The biggest advantage of the Petzl Connect Adjust is not that it uses a stretchy rope instead of a static piece of Dynema. The advantage is that you can easily adjust its length so that there never is any slack.

The petzl connect adjust will also slip a bit which makes the the force even lower. HN2 did a recent video on that.

Ryan (HowNot2) did tests on 7 year old Dyneema slings which startet at like 26 kN breaking strength and went down to around 11 kN over those 7 years. In the same video, an overhand knot reduced the breaking strength of another (new) Dyneema sling by as much as 2/3. Worst case, you have around 4 kN breaking strength with your knot (instead of perfectly safe 11 kN) - you can definitely reach those forces with just a little slack in your sling and a static fall.

Great video. Important info for climbers to have. We should know the limitations of our gear but also the different situations in which those limitations can change.

I put knots in dynema slings ~9 times just today alone (did some cheeky multi-pitching after work). It's not a thing we worry about in the US. Me and my partner are never taking factor 1s, let alone factor 2s!, on anchors.

Really well explained, I sometimes struggle with videos where there’s lots of diagrams/numbers on screen (perks of the ADHD I think) but this helped me grasp it a little clearer, cheers!

FF1 or 2 onto a lanyard of any sort is so scary! Context is everything. Always stay tight

makes you think, i use a safty harnis at work somtimes and this is stuff they don't tell you!! now we do use rope think it's 13mm normaly but its not dynamic so there's no strech if i did fall coz not all off them have a shock absorber on them some are just adjustible, normaly to as long as posible so you can move. then if you did fall you also have suspention traumer to deal with wich is another kettle off fish!!

I use a 480cm sling with overhand knots for my PAS. I typically use one of the overhands as a shelf. I like how versatile it is. Can be a quad if needed, or a step for an ascender. Can even string it together with a microtrax for a ghetto ascender in a pinch. Plus an overhand in dyneema slips are 8kn, so as long as I'm clipped into a shelf, it should slip, not tear. Still don't clip into anything with a fall risk though.

As always a well thought out and excellent explained video. Keep,doing these please great work

That was a belter Jez! As you said it’s understanding of what’s behind the decision making that is key. I think that people latch onto the number that is associated with the knot making the sling weaker. They don’t necessarily marry that up with the presence of a rope, or not, in that system. I use a Petzl Connect, but would not like to take a FF1 on it, let alone anything bigger. Even at maximum extension of just under a metre, that’s not a lot of rope. I would be interested to know how much it would stretch in a fall situation and therefore how much force/energy it would absorb?

Great video I use slings a lot and true if they are use correctly and your mindful on the incorrect use it’s all about boing your kit and watt could happen if used wrongly!!! Keep up the great work on the vids

As someone with serious back issues who has not been doing roped climbing for very long i chose to go with a kong slyde specifically because i could choose a really stretchy rope for it (and take out any slack). Taking any kind of shock load when I'm already in a lot of pain all the time is something i can do without.

Dynamic lanyard/sling standard limits max force for a ff2 < 10kn. High, but made not to break.

Thanks JB, great vid. Slightly tangential comment (nerd alert!): the force on protection points (e.g. Dave Mac's bust nut) is higher than the climber feels: basically it is the tension from the belayer plus the tension from the climber minus the energy absorbed by the rope and other dissipating bits (knots etc). So trad gear and compromised rock can break even if the fall isn't massive. Soft catches (or quickdraw screamers) can help in scenarios where the leader isn't going to hit something!

The way I understood the how not to video is that the rock enforcer result of 4.4kn was an erroneous result as it wasn’t set up for shock load measurement. Both linescales measured 2.9 ish iirc.

The only thing you did'nt mention and you hopefully know is that if anyone tie a knot on anything (dynema, nylon, or rope) it should be removed/untied immediately after use. This is very important for dynema and nylon because a lot of people get lazy and don't untie it for months or even years and you cannot inspect if it is damaged from inside. Otherwise whatever you said I agree with you.

