Super 8 Knot - are the bunny ears actually redundant?
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- เผยแพร่เมื่อ 23 ส.ค. 2024
- Is the super 8 or double figure of 8 redundant if one eye fails? ABOK 1085 names it Double Figure of 8. We show how to tie the bunny ears then pull it to 4kn and 9kn to see if we can untie it. Some knots are impossible to untie, and some are very easy to untie after being pulled. This was pretty much in the middle.
Then we pulled both ears and it broke in the knot at the same force we usually get with this rope at 18.30kN. We clipped one eye and it still broke in the knot at 17.33kN which is pretty much normal. The friction of the Beal Spelenium 10mm Static Rope doesn't let it slip to failure. So we tested it tied in dyneema because that will slip and show us how it would fail if it could slip. If you clip one eye, it turns into a normal figure 8 but if you clip the other like we did in our final test, it slipped to failure.
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Super 8
0:17 How to Tie
1:20 How to tie over shoulder and use
3:10 UNtie test at 4kn
4:21 UNtie test at 9kn
6:09 TEST 1 - Both ears clipped
7:03 TEST 2 - 1 eye clipped
7:52 TEST 3 - Slip test
10:23 Cuddling ABOK
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Being a project caver, it's good to know that a single loop can be loaded way beyond anything we can generate and still not fail. Thank you for putting this info out there!
Our spines will definitely be what breaks in a fall on our ropes... unless we're on our ascenders :E
This was a go-to knot in roped access and caving also. I've spent nearly 30 years wondering if it was actually redundant. So THANK YOU for testing it in these conditions
I looove how many time he said "you do not tie knots it dyneema" and people still argue about it.....keep up the good work!!
I dig the POV for tying knots, I think it's definitely a lot easier to understand what's going on that way. Also liking the addition of the attempts at untying the knot at various loads, definitely some useful info.
Love the plug of Ashley's book of knots! great video as always.
Thank you, finally won a bet from 8 years ago. They conceded about 3 years ago but never said no knots in spectra cord.
Do break checks of common and uncommon knots properly and improperly tied/dressed! That would be so cool. And a great reference for people who “just tie a knot”
very interesting, Ryan. I learned the knot keeping the end of the bight to the the loop side of the two wraps instead of the working end of the two wraps. Richard Delaney got 18kN on his pull tests with one unclipped loop tied the way I described, so it doesn't look like theres that much difference.
Damn, Ryan, a bunch of people have told me about how this knot was the best thing ever for TR solo, and I just never understood it, because when I tried it, it just cinched down and became unweildy to adjust. 0:59 where you show how to adjust it was mindblowing.
you're channel is getting more value by the hour , keep up
Finally proof👏🏼👏🏼. All we need is someone saying “but what if the common strand was cut!” 😉😉
This is definitely super good enough!🤙🏻🤙🏻
I'd love to see it where the 2nd bite is ontop not under the knot, i have been told that if a loops fails and the 2nd bite is on top, then the knot will fail. I would also love to see a figure 8 VS figure 9 for undoing the knot after it has been tensioned to 8-10kn. Loving the videos! keep up the awesome work.
I'd love to see this too but for different reasons. I think is likely similarly "redundant" to this way of dressing the knot. But I'm curious to see if it breaks at a similar force and in the same place.
Love the different views and explanation of the knot tying, really helpful :)
Top form HN2. Concise, to the point & almost scientific (hypotheses are for nerds).
P.S. ABOK is my teddy bear.
Hi Ryan, as others have mentioned- it would be interesting to see the same tests on the bunny with the ‘common strand’ placed above instead of below the other two strands …
I'd love to see water/beer knot on tubular webbing vs. the same type of knots but tied with a figure 8 (flemish bend) instead of an overhand.
I'm pretty sure the water knot would slip and the flemish bend wouldn't. That's if you used dyneema. I don't think either would slip with nylon. Unless the water knot was cyclicly loaded.
@@JoBianco Common wisdom says that you should only use water or beer knots to connect tubular slings, so that's what I've always done. But I imagine a flemish bend would be equally good, if not even stronger, and probably easier to untie. I'd love to see how they compare in real life. Cyclical loading test would be an awesome bonus!
