Yeah, it would be very interesting to see on real rock... especially the difference between granite vs sandstone if possible! I'd think friction might not matter as much on sandstone though: the rock itself might shear more easily under those forces which would make obsolete any frictional resistance the rope might encounter.
Also the difference between hard sandstone and the soft sandstone where these are used. Sometimes it feels like grabbing sand not actual rock. I think the rock is likely to break
Sandstone in Czech Republic, Poland and Germany is delicate. Using metal pro leads to rockfall and changes cracks into lines made of holes. Moreover people often climb after rainfall and break the rock. That's long & short :)
@@marekholub8668 It would be interesting to see actual drop tests that proves if this actually happens. I've climbed in Germany's Pfalz mountains on sandstone and didn't observe that. What if you place a cam deep into a crack system? Perhaps longer stemmed cams could increase safety in soft sandstone. I liked someone's comments below. He said that using such gear as knots and climbing in Czechia is a lifestyle and adventure. Others have said it is about the cost of gear. Others have said that the American use of cams is more about a desire for a label and shiny metal. I'd like to see tests comparing cams and knots on actual cracks in Czechia. That will chase my skepticism away and replace it with scientific fact.
@@Davidadventures Nah, the point of not using cams is that we don't have enough sandstone for everyone, which means we have to be gentle, otherwise there won't be any left for the next generation. And no chalk allowed for the same reason.
I have a feeling that these rely on frictional forces to a great deal, especially since they are being placed in soft sandstone. I think it would be great to see some real rock tests, or maybe you could add some sandpaper to the inside of "your crack"?
@@antonf.9278 These are quite specific, here the sandstone is very rough (about 40 sandpaper) and sometimes you want your sling to really hold and stay on smaller tips (sorry, I have just realised that I have never heard English phrase which would describe throwing sling over a pointy rock feature). The slings then work as velcro and are far less likely to fall off the point when you pull on them with a rope as you climb further.
I think they could try getting the faces if the cam crusher sandblasted. It would give a more realistic rough face without the problems that sticking sandpaper to it would cause.
As a climber from Czech republic, who uses these a lot, I can share following two remarks: first, yes, the knots indeed do rely on friction a great deal and second and foremost, there is a fundamental error in your test machine setup. I can clearly see, that you screw the one end as tight as possible, so the knot can not be pulled through, but once you start the machine the far ends of the contraption are not kept in place, they get closer to each other and that makes the gap with the knot to become slightly wider and the knot gets pulled through. I think you should have used something to keep the far end the same width. Also, this kind of strain does not occur during climbing, there is no steady pull with increased force, instead there is a really short twitch, so the knot does not have time to deform that well. Once you complete your tower, much more representative tests could by done by throwing weights from the top to the anchor made of the knots.
I live and climb in Czech republic. Rock in some crags is actually that much soft, that if you don't have a hold and you'd rub your foot for 5 minutes in one place, you'd have a pretty good foothold. Friction makes a difference, but it's not all. Placement is key. On a great placement you actually can whip. It's not that uncommon, to put several knots close to each other and clip them the way, that they all are weighted in a single moment in case of fall and weight distributes. Knots don't work all that well when they are on they own, I tend to put more knots in the rock than I would with metal protection. A lot of the routes have metal protection hammered into the rock that is usually pretty good and you can whip on it all day long. If you'd ever have a trip to Europe, definitely come to Czech republic and have a look on how that work!
Same rules of using knots over hardware are in southern Poland where the sandstone rocks are present. Also no chalk allowed. Some examples of such gear placement are here: th-cam.com/video/HXTgPUOEQbs/w-d-xo.html
It is sweet indeed, just please be careful, most of the placements you would consider absolute bomber in granite are still rubbish in sandstone. The angle at which the sides are joining should be over 30 degrees and you should place in a slot where the loaded end hardly passes through the tight end. And everything crumbles. Don't be afraid to spend evening before in pub - making some local friends and getting tips, mabye even a experienced lead climber :)
8:30 Yes friction would make a huge difference. Friction also makes the figure 8 much stronger I believe because the knot folds in on itself while beeing as slim as an overhand while placing it.
Yes please. I almost exclusively use monkeys fists in sandstone (sometimes also in other rocks). I was hoping to see those here, but maybe another time then ;)
Stoked for all the engagement so far! The ground is prepped for drop tower, crane is 100% working and all the parts are painted. We "just" have to assemble it now, lift it up and decorate it. Donations really appreciated while we take the drop tower project over the finish line. 😀 www.slackline.com/donate
just fyi - "How does the comparison of knot loop and cam look like? The discussion about local usage bans should be disregarded here. Therefore, the range from loosely pushing through to tight is very small. The range of extensions 30mm is better covered; cams are also easier and quicker to lay. With Friends you can then secure completely parallel cracks. A knot loop is softer and therefore has a larger contact surface. This means that the risk of rock damage is lower with soft rock. Knot loops are a bit more complex to lay, you shouldn't forget that there is a certain range from lying well to pulling through. A knot loop has more friction with the rock. This has the advantage that a knot loop does not loosen as quickly as a cam through rope movement. Knot loops can also be placed in relatively open cracks and holes, in places where a cam would immediately fall out again. The experiments were carried out by Jörg Brutscher, André Hoose and Jens Freudenberger. We would like to thank the Institute for Materials Science for making the tensile testing machine available for these experiments. Thanks also to Martin Lange for reviewing the article. Further details of the experiments are available from the author." [1] See diss. Helmut Mägdefrau: The stress on the human body when falling into a rope and its consequences, available from the DAV safety group. Also: More safety in mountain sports, part 10, Bavarian State Ministry for Labor and Social Affairs - www.joergbrutscher.homepage.t-online.de/knoten.htm
Hi guys, I just had an idea, you might be able to create a more rock like surface in your clamp by coating the steel with epoxy and dusting it with sand while still wet. Kinda like non slip epoxy floor coating.
I don't know much about the whole using knots in rock vs in that clamp, but I do know that some rock like limestone and such, don't look anything like that clamp, with all those grooves and whatnot, on account of how smooth it is, and in some cases probably even more cushioning than that metal clamp... If I'm wrong in any of this, please correct me, but just given what little I know about rock, I know that different types of rocks might have different grip properties and characteristics, the same as testing out those forces in a metal clamp will likely behave differently in rock
You could try replacing the steel with concrete paving slab type things tho the slabs themselves might not be able to take the stress of a pull. I would love to see both this in real rock and it done dynamically in the drop tower. I can see the results of a dynamic drop being very different from these results.
Guess, when its about knotslings, soft Sandstone will be way different from steel or concrete areas. The more grip, the more friction, the more Power -Transmission.
@@cutt7837 yes that's who I was thinking. A paving supplier may even just give you various rock types as you only need a few small scrap bits to them. Sandstone and limestone paving common. Granite less so.
Good idea, but like you mentioned concrete don't like pull forces. But small concrete pieces inside of the crack would one dive them pressure force. Which concrete is very good at.
It is the same in saxonia, there is a long-standing tradition of climbing with rope as protection. I am no geologist. But probably a similar sandstone. Works apparently well and all the top anchors are bolted. Locals get really grouchy if you climb with other gear and it does actually damage the sandstone which is considered a heritage site... welcome to European climbing
The problem with German and Czech sandstone, which are one geological unit, is not really that it is to soft. In some places it is actually quite hard because of regional metamorphosis I suppose. But even in regions with hard sandstone metal protection does not work, because when taking a fall on it, the surrounding surface just gets broken out of the rock. Because the real problem of the sandstone over there, no matter how hard or how soft it is, is the overall porosity of the stone. The porosity is so high, that climbing is forbidden, if it rained in the past 24 hours, because the rock is just too wet and therefore more likely to fail/break. From my own experience I can say, that I have never climbed on better rock than the sandstone in the Bielatal in Saxony, Germany and it is definitely a recommendation for everyone, as long as you have a lead climber, who knows his way around.
