Best rope bridge
- Thread starter Hosocat
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Stumpsprouts
Been here much more than a while
- Location
- Asheville
Really? I had a learning moment with a cordage nerd who would disagree strongly. That was long ago enough I don’t remember the details, but my takeaway was that a rope bridge requires different kinds of wear and forces and requires a different construction. Point being, if it is not manufactured for the purposes of use in a rope bridge, do not use.
I see the cougar would be eye to eye style rope bridge? Had long life with petzl rope bridges. I have the courant bridges now and they are slightly beefier and so far similar wear as the petzl.
the original bridge on my saddle is some super stiff rope, im assuming a stiff kernmantle
I use samson vortex for a second bridge, so far it works good, has settled about 3 inches and is no longer the same length as my other bridge, but so far I like it
Crimsonking
Been here a while
Many bridges today are common ropes in our industry. Km3 max is very common on saddles, sometimes in a non-standard color scheme. Samson Ivy is on the Sherrill edge, velocity on the ergovation, BRW on the monkey beaver.
Perhaps he was referring to not using an aramid cored rope, these self abrade and have broke in the past when used as a bridge.
In the past it was recommended to not use a double braid for natural crotch rigging, they would break where the rope was pinched in the crotch, this might also be a concern with the small bend radius of the typical rings used.
moss
Been here much more than a while
- Location
- Carlisle, Massachusetts, U.S.
This will be a never ending arms race between the harness manufacturers who have to test/certify (in the EU) all the harness life support components and the do-it-yourselfers. The Tree Motion Globe 3000 10mm bridge cordage era was a beautiful thing, we could simply get it by the foot and replace bridges as needed. There must have been a meeting with liability lawyers at Teufleberger HQ, suddenly it was declared that Globe 3000 was not the same as the TM stock bridge cordage. Cordage fanatics dissected both "versions" and could not discern the difference. Shortly after Globe 3000 10mm disappeared from the marketplace. It took a while for all of it to disappear from the nooks and crannies of the rope world but it eventually did.
As mentioned by @Crimsonking there are a fair number of widely available lines used as stock harness bridges today. The manufacturers who need to meet EU regs are building harnesses using custom orders with colors patterns changed from the "originals". The arms race between do-it-yourselfers and manufacturers continues as insider knowledge leaks out and climbers realize they can just pick up some KMIII Max (for example) and make a bridge out of it.
The crux of the Globe 3000 problem (I think) is that the braided Dyneema SK78 fiber core is very slippery and it was too much risk for Teufleberger to trust that climbers utilizing Globe 3000 by the foot would terminate the bridge cordage safely. Platinum is the logical solution, with the cover linked to the core the slippage problem goes away. What's lost with Platinum is that the rope construction can't achieve 10mm diameter because the core is Polyamide (Nylon). Even at 10.5mm cover/core diameter Platinum has a minimum breaking strength of 6300 pounds compared to Globe 3000 10mm at 9500-10,000 lbs (can't remember the exact value). Whether or not climbers need more than a 6300 lb strength bridge is another discussion. Good news is that most of the harnesses out there don't require a 10mm diameter cordage like the OG Tree Motion does.
And so it goes, folks on one side of the discussion will say "Don't be a dummy, just use the manufacturer recommended stock bridge", those who like to grow their own will say, "This isn't rocket science, if we know the spec/requirements of a safe cordage bridge we should be locate it and buy it by the foot".
-AJ
As mentioned by @Crimsonking there are a fair number of widely available lines used as stock harness bridges today. The manufacturers who need to meet EU regs are building harnesses using custom orders with colors patterns changed from the "originals". The arms race between do-it-yourselfers and manufacturers continues as insider knowledge leaks out and climbers realize they can just pick up some KMIII Max (for example) and make a bridge out of it.
The crux of the Globe 3000 problem (I think) is that the braided Dyneema SK78 fiber core is very slippery and it was too much risk for Teufleberger to trust that climbers utilizing Globe 3000 by the foot would terminate the bridge cordage safely. Platinum is the logical solution, with the cover linked to the core the slippage problem goes away. What's lost with Platinum is that the rope construction can't achieve 10mm diameter because the core is Polyamide (Nylon). Even at 10.5mm cover/core diameter Platinum has a minimum breaking strength of 6300 pounds compared to Globe 3000 10mm at 9500-10,000 lbs (can't remember the exact value). Whether or not climbers need more than a 6300 lb strength bridge is another discussion. Good news is that most of the harnesses out there don't require a 10mm diameter cordage like the OG Tree Motion does.