I would be stoked if i could get my hands on a cyclic loading machine someday
@@HowNOT2 Walter Siebert, has a youtube video and has a machine, he did this on a water knot
Here you go I found it: th-cam.com/video/W00xgm-wEzI/w-d-xo.html
Damn, I was really hoping you'd machete one of the ears off and see how the other ear holds. Afterall, we're never worried about pulling on a rope so hard that it'll break-- however, we *are* worried about rockfall or rodents demolishing one ear.
I'm much more concerned about gear ripping than rodents and huge rock fall that would sever the rope.
It isn’t redundant if one of the strands within the knot is cut- which is a possibility if the knot is loaded over an edge or hit by rockfall
somebody's been watching Looney Toons.
Like a full hair cut of the entire loose loop? I'll do that when I test your beloved fusion knot :)
@@sebastianflynn1746well yeah, that's because you're rock climbing.
I'm caving.
🙃
When we route set at the gym I work at most people use the dog/bunny ear figure 8 to anchor and end of the rope, I use a different knot and you’ve got me curious about it now. I tie in with a bowline that has two loops and I tie a stopper knot. I don’t know what to call the knot, maybe a dog/bunny ear bowline? To tie it you make a large bite, tie and overhand one a bite with a large loop, fold the loop over the knot so you have a similar three parallel strand spot on the knot as this dog ear figure 8, then pull two of the overhangs loops simultaneously and the knot will pull into basically a bowline but with two loops. Last step is just thing a stopper, note, the stopper know will be on the main line as opposed to inside the loop like a double bowline one might tie in with. I use this know because it’s substantially easier to untie than the dog ear figure 8 and I’m super curious how it would fail and the degree to which is redundant.
I don't use the figure 8 nor the bunny at all anymore. Not even the bowline. I teach rope and cave rescue and we favor the double Dragon and alpine Butterfly loops. This is more secure and less knots to practice and remember. Having said that, personally I don't think I could ever forget the bowline. It's muscle memory.
This is good, I've heard for a long time that this knot isn't truly redundant, but in a real-world scenario the failure of the interface between rock and hardware is more likely, meaning one loop of the bunny ears couldn't possibly pull through with a carabiner and bolt attached. I really love how you guys think outside of the real world stuff too. In reality pulling 8kN onto a knot used for static loads is highly unlikely, but it's nice to know this will still untie relatively easily. Maybe not so much with a dynamic rope (tie into bolts to retrieve stuck gear etc, but then you'd only apply 1-2kN on abseil)
I wonder if a cut loop could pull through, seems unlikely if dressed properly as the non-attached loop didn't shrink (much?)
Good stuff Ryan! Thanks for the tests!
Awesome video, I love seeing you test things I've used for decades
I've used UHMWPE, Dyneema, Spectra whatever you want to call it for decades. You 100% can tie knots in it. But you have to use knots that generate huge amounts of friction. A figure 8 or bowline is not going to cut it. One trick to tying a knot in HMPE is to use a nylon sleeve around the rope. This is a method used in kites and fishing for decades. Now would I use these methods for life critical safety equipment? Probably not there are safer ways. But there are knots specifically used for HMPE, the spectra knot for example. It is right there in the name.
Adding nylon sleeves can affect on slippage but won't change MBS on knots. You should avoid knots on UHMPE because it is too static , and the bends you get on the knots reduce the MBS more than 50%.
Yay! Love this video, been curious about this knot for some top rope soloing. Interesting to see that it cinches down enough for either ear not to slip
I am a caver from italy, once i was going up from a rope tied with a bunny knot on the roof of a cave. Suddenly one of the two fixes the rope was tied on failed and i remained only on one ear of the bunny so i can confirm that this type of knot is redundant!
I learned to tie the bunny ears figure eight differently, where you get 3 loops instead of 2, though you can turn it into 2 if that's all you want. I assume that version should hold up, but it would be cool to see. Great video!
In caving with knots like the figure 8 bunny ears and the bowline on a bight general wisdom seems to be: when clipping cows tails in to these knots, the crab needs to go through both loops not just one -
It would be fascinating to see a test where you pull the knot from just the loops, one loop attached to the “bolt” and the other loop attached to the load of the unwary caver who didn’t properly clip in to both loops
Awesome! Thanks for confirming this!
