stress. In the case of keeping the anchor tensioned -- depends. I like Lambones suggestion for using the pig as a counter-weight for belay. There are circumstances when this won't work (going light and fast, or toward the end of a climb when the pig doesn't weigh much). When I'm on shorter practice climbs I used to clove hitch to the first piece to keep the anchor tensioned. I eventually switched to using a hairband (stronger than rubberband) to keep it taught. I've never taken a lead fall on that configuration, though. The plan was -- band fails during fall, and I'd just re-belay from the next solid piece. Pull the anchor end tight, slap on another hairband, and clip it to the solid piece.
Ed