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kman
Jul 23, 2003, 10:05 PM
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How many of you use 6mm cord on multi-pitch routes for anchors? Right now I am using 7mm, but I want to replace it and am wondering if 6mm is getting a bit on the thin side.
Thanks for your replies.
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sspssp
Jul 23, 2003, 10:20 PM
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Are you talking for a cordelette?
If so, I wouldn't recommend 6mm nylon. If you are going for light weight, go for 5.5 spectra cord. Blue water sells this as Titan. There are a couple of others on the market.
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adamwvt
Jul 23, 2003, 10:35 PM
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I love the titan cord for a cordelette, I have used it to sling a large hex also. Its light, ties well. lately, though, I have been using doubles, and setting up the anchor with one of the ropes, as long as the pitch isn't a rope strecher.
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epic_ed
Jul 23, 2003, 10:59 PM
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For lighter/smaller cordalette, this is also good sh!t:
http://www.gx.starvedrockoutfitters.com/cgi-bin/miva?Merchant2/merchant.mv+Screen=PROD&Store_Code=G&Product_Code=5311
I've been using it for about a year and it's nice stuff. At $17.50 for 20 ft, it's also a good value right now.
Ed
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vegastradguy
Jul 23, 2003, 11:00 PM
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yup, BlueWater or Black Diamond make it, I use Maxim 5mm.
Anyway, they've actually gone to straight 5mm now, and its tensile strength is like 5000lbs.
6mm cord isnt quite strong enough for cordlette. So stick to either 7mm or the spectra. The spectra is a little stiff at first, but I like mine now, super light and strong!
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kman
Jul 23, 2003, 11:11 PM
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I don't really like how stiff that spectra stuff is. Does it loosen up over time? And it's pretty expensive.
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drector
Jul 23, 2003, 11:16 PM
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I used 5mm spectra for a short while but switched back to standard 7mm cord. The spectra stiffness made it a little less comfortable to work with when tying the big knot and for racking after taking apart an anchor. The only way to know is to try some if you can afford it.
Dave
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mntnman1973
Jul 24, 2003, 12:19 AM
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The Maxim 5mm cord is stiff like a cable, but it is strong and light. I was using standard 7mm cord that was 29' long :cry:. That was horrible stuff and will never go back. Both my partners now carry it on there racks.
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kman
Jul 24, 2003, 1:08 AM
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I am definately not going with that 5 mil tech cord stuff. It is too expensive and I don't like the stiffness. I am not looking to use it for t-r anchors as I use 8 mil for that. I will only be using it for anchors on multi pitch climbs. I have heard of a few people that use 6 mm but I am wondering about it's strength versus the 7 mil. I can't seem to find info anywhere right now on the strength difference, can any one point me in the right direction. Any one have experience with this matter?
I will continue searching.
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papounet
Jul 24, 2003, 5:51 PM
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http://www.beal-planet.com/produits/anglais/produit6.html
MULTI-USE ACCESSORY CORDS
DIAMETER 2 mm 3 mm 4 mm 5 mm 6 mm 7 mm 8 mm 5,5 mmARAMIDE 5,5 mmDYNEEMA
WEIGHT PER METRE 2,4 g 6,5 g 11 g 19,5 g 23 g 31 g 40 g 23 g 20 g
MINIMUM BREAKING LOAD 70 kg 180 kg 330 kg 580 kg 750 kg 1050 kg 1400 kg 1800 kg 1800 kg
Aramide 5,5 mm
Perfect for loops on chocks, but must never be used as fixed line.
Dyneema 5,5 mm
Much lighter and more versatile, it may be used on chocks or as fixed line.
http://www.millet.fr
cordelettes
2 mm - 80 daN (normes CE)
3 mm - 180 daN
4 mm - 390 daN
5 mm - 660 daN
5.5 mm - 1860 daN
6 mm - 820 daN
7 mm - 1050 daN
8 mm - 1510 daN
http://spelean.com.au/BW/BWindex.html
http://spelean.com.au/BW/specs.html#webbing
Accessory Cords
2.5mm 100 kg
3mm 200 kg
4mm+ 295 kg
5mm+ 579 kg
6mm+ 772 kg
7mm+ 1181 kg
8mm+ 1409 kg
5.5mm Titan 1100 kg
Climb Spec Webbing
Tensile Strength
14 mm 1100 kg
25 mm 2050 kg
50 mm 2700 kg
You may want to compare the numvber for 8 mm accessory cord with semi-static line
http://www.beal-planet.com/produits/anglais/produit4.html
http://www.beal-planet.com/anglais/beal7.html
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papounet
Jul 24, 2003, 5:55 PM
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when choosing 6 mm cord, be sure to read
http://www.xmission.com/~tmoyer/testing/
http://www.xmission.com/~tmoyer/testing/High_Strength_Cord.pdf
EXTRACT
======
The decrease in strength with use is a worry for any of the Technora, Kevlar or Vectran materials. The Gemini and the Spectra-A are also extremely stiff and difficult to tie and untie. An 18 -foot piece makes a bulky object hanging from the harness.
