We tested 3 types of soft shackles made with 3 different qualities of Dyneema.
Dyneema is Ultra-High-Molecular-Weight-Poly-Ethylene or strong plastic for short, and it's 15x stronger than steel BASED ON WEIGHT but can float on water. It's slippery, very static and has a low melting point. Tying knots in it can reduce its strength over 70% if the knot even holds as they more often just slip. However, you can tie knots in it to create a head for a noose to go over to make a soft connecter that can be stronger than some metal connectors.
Dyneema is a thread that comes from DSM in the Netherlands and Samson, and Marlow are some of the companies that make 12 braid ropes out of it. It comes in all sorts of qualities. It's labeled "SK" for the names of the two people who invented the modern version, Paul Smith and Rob Kirschbaum. Back in the 60s, SK60 was what was available, but DSM improved it, and in 1996, SK75 came out and started to become more mainstream. In 2003, SK78 was developed. It wasn't stronger but had 3x less creep and was more durable. Then in 2013, they figured out yet another way to make it, so it had all the SK78 properties but was "20% stronger". But according to the Average Breaking Strength on SK78 and SK99, it's only like 14%. THEN they figured out how to make it even better and with biomass, so it's more eco-friendly, has all the minimal creep and durability but is about 2x as strong.
You can see the bio fuel promo from DSM in this VIDEO.
Read about the story of Dyneema at The Dyneema Project
This was a very interesting ARTICLE about Dyneema
This is who ACTUALLY discovered it University of Groningen
We tested these 3 qualities. Generic, low quality name brand and the best stuff on the market.
Samson Amsteel Blue Sk75
Amazon "Synthetic winch line"
Marlow's D12 MAX 99
Now there are 3 types of soft shackles we compared in this video as you can make them in several different ways. The Button Knot requires some talent and patience to tie, but it has the lowest profile and is the sexiest looking. The Overhand knot is simple to tie after you splice two eyes in the Dyneema, but it is a massive head. Ted Simpson did something very similar, and girth hitched it onto itself after he spliced it in a continuous loop. There is also an aluminum circle with two holes, that you can use and have no knot in it, which is popular among sailors.
Here are two of our many Dyneema videos showing you how to tie soft shackles
Our Results
Behind The Scenes
It's interesting how some of my audience doesn't slack or climb or cave. Either, they just find it interesting or are into hobbies/sports that I wasn't fully aware of before starting this channel. Canyoning is one of them, but so is overlanding. Apparently, people with big jeeps who drive off the road use Dyneema to winch themselves out of the pickles they intentionally got themselves in! I think it's amazing to cross-pollinate sports that would not likely cross otherwise. Ted Simpson hit me up as a fellow Dyneema nerd and asked me about some nerdy details, and it led to us working together to bring you this episode. It's a lot of work to make 18 soft shackles and 3 eye-to-eye spliced samples which I appreciated him making.
In my selective memory, I broke these in a somewhat timely manner but sat on the footage 6 months. This was because I 1) got behind doing too much at once and 2) the data was all over and so making a clear video felt overwhelming. I also find it helpful to let the information marinate in my brain and, as an opportunivore, I can usually add more value to a video if I hear about some new information that helps fix the gaps. It's also very awkward for me when Amazon and eBay gear outperforms in my tests, but I know the quality is still shit which is hard to portray if people just look at the numbers. Luckily the soft shackles showed their lack of durability when put in actual use.
After Posting Thoughts
I talked to an engineer at Cortland Ropes and he told me if the weave is longer it produces a stronger result but is less resilient to use and abuse. So that makes so much sense why the cheaper stuff breaks higher eye to eye but when tied in a soft shackle just cannot perform. He compared it to the top speed of a car being the main reason for a purchase decision even if you just plan on driving 65mph with it anyways. If the engine fails after 25,000 miles, you aren't getting a good engine.
If you have other great thoughts, I can add them here. Hit me up at ryan@slackline.com
Next Video: Are tapering splices that important in Dyneema / HMPE?
