Sterling Oplux Sewn Eye

[Jrybicki]

As promised, here is the official results, Over the phone I thought they had said it broke at 2979lbs but the paperwork shows 2279lbs... way less than ideal. The splice that failed was my first splice and appears it pulled out from the bury and the whipping method used on that side also mostly pulled out. The 2nd splice is still in tact however you can see where that whipping also started to fail and pull out so that end probably wouldn't have lasted much longer. Either way this splice only retained 41.4% of the ropes breaking strength though knot & rope did mark the test results as acceptable and yes may hold you fine in a static position, I would not trust this hanging 20+ feet as a potential life saving device. I am still curious about a double length bury as well as trying the class II splice with a tapered bury on the 2nd inner core with hopes of seeing closer to 80% of the ropes strength retained. For this season however, I will be sticking with the double fisherman's knot on my triangle link for the rappel line.

 

[sojourner]

I don’t have a dog in this fight (when using oplux, I use either a figure 8 or scaffold knot/double fishermans)

That said, I read something when I was researching my favorite 8mm friction cordage, armor prus

8mm Armor Prus spliced friction cord test results

treetools.co.nz

“All knots reduce the strength of the rope in which they are tied, generally by 20% to 40% of the unknotted strength. . . . A rough estimate of a knot’s strength can be made by examining the severity of its bends. . . . Bending a rope around a carabiner is likely to cause a greater strength loss than any common knot.”
– Neil Montgomery, Single Rope Techniques, 1

Or more reading on knots.

All About Knots: Knot Strength: Structures that Make a Natural-Fiber Knot Strong or Weak

allaboutknots.blogspot.com

It seems to me that the curvature of bending a rope around a carabiner will weaken it regardless of knot type, splice type or stitching. I guess the real question is where is the weakest link.

 

[skyjacker]

As promised, here is the official results, Over the phone I thought they had said it broke at 2979lbs but the paperwork shows 2279lbs... way less than ideal. The splice that failed was my first splice and appears it pulled out from the bury and the whipping method used on that side also mostly pulled out. The 2nd splice is still in tact however you can see where that whipping also started to fail and pull out so that end probably wouldn't have lasted much longer. Either way this splice only retained 41.4% of the ropes breaking strength though knot & rope did mark the test results as acceptable and yes may hold you fine in a static position, I would not trust this hanging 20+ feet as a potential life saving device. I am still curious about a double length bury as well as trying the class II splice with a tapered bury on the 2nd inner core with hopes of seeing closer to 80% of the ropes strength retained. For this season however, I will be sticking with the double fisherman's knot on my triangle link for the rappel line.
View attachment 32080View attachment 32081

To retain close to 80% just get it sewn. That's what Sterling (the manufacturer) recommends? WE already offers a sewn option for tethers and LB or you can order a sewn eye on any length of Oplux directly from Sterling.

 

[Jrybicki]

I don’t have a dog in this fight (when using oplux, I use either a figure 8 or scaffold knot/double fishermans)

That said, I read something when I was researching my favorite 8mm friction cordage, armor prus

8mm Armor Prus spliced friction cord test results

treetools.co.nz

“All knots reduce the strength of the rope in which they are tied, generally by 20% to 40% of the unknotted strength. . . . A rough estimate of a knot’s strength can be made by examining the severity of its bends. . . . Bending a rope around a carabiner is likely to cause a greater strength loss than any common knot.”
– Neil Montgomery, Single Rope Techniques, 1

Or more reading on knots.

All About Knots: Knot Strength: Structures that Make a Natural-Fiber Knot Strong or Weak

allaboutknots.blogspot.com

It seems to me that the curvature of bending a rope around a carabiner will weaken it regardless of knot type, splice type or stitching. I guess the real question is where is the weakest link.