@@edwinmahlo427 Porosity isn't a measure of the weakness of the rock, it is the property of friability. However, you are correct that porosity increases the failure of rock when it is wet. If you want to make a landslide happen, add water. If you want your rock to fail, add water. Therefore you have multiple problems. You can't use cams because the rock is friable and you can't climb after rains because the porosity decreases the rock strength. Here in California's North Bay we have cemented rhyolites, some of them are like sedimentary conglomerates, but occur through igneous processes. We can't climb on them after rains for the same reason. But since it hasn't rained here in a few years, the climbing is good, except when the fires sweep through the climbing areas and destroy the bolts. I am an engineering geologist by the way.
@@edwinmahlo427 Actually there was an short investigation considering metal gear (at that time = nuts) on saxony sandstone. It didn't find the the often citated rock failure, at least not different to slings. Back then it was decided to stop testing nuts to preserve the tradition. It was definitely not a fact based decision to ban metal gear but rather a highly emotional one (as it's the case for many of the saxony climbing rules). If you look closer it's an repeating pattern to argue based on "facts" that have never been proven in most of the discussions surrounding climbing in Saxony. The funny thing is even evidence often times can't change the believe in these alternative facts...
@@Davidadventures the problem in saxon or bohemian sandstone (its the same) is that the compuond that holds it together is water solvable, so basicly it falls apart when wet because there is no „glue“ holding it together, assoon as it dries its solid again. This happens less with sandstone that has a major metal component like the dark sandstone found all over bilathal (lots of iron working as „glue“) so you can climb those towers pretty shortly after rain, just 20km away the „rathener gebiet“ is called cookies or „rathener keks“ among locals as its so likely to break, even when dry. Sandstone geology is wild 😂
Why does that guy ask us "IF" we want to see real rock test ? Shouldn't he ask about "WHEN" we want to see it instead ?? We are not gym climber here, we want rock by the roll of course !! PS : greetings from Chamonix, keep up the great work guys
@@marekholub8668 knot stuck in cracks have been wildly used for climbing all over the world in all sort of rocks long before metal protections been on market (just read old books from Bonatti or Rebuffa and al.). As of the present, fact is it is lighter, it is much much cheaper, and it has better availability. So having test that show if it can be a viable option is indeed of great interest far beyond the particular case of one small portion of one country. From this video i can see some potential for it. So yes any test in any type of rocks makes us all advance, no matter the country.
@@lolaa2200 Yeah, I know it has been used on all types of rock. I'm just saying the tests in other rock wouldn't be relevant to Jenny's videos. If you can use cams and nuts on your climb, you are safer using them over textile pro. If you can't, they are definitely better than nothing.
In a moment of desperation i have placed a prussic into a crack an fell with it at my hip height. And it held. It was really hard to remove it though... So I know for a fact that it can work. But i like my solid cams better. Or even the emergency BD guide stopper like you instructed on one of your videos! LOL
Well, anything metal might also be likely to rip or break out enough stone as to come loose. An expanding dynamically loaded knot might hold a lot better.
Just came back from a beautiful day in Elbe valley, climbing some fun sandstone and what a pleasant surprise I found in the subscriptions. Great job, nice to see these tested.
Climbing sandstone in Czech republic or in Germany is more a lifestyle or adventure than technical pro climbing. I'm happy when my sling holds 6kN because dynamic rope doesn't allow to generate more. Knot will slip away rather than break the cord.
I imagine these would hold up better on real rock, especially when being pulled from an angle. Super entertaining video though! Probably one of my favs!
Note that the metal plates open up, once the knot is in between the left two bolts. You can easily see this as the right two bolts lose tension. This effectively means that the distance between the plates at the location of the bolts controls the size of the slit. Would recommend to fully lock the two metal plates, during further testing.
Hey Rian, maybe your jig isn't that optimal for soft nuts. The side plates change angle when pulled (good to see at 08:00) . Therefore the front of the gap opens for smaller knots. Maybe you could test the small pieces again with a jig with fixed angles? Best regards from germany :)
Yep, exactly what I noticed. The knots actually pushed the side plates open. Should be easily fixable by fixing the rear of the plate so that it doesn't move.
Local here... The trick about the figure 8 is that you can tie it super flat (basically you get only twice the rope diameter). You can see this really nice in the video of Jenny. When you put it in a crack or feature and pull (on all 4) strands, the knot becomes a lot thicker... and pinches against the rock, which adapts the surface of the knot very well to the rock. Its a lot about friction! try it ;-) Same is for figure 9 knot.
- Sand friction is different.. - Any metal stuff is not allowed to be used on sand rock. (Most of sands are kind of National Monument or protected zone) - You always fall with angel 60-80 degree - Its possible that second or 3 knot catch you - we call this zipping :) (the first 1-2 can go out and just slow your motion ) - I think this need to be tested with real sand rock but nice video... - You wanna fall to ring not to knot :P but some knots are better than nothing you know :P Because distance between rings are sometimes length of route itself :D
I always wondered how secure those sketchy looking Czech knot nuts were. Ended up taking a greater load than I would have guessed. Thanks, as always, for doing the tests! A note on why the knots were popping through your machine like mice slipping through a crack. If you re-watch (for example) 5 min 20 sec in and 13:50 you will clearly see that as the knot hits the forward 2 bolts and starts to slip past the bolts, those bolts act as a fulcrum for the plates to pivot on. There are no nuts on the 2 rear bolts on the inside to prevent the plates from squeezing together therefore allowing the gap in the lip at the front just past the front bolts to spread and allow the knot to slip through the increased gap. Watch the rear of the plates at this point and you will see them creep together slightly. 4 nuts with washers on the inside of the 2 rear bolts should solve this problem.
Disregarding the friction aspect missing in the test, I would suggest that the test jig itself is flawed. This is best seen in the test at around 7:20. In that test, you can see that the wide end of the test jig/fixture is closing which correspondingly causes the narrow end/mouth of the fixture to open wider. This results in creating a condition which doesn't exist in real rock. If you secured the rear bolts by placing stop nuts on them (inside of the plates) so the rear plates are set at a more fixed position, you would most likely eliminate this condition. The "loosey-goosey" rear end of the fixture not only causes the narrow end to widen, it thereby also reduces the plates' angle where the "rubber meets the road". Less angle would also make less resistance to the knot.
yeah, do it in real rock...and also if you're ever going to use it again, put some texture in the cam-crusher! (maybe epoxy some flat pieces of actual rock into the jaws of your cam-crusher)
@@kevinmcdonough9097 uh, yes...? epoxy is good for thousands of PSI which should be super-good-enough if the force is distributed by a flat piece of rock above it -- we epoxy in bolts that hold >40kN. I dunno if that's even a great solution, just that slippery grooved metal plates are NOT the right medium for this type of test. Maybe the steel can be textured directly, but I'm pretty convinced rock has different enough friction characteristics compared to metal as to be a poor facsimile.
It would be awesome to see this in real rock. Would be very interesting to see the effect of friction. Thanks for all your work Ryan, you are one of the best channels on youtube.
Definitely think it makes sense to test these in real rock; seems like friction plays a huuuge role on how the knots hold up vs. slip through under max kN.
Finally, i was looking for vids about it. In germany we have the same rules (also sandstone rocks) but you really don't find too much Information on how too use them
I do climb in the saxonian swiss. A few points: Noone i k now uses overhand knots for slings, a fig 8 is nearly allways the better option. We are usually not too concerned with the breaking strength of the gear >4 mm since dyneema slings. (we start using nylon only slings >7 mm) All that is in question is the friction and integrity of the rock. Laying slings is an artform of feeling how the sling compacts in the rock. And even then noone here likes to test if the knots actually hold.