They make excellent chock cord (where a stiff cord is desirable), but would make a poor cordelette. Among the high-strength cords,
Titan seems to be the most suitable material for cordelettes.
The Ultratape is even better, and the webolette is an elegant solution to multi-point anchors, although we'd prefer to see slightly higher strength on the single-strand arms.
Last, Nylon cord and webbing may be the best of all. Although heavier, they are cheap, strong, universally available, and seem to have a virtually unlimited flex life.
=====
What will you choose ?
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jliebgott
Jul 24, 2003, 6:03 PM
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For some good reading check out Comparative Testing of High Strength Cord at:
http://www.xmission.com/~tmoyer/testing/High_Strength_Cord.pdf
Cutting to the Conclusions:
How strong should your anchor be? One arm of a Vectran cordelette, for example, fails at only 2600 lb (11.5 kN). This is little stronger than a good carabiner in the open-gate mode - and the material gets weaker with use. Is this strong enough? One can easily argue that the drop test we performed is unduly harsh. First, it uses a completely static belay. A sticht-plate or tube belay-device can reduce the peak impact forces ignificantly. Second, the lead rope is run through the central anchor point. This practice increases the load at the anchor. Third, the test loaded only one arm of a cordelette. While the cordelette anchor does not equalize when the belayer shifts position, there is typically enough stretch in each arm that all three will be loaded to varying degrees in a major impact. Fourth,
Chris Harmston, Black Diamond's Quality Assurance Manager, has reviewed field failures of climbing gear for eight years. He has never seen a stopper rated at over 10 kN fail, and has seen only a few carabiners fail in closedgate mode. He believes that forces exceeding 10kN rarely happen in climbing falls.
All that said, we do not think it is unreasonable to expect one arm of the anchor to hold at least one UIAA fall on a soft rope when both the rope and the cordelette material are new! The decrease in strength with use is a worry for any of the Technora, Kevlar or Vectran materials. The Gemini and the Spectra-A are also extremely stiff and difficult to tie and untie. An 18 -foot piece makes a bulky object hanging from the harness. They make excellent chock cord (where a stiff cord is desirable), but would make a poor cordelette. Among the high-strength cords, Titan seems to be the most suitable material for cordelettes. The Ultratape is even better, and the webolette is an elegant solution to multi-point anchors, although we'd prefer to see slightly higher strength on the single-strand arms. Last, Nylon cord and webbing may be the best of all. Although heavier, they are cheap, strong, universally available, and seem to have a virtually unlimited flex life.
jason liebgott
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papounet
Jul 24, 2003, 6:07 PM
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I can type faster than you, but you are welcome to take the next lead
;-)
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petsfed
Jul 24, 2003, 7:15 PM
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In reply to: I am definately not going with that 5 mil tech cord stuff. It is too expensive and I don't like the stiffness. I am not looking to use it for t-r anchors...
You want something stronger for multipitch than TR as there is an upper limit to how much force can come on a TR anchor based soley on the situation. Multipitch anchors are different. They need to be stronger. As to the issue at hand, spectra will be stronger than 7mm cord, obviously. Its built different. Black Diamond has a handy chart for you. You shouldn't see too much variation from one brand to the next, even with the spectra cord. As you can see, Gemini 2 (which is a different name for Titan essentially) is nearly two and a half times stronger than 7mm cord. Noting the kind of forces that can come up in a factor two fall, I think the spectra cord is worth it. You see, if your partner biffs it 10 feet off the anchor and falls clean past, your anchor sling will fail before your anchor pieces. See the issue?
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kman
Jul 24, 2003, 9:59 PM
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That's the info I was looking for. Thanks guys.
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