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Who raps on 5.5mm?


Plinko

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I've rapped on a 5.5mm spectra cord before. Just use an extra biner like RBW suggested. I did the redirect and it worked fine. You can also use it to do full single raps if you use the method that's been discussed on this site before to rig the ropes. It's a lightweight second rope for raping if you need one. (expensive but lightweight)

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Here's the factory specs for this stuff:

 

http://www.neropes.com/techdata/tech_cord.htm

 

And from this site, http://sierramountainworks.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=rop-2104&Category_Code=webbing

they say, "Originally designed for the military's special forces, Tech Cord is the strongest and lightest cordellete or chock cord available. Made from superior Technora fibers, Tech Cord boasts a whopping 5000 lbs tensile strength (50 percent stronger than Spectra) and a melting point of 932 °F (compared to Kevlar's melting point of 260 °F)."

 

Sure, it's all heresay cuz I haven't marked up samples with temp chalk and tossed them in the furnace, but it looks safe to say that heat build up would NOT be an issue with this stuff...

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I am assuming you mean that you will be rapping on your rock rope and your 5.5? The diameter difference gets tricky there. You would likely have to use to hands to rap (one rope in each hand) to assure that the 5.5 doesn't get pulled through faster.

 

I think the post somewhere up there described connecting the ropes, tying a biner to the 5.5 retrieval line, clipping the biner to the lead rope and rapping on the lead rope. It's in the GriGri instructions too. I've used it with a 5mm nylon retrieval line where the rap was a straight shot down snow & ice--the attachment between ropes is a bulky affair for getting down rock with lots of cracks.

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The only problem with that method would be if somehow the knot managed to get on the wrong side of the sling. Then you'd have a devil of a time retrieving the rope by pulling on the dinky little retrieval line. Granted it would be very unlikely if you were careful AND you could always jug back up and fix it. If you had a rap ring that couldn't happen. For that matter, it would be unnecessary to use the biner in the first place.

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As many have said above. Rapping on 5mm Tech cord is very safe if you pay attention to edges etc. I would do it any time single or double. I have rapped full length on single 6mm perlon. I think this was pushing the envelope on rock but reasonable on snow. With smaller diameters you do indeed have to pay attention to the divice friction. One extra rap around the master biner works okay, twice causes alot of twisting. Try 2 biners with an extra rap...plenty 'o friction.

 

You should rap slowly and smoothly to avoid shock loading and extra heat build-up.

 

 

The real question I have is "Is it reasonable to rap on doubled 3mm tech cord?" I think it may be; but it would certainly be a pucker.

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I use 60 m of 7mm perlon for alpine soloing. It is light enough to not be a big concern. It is strong enough to double and lead on.

 

uhm. isn't perlon static?

This is a 7mm Mannut 1/2 rope. It is the only one I have seen anywhere. I bought it at a shop in Missoula.

Cracked. When I lead on a doubled 7mm, it is with great care. First, I tie into two loops. Second, It is for soloing where the option is to go totally unroped. Third, Edges are the only real problem anyway according to the test data. But I try really hard not to test it. Fourth, Do not try this at home. I have been climbing solo for decades.

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It is dynamic. Lots of stretch. Too much stretch. Compare 11mm to 9mm and extrapolate.

Even if it were static, I would use it over nothing. A short fall with friction etc would not snap me like a twig. Do not assume that I would be leading out like I was on a normal rope with a belayer. I am soloing. Hemp ropes were used for a lot of climbs before our current technology. It was not as good but with the proper adjustments to style, it was better than nothing. If it is true that, as you say, "you WILL die" in a fall. Hemp rope would never have been used at all. When soloing, I always try to avoid using the rope. Too slow. When I have to, I use it for short pitches and place pro with slings that I can grab easily. The likelyhood of a freefall generating massive forces is low. The chances I do take are my own. I use the techniques after a lot of free soloing and soloing and normal trad climbing for many years. I doubt that many people would argue that free soloing is safer than climbing with a doubled 7mm. And it is certainly safer to rap on a 7mm than on a 6mm or less.

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I've rapped out of the Seventh Heaven chair at Stevens several times for self-evac practice with two strands of 6mm perlon back when I patrolled there. No problem with that stuff, you just go slow and don't heat the rap device up too much.

 

I've just switched from the perlon to 5.5 mm tech cord for a ski rap rope. If you look in the right spot you can buy it off of big spools and get 100'+ lengths. I found a 100' section for $30 but it was a closeout and the guy sold out of it.

 

I know several climbers and skiers in France who used to use Spectra lines for unplanned retreats or emergencies. Nobody ever seemed to have a problem with it. I'm sure that the newer Tech Cord is a much improved alternative.

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You would be right about the static but not right about the effect IF you adjust your style. My point is that you would have to adjust your style to provide for the forces. When there are two, use a dynamic belay. When alone weigh the options of free soloing or using the rope as a swing line.

This is almost always the way I use my dynamic 7mm anyway. There are time when I am extended beyond my comfort zone of a fall on the rope but I keep those at a minimum and can usually slow my fall by grabbing the rope and swinging or prevent a fall by leaning against the rope. It is really kind of silly all in all since soloing with kids at home is pretty selfish. But what can I say? I love what I love.

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