Greetings from over the border :) I am big fan of the overhand knot, because I have much better feeling from placing it in the spot. I feel like having an overhand on the sling gives me nicer v shape at the bottom end and better movement of the top end as overhand is smaller than fig 8. Only this vid made me realise that fig 8 might be ever useful.
when I was about 12 my uncle took us up Thumb Butte using knot pro and over the shoulder belay, 50 yrs later I have about 50 lbs of aluminum but this video made me smile
The sandstone mountains are actually a national park split by the German/Czech border. The park service allows climbers but prohibits the use of chalk or any metal-on-rock trad protection. Some of the routes are bolted, mostly only at the anchor or every 30m with a thick metal ring.
I did that in the day. It's depicted in Royal Robbins' Basic Rockcraft, so I tried it with many regular pieces for back up. It worked. In those days you never expected that a helicopter was going to come and rescue you. Nor was some gym employee telling you that this is a "safe" sport so we learned everything we could since knowledge weighs nothing and could, at the least, save you from the embarrassment of having skilled people have to rescue you due to your ineptitude.
Great work, both yourselve and the local climbers who developed this tradition to look after a fragile resource. I look forward to the friction version.
They were all WAY better than I expected. Still wouldn't whip. But if I had a choice of nothing or this - then I'd be tying knots :-). Would love to see these in real rock!
Really stoked to see how strong these are! Friction on rock would defenitly make a difference. I guess shockloading would make them slip less…insert drop tower here! 🤔
Can’t wait to see this on the fall machine when it’s up and running. Thing with this test (video) is that it’s unrealistic as you’d never get such sustained high forces. A fall test would be more realistic as you’d get the high force temporarily, for a short time, so i got a gut feeling the protection would behave differently under a shock load, compared to it experiencing a sustained and incrementally higher load.
I live in the Czech Republic, used to climb on sandstone sometimes. The friction from sandstone is vital to how the knot works, as you pull the rope and the knot tightens, it should try to expand against the rock and 'mold' to the crack's shape, speading the load. These knots are not for big falls with high kN values, if you are worried you will fall you put a knot every meter or so. The sandstone is too soft for metal placements. In a fall, they do not mold to the sandstone so all the pressure is on a small area (the grains which are in actual contact with the metal), which will crumble or snap off. Maybe you could test with some sandstone blocks?
You should get various stone sample pairs and a good stone drill bit, drill 4 holes like those metal plates you're using and secure them with the bolts. Then you could determine how the type of rock, and their respective coefficient of friction, affects breaking point using a consistent anchor type. Great video! Love to see these tested in a controlled environment.
DEFINITELY test on rock! I am certain the ability for them to deform like putty so much in this test is undoubtedly due in part to the slickness of the metal allowing the exterior fibers to easy change position and placement, as well as the entire not to more more easily into the narrow part of the wedge. Contact on a surface with much higher friction will, I think, improve the strength performance in practice.
I'm pretty new to climbing and currently in the market for my first bit of rope. In the discussion on reddit about treated and untreated rope, there is also a conversation about rope weakening when it is wet. Outside of alpine or glacier scenarios, it is still entirely possible to encounter a situation in which the rope could become completely soaked (even during a retreat for example). I think it would be interesting to see you guys test the strength difference between dry and wet rope!
I am really looking forward to seeing your drop-tower in action! Super curious to see the differences between those dynamic forces and the static / slow ones.
As a person that starter his climbing adventure in saxon switzerland, german sandstone region near to Czechia I have two remarks: 1 the friction makes a lot of difference. People in engineering department of technical uni in Dresden did similar experiments but with knots placed in sandstone crack and limestone crack as benchmark. It turned out that on limestone they dont hold. 2 the shape of your nut catcher is suboptimal for placing a figure 8. The cone formed by the metal sheets has far too small opening angle, its just too slim for solid placing. If the angle was twice that, the front loop of figure 8 would move backwards and you'd get more solid placement. I dont know if thats clear what im saying, but if Infond some references i'll send them.to you!
Please please do monkey fists. Both with 3 wraps with 1 strand, and 2 double wraps with 2 strands (Both ends of the rope in the knot) I've been setting up hammocks and rodeos like that for a long, cant wait to know how they hold up.
Yes, also testing the monkeyfist vs crown knot?? in a soft shackle - is it less crucial to fully tighten / dress or not?? NB a monkey fist can be made pretty-much as bulky as one wants, 2,3.,4 wraps, easy to bulk up....
So glad you did this! Definitely somewhat surprising results. I'd love to see these tests done on the drop tower, maybe between cinderblocks or something rock-like that you could still adjust the gap on (maybe the same as your rig in this video, but with some sort of rock-like tiles/patio stones?). I bet the friction really matters, and falling forces are probably more like prolonged spikes, compared to steady forces seen in the slacksnap machine. If the knot moves a little at high impact, but the impact dies down before it manages to slip out, these knots might perform better than expected.
Hey, actually I`ve some experience in sandstone but in saxony, not in czech republic. Here in germany in this area, even fever bolts are placed and therefore we rely even more on knots (and UFOs) :D Well and it`s not so secure like bolts or friends or nuts. Buts actually I think it`s necessary. Sandstone is really soft, so you could damage it with harness or with too many people climbing on it. So there is a debate about how much protection we allow, because the more protection, the more people will climb. This is a difficult consideration. (Fun fact: There are some people severely injured or even dead each year in this area. Most of them made mistakes during abseiling, not with the knots ) But at the end, its an ideological thing. We learn that climbing is something you should have respect for. I will not start a route if i´m not sure that I can do it. I don´t want to fall under all circumstances. My protection is there to save me from death, and its working. With some experience and the right eye for knot placement (and the friction of sand stone of couse :D) it is a lot saver than it looks. And for me it has to do with appreciation and not to overestimate myself. But how I said: You should not fall (At least I don´t want to fall, there are some people without this kind if concern). So its not classic sport climbing. It is a developed traditional climbing with some real special moves. Thanks for the video, it was quite interesting. How others said, friction is key regarding this topic. Would be really interesting to see what happens with real sandstone (maybe some stone plates in the testing device?). For me it would be nice to not rely only on experience or feeling, but on facts :D
Yes, please test these on rock outside!! I live in Germany (by the border with Czech Republic) and here we also have to use these knots and slings. I was thinking about asking you to test these over patron (I'm a supporter these since a couple months), especially the monkey fist, that I use quite often as well! And yes, it is pretty sketchy climbing with those, I do it since I moved here, but I never try anything too hard when leading here! (by the way, you can't use chalk either, a real bummer :P)
I like the idea of modifying your cam crusher to accept concrete paving slabs or even just some kind of ceramic tile with the rough side facing the cam/nuts. I say that because I think the steel is too slick for the soft nuts to work as intended. That having been said, you did test what happens when you pull these nuts apart if the end is clamped in place. It is kind of amazing to think that most of these, if they held, would not explode during a whipper. Maybe we should all start adding some soft gear to our racks? It weighs nothing, it costs nothing, and you can use it to supplement your more conventional protection. Imagine not having to waste cams at the anchor because you can replace one or two with solid soft nut placements? Pretty rad.
Ad putting the knots in your rack: it really takes awful lot of skill to place them properly, they need super specific spots to hold (quickly tightening crack, deep...), they can be real pain in the ass, typically it takes few minutes to get them in and there are about milion other reasons why they are pain in the ass. Only two positives are nature protection and low price. Still I am really happy when I go for soke hard rock and can shove a bomber cam in less than 10 seconds, rather than spend 10 minutes with shitty sling, which goes in harder than out. I don't want to discourage you from trying them out, but be careful, mostly they are trash.