I have an related question: Consider a two point cordelette style anchor using say a 120 cm sling. This gives two ”ears” at the bottom. In many scenarios it is nice to use them individually, for example one point for the belayers safety and one for the Reverso.
Now, what if one ear is unused. Will the knot collapse under heavy load on the second ear? There is some dissgreement on this and some real science would help!
Bobby must be a menace on the roads. Red means go!
I almost sent this as a request last month... great experiment thanks
This is great I have always wondered about this knot I learned it a long time ago and have only used it a few times because I was unsure of how redundant it really was.
Great vid! I've been curious about bunny-ears figure 8s being redundant for a long time!
You read my mind, I was just wondering about this. As a caver this is great info. Could you also do the same with the double loop Bowline and the Fusion Knot? They both allow for easier loop length adjustment than the double figure 8 but does that come at a cost? Keep up the great work!
I'll be testing double loop bowline and fusion knot for sure
Slippage of the double loop bowline (aka bowline on a bight), with only 1 loop anchored, happens at such low forces that any of us could witness it at home with no special equipment. But it depends on which of the 2 loops is anchored and how the knot is dressed, so you might not get it on 1st try.
Can't wait for the double bowline!
Add this to your list of slow pull failures to try to recreate on the drop tower! It'd be interesting to see, now that we know it *can* fail with dyneema, how close does it get to failing in shock load situation?
I'm guessing that even the Dyneema version of this test would pass if you left a carabiner on the open loop to simulate a slightly more realistic climbing scenario. Thanks for this video -- it does a good job confirming that bunny ears are safe in the real world, in spite of some academic questions that I've wondered about in the past.
Bobby loosened that knot for you.
I work in rope access, i use it everyday for years. In France we call it "bunny" knot.
Good ol'fashion break stuff video...
Dyneema was interesting...
I'm very interested to see this with double 7mm cord like Jeremiah uses for some of his master points, especially in a shock load situation. I'd also be interrested to know if it makes a difference to grab a loop from each side of the choke and cross match for the two master points.
to self-equalize version....... u need to make 1 loop extra big to pass throw both bolts... and the other one small to just clip one carabiner to it and the middle line pass between both bolts........ this will self-equalize the force on the 2 diferent bolts.... but only 1 loop are really attached.... we use that version on industry climbing work so im sure that 1 loop will be ok in strength with out being watched the video yet...
Why don't y'all keep a marlin spike around for untying knots?
Edit: Didn't mean to sound grumpy, just a friendly suggestion :)
I’d like to see a two rope alpine butterfly’s tie together and force on one rope only. I use in rope access to join ropes to get the angle (direction ) for the working area. So its two ropes on separate anchors then joined with a alpine butterfly, so then both ropes are join like one. We only have force on the main working rope leaving the safety rope unweighted.. Love to see if both anchors are load equally which I’m guessing would be close equal. Ive been told that this could be dangerous because the force from working rope could rub in the alpine butterfly Knot under load causing failure. Thanks. Great channel !!!
Thanks!
it is better if the loop is at the top...this also makes the knot nice and parallel...
Could we do micro traxion episode with top rope soloing and the ways they can fail? Also micro traxion lead and top rope belays?
Love your stuff but in this case I feel like we never got a true result. One ear allows it to slip into a type of figure 8 the other let's it slip out completely. I realize that they didn't slip but which eye were you pulling? Maybe the other eye actually does let it slip? Keep up the good work get well and hope you have the time of your life running your new store. Can't wait until you start shipping to Canada, hoping you team up with someone other than MEC (Mountain Equipment Company).
Ryan. We have a strap we would like to test the strength of. How can we get in touch with you?
Fun tests!
I see quite smooth 5kN curve there. Could you DIY a shock absorber using slipping dyneema rope? Totally not going to do that at home no worries. Purely academic interest.
I'd like a comparison test with double bowline and fusion (aka Karash) knots!