Well that question is very easy to answer... the weakest link will always be the knot... or the splice as both cause a reduction in the ropes rated breaking strength. The question is really what method causes the least amount of total breaking strength loss. Typically a splice will retain more of the original than a knot... however, that is assuming the rope has an approved splicing method and the splice was done correctly. Oplux though is considered from the manufacturer to be unsplicable. Those of us that don't care much for the added bulk of a knot or the amount of rope lost by tying your preffered knot of choice would like the option of having a spliced eye. This thread was a stepping stone exercise to see if it was possible... the answer is yes this rope can be spliced, however the current results show that this splice as outlined in previous posts does not sufficiently enough retain the ropes strength to be utilized as a safety device.
As of now, you are better off tying the appropriate knots with this rope than to attempt splicing. Though I will continue the search for a splice that retains grater than 80% of the ropes strength. The splicing technique currently is not something I personally would trust in the application we are using it for but, each person will gauge there own risks. This undertaking was to have that conversation and to provide additional options and information for those that were curious. Which is the only way we can grow as a community, through trial, error, and hard conversations.

 

[sojourner]

Well that question is very easy to answer... the weakest link will always be the knot... or the splice as both cause a reduction in the ropes rated breaking strength. The question is really what method causes the least amount of total breaking strength loss. Typically a splice will retain more of the original than a knot... however, that is assuming the rope has an approved splicing method and the splice was done correctly. Oplux though is considered from the manufacturer to be unsplicable. Those of us that don't care much for the added bulk of a knot or the amount of rope lost by tying your preffered knot of choice would like the option of having a spliced eye. This thread was a stepping stone exercise to see if it was possible... the answer is yes this rope can be spliced, however the current results show that this splice as outlined in previous posts does not sufficiently enough retain the ropes strength to be utilized as a safety device.
As of now, you are better off tying the appropriate knots with this rope than to attempt splicing. Though I will continue the search for a splice that retains grater than 80% of the ropes strength. The splicing technique currently is not something I personally would trust in the application we are using it for but, each person will gauge there own risks. This undertaking was to have that conversation and to provide additional options and information for those that were curious. Which is the only way we can grow as a community, through trial, error, and hard conversations.

I hope I didn’t come off argumentative. That was not my intent. It is all good information. I just wanted to share what I read. I meant it as another thing to think about (the diameter of carabiner the rope would be attached to).

I did talk to someone at wesspur about sewn vs spliced and was told spliced was slightly stronger. For me, when I bought some predator and armor prus, I got the sewn. I don’t think they had them available as spliced.

 

[Jrybicki]

I hope I didn’t come off argumentative. That was not my intent. It is all good information. I just wanted to share what I read. I meant it as another thing to think about (the diameter of carabiner the rope would be attached to).

I did talk to someone at wesspur about sewn vs spliced and was told spliced was slightly stronger. For me, when I bought some predator and armor prus, I got the sewn. I don’t think they had them available as spliced.

Not at all man, just adding to the conversation as to why we were attempting the splice. Also of note, we are aware that the manufacturer and others provide a sewn eye option which has tested well. The issue with a sewn eye is they can sometimes be very stiff and can cause issues in retrieving your rope (think rappel line recovery) adding an additional hang up area. There's no one way to skin the cat on this one nor is one way more correct than another. Just helping along the conversation of what is possible with this rope and allow others to make an educated decision on whats best for them.

 

[jakhammer]

I'm not sure if they sell it. My buddy and I contacted them and mailed our ropes to them last September. We had them back within a couple of weeks or less. I don't recall the exact turnaround time but it was quick and we were happy with their service.

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how much did they charge to splice an eye in oplux?

 

[Arkrider]

how much did they charge to splice an eye in oplux?

I got it done a couple of years ago, so I can't remember exactly but I think it was within a few bucks of a sewn eye. Nothing significant enough to worry about.

Sent from my SM-N975U1 using Tapatalk

 

[Sechelik]

I did my own sewn eyes on OPLUX and it hold my big arse just fine...even a short drop from a stick kickout.

Hello,
I'm thinking of sewing an eye to my new sterling oplux 8 mm, OD and i was thinking of doubling up a 50# spiderwire(dyneema, I think).What's the recommended number of stitches? Is there a formula that you followed to set yours up?
Thanks