@@alcupone6462 I dont know that I suggested using them mid-climb. Rather, I think they would be great at anchors where you typically have a little more leeway on timing and setting things up. Instead of using 3-4 cams, you could use 1-2 cams and then like 1-3 more soft nuts to supplement and make sure you have a piece placed against upward pulls, which I think it an often overlooked component in a lot of anchors demoed online. What is nice about them is that you can augment some of your existing materials to function as nuts (dyneema slings, accessory cord, cordelettes, etc.) and basically get a bunch of gear for free. Sure, it won't help you on splitter cracks, but I live in CO where I haven't really climbed any red sandstone splitters....yet. I dunno, I think there is a place for this stuff. Ill try it out and if I dont die and dislike it, I will come back and comment :)
@@arnoldkotlyarevsky383 I don't think that you suggested using them mid climb, I just wanted to give you the feeling what using slings is like. It is awful lot of time for placing it and it needs very specific spot. I think you would be better off with using nuts if you want to save some cams instead of using them for anchor. As you have seen in the video, you need a crack which is at least 2x the diameter of the sling which narrows to approx the diameter of the sling. This is usually hard to find on hard rock and it is easier and safer to use metal nut for few bucks. Be safe if you go try it out :)
I finally followed your advice and climbed with my totem cams with the tag still on! Was nice to have something to read on the belay. Thanks for the tip
Yes I'm very intrested in seeing this on rock. Especially on sandstone where they are "made" for use. But any rock could do. Thanks for the awesome vids.
OMG thank you for this! I can't wait for drop tower to test this on real whippers! This pull machine apply force for infinite time where whippers have only limited time (like 1 second?), so maybe knots don't have that much time to deform and will hold? We shall see :-). However, I would do couple of improvement for the tests so they are a bit more real: 1. Don't cinch down the bottom after placing the knot: Once in the video, you mentioned you had cinched the bottom, please don't do this, you cannot do this with real rock ;-). You can place knots only where you actually can put the sling below the knot through (which can also be difficult because of friction and you have only 1 hand etc.) 2. Friction - sandstone has a lot of friction, that could be important factor.
In 1983 in the kitchen of Wolfgang Güllich and Kurt Albert, Wolfgang held up a piece of rope with a figure 8 to show everyone at the table how knots are used in what was then East Germany (I climbed in the Elbsandsteingebirge twice in 1983, once in 1985, and once in 1994, plus in 1983 in what was then Czechoslovakia, on the soft white sandstone of the Böhmische Paradies, where the rock is much softer than in the Elbsandsteingebirge): "You make ze knot theen, like so, and zen put in ze crack, and pool ze rope so ze knot gets bigger. Just like a Friend, except it does not hold ze bodyveight." 😆😬☺️
If you retest on slack snap add some nuts on the inside of the plates on the back bolts to stop the front opening from getting wider while you pull. If you watch the slow motion, the back plates pull closer opening the front gap allowing the knots to pull out.
Love this! I love the conventional stuff, but these obscure gear tests are such a nice bonus. I have always wondered about these and other odd pieces of gear like the beal escape and I loved the video on that too. Please test these in real rock!
I've been waiting forever on this! As a german I have some friends of the german side of that region. Those freaks also don't use chalk!! Crazy. Now I at least know how safe they are once i go there :D Great work man, keep the channel going, so excited for the droptower :D EDIT: Do it in Real rock, especiall in the sandstone region, where this is mostly done, the rock has a lot of friction.
I feel like some kind of coating or liner to ad some friction on the jaws would make a difference and possibly reducing the angle of the plates would help because you’re not getting as much contact between rope and the jaws as you could and the compressive force between the plates would be distributed over a larger portion of the rope thus giving more pportunity for the knot to catch or get hung up further up the jaws
it would be super cool to get a stone saw and cut a couple blocks out of sandstone boulders in order to make a couple stone wedges. But yeah, the friction would totally help a ton, think about jamming your hand in a slick crack at the gym compared to actual sandstone, the smooth gym crack hurts more than gritty sandstone because your hand slips easier at the polished gym. My skin gets way more wrecked when I'm jamming at the gym at least. So the friction on the rock will help the knots stay in place and not slide out. I'd assume as much as 50% strength increase in the placement by getting it to stay in place (with a limit being the webbing or rope strength)
The jig faces change angle at high forces, it "resets" to less angle on most, my flash is a third set screw that keeps the wingnut side from moving needed with an expectation of better results from a static angle. For friction put some skateboard deck on the jaws ... Cheers 🍺
I'm picturing some of the cracks near me where the two sides don't just taper, like the slack snap crack cam crusher, but even looked like it had crimps either side for the 'shoulders' of a knot to sit upon. Add that to friction and you're looking at some pretty bomber, 'I might not actually whip and die' placements.
It’s not only on the Czech Republic. In Germany - Special in the Saxon switzerland where free climbing starts in 1864. climbing is there very traditional no chalk, no friends, no wallnuts. Knot loop in sand stone is much more effective as in your test with metal plates :-)
I too would like to see this on real rock. The kn protection was impressive on some of those. Placement would be REAL important though, so I'm very interested to see how they hold up on real rock.
Yeah! Please do it in real rock. I’m most interested is seeing monkey fists done. Some with no solid core and some with a solid core (likes a bearing or metal marble)
Greetings from czech republic. First, our sandstone is soft, but not dangerous at all. Second, if you know how to place it, you are safe. I took some whips on those and survived 🤗 And the last thing, chalk is also banned on the czech sandstone 😁
Love you're videos! Always incredibly informative, while still being surprisingly entertaining! That line though! "Take the helmet, try not to die, and and don't forget to have fun. This is..is..fun" Not sure how many times I've stared up at a trad route and reminded myself that! 🤣
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See our other episode in real rock th-cam.com/video/Qkbz0aP4pN4/w-d-xo.html
Check out our new store! hownot2.store/
Yeah, it would be very interesting to see on real rock... especially the difference between granite vs sandstone if possible! I'd think friction might not matter as much on sandstone though: the rock itself might shear more easily under those forces which would make obsolete any frictional resistance the rope might encounter.
Also the difference between hard sandstone and the soft sandstone where these are used. Sometimes it feels like grabbing sand not actual rock. I think the rock is likely to break
Metal would slide out immediately as it would shear the top layer off the rock. That can happen even under your foot while hiking/climbing
Sandstone in Czech Republic, Poland and Germany is delicate. Using metal pro leads to rockfall and changes cracks into lines made of holes. Moreover people often climb after rainfall and break the rock. That's long & short :)
@@marekholub8668 It would be interesting to see actual drop tests that proves if this actually happens. I've climbed in Germany's Pfalz mountains on sandstone and didn't observe that. What if you place a cam deep into a crack system? Perhaps longer stemmed cams could increase safety in soft sandstone.
I liked someone's comments below. He said that using such gear as knots and climbing in Czechia is a lifestyle and adventure. Others have said it is about the cost of gear. Others have said that the American use of cams is more about a desire for a label and shiny metal. I'd like to see tests comparing cams and knots on actual cracks in Czechia. That will chase my skepticism away and replace it with scientific fact.
@@Davidadventures Nah, the point of not using cams is that we don't have enough sandstone for everyone, which means we have to be gentle, otherwise there won't be any left for the next generation. And no chalk allowed for the same reason.
I have a feeling that these rely on frictional forces to a great deal, especially since they are being placed in soft sandstone. I think it would be great to see some real rock tests, or maybe you could add some sandpaper to the inside of "your crack"?
There are even some extra fuzzy slings that you just lay on small features on the rock and rely on friction to stay in place.
Terrifying
Yeah. Put some chafing in your crack Ryan
@@antonf.9278 These are quite specific, here the sandstone is very rough (about 40 sandpaper) and sometimes you want your sling to really hold and stay on smaller tips (sorry, I have just realised that I have never heard English phrase which would describe throwing sling over a pointy rock feature).
The slings then work as velcro and are far less likely to fall off the point when you pull on them with a rope as you climb further.
I think they could try getting the faces if the cam crusher sandblasted. It would give a more realistic rough face without the problems that sticking sandpaper to it would cause.