I would like to see the same test on a bowline on a bight, which also creates 2 ears with just just one tongue. I prefer to use it, because it's so much easier to untie. Since I do not know if each ear itself is redundant I haven't used this one yet for load sharing. I only clip both ears to one bolt, then tie another one a bit further down the rope and clip that one to the second bolt. So unfortunately only one bolt gets weighted.
On a similar subject - I'd love to see if the girth hitch master point carabiner anchor is redundant in a "dynamic" situation with a fall factor 2! That's something that's been bugging me, and one of the reasons why I refuse that method as an anchor - I have yet to see a proper test of that situation.
Also anchor knot set ups but on the drop tower so the falls are not slow but realistic to being a whipper.
Great content Ryan, thank you
Would be curious to see if one strand was cut before loading, would it slip through?
Great video! Need to know breaking force? Thanks
lots of companies in the UK don't re-sew cam slings.. so the recommended replacement is dyneema accessory cord 5.5mm tied in a triple fishermans. Can we see how resistant this is to slipping, and how long the tails should be?
The super tight knot at 5.45 - was that the side pulled with both loops to one anchor point, or the one "equalised"
Thanks! As a caver I use the bunny ears very often and like it a lot.
Do you also use the fusion knot?
@@HowNOT2 I do. When there is only one anchor I use the fusion instead of an figure of eight and clip into both eyes, just because it’s easier to open than an eight.
I seem to recall that there was a way to tie double sliding knots on a single loop - sort of making it an adjustable necklace, bracelet etc..
I’ve been curious about the bunny ears redundancy for a long time, thank you for this pull test!! I’m curious how the knot would have behaved in a shock load situation, but it seems likely it’s have been fine. In the one-eye-to-one-eye test, were the knots pre-pulled or just hand-dressed before pulling?
Sorry I haven't scoured the comments.
We're the failures not all before the knot when force was applied 180° against the in-feed to the knot. Were these results more related to rope bend radius than knot integrity?
Great as always thanks
Have you ever tested a double bowline vs a double figure 8? A german climber I know only ties in with a double bowline which makes it super easy to untie after a whipper.
3:03 Ryan is a phlebotomist's dream.
The dynema! 😮
Can you explain what you said about not tying knots in dyneema? I just watched your top rope anchor video where yall put two limiters in a quad made from a dyneema sling. Is it only a hazard when slipping can lead to the whole system failing?
Could you please compare the super 8 with the main loop going on the bottom of the knot with the super 8 that has the loop going in the middle - just over the two lower strands. Does it affect the strength? The first version is bending after loading, but the second looks better, becouse of even force distribution. I love your channel and apreciate all of the useful knowlage from your job. Thanks and salute ;)
would love to see these same tests with the 'fusion' knot
ID REALLY love to see what types/brands of ropes can take the most fraying on a sharpo edge say your sure of your line and where the pressure is gonna be but w/e happens and now its on a sharp edge. doesnt how much weight its under effect how fast it will shred. will just touching a sharp spot make any of them fail 100 percent. id be super curious what happens.
i was reading some other comments yeah rock fall would be a good example if a rope under weight gets straight up crushed wil it still hold? if the crushing object is stil on it is it weaker or bettter? does sharpness matter alot or a little? little details can answer a LARGE range of possiblities
If you do a video on dynema slings with knots I’ll become a patron. Basket hitch anchor with overhand. 3 point with overhand. How do dynema slings respond to being in a big knot
I added it to the list. It's a good test idea.
Try loading your system at a lower rate. I work in construction materials testing ( mainly concrete) and when testing the compressive strength of concrete if we load the test cylinders at a hight rate we get a higher compressive strength. Same with tension testing of steel reinforcement. The rate is very important in determining the actual strengths.
You could lower the rate, but it would be unrealistic to a climbing fall
@@JoBianco agreed, but dou you think the machine they are using for testing simulates dynamic shock loading like that of falls?
Yes, rate changes the results for sure. If I can figure out a movable dummy weight (500lbs aint it) and how to attach it to the drop tower, I'd test more knots and a lot of stuff on the tower. Good news: it's really hard to break ropes with just gravity.
@@mojavered. It's a good point
How to know which one of the ears is the one that holds if the other slips? Seems important.
Also, if just clipping to one point, it's as strong as a normal figure 8?
