Dynamic vs static cord for adjustable daisy’s
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Wondering how much of a difference dynamic vs static cords really make. Since it’s only about a 4 foot section of rope do you really benefit from the small amount of stretch if you accidentally take a “daisy whip”? It seems like the thinner the rope, the lower the fall factor would be and the more benefit one would get from using dynamic daisy's. (ex. 7.3mm would be more gentle than 8.5mm) I currently use 7.8mm half rope for aid climbing but like how much smaller and lighter the 5.9mm sterling power cord is which I use for general PAS use. |
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I think it is a worthy question and probably something that needs to be actually tested. Maybe the HowKnot2 crew could do some drop testing. Don’t they have some tower to do that on now?
I’d pitch in some money if someone could organize some testing with HowKnot2. |
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I find the static cord superior for bounce testing on tricky aid. Avoid daisy whipping as usual. Otherwise, whatever. The 6 mil makes me a bit nervous though, whether justified or not. I use static probs somewhere near 8 mil. |
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Brandon Adams wrote: I agree about the bounce testing being superior on static. I avoid the daisy fall by using my Evolv more like an Alfifi- and climb “daisy-less”… so I’m only ever connected to one piece/ladder at a time (the one I’m testing/moving to/standing on) my 2nd Evolv remains clipped to the side until I’m jugging. I tested the 5.9mm power cord and thought it worked fine- but found it too thin for repeatedly winching on each piece.. yarding on 8mm is just more comfortable.. YMMV as far as Daisy Falls on static… I dunno what all the fuss is.. I’ve taken thousands of them and lived to tell about it.. |
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Quinn Hatfield wrote: |
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That last quote is Lengendary!! :) |
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Results of drop tests done on lanyards of various materials and configurations are on Rigging for Rescue’s Webpage. The results showed that lanyards constructed of HDPE (Dyneema) had higher maximum arrest forces than nylon and they concluded that HDPE was a poor choice for lanyard material. |
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Bob Harrington wrote: The conclusions of that research are only tangentially related to the conversation and it would be a mistake to copy and paste them into the application being discussed here. They tested daisy chains and Purcell prusiks extensively, but never tested any of the modern tethering techniques. They also used a rigid mass for the tests which can behave differently than a human body. I’m not saying the data is wrong, but rather that the RFR studies didn’t really shine new light any particularly useful places. The experience of many people taking daisy falls on static materials (I’ve taken up to a FF1 a bunch of times) is testament to the fact that more is going on than we currently understand. |
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Kevin DeWeese wrote: You're looking at the problem as an aid climber. Think about free climbers fix and following and the second having to tether in. Using the lightest possible material makes a big difference, but we don't know right now what's 'too light.' One of the main reasons to try and gather data on the breaking strength of modern tethers is the scenario in which the belayer is using one to attache to the anchor and the leader FF2's on the them. This is a relatively unlikely scenario, but is far from an impossibility. Right now, I'm with Mikey: skinny spectra seems sketchy, but I don't have any data to back it up and am curious to know how it behaves when loaded that way. |
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https://youtu.be/ZWaDh6-roMI?si=zKQA__7Y1qdjPRHe From hownot2, on the subject. |
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Max Tepfer wrote: I mean- OP did say “I currently use 7.8mm half rope for aid climbing” in the BigWall and Aid Climbing forum… Not saying your point about fix and follow systems shouldn’t be discussed.. lots of variables to consider- short fixing, bolted anchors- are the tethers tensioned when the FF2 fall is caught… |
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What the OP also was curious about is the forbidden practice of daisy soloing which he does on occasion when absolutely necessary. Weight and bulk are certainly a big factors as well as I do a fair amount of rope soloing and switching between free and aid. |
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Kevin DeWeese wrote: I have found and I think others would agree it’s pretty nice to be securely attached to your last piece with a daisy in a lot of climbing scenarios. Especially for moving fast when you are just slamming gear without bounce testing and generously back cleaning or for rope soloing when falls can be less predictable and more consequential. |
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Being attached to your last piece via the rope isn’t less secure than being Daisy’d to it.. being attached to your last piece via the rope will significantly reduce shock-load forces compared to a static or a dynamic Daisy fall.. I can’t see how being daisy’d to the last piece is anything but inferior in any of your examples |
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Quinn Hatfield wrote: Think the #4’s pitch on lurking fear or the upper splitters of the nose where you are pretty much going anchor to anchor without leaving behind pieces and just walking 2 cams. It’s nice to be connected to a lower cam temporarily while you make sure your next peice is bomber but since you are going to back clean it anyway it doesn’t make sense to clip the rope to it (but you can just leave your daisy’s clipped). There are plenty of scenarios, including the two I mentioned, where it makes sense to care about these things that may be outside the realm of climbing experiences you have encountered. |
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Max Tepfer wrote: Sure, the work they did is almost twenty years old, and there are new tether configurations and materials that merit testing. The question initially posed was whether dynamic versus static material makes a difference when falling on a short length. Actual testing under controlled conditions suggests it does for nylon versus dyneema. Other than that, I'm pretty ignorant about what you guys are up to with the adjustable daisies. I think we all understand that a rigid mass behaves differently than a human body, and that the maximum arrest force is greater for the rigid mass than what a human would experience. The virtue of using a rigid mass for this testing is that it behaves consistently between tests. |
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Bug Boy wrote: Fair enough… I’d cam walk with Daisy Tethers on that pitch too.. |
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Kevin DeWeese wrote: I think this comment shows that some people are using different aider/daisy setups than you and with the type of set up I am thinking of (where you just leave your adjustables clipped to your ladders and don’t clip the rope through your cams that you are walking) the cord type is worth considering. I also think that cord type is worth thinking about for inexperienced climbers and it’s not that hard for “inexperienced” aid climbers to be climbing the nose or lurking fear in a day during their first season in the valley. |
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Kevin DeWeese wrote: It's pretty common for the leader to not clip a component of the anchor. (particularly when it's easy) Studies have shown that it amplifies force on the anchor after the leader gets past a certain distance in addition to putting the belayer at risk of getting smashed into the anchor and wall. ( drive.google.com/file/d/1qW…) It's also possible for the rope to come unclipped in a fall. (not hard to imagine if you're clipping a draw into a weirdly tensioned amalgamation of chain links, hangers, carabiners, and webbing) These are both pretty low likelihood, but are by no means impossible and the potential outcome we're trying to avoid is catastrophic. You're absolutely right that other solutions exist, (at the expense of time and fiddling) but the point I'm trying to make is that it would be nice to know more specifically what the tool I'm using is capable of in a given 'insignificant fiddly gear hypothetical.' If skinny aramid cord is plenty strong enough in this application, it would make life a lot lighter and svelter. But that's fully not worth it if I'm looking at a low likelihood, catastrophic event as a tradeoff. |
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There's certainly some solid nerding over gear on this thread for sure. Haha. I would say that being solid and speedy are certainly both attainable. The key is being light and efficient with your system that also provides security. I advise against climbing with, say, 8 daisies of different configurations and 6 ladders. We are up there to climb rather than to just tinkle with gear... right? Maybe I'm wrong on that one. Single set of adjustable corded daisies with a single set of ladders for the win. Of course, we are talking about aid climbing here. But also of course, that's just my opinion. |
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I soloed a few pitches using two adjustables, one with a 5.9mm sterling powercord and one with my usual 7.8mm half rope. I really liked how much easier it was to tighten and release the thin cord and the slicker material was less prone to getting twisted in the faff. As an added bonus the thinner cord allows the attachment knot to be quite a bit smaller and could suck in closer to my body when making the transition to top stepping in overhanging terrain. |