As a climber from Czech republic, who uses these a lot, I can share following two remarks: first, yes, the knots indeed do rely on friction a great deal and second and foremost, there is a fundamental error in your test machine setup. I can clearly see, that you screw the one end as tight as possible, so the knot can not be pulled through, but once you start the machine the far ends of the contraption are not kept in place, they get closer to each other and that makes the gap with the knot to become slightly wider and the knot gets pulled through. I think you should have used something to keep the far end the same width. Also, this kind of strain does not occur during climbing, there is no steady pull with increased force, instead there is a really short twitch, so the knot does not have time to deform that well. Once you complete your tower, much more representative tests could by done by throwing weights from the top to the anchor made of the knots.
I live and climb in Czech republic. Rock in some crags is actually that much soft, that if you don't have a hold and you'd rub your foot for 5 minutes in one place, you'd have a pretty good foothold.
Friction makes a difference, but it's not all. Placement is key. On a great placement you actually can whip. It's not that uncommon, to put several knots close to each other and clip them the way, that they all are weighted in a single moment in case of fall and weight distributes. Knots don't work all that well when they are on they own, I tend to put more knots in the rock than I would with metal protection.
A lot of the routes have metal protection hammered into the rock that is usually pretty good and you can whip on it all day long.
If you'd ever have a trip to Europe, definitely come to Czech republic and have a look on how that work!
Good feedback. Thanks
I'd be psyched to see a video of these in real rock. The climbing in the Czech republic looks sweet and if I can trust the gear I'm more likely to go.
Same rules of using knots over hardware are in southern Poland where the sandstone rocks are present. Also no chalk allowed.
Some examples of such gear placement are here: th-cam.com/video/HXTgPUOEQbs/w-d-xo.html
It is sweet indeed, just please be careful, most of the placements you would consider absolute bomber in granite are still rubbish in sandstone. The angle at which the sides are joining should be over 30 degrees and you should place in a slot where the loaded end hardly passes through the tight end.
And everything crumbles. Don't be afraid to spend evening before in pub - making some local friends and getting tips, mabye even a experienced lead climber :)
8:30 Yes friction would make a huge difference. Friction also makes the figure 8 much stronger I believe because the knot folds in on itself while beeing as slim as an overhand while placing it.
Yeah, and I think this why the slings were noticeably better, more contact area!
This needs so many follow ups! Real rock, monkey fists, all of the good stuff.
Yes please.
I almost exclusively use monkeys fists in sandstone (sometimes also in other rocks). I was hoping to see those here, but maybe another time then ;)
monkey fist with a pebble inside?
Stoked for all the engagement so far! The ground is prepped for drop tower, crane is 100% working and all the parts are painted. We "just" have to assemble it now, lift it up and decorate it. Donations really appreciated while we take the drop tower project over the finish line. 😀 www.slackline.com/donate
just fyi - "How does the comparison of knot loop and cam look like?
The discussion about local usage bans should be disregarded here. Therefore, the range from loosely pushing through to tight is very small. The range of extensions 30mm is better covered; cams are also easier and quicker to lay. With Friends you can then secure completely parallel cracks.
A knot loop is softer and therefore has a larger contact surface. This means that the risk of rock damage is lower with soft rock. Knot loops are a bit more complex to lay, you shouldn't forget that there is a certain range from lying well to pulling through. A knot loop has more friction with the rock. This has the advantage that a knot loop does not loosen as quickly as a cam through rope movement. Knot loops can also be placed in relatively open cracks and holes, in places where a cam would immediately fall out again.
The experiments were carried out by Jörg Brutscher, André Hoose and Jens Freudenberger. We would like to thank the Institute for Materials Science for making the tensile testing machine available for these experiments. Thanks also to Martin Lange for reviewing the article. Further details of the experiments are available from the author."
[1] See diss. Helmut Mägdefrau: The stress on the human body when falling into a rope and its consequences, available from the DAV safety group. Also: More safety in mountain sports, part 10, Bavarian State Ministry for Labor and Social Affairs - www.joergbrutscher.homepage.t-online.de/knoten.htm
Hi guys, I just had an idea, you might be able to create a more rock like surface in your clamp by coating the steel with epoxy and dusting it with sand while still wet. Kinda like non slip epoxy floor coating.
@@justindunlap1235 or grip tape. 🧗🏽♂️
Would love e to see real rock testing on them!
I don't know much about the whole using knots in rock vs in that clamp, but I do know that some rock like limestone and such, don't look anything like that clamp, with all those grooves and whatnot, on account of how smooth it is, and in some cases probably even more cushioning than that metal clamp... If I'm wrong in any of this, please correct me, but just given what little I know about rock, I know that different types of rocks might have different grip properties and characteristics, the same as testing out those forces in a metal clamp will likely behave differently in rock
You could try replacing the steel with concrete paving slab type things tho the slabs themselves might not be able to take the stress of a pull. I would love to see both this in real rock and it done dynamically in the drop tower. I can see the results of a dynamic drop being very different from these results.
That would probably be better but I think even concrete has way less friction than the stone around here in Dresden where people use these
Guess, when its about knotslings, soft Sandstone will be way different from steel or concrete areas.
The more grip, the more friction, the more Power -Transmission.
Or add paving stones the “crack”
@@cutt7837 yes that's who I was thinking. A paving supplier may even just give you various rock types as you only need a few small scrap bits to them. Sandstone and limestone paving common. Granite less so.
Good idea, but like you mentioned concrete don't like pull forces. But small concrete pieces inside of the crack would one dive them pressure force. Which concrete is very good at.
It is the same in saxonia, there is a long-standing tradition of climbing with rope as protection. I am no geologist. But probably a similar sandstone. Works apparently well and all the top anchors are bolted. Locals get really grouchy if you climb with other gear and it does actually damage the sandstone which is considered a heritage site... welcome to European climbing
The problem with German and Czech sandstone, which are one geological unit, is not really that it is to soft. In some places it is actually quite hard because of regional metamorphosis I suppose. But even in regions with hard sandstone metal protection does not work, because when taking a fall on it, the surrounding surface just gets broken out of the rock. Because the real problem of the sandstone over there, no matter how hard or how soft it is, is the overall porosity of the stone. The porosity is so high, that climbing is forbidden, if it rained in the past 24 hours, because the rock is just too wet and therefore more likely to fail/break. From my own experience I can say, that I have never climbed on better rock than the sandstone in the Bielatal in Saxony, Germany and it is definitely a recommendation for everyone, as long as you have a lead climber, who knows his way around.
@@edwinmahlo427 Porosity isn't a measure of the weakness of the rock, it is the property of friability. However, you are correct that porosity increases the failure of rock when it is wet. If you want to make a landslide happen, add water. If you want your rock to fail, add water. Therefore you have multiple problems. You can't use cams because the rock is friable and you can't climb after rains because the porosity decreases the rock strength.
Here in California's North Bay we have cemented rhyolites, some of them are like sedimentary conglomerates, but occur through igneous processes. We can't climb on them after rains for the same reason. But since it hasn't rained here in a few years, the climbing is good, except when the fires sweep through the climbing areas and destroy the bolts. I am an engineering geologist by the way.
@@edwinmahlo427 Actually there was an short investigation considering metal gear (at that time = nuts) on saxony sandstone. It didn't find the the often citated rock failure, at least not different to slings. Back then it was decided to stop testing nuts to preserve the tradition. It was definitely not a fact based decision to ban metal gear but rather a highly emotional one (as it's the case for many of the saxony climbing rules). If you look closer it's an repeating pattern to argue based on "facts" that have never been proven in most of the discussions surrounding climbing in Saxony. The funny thing is even evidence often times can't change the believe in these alternative facts...
@@Davidadventures the problem in saxon or bohemian sandstone (its the same) is that the compuond that holds it together is water solvable, so basicly it falls apart when wet because there is no „glue“ holding it together, assoon as it dries its solid again. This happens less with sandstone that has a major metal component like the dark sandstone found all over bilathal (lots of iron working as „glue“) so you can climb those towers pretty shortly after rain, just 20km away the „rathener gebiet“ is called cookies or „rathener keks“ among locals as its so likely to break, even when dry. Sandstone geology is wild 😂
Why does that guy ask us "IF" we want to see real rock test ? Shouldn't he ask about "WHEN" we want to see it instead ?? We are not gym climber here, we want rock by the roll of course !!