Good info well presented.

Ok, so, if I am belaying a leader who is heavier than me, and I'm clipped into a dyneema anchor with a petzl adjust, and the leader falls, yanking me into the air... should I then be wary of the petzl adjust? I generally get pulled higher into the air with a lead fall than the length of my landyard and anchor. Meaning they would be subject to force. Just upwards rather than downwards.

I dont think you conclusions are correct. You need the 80 kg rigid steel mass to break the sling. I definitly dont think you will be able to break a sling by falling onto it with your body. You will have other problems, but not breaking the sling.

Sound. 👍

Loved the video. If I remember correctly the DMM literature that comes with their slings tells you not to tie knots in them?

I don't think you mentioned it, but the DMM tests used a steel weight. Humans are fairly squishy, so forces will be a lot lower than the DMM test results

Thanks, JB for the great video However, the real tragedy is the simple fact that you have to make such a video. Climbing is objectively hazardous and the data and testing on every single piece of gear has been completed and analyzed into oblivion. Compounded with the eternity of climbing experience of those working professionally, along with those performing the gear tests. How there can still be so much incessant and mindless chatter around this issue is absolutely baffling!! and for those who still find climbing dangerous and desperately and earnestly try to root out every conceivable hazard and danger, YOU WILL MAKE A BOZO NO NO MISTAKE BEFORE YOUR GEAR FAILS! I could go on forever about how tying knots in Dyneema or nylon will not cause the universe to implode. though, it never keeps folks from mistying their knot, putting the rope through the belay device backward, and not paying attention when belaying. Or simply overwhelmed by problems that have already been solved.

Some of the comments are funny. Your wasting your breath Jez

A common scenario that happens a lot is that the leader forgets to unclip from the master point as they continue the climb. A slip before unclipping could mean a potential FF2 into the Anchor (without having "loads of stretchy rope"). For me, the lesson from this video is that Dyneema is often misused, for example for lanyards and anchorbuilding. It's literally the worst possible material for this use. Try anything else and it works better. Dyneema Slings are for extending protection, slinging trees, quickdraws etc.

If people are worried about slings, due to newtons law, they should be more concerned about slings on draws not anchors. The last piece of pro you fall on, be that a sport draw or cam with a sling extension, is taking 200% of the fall force (mitigations from rope stretch or friction not subtracted). The anchor opposes (newton) the forces generated by gravity and the climber which means that a 6kn fall is putting 12kn through that last piece (in theory).

The biggest issue is the use of a metal mass. It is simple and convenient and we have built the norms for climbing gear on tests with a metal mass. However, metal does not absorb any energy. So this is not the worst case that could happen in reality, it is a lot worse. (!!) Nowadays, lots of research into climbing gear does not use a meal mass but instead uses sandbags (still very rigid) or a tractor tire. To my knowledge, the tire behaves best like a human body and is better suited to establish a worst case scenario. Repeating the same test with tires showed that the slings do not break. A climber's back would, however. So this does not change the recommendation to avoid slack when falling on slings

I may be one of the persons who commented strongly about this subject and my opinion hasn't changed much over the years: reaching the end of multi pitch and getting any skinny dyneema sling for connecting oneself for abseiling is something I consider sketchy. Especially if you knot it to attach your belay device. 1) its the moment you are most tired and have higher chances of 'falling' into the sling in a shitty belay station 2) you are using gear which you have no intimacy with, perhaps it's the least regarded piece of equipment anyone has in their rack. You often don't know what it has been through and now it's employed as your only life line. 3) i feel like arguing "you should not fall and always stay tight" is unrealistic. even the pros will make basic mistakes when tired after a long day Still, regarding all that, I'm not saying I would never do it, its just not part of my routine and I would not recommend it to a friend. I want to add that I really like your videos and the thoughts you share.

terribly english channel, have to play at twice the speed to cut the fluff about the dog and the weather, don't change haha

Shout out to Ryan at @HowNOT2 , love you and him both!