What are the thoughts of using an Amsteel 7/64” UCR (utility constrictor rope) along with some soft shackles for bow and stern tie downs? Kayak(s) will be on Yakima Q-tower roof rack on Honda Civic or Ford Fusion, and will be using hood loops and and trunk quick loops.
Amsteel is probably overkill for the strength, but I have it from Hammock lines and I like the idea of avoiding metal . They can also server additional purposes beyond tie downs, including use as hammock suspension.
For those that are not aware, Amsteel UCRs are frequently used for hammock suspension
https://www.youtube.com/watch?v=Yw6P3pHt8KI
Most of the Amsteel that I have seen is quite thin, yes it is strong. However, for me I want a thicker line, it's easier to handle. My kayaks are on a Honda insight, with Thule bars and whispbar 400 cradles, I started using regular cordage to reduce visual distraction, but went back to the whispbar ratchet system. It was easier to use.
7/64" And just to clarify, would be strapping the kayak to J-cradles on the rack.
I’m not concerned about it being thin because it wouldn’t be handled all that much since there wouldn’t be any knot work. Just close the soft shackles and then pull out the slack.
... you are asking a question about a product that's so obscure that hardly anyone will know what it is or what to say about it. I just googled it, along with soft shackles, and I still don't have a clue. All I found was a few sources that say they sell the stuff. It seems descriptions and pictures are not easy to find.
What advantage is there to this stuff over rope? The word "shackles" does not conjure up the idea of unlimited length adjustment, but of course the word may not be as descriptive as it ought to be. What are you tying it to? It may be really strong, but if you are tying it to the carry handles on your boats, 3/8ths-inch rope is already strong enough to rip the handles off the average boat. You want something stronger?
I found a video about how to make a "utility constrictor rope". The video is half an hour long (!), and the process ends up with a line that's a certain working length and that's it. I'll stick to methods that give any length I need in a matter of a few seconds, rather than one that requires lots of tedious manufacturing time in advance, for each and every "exact length" that you might need. Looks like an incredible amount of work to go to for tying down a boat.
Oh, and I THINK I just figured out something else. You say you want to avoid metal (like the metal parts on store-bought adjustable tie-downs, perhaps?), so I'm guessing that's why you want to used those spliced loops. Um, you know you can just *tie* a rope to something without custom building the ends ahead of time.
Nylon clothes line is my favorite. I tie it with knots. It works really well and it is multipurpose. I've never seen the stuff you are referring to in the OP. But if you have it hanging around might as well use it.
strength is a priority but that’s easy. The thing I really look for is stretch. Nylon stretches a lot especially when wet and can lead to loose tie downs. Cotton does not stretch as much but does not last as long and tends to fray more. Polypro seems to be a good compromise. HTH
Not so obscure elsewhere Amsteel is very frequently used with larger watercraft and sailboats. Strong as steel line of same thickness and it also floats.
Soft shackles are not the adjustable length part they are basically a rope caribiner. The utility constrictor rope is not actually a fixed length but one fixed length that runs through the inside of another fixed length rope. When tension is applied the outside rope grabs the inside rope tightly. So tight it is effectively a single rope. It makes for very easy length adjustment without having to retie any knots. it could be thought of as like the rope ratchets frequently mentioned here. The system is used by many for hanging hammocks.
Don’t need tons of strenth - Nylon clothes line from the hardware store in 100’ hanks - 3/8 inch - works very well. Stretch has never been a big issue for me. Plenty strong. Don’t want over tight anyway - you can bend the boat.
of course… 1400 pounds in 1/8th" amaze your friends and naybors…
I fancy Kevlar light yacht rope in an excessive weave especially if I find 25’ in the dumpster.
I have 4mm steel cable in plastic sheathing for those sensitive areas in Montana, LA and the South Bronx.
But seriously, 3/16th Walmart poly rope is enough…not for Texans but most everyone else.
The Dyna what in the Amsteel is prob a polyester. Conti bicycle tire has a polyester weave…an excellent weave to be sure but despite the exotic name still a variant of polyester and NOT Kevlar.