PS : greetings from Chamonix, keep up the great work guys
Problem is that Czech and Saxon soft sandstone is protected. You can't just rip gear by purpose. That's illegal. Also using metal pro is illegal
@@marekholub8668 i don't think HNTHL is Czech, sooo.... ?
@@lolaa2200 It wouldn't make much sense to test in different rock. This kind of sandstone is very different from the kind they used for testing bolts.
@@marekholub8668 knot stuck in cracks have been wildly used for climbing all over the world in all sort of rocks long before metal protections been on market (just read old books from Bonatti or Rebuffa and al.). As of the present, fact is it is lighter, it is much much cheaper, and it has better availability. So having test that show if it can be a viable option is indeed of great interest far beyond the particular case of one small portion of one country. From this video i can see some potential for it. So yes any test in any type of rocks makes us all advance, no matter the country.
@@lolaa2200 Yeah, I know it has been used on all types of rock. I'm just saying the tests in other rock wouldn't be relevant to Jenny's videos. If you can use cams and nuts on your climb, you are safer using them over textile pro. If you can't, they are definitely better than nothing.
I don’t climb,,, why are your videos entertaining to me ? You have a knack
thanks. i realized quite a bit of audience doesn't climb. the myth busters for extreme sports? haha
Definitely want to see this in real rock. I feel like static rope is a win for these types of pro
In a moment of desperation i have placed a prussic into a crack an fell with it at my hip height.
And it held. It was really hard to remove it though...
So I know for a fact that it can work. But i like my solid cams better.
Or even the emergency BD guide stopper like you instructed on one of your videos! LOL
Well, anything metal might also be likely to rip or break out enough stone as to come loose. An expanding dynamically loaded knot might hold a lot better.
Just came back from a beautiful day in Elbe valley, climbing some fun sandstone and what a pleasant surprise I found in the subscriptions.
Great job, nice to see these tested.
Yes to real rock tests. Awesome work, as usual!
Climbing sandstone in Czech republic or in Germany is more a lifestyle or adventure than technical pro climbing.
I'm happy when my sling holds 6kN because dynamic rope doesn't allow to generate more.
Knot will slip away rather than break the cord.
I imagine these would hold up better on real rock, especially when being pulled from an angle.
Super entertaining video though! Probably one of my favs!
Note that the metal plates open up, once the knot is in between the left two bolts. You can easily see this as the right two bolts lose tension. This effectively means that the distance between the plates at the location of the bolts controls the size of the slit. Would recommend to fully lock the two metal plates, during further testing.
Perhaps the slit needs to do kegels. If the slit were stronger it would help.
Hey Rian, maybe your jig isn't that optimal for soft nuts. The side plates change angle when pulled (good to see at 08:00) . Therefore the front of the gap opens for smaller knots. Maybe you could test the small pieces again with a jig with fixed angles? Best regards from germany :)
Had to scroll way too much to find this comment
Yep, exactly what I noticed. The knots actually pushed the side plates open. Should be easily fixable by fixing the rear of the plate so that it doesn't move.
@@stangwara shockingly, in the wild, a group of people who didn't watch the whole video lmao
I'd like to see how much the soft pro makes a difference on friction
Local here... The trick about the figure 8 is that you can tie it super flat (basically you get only twice the rope diameter). You can see this really nice in the video of Jenny. When you put it in a crack or feature and pull (on all 4) strands, the knot becomes a lot thicker... and pinches against the rock, which adapts the surface of the knot very well to the rock. Its a lot about friction! try it ;-)
Same is for figure 9 knot.
- Sand friction is different..
- Any metal stuff is not allowed to be used on sand rock. (Most of sands are kind of National Monument or protected zone)
- You always fall with angel 60-80 degree
- Its possible that second or 3 knot catch you - we call this zipping :) (the first 1-2 can go out and just slow your motion )
- I think this need to be tested with real sand rock but nice video...
- You wanna fall to ring not to knot :P but some knots are better than nothing you know :P Because distance between rings are sometimes length of route itself :D
I always wondered how secure those sketchy looking Czech knot nuts were. Ended up taking a greater load than I would have guessed. Thanks, as always, for doing the tests!
A note on why the knots were popping through your machine like mice slipping through a crack. If you re-watch (for example) 5 min 20 sec in and 13:50 you will clearly see that as the knot hits the forward 2 bolts and starts to slip past the bolts, those bolts act as a fulcrum for the plates to pivot on. There are no nuts on the 2 rear bolts on the inside to prevent the plates from squeezing together therefore allowing the gap in the lip at the front just past the front bolts to spread and allow the knot to slip through the increased gap. Watch the rear of the plates at this point and you will see them creep together slightly. 4 nuts with washers on the inside of the 2 rear bolts should solve this problem.
Disregarding the friction aspect missing in the test, I would suggest that the test jig itself is flawed. This is best seen in the test at around 7:20. In that test, you can see that the wide end of the test jig/fixture is closing which correspondingly causes the narrow end/mouth of the fixture to open wider. This results in creating a condition which doesn't exist in real rock. If you secured the rear bolts by placing stop nuts on them (inside of the plates) so the rear plates are set at a more fixed position, you would most likely eliminate this condition. The "loosey-goosey" rear end of the fixture not only causes the narrow end to widen, it thereby also reduces the plates' angle where the "rubber meets the road". Less angle would also make less resistance to the knot.
Always good to have the knowledge in case of an “epic.” Repelling from knotted sling and chokestones is an alpine nightmare but…
Keep it up.
Rappelling
Got sweaty palms just from reading this, wouldn't want to be in that scenario.
Yes, please try these in rock.
yeah, do it in real rock...and also if you're ever going to use it again, put some texture in the cam-crusher! (maybe epoxy some flat pieces of actual rock into the jaws of your cam-crusher)
Epoxy vs multiple kN...
@@kevinmcdonough9097 uh, yes...? epoxy is good for thousands of PSI which should be super-good-enough if the force is distributed by a flat piece of rock above it -- we epoxy in bolts that hold >40kN.
I dunno if that's even a great solution, just that slippery grooved metal plates are NOT the right medium for this type of test. Maybe the steel can be textured directly, but I'm pretty convinced rock has different enough friction characteristics compared to metal as to be a poor facsimile.
I'd watch it again. Also, an orbital sander with 80'ish grit +/- to the surface of your plates may work as a simple mod.
thanks for testing them. I'd definitely watch more tests of those!
I've been waiting for this video for ages! Thank you!
It would be awesome to see this in real rock. Would be very interesting to see the effect of friction. Thanks for all your work Ryan, you are one of the best channels on youtube.
4:35 is still my favourite pull test ever by hn2 😂
Now that this video is finally here I´m not sure I actually want to see at what forces my slings would break.
He has a video on slings, they're very strong.
I think 95% the sling doesn't break, it just slips or the rock breaks
@@ferdinandheinrich340 yeah in Rathen the rock definitely breaks first. :D
Definitely think it makes sense to test these in real rock; seems like friction plays a huuuge role on how the knots hold up vs. slip through under max kN.
Finally, i was looking for vids about it. In germany we have the same rules (also sandstone rocks) but you really don't find too much Information on how too use them
I do climb in the saxonian swiss. A few points:
Noone i k now uses overhand knots for slings, a fig 8 is nearly allways the better option.
We are usually not too concerned with the breaking strength of the gear >4 mm since dyneema slings. (we start using nylon only slings >7 mm) All that is in question is the friction and integrity of the rock. Laying slings is an artform of feeling how the sling compacts in the rock. And even then noone here likes to test if the knots actually hold.
Greetings from over the border :)
I am big fan of the overhand knot, because I have much better feeling from placing it in the spot. I feel like having an overhand on the sling gives me nicer v shape at the bottom end and better movement of the top end as overhand is smaller than fig 8. Only this vid made me realise that fig 8 might be ever useful.
