The difference is INSANE

hey my name is John with alpine Savvy something I've been curious about for a long time is the difference between diameters of accessory cord and increased strength if you look at the manufacturer's rating there's a big increase in strength going from six to seven millimeter cord it's only one millimeter difference but the strength rating jumps about six or seven kilonewtons today with Orion at how not to we're here to check that out and find out why that's true so the strength difference we're curious about is between the six and seven millimeter accessory cord but we also got five and eight millimeter accessory cord so we can compare how diameter changes the strength of this stuff so what we have between five six seven and eight is a 5.5 7.5 13 and then Seventeen and you can see it's a 36 percent jump in strength and then a 73 jump in strength and then a normal normal 31 jump in strength so when you're increasing just by one millimeter your accessory cord you're actually increasing the area you can fit in the nylon string imagine a pipe here you can fit in x amount of strands of nylon and here you can fit a lot more strands of nylon with just a one millimeter jump so even though it looks linear here it's actually changing a lot here now if you had a one millimeter accessory cord and you jump to two millimeter that's a big jump if you had a 20 millimeter rope and you went to 21 millimeter rope it's not quite as big of a jump so this is square millimeters for five millimeter accessory cord and to go from five to six is a 44 jump and the amount of space that you have to put the nylon cords and then it's 36 and then a 30 Jump in this amount of space you have so technically the biggest jump we should see is hear and strength not here and that's quite a big difference now the question is can they weave it difference once you get to a certain size can you add more core versus cheese because you have to have a certain amount of sheath to protect the core I don't know those answers but I have a brake test machine and we're gonna test this basically so we looked up Sterling's numbers and we see that you have a 69 jump in strength than a 41 jump in strength and then a 25 jump in strength and that kind of makes sense with the surface area gradually getting smaller jumps however it doesn't line up with a 69 with only 44 percent more fill area that you can put in the nylon and then 41 doesn't line up with 36 and 25 doesn't line up with 30. so I don't know any more than that and I had Google calculate that for me so if that's wrong tell me why let's show you how we're going to break test this stuff so normally we test most things here with a figure eight on one side and a figure eight on the other and that adds a lot of variation to the the test because knots have a lot of different results that you can get welcome to the first time on how not to we are going to intentionally use diverters we're going to wrap this row four times around this pipe and that should retain full strength in here and we will hopefully actually get for the first time on how not to the actual MBS of the rated rope because normally a rope's rated for let's say eight kilonewtons and you tie a knot in it all of a sudden you're not getting eight which is good to know if you're going to tie knots in it but because we're nerding out over some spec we saw online we're going to go scientific here hit that if you think that's cool we want 5.5 give me 5.5 look how much it stretches four come on 5.5 [Laughter] wow 6.5 I've never said on this channel before wow that rope wrote stronger than I thought that is impressively strong still a little higher than MBS so it's clove hitched here in the back and um the idea is it's gonna break somewhere behind this Bollard so when I put Slackline webbing in this web block it has a similar thing going on where it's a diverter it's just not full size or full strength it always breaks in the back of the web log and that's what the Rope is doing here on our next sample we're going to put a Sharpie Mark to see how much it's stretched and to see where it broke relative to where I put the Sharpie Mark um but this stuff is not just stretching the cord here it's stretching all the material around which is why these things spread out so far before it finally broke now there's not a lot of friction on this Bollard but it's enough to not have this clove hitch be the reason it breaks it breaks around this thing giving us obviously full strength let's do it again foreign mic here on the drum and another Mark right there so it broke in the back right here that's it's all stretched out but it was basically right here is when it broke so it broke on the first strand around the drum This is highly impressive and loud and still a little bit scary but I'm getting used to it so so MBs is a sigma 3 calculation that you're going to get 99.7 percent chance it'll never be below this number in the best case scenario which is not very helpful because you tie knots in it but when we are testing with a baller that it's pretty cool that it is higher [Music] now for the true test to see if this is 73 stronger wow they're right I've never seen that before imagine that I do need to figure out a way to prevent that from falling I'll probably just put a hanger in here and connect it to the side because this is stationary but what's neat is this is an ASAP used by the Rope access community and see it goes this way until you pull it and then it catches and so that way this can extend with my rope ever so slowly without affecting our number and it's been working pretty good because this is free-floating and a lot of times this is actually permanently attached to the actual piston so um yeah this whole u-shaped brake test machine is working great we did a whole video on musty hooks you should check that out [Music] so ghetto whoa 99.7 chance it's going to break below what below 13. I mean it's freaking good enough foreign [Laughter] yeah that's a full one and a half KN over then BS still over 17. what do you think about the inside of a rope I'm wondering what the little red lines for that I believe is a tracer to know that it's their rope or the size or the length it's uh information I think okay I could be wrong and that'd be bad information the best way to find out correct information on the Internet is to post something wrong and wait for smart people to correct you [Music] so we did get a bigger jump between six and seven millimeters which is consistent with the manufacturer's fix that we saw but it wasn't as much because they said it was about a 73 jump and we got about a 55 jump that means we're just nerds but it is a much bigger jump than the um 34 and 37 jump between the other ones interesting how the diameter really changes the strength of things and if you tie knots in any of these or use them in any other way then big bollards then you're not going to get these numbers so please don't go repelling on a five millimeter accessory cord because you saw that it held you know 1500 pounds of force or around six ish kilo newtons that's not how that works so make sure you understand ropes before you push their limits this was very nerdy Niche thing we're testing we are going to be testing six millimeter super cords with Brent Roth who we did the canyon course with we're gonna do a whole abrasion test drop test slow pull fast pull and through different friction devices because there are six millimeter ropes out there that you can actually repel on and it seems really thin to do that when I touch the six mil have you ever repelled on a six mil um only in training with like a pencil rad line it's pretty scary depending on the device you use yeah because if you don't have or feel like you have enough friction it can feel like you're just death gripping the thing but you don't always just use a normal ATC with a rope like that nope so you're saying you have to know more than just watching a apparently so those trained and skilled instructors are a really good place to learn that kind of stuff now you have a lot of tips on your website and you have an Instagram where you post all of that on there you said you also did classes I'm leading organizing a series of classes through the mazomas in Portland Oregon and anyone in the Portland area is welcome to go check those out at mazamas.org

Channel: HowNOT2

Views: 71,746

Keywords: Highline, highlining, highlines, slackline, slacklining, slacklines, ryan jenks, how not to highline, hownottohighline, highliner, slackliner, tutorial, how to, rope, webbing, rigging, rig, extreme, SlackSnap, break test, bolt buster, boltbuster, break tests, stunts, world record, slo mo, climbing, science, mythbusters, carabiner, daredevil, rope swing, rope jump, big wall, gear, climb, rappel, spacenet, cams, anchors, hownot2, how not to, linescale3, extremegear, caving, canyon, sport climbing, gear testing

Id: JkjB6LRT2dw

Length: 10min 14sec (614 seconds)

Published: Wed May 24 2023