Forums: Climbing Information: The Lab: Re: [rgold] Stupid Simple Elette: Edit Log




Neoshade


Aug 18, 2011, 9:40 AM

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Registered: May 11, 2009
Posts: 31

Re: [rgold] Stupid Simple Elette
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JimTitt wrote:
Canīt see itīs equalised anyway, looks like 50/25/25 to me.
Jim

Wow. Big apologies. That was just blatantly stupid of me. I completely failed to address some major issues, and I definitely over-claimed the whole self-equalizing properties of this.
Also, sorry Patto for getting preachy and aggressive when I was treating John Long's work and the extension testing like gospel and just beating the bible at you. I think the community at large needs better, more extensive testing much more that it needs new rigging ideas in order to move forward right now.

1) It is not perfectly equalized. It's definitely a 50/25/25. I find that is OK myself, as most of my real world placements have better pro and sketchier pro, and offsetting the load is handy.
Also note that you can tie the same knot in both legs for a 25/25/25/25.

2)The double 8 is definitely not self-equalizing in the classic sense, as it's a knot in the cord, and not a carabiner or ring sliding along the cord. So, to be more precise, this knot will adjust itself a good amount while still loose, a nice advantage over clove hitches.

JimTitt wrote:
Equalising the right pieces by nylon sliding on nylon, youīre joking right?
Jim

Yes, it's nylon on nylon, but that's actually pretty normal use for cord/rope. We're not talking about lowering off a sling, but rather casual sliding of the knot during belay, and a small amount of slippage as it's loaded. That's not very dangerous or uncommon. Think Munter Hitch or the cinching of your harness knot during the first fall or take. That's all. No crazy friction danger here. Also, I like double 8 here only as a smaller knot. However there are people that have been climbing on full size Double 8 anchors for a while. (ie: Ultrabiker)

So what I mean to say, is that the Double 8 is a quick and versatile replacement for cloves on additional pro. It can also be adjusted at any time very easily, and less importantly, it will somewhat self-equalize while the knot is still loose. Further slippage of the knot under load for a dynamic equalization is possible, but I can't say without more research & testing. (I really need to see how the knot slips or equalizes under fall loads, that's very important to know. Right now I only believe it slips an inch or so and equalizes. But that remains to be seen for a sloppy knot and for small Vs large forces.)
I'd really love to hear from anyone that has used Ultrabiker's Fig 8 for the entire anchor rig, or who has any further experience with the knot.

JimTitt wrote:
Increased loading with increasing extension is inevitable, is real and not to be ignored.
Use the rope or clove hitches.


As far as small extension (4-10") and increased loading goes, that is going to need some serious looking into. My entire concept is based on small extension being OK, and Jim Ewing's testing and John Long's opinions being valid. If the equalette & limited Sliding-X is debunked as dangerous for reasons of extension, then we all need to go back to cordalettes, manual equalizing, and bomber MP knots.
However, the Double 8 needs its own testing to see if it slips a little (self-equalizing) or tightens up bomber under high fall loads. Really, I want to address this so badly, please pardon my lack of info.

JimTitt wrote:
Well, as usual the DAV have done this one (Panorama 2/2009, also interesting for the dynamic and static tests on various sling materials tied with a clove hitch).

5m drop, 80kg, dynamic rope belayed with HMS on sliding X with 60cm legs. Hanging belayer weight 65kg.

Well shucks, I feel like being a John Long believer is now a black mark upon my soul. :-/
Did they use limiter knots? Or was the extension a full meter or so?
I'd really like to see the data if you can find it. I'm still a little unsure how the FF are so high for small extensions. Is the rope under full stretch at the time and no longer helping?

Thanks again all for the input, I really want to know more about the Double 8 and how it takes falls.
I still think it's a nice improvement over cloves. (in the world of acceptable equalizing & extension)


(This post was edited by Neoshade on Aug 18, 2011, 9:51 AM)



Edit Log:
Post edited by Neoshade () on Aug 18, 2011, 9:51 AM


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