Thank you for making this video!!!
when I was about 12 my uncle took us up Thumb Butte using knot pro and over the shoulder belay, 50 yrs later I have about 50 lbs of aluminum but this video made me smile
The sandstone mountains are actually a national park split by the German/Czech border. The park service allows climbers but prohibits the use of chalk or any metal-on-rock trad protection. Some of the routes are bolted, mostly only at the anchor or every 30m with a thick metal ring.
I’m totally interested to see in real rock
You channel is awesome and you really help the climbing community sooo much leaps and bounds
I did that in the day. It's depicted in Royal Robbins' Basic Rockcraft, so I tried it with many regular pieces for back up. It worked. In those days you never expected that a helicopter was going to come and rescue you. Nor was some gym employee telling you that this is a "safe" sport so we learned everything we could since knowledge weighs nothing and could, at the least, save you from the embarrassment of having skilled people have to rescue you due to your ineptitude.
The idea behind using a figure 8 is, that it spreads out with friction.
You have to Rock test these knots. Absolutely want to see that, as I used to climb on them
Great work, both yourselve and the local climbers who developed this tradition to look after a fragile resource. I look forward to the friction version.
They were all WAY better than I expected. Still wouldn't whip. But if I had a choice of nothing or this - then I'd be tying knots :-). Would love to see these in real rock!
Fascinating! This definitely needs the something-to-one test. I have no idea if the friction will help or if they'll still squish out of there.
Have never climbed on all soft pro, don’t think I intend to but I would definitely tune in to see you test it in rock.
Very cool! And would definitely be interested in seeing how well they hold in real rock.
Some really interesting results so far
Really stoked to see how strong these are! Friction on rock would defenitly make a difference. I guess shockloading would make them slip less…insert drop tower here! 🤔
Finally!!! Thanks for putting in the effort to test this. Will be back in the sandstone in a couple of weeks. :)
Can’t wait to see this on the fall machine when it’s up and running. Thing with this test (video) is that it’s unrealistic as you’d never get such sustained high forces. A fall test would be more realistic as you’d get the high force temporarily, for a short time, so i got a gut feeling the protection would behave differently under a shock load, compared to it experiencing a sustained and incrementally higher load.
This channel has been getting good! Loving it!!!
I didn't even knew one would think about this kind of gear! I wanna see more!!
Definitely would love to see this on real rock. Love this scientific data you get
excited to see these in real rock. Knot chocks get used all the time in canyoneering circles and I'm always super sketched out by them
I live in the Czech Republic, used to climb on sandstone sometimes. The friction from sandstone is vital to how the knot works, as you pull the rope and the knot tightens, it should try to expand against the rock and 'mold' to the crack's shape, speading the load.
These knots are not for big falls with high kN values, if you are worried you will fall you put a knot every meter or so.
The sandstone is too soft for metal placements. In a fall, they do not mold to the sandstone so all the pressure is on a small area (the grains which are in actual contact with the metal), which will crumble or snap off.
Maybe you could test with some sandstone blocks?
I am curious about seeing these in real rock. Cheers, and keep up the awesome work.
Please test on real rock! I've used these when out of gear!!! :) Thanks guys!!!
i’m going to finally subscribe since i feel like you’ve became a ton more relaxed and explosive. way more chill than your traditional intros. thanks
You should get various stone sample pairs and a good stone drill bit, drill 4 holes like those metal plates you're using and secure them with the bolts. Then you could determine how the type of rock, and their respective coefficient of friction, affects breaking point using a consistent anchor type. Great video! Love to see these tested in a controlled environment.
DEFINITELY test on rock! I am certain the ability for them to deform like putty so much in this test is undoubtedly due in part to the slickness of the metal allowing the exterior fibers to easy change position and placement, as well as the entire not to more more easily into the narrow part of the wedge. Contact on a surface with much higher friction will, I think, improve the strength performance in practice.
I'm pretty new to climbing and currently in the market for my first bit of rope. In the discussion on reddit about treated and untreated rope, there is also a conversation about rope weakening when it is wet. Outside of alpine or glacier scenarios, it is still entirely possible to encounter a situation in which the rope could become completely soaked (even during a retreat for example). I think it would be interesting to see you guys test the strength difference between dry and wet rope!
I am really looking forward to seeing your drop-tower in action! Super curious to see the differences between those dynamic forces and the static / slow ones.
As a person that starter his climbing adventure in saxon switzerland, german sandstone region near to Czechia I have two remarks: 1 the friction makes a lot of difference. People in engineering department of technical uni in Dresden did similar experiments but with knots placed in sandstone crack and limestone crack as benchmark. It turned out that on limestone they dont hold.
2 the shape of your nut catcher is suboptimal for placing a figure 8. The cone formed by the metal sheets has far too small opening angle, its just too slim for solid placing. If the angle was twice that, the front loop of figure 8 would move backwards and you'd get more solid placement.
I dont know if thats clear what im saying, but if Infond some references i'll send them.to you!
Please please do monkey fists.
Both with 3 wraps with 1 strand, and 2 double wraps with 2 strands (Both ends of the rope in the knot)
I've been setting up hammocks and rodeos like that for a long, cant wait to know how they hold up.
Yes, also testing the monkeyfist vs crown knot?? in a soft shackle - is it less crucial to fully tighten / dress or not??
NB a monkey fist can be made pretty-much as bulky as one wants, 2,3.,4 wraps, easy to bulk up....
What's a rodeo? I ask because I can foresee it being hard to google.
@@rokronroff a very loose slackline.
So loose it is easy to swing on it.
So glad you did this! Definitely somewhat surprising results. I'd love to see these tests done on the drop tower, maybe between cinderblocks or something rock-like that you could still adjust the gap on (maybe the same as your rig in this video, but with some sort of rock-like tiles/patio stones?). I bet the friction really matters, and falling forces are probably more like prolonged spikes, compared to steady forces seen in the slacksnap machine. If the knot moves a little at high impact, but the impact dies down before it manages to slip out, these knots might perform better than expected.
Hey, actually I`ve some experience in sandstone but in saxony, not in czech republic. Here in germany in this area, even fever bolts are placed and therefore we rely even more on knots (and UFOs) :D
Well and it`s not so secure like bolts or friends or nuts. Buts actually I think it`s necessary. Sandstone is really soft, so you could damage it with harness or with too many people climbing on it. So there is a debate about how much protection we allow, because the more protection, the more people will climb. This is a difficult consideration. (Fun fact: There are some people severely injured or even dead each year in this area. Most of them made mistakes during abseiling, not with the knots )
But at the end, its an ideological thing. We learn that climbing is something you should have respect for. I will not start a route if i´m not sure that I can do it. I don´t want to fall under all circumstances. My protection is there to save me from death, and its working. With some experience and the right eye for knot placement (and the friction of sand stone of couse :D) it is a lot saver than it looks. And for me it has to do with appreciation and not to overestimate myself.
But how I said: You should not fall (At least I don´t want to fall, there are some people without this kind if concern). So its not classic sport climbing. It is a developed traditional climbing with some real special moves.
Thanks for the video, it was quite interesting. How others said, friction is key regarding this topic. Would be really interesting to see what happens with real sandstone (maybe some stone plates in the testing device?).
For me it would be nice to not rely only on experience or feeling, but on facts :D
Yes, please test these on rock outside!! I live in Germany (by the border with Czech Republic) and here we also have to use these knots and slings. I was thinking about asking you to test these over patron (I'm a supporter these since a couple months), especially the monkey fist, that I use quite often as well!