And so it goes, folks on one side of the discussion will say "Don't be a dummy, just use the manufacturer recommended stock bridge", those who like to grow their own will say, "This isn't rocket science, if we know the spec/requirements of a safe cordage bridge we should be locate it and buy it by the foot".
-AJ
Last edited:
moss
Been here much more than a while
- Location
- Carlisle, Massachusetts, U.S.
S[peaking of insider knowledge (or not), what's the spec on the TM Evo bridge cordage?
-AJ
-AJ
Crimsonking
Been here a while
I can’t speak to the tm bridges.
To clarify between km 3 and km 3 max. Max is often used, but not standard km 3. It was used briefly as a replacement on the notch sentinel, but was capable of herniating at the bend at the rigging paws. I experienced it personally.
If anyone is using km3, please inspect it regularly as we should be doing anyway. Mine herniated after 4 climbs.
moss
Been here much more than a while
- Location
- Carlisle, Massachusetts, U.S.
Serf Life
Been here much more than a while
- Location
- Maine Island
Pic?
Stumpsprouts
Been here much more than a while
- Location
- Asheville
The thin brittle eggshell of my mind has been blown!
When I first joined this forum, I asked what I thought was an easy question about using KMIII for a rope bridge, also for a Liger mod. It turned into something similar to this. There are tons of good choices that are cheap and a few bad choices. After having my mind blown, I found some 1/2 sailing line with a 12K breaking strength but if I had to do it again I'd just use Samson Arbormaster. Tons of accomplished working climbers and people like Richard Mumford who test everything ten times over use Samson 16-strand so it's definitely good enough and it's cheap too.
I’ve been using Fly for a bridge for a couple years. It’s fine and I had a short piece of it. I’m not sure I could ever notice any performance difference in different bridges, so long as they’re similar. I’d probably notice a little change if I tried 3 strand or something really different.
On second thought, we have to make a UAB run tuesday for an overnight and back on wednesday. I could drop it off on the way back. Let me know.
Shadowscape
Been here a while
- Location
- far north
For what it is worth...
About a year ago I nicked my bridge with the saw. I run an adjustable bridge with a Petzl MicroGrab. I dug about in my kit and found a short piece of (NEW-UNUSED) 1/2" Double Esterlon. I was a bit concerned that with the MicroGrab the short piece of double braid would milk too much and create a problem. But it was what I had, and I intended to replace it with a 16 strand when the job was finished. I milked as much of the cover as I could before tying the last stopped knot. Well, I'm still operating with the Double Esterlon as my bridge. I have found no reason to change it out so far. All of my concerns have come and gone, and I find it much more friendly to use than any of the 16 strands I have tried. The jacket is starting to wear to the point that I will change it out this spring (or sooner if I get careless) and think I will just whack off another hank of the same for the next one. If there was a downside to this story I would have to say it would be that whatever you run (ring, pulley, carabiner) tends to dig into the double braid more than the 16 strands, or the kernmantles, thus making a smooth shift on the bridge not quite as smooth as I would like. But I am willing to trade that off for the smooth performance as an adjustable bridge, which I don't get with the others that are much stiffer. Ford/Chevy
I know this is an old post, but I came across it and thought I would add my 2 cents, which is about what it is worth.
About a year ago I nicked my bridge with the saw. I run an adjustable bridge with a Petzl MicroGrab. I dug about in my kit and found a short piece of (NEW-UNUSED) 1/2" Double Esterlon. I was a bit concerned that with the MicroGrab the short piece of double braid would milk too much and create a problem. But it was what I had, and I intended to replace it with a 16 strand when the job was finished. I milked as much of the cover as I could before tying the last stopped knot. Well, I'm still operating with the Double Esterlon as my bridge. I have found no reason to change it out so far. All of my concerns have come and gone, and I find it much more friendly to use than any of the 16 strands I have tried. The jacket is starting to wear to the point that I will change it out this spring (or sooner if I get careless) and think I will just whack off another hank of the same for the next one. If there was a downside to this story I would have to say it would be that whatever you run (ring, pulley, carabiner) tends to dig into the double braid more than the 16 strands, or the kernmantles, thus making a smooth shift on the bridge not quite as smooth as I would like. But I am willing to trade that off for the smooth performance as an adjustable bridge, which I don't get with the others that are much stiffer. Ford/Chevy
I know this is an old post, but I came across it and thought I would add my 2 cents, which is about what it is worth.
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