Combining different size Amsteel for UCR

[LearnedHat]

Was watching (rewatching) a Shug video on suspensions. He was showing/explaining the UCR and the one he was showing used 7/64ths going through 1/8 Amsteel. Or maybe it was reverse - can't remember. When this is done does it change the necessary bury length?

[Yarome]

....used 7/64ths going through 1/8 Amsteel. Or maybe it was reverse - can't remember.

IIRC, he once showed a UCR that was 7/64" passing through 1/8" with a 10"-12" bury, but wasn't one that he had put together.
I'm in no way an authority on the subject, but understand the "theories" to be:

1. 1/8" bury on 7/64": A 12 strand (1/8") will have more "grip" on 8 strand 7/64".

2. 7/64" bury on 1/8": Smaller diameter 7/64" will have a better grip on the larger 1/8".

3. Either 7/64" on 7/64" or 1/8" on 1/8": Best balance between performance, grip when the braids are matched/interlocked (maximum friction points), least amount of wear and highest load capacity without slippage. Bury length factors here being only diameter. Ie., Thicker lines requiring longer bury's than thinner.

In comes the argument of mix matched braiding having more "hold" power vs. matched braiding having more grip and the potential wear issues and dynamic stresses between the two.

IMHO, I say "theories" because I don't believe anyone really knows, yet, the long term viability and wear factors. As far as I know, no one has done any tensile pull tests to compare them.

In my own mind... down to "basics" I tend to believe:

1. A larger diameter over a smaller will inherently have less gripping power and require a longer bury.

2. A smaller over larger diameter has greater grip (shorter bury) but will create greater dynamic stress on the smaller diameter so the failure potential is much greater.

3. The same diameter on itself is the best compromise, and in the long term, most cost effective. More than adequate hold in a moderate length bury and least amount of dynamic stress.

You decide.

[MikekiM]

I've played with different sizes of similar cordage and mixing both size and cordage type.

Using a larger core of the same cordage in a smaller bury creates a better bite, can typically reduce the size of the bury but also can potentially make adjustments more difficult.

I've done smaller core in larger constrictor as well.. most frequently using 1.2 ZPacks ZLine with a zingit constrictor. I put a whipping at the end of the bury on all of my ucrs and this cordage combination works great for both ground lines and tarp ridge lines.

I don't mix cordage when I am hanging from it, though no reason you couldn't use a larger core. These days I don't use ucrs much, if at all, though I do carry a Dynglide UCR in my stake/suspension kit.

[Bubba]

Are you interested in trying it? I don't see a huge advantage in mixing it up but it's always fun to experiment with things. Personally I'd just match the sizes.

[LearnedHat]

Are you interested in trying it? I don't see a huge advantage in mixing it up but it's always fun to experiment with things. Personally I'd just match the sizes.

Really more intellectually curious about the physics/theory than anything else.

Thanks guys

[Phantom Grappler]

Long time ago, I used 1/8 as sheath
I spliced some real grainy rope that was considerably fatter than 1/8. That grainy rope was not amsteel
It was hard to splice, barely got fat rope through skinny 1/8 rope
It had unbelievable firm grip
And adjusting was difficult
I might have also spliced 1/8 amsteel,as inside bury, into 7/64 amsteel. It gripped real good too, but not as good as my first try with real fat grainy rope
Still better than same size both ropes
Is there more stress on UCR when using a fat rope inside a skinny rope—yes
And more so when a fat grainy rope is inside amsteel bury
More stress increases chance of breakage or getting locked or stuck—I don’t think anything is going to wear out or break—if good quality ropes are used—amsteel on amsteel or amsteel on fat grainy rope of good quality and strength

Phantom—No reason to reinvent the wheel
And if it ain’t broke, don’t fix it

I like having fun and helping—a poster said his UCR was slipping
To reduce chances of slipping
Splice a bit longer bury
Milk bury—set it hand tight before getting in hammock
Use a prusik or klemheist at end of bury and hand tighten when milking bury
After setting bury there will be loose amsteel hanging out of bury—tie a slipknot as close as an inch from bury exit, hand tighten slipknot—if UCR slips, it will stop slipping when slipknot bumps into bury exit—in one inch of travel, preventing rude introduction to terra firma.
Splice 1/8 inside of 7/64 amsteel

Good luck! Hike your own hike as your Mileage May Vary. Do some backyard testing to see what works for you

[MikekiM]

What Phantom says... ^^^^^

all good stuff

[BradA72]

Excellent information, thanks!