And yes, it is pretty sketchy climbing with those, I do it since I moved here, but I never try anything too hard when leading here! (by the way, you can't use chalk either, a real bummer :P)
I like the idea of modifying your cam crusher to accept concrete paving slabs or even just some kind of ceramic tile with the rough side facing the cam/nuts. I say that because I think the steel is too slick for the soft nuts to work as intended. That having been said, you did test what happens when you pull these nuts apart if the end is clamped in place. It is kind of amazing to think that most of these, if they held, would not explode during a whipper. Maybe we should all start adding some soft gear to our racks? It weighs nothing, it costs nothing, and you can use it to supplement your more conventional protection. Imagine not having to waste cams at the anchor because you can replace one or two with solid soft nut placements? Pretty rad.
Ad putting the knots in your rack: it really takes awful lot of skill to place them properly, they need super specific spots to hold (quickly tightening crack, deep...), they can be real pain in the ass, typically it takes few minutes to get them in and there are about milion other reasons why they are pain in the ass. Only two positives are nature protection and low price. Still I am really happy when I go for soke hard rock and can shove a bomber cam in less than 10 seconds, rather than spend 10 minutes with shitty sling, which goes in harder than out.
I don't want to discourage you from trying them out, but be careful, mostly they are trash.
I really do want to modify cam crusher so we can get some real rock vibes. It's really hard to do real rock real well. I got some ideas....
@@alcupone6462 I dont know that I suggested using them mid-climb. Rather, I think they would be great at anchors where you typically have a little more leeway on timing and setting things up. Instead of using 3-4 cams, you could use 1-2 cams and then like 1-3 more soft nuts to supplement and make sure you have a piece placed against upward pulls, which I think it an often overlooked component in a lot of anchors demoed online. What is nice about them is that you can augment some of your existing materials to function as nuts (dyneema slings, accessory cord, cordelettes, etc.) and basically get a bunch of gear for free. Sure, it won't help you on splitter cracks, but I live in CO where I haven't really climbed any red sandstone splitters....yet. I dunno, I think there is a place for this stuff. Ill try it out and if I dont die and dislike it, I will come back and comment :)
@@arnoldkotlyarevsky383 I don't think that you suggested using them mid climb, I just wanted to give you the feeling what using slings is like.
It is awful lot of time for placing it and it needs very specific spot. I think you would be better off with using nuts if you want to save some cams instead of using them for anchor.
As you have seen in the video, you need a crack which is at least 2x the diameter of the sling which narrows to approx the diameter of the sling.
This is usually hard to find on hard rock and it is easier and safer to use metal nut for few bucks.
Be safe if you go try it out :)
I finally followed your advice and climbed with my totem cams with the tag still on!
Was nice to have something to read on the belay.
Thanks for the tip
Good. That way they still feel new since they cost so much. Worth the extra weight!
Yes I'm very intrested in seeing this on rock. Especially on sandstone where they are "made" for use. But any rock could do. Thanks for the awesome vids.
OMG thank you for this!
I can't wait for drop tower to test this on real whippers! This pull machine apply force for infinite time where whippers have only limited time (like 1 second?), so maybe knots don't have that much time to deform and will hold? We shall see :-).
However, I would do couple of improvement for the tests so they are a bit more real:
1. Don't cinch down the bottom after placing the knot: Once in the video, you mentioned you had cinched the bottom, please don't do this, you cannot do this with real rock ;-). You can place knots only where you actually can put the sling below the knot through (which can also be difficult because of friction and you have only 1 hand etc.)
2. Friction - sandstone has a lot of friction, that could be important factor.
The figure 8 knot is much flatter before tightening, so it fits to the thiner cracks. Jan, Czech rep.
In 1983 in the kitchen of Wolfgang Güllich and Kurt Albert, Wolfgang held up a piece of rope with a figure 8 to show everyone at the table how knots are used in what was then East Germany (I climbed in the Elbsandsteingebirge twice in 1983, once in 1985, and once in 1994, plus in 1983 in what was then Czechoslovakia, on the soft white sandstone of the Böhmische Paradies, where the rock is much softer than in the Elbsandsteingebirge):
"You make ze knot theen, like so, and zen put in ze crack, and pool ze rope so ze knot gets bigger. Just like a Friend, except it does not hold ze bodyveight." 😆😬☺️
Looking forward to seeing more about this
You guys deffinatley need to try this on rock! , I subscribed just because of this!
If you retest on slack snap add some nuts on the inside of the plates on the back bolts to stop the front opening from getting wider while you pull. If you watch the slow motion, the back plates pull closer opening the front gap allowing the knots to pull out.
Knot Pro: “Protection for your confidence, not your body”
I'd be super stoked to see this repeated on real rock! Dope work man!
Love this! I love the conventional stuff, but these obscure gear tests are such a nice bonus. I have always wondered about these and other odd pieces of gear like the beal escape and I loved the video on that too. Please test these in real rock!
I've been waiting forever on this! As a german I have some friends of the german side of that region. Those freaks also don't use chalk!! Crazy. Now I at least know how safe they are once i go there :D
Great work man, keep the channel going, so excited for the droptower :D
EDIT: Do it in Real rock, especiall in the sandstone region, where this is mostly done, the rock has a lot of friction.
Super interesting, I hope you get to make the next video on these!
Great stuff. Wild and crazy to think they climb on that stuff.
I think the soft shackle heads deforming makes sense, since dyneema doesn't handle friction well.
I feel like some kind of coating or liner to ad some friction on the jaws would make a difference and possibly reducing the angle of the plates would help because you’re not getting as much contact between rope and the jaws as you could and the compressive force between the plates would be distributed over a larger portion of the rope thus giving more pportunity for the knot to catch or get hung up further up the jaws
it would be super cool to get a stone saw and cut a couple blocks out of sandstone boulders in order to make a couple stone wedges.
But yeah, the friction would totally help a ton, think about jamming your hand in a slick crack at the gym compared to actual sandstone, the smooth gym crack hurts more than gritty sandstone because your hand slips easier at the polished gym. My skin gets way more wrecked when I'm jamming at the gym at least.
So the friction on the rock will help the knots stay in place and not slide out. I'd assume as much as 50% strength increase in the placement by getting it to stay in place (with a limit being the webbing or rope strength)
Keep it coming for sure! Love the content.
loved this, and would greatly appreciate a knot vid on real rock
I wish I had found your channel a year ago! Thanks
I want to see a test of the master point of the Wild Country Revo (lots of people use it for lead solo climbing).
Great video by the way!
There are a couple of revo attachment break tests on FB
@@GregSidberry do you remember how many kN?
The jig faces change angle at high forces, it "resets" to less angle on most, my flash is a third set screw that keeps the wingnut side from moving needed with an expectation of better results from a static angle.
For friction put some skateboard deck on the jaws ...
Cheers 🍺
I'm picturing some of the cracks near me where the two sides don't just taper, like the slack snap crack cam crusher, but even looked like it had crimps either side for the 'shoulders' of a knot to sit upon. Add that to friction and you're looking at some pretty bomber, 'I might not actually whip and die' placements.
do more tests! definitely curious seeing how these behave in real rock
I would like to see these on the drop tower rather than a slow pull. I feel like it would make a significant difference
It’s not only on the Czech Republic. In Germany - Special in the Saxon switzerland where free climbing starts in 1864. climbing is there very traditional no chalk, no friends, no wallnuts.
Knot loop in sand stone is much more effective as in your test with metal plates :-)
I too would like to see this on real rock. The kn protection was impressive on some of those. Placement would be REAL important though, so I'm very interested to see how they hold up on real rock.
Yeah! Please do it in real rock. I’m most interested is seeing monkey fists done.
Some with no solid core and some with a solid core (likes a bearing or metal marble)
Greetings from czech republic. First, our sandstone is soft, but not dangerous at all. Second, if you know how to place it, you are safe. I took some whips on those and survived 🤗 And the last thing, chalk is also banned on the czech sandstone 😁
Love you're videos! Always incredibly informative, while still being surprisingly entertaining!
That line though! "Take the helmet, try not to die, and and don't forget to have fun. This is..is..fun"
Not sure how many times I've stared up at a trad route and reminded myself that! 🤣
Ryan please do outdoor tests! Specifically on granite. Keep these vids coming, loving it!