I've always wondered about the redundancy. Thanks for answering! Now a double bowline on a bite?
Why no knots in dyneema? Just because it slips? Or other reasons? Have you guys done a video on this?
Curious to see what is the difference between the third strand on bottom instead of top
Great vid
Could you do another test with loop on top of knot? Most rope access centres teach bunny with last loop on top. Just curious what difference in reading it will be
High i install glass on skyscraper in Philadelphia
And occasionally we are handed termination bars
Uses no knots just friction
I would like it if you could test that setup
Thanks for that video.. i always tie this knot on My pas yo conect it to my arness yo have redundancy and doble Surface. But i usted to dress the loop on top in stead of the bottom. Do You think its good
I would love to see a double longtail bowline tested!
when you say you're knot supposed to tie knots in dyneema, youre knot talking about sewn dyneema runners... right? Cuz like I used those in anchors every weekend. 😶sorry for potetially dumb question
Does it matter where you put the bight, I've heard for fig 8's it should be in middle of the knot, not the bottom. Where as a fig 9 goes at the bottom of the knot. But I've also heard the opposite for both
Don't tie knots in dyneema. But haven't we all tied an overhand or figure 8 in a dyneema sling? How wrong is this or is it irrelevant at the forces we generate at the anchor?
Slings are closed loop so usually its kind of redundant even if the knot slips. But you have to be weary of strength reduction, up to 70%. Which could be bad dependend on application and knot. You shoudnt tie an overhand in a single strand of a sling for example. But on the other hand tying one in the 4 strands for an anchor masterpoint is totally fine.
That was surprising that the rope actually caught - curious if having one of the loops cut would make a difference - especially if the loop that got cut was the smaller ear - could that create a shock load enough to pull the remaining ear out of the knot?
When can we see the test of a bowline rethread
Maybe even looking at the different eyes of that as redundant? ( I doubt they are)
Hi in the level one french rope acces we are tell to tie the girth hitch at the top of both strands and not at the bottom ,i wonder if it make a big difference of strength or if its harder or easier to untie ?
So what if you added an overhand stopper knot to the weak side of the loop? Add a bit of failure safety and since you don't expect it to self adjust anyway and it always breaks in the first knot then that "shouldn't" weaken anything, right?
always have wondered about this knot because it makes life a lot easier and i use it a lot, nonetheless have always worried about the strength and if there’s any way it would roll or something along those lines
I am curious about the "don't tie knots in dyneema." And the quad anchor. Is there something I'm missing here?
So my anchor is redundant if I tie a super 8 on a piece of static rope and connect the ears to two bolts? I was thinking about using this to extend my master point over an edge for a top rope anchor.
1:52 isn't it better to put it on the top? I see many people do it this way and I think it "look better" if I pull the knot, if you know what I mean.
Hi, did you test side forces on single rope loop that bend with itself with figure 8 bend?
I'd like to see a drop test using the same setup as the last test.
I had to laugh when you were cuddling that book. Great book. Brilliant book in fact but it nearly killed me.. Actually no, I nearly killed me but my advice to anyone buying it would be to find the page that tells you how you can abseil using your feet as a descender and tear it out before you get too comfortable trying out too many old sketchy techniques like this idiot here did 😂
Great video as always man. I did wonder if the bunny ears sorta compromised the knot if one broke. Now I know it's probably good enough. Thanks 👍
I dress mine slightly differently than how it is shown in here. Instead of placing the passed through loop at the bottom of the knot, I place it at the middle, thus eliminating any excess rope from the knot.. I dont expect you to redo this video but I wonder if this affects how well the knot resists collapse in the event of a partial failure.
I'll tinker with that other way of dressing it
I'd love to see the bowline with bunny ears tested.
Can you use a knot in the dynma to make a screamer
You are not supposed to knot dynema, but what if that was the only rope at hand and you dont have the ability to splice it, is there any knot that isnt too bad?
I think that I missed it in an episode but whatever happened to the drop tower?
Grog Knots says both the Poacher’s Knot and the Double Dragon Loop are safe in Dyneema. Can you test those?
I would probably prefer the double Alpine butterfly knot were whatever it’s called