Knot suggestion

[pinballwizard]

My thought is that I'd never really have to retie "in the field" since most adjustments could be done by choosing a new Python loop. But we all know that never comes to pass more often than one would expect.

Oh yeah, I forgot you had python straps. I still like a system that is more adjustable, but since you have the straps, that should work fine. I would probably tie off somewhere on a lower strap loop though, leaving me a loop or two to go down, but lots to tighten up. I typically find that if I hang what "appears to be" the right angle, sag, and distance from the ground before putting weight in my hammock, and then I need to readjust after sitting, it's typically to tighten up the line. That's just my two cents and it's probably worth about half that.

[Laochri]

Will you tie the knot once and never readjust it? Then I'd also go for the figure eight. As said before it locks up and can be hard to untie, especially in thinner diameter ropes. After a fall, I even find it hard to untie it from my climbing rope which is about 10mm in diameter.
If you want a knot that's easier to untie go for a clove hitch. Once you take the biner out it actually unties itself.
In between the would be the bowline on a bight. It's the most difficult to tie out of these three, but is easy to untie and stays on your rope when you detach the biner.

I highly disagree, the figure WILL NOT LOCK UP. It will get tight as all get out, but with some effort, it will come undone.

I used to be a climber as well, and let me tell ya, if you use a figure 8 on the HH spectra cord, and then suspend from it, enjoy spending the rest of your day untying that thing. On climbing rope, a figure 8 works well, but spectra is too thin and that knot will lock up pretty darn tight. I know because I have done it once, and that was enough to never tie that knot again with the included spectra. The above knots will work well. Hennessy also recommends a knot followed by a slippery hitch that works well enough. https://www.youtube.com/watch?v=VXk26e4kt4U However, the best move, IMOH, is to get 4 aluminum rings, two on each side, and rig it that way. Finish it off with two slippery hitches at the end. The reason I like this is because the line becomes more adjustable this way. https://www.youtube.com/watch?v=wVnR29ETQEs It's more like whoopies, where as the system can be dialed in after putting some weight in the hammock or whatever. Having to tie and retie knots can become a bit of a pain, IMO.
HYOH, and YMMV. Good luck and happy hanging!

You're right. I didn't take into account the diameter. Yes small ropes and cords will lock and virtually be impossible to get undone.

[jolunder]

I highly disagree, the figure WILL NOT LOCK UP. It will get tight as all get out, but with some effort, it will come undone.

That's sort of what I meant. If course you will be able to work it loose, but that would be quite a piece of work, especially on thin diameter rope. I thought I made that clear in the sentence after the one you quoted. Seems this is one of the occasions where my poor non-native-speaking English interfered.

You're right. I didn't take into account the diameter. Yes small ropes and cords will lock and virtually be impossible to get undone.

Yeah, that's what I meant. They come apart, but you've got to earn it :-)

[ColoGator]

In my experience, an Alpine Butterfly that has been under load is not especially hard to untie. You just sort of fold the "wings" back. Maybe I'll try a figure 8 on one side and the alpine butterfly on the other and see how it goes.

[nothermark]

Aside from the lockup problems with thin line the bending radius of the line over itself is a major weakening factor. That is why all the knots have a problem that is easily overcome by the clove hitch around the biner body. It is also why I like the old ovals made out of round stock. The thinner the line the better the biner is. ;-)

[MGLion]

I would recommend the bowline, since it will not slip and be easy to untie if desired.

It could be left in permanently if adjustments are done with that carabiner and the python loops.

[ColoGator]

Aside from the lockup problems with thin line the bending radius of the line over itself is a major weakening factor. That is why all the knots have a problem that is easily overcome by the clove hitch around the biner body. It is also why I like the old ovals made out of round stock. The thinner the line the better the biner is. ;-)

Yeah, maybe I'm over-thinking this. I'm sure a clove hitch would be fine.

[gmcttr]

I have seen the anchor hitch backed up with a half hitch on arborist websites used as well to attach to a biner.

[ColoGator]

update... I decided to tie alpine butterflies every 10" or so along the line. This provides a great deal of instant adjustability.

[ColoGator]

Ok, I tried out my "multiple - butterfly" solution today.

Worked GREAT!