Rope Choice

[ratagonia]

Pelican ropeworks makes an 8mm technora cord with a polyester core that has an MBS of 6100lbs. Sheath heavy and very durable. I use it as vt cord for tree work and would be interested to use it as a short back up rope in canyons. It can be had online for about $.90/ft

"Sheath-heavy" has a specific meaning, and I could find no evidence that this is a sheath-heavy rope. Please retract your claim - it is bogus.

Tom

[ratagonia]

Re BW Canyon Pro DS (Dual Sheath). Rope lists at Backcontry.com for $362.95 at 200 ft. I know folk that got the line the first year it came out for around $300. Those working in retail shops would do better. The line is stiffer than the Canyon Pro and generally does not scuff up as much as the canyon pro. But the big caveat for this line and the Canyon Pro (aside from the cost) is the sheath slippage, particularly when folk (heavy lads) are rapping single strand. I've seen brand new DS ropes come loose, sheath wise; the slippage was from 4-6 inches, or up to a foot. In Canyon Pro, in wet canyons, the slippage often occured on the ends of the line (sometimes elsewhere); with the DS I saw it in near middle sections of the rope. Generally it's a nice, versatile rope. I know some that say they have never had a problem with the line, and scoff when I suggest otherwise.

By way of comparison, I've never seen sheath slippage on PMI Sport Static, on any of the BW 9mm ropes and not on the Imlay Canyon fire or the Imlay 9mm lines. Ditto re the Sterling 9m ropes. And the cost? The new Sterling 8mm line can be found on sale for around $200; and the Canyon Fire for less than that (at 200 ft.). Weight wise the Sterling just about matches the DS with the Canyon Fire a tad heavier. It's just money though and those with BW in their blood, can infuse their quiver with as many BW lines as they wish. (that happened to me a decade ago when BW canyon lines came out; but the luster faded;, Cancord Hercules/Imlay appeared and more recently the Canyon Fire.) Had I the money, would I put it (the DS) in my quiver? Probably not. I still recognize though that opinions vary and exeriences differ. I know some that have used Canyon Pro and Canyon Pro DS and claim they have NEVER had a problem. I salute you, but on my side I no longer pledge allegiance to those pricey/dicey ropes. (even though I still own and sometimes use, some of the canyon pro)

Many ropes have sheath slippage problems, including my Canyon Fire and Canyonero, at times. And the Canyon Pro and DS at times.

As delivered all of these ropes are not 100% tight, sheath to core. So if you take em out of the bag and take your Bubba-esque friends out and all slide down the rope in one direction, you are going to induce a lot of sheath slippage. If you are near an end, the slippage will go off one end. If you end near the middle, then you will have a pile of extra sheath just past where everyone stopped rappelling.

The rope being wet seems to make this worse, sometimes MUCH worse. Using an ATC rather than a Pirana tends to make it worse. In odd-numbered months, it tends to be worse. Within a few days of the full moon - much worse! (OK - those last two - )

To avoid this, you CAN soak the rope in water and let it dry a couple times before you use it. This will also shrink the length some. I don't do this personally, but I recommend it, especially if you expect to use the rope the first few times in dry canyons, or your canyoneering buddies go by "Bubba".

Canyon Fire x 200 feet => $ 160.00

I have used the BW Canyon Pro about 180 days while guiding in the last 5 years, and it is a nice rope. But when I go out on my own, yes I use my own ropes. Yes, because I like them, and I don't want to give the opportunity for a photo of Tom rapping on BW rope to pop up on the Interwebs!

Ropes also shrink in length, but it is really hard to put a number to that, as it varies widely with the details of use. We might try to establish a protocol for that and run some tests, this summer.

Tom

[ratagonia]

.

-Lastly, it becomes an unusable cord for lead climbing anymore because of all the sand that works its way into the core. the $$ that you would've spent on a replacement dynamic lead rope could have gotten you outfitted with two new static cords.

Really? The ropes these guys are recommending cost as much or more than dynamic ropes. I've seen cheaper 60 meter dynamic ropes for as little as $100

Just to be clear, your "Really?" is limited to the discussion of price, correct?

REI.com cheapest New England 10.2 x 60m = $ 144.00
Sierra Trading Post: Tendon 10.4 x 60m = $ 150.00
Summit Hut.com: Mammut Supernova 10mmx60m = $ 160.00

So I will claim equal exaggeration:
A. No, a dynamic 60m climbing rope does not cost twice what canyoneering rope does; and
B. While on-sale dynamic 60m climbing ropes may occasionally be on sale for only a hundred bucks, the normal SALE price would be more like $ 150.00

Let's call it a draw!

Tom

[Bootboy]

"Sheath-heavy" has a specific meaning, and I could find no evidence that this is a sheath-heavy rope. Please retract your claim - it is bogus.

Tom

No. It's not. I own the evidence.

That's like me interrupting you every three seconds and saying "prove it....show me.... Where does it say that ?" And so on....

Although you may not have found anything that says it is in fact "sheath heavy", doesn't mean it isn't. If by sheath heavy you mean that more than half of the rope's fibers are found in its sheath, this rope fits that definition. I own some of it and if you were to examine a cross section of this rope you'd see what I mean.

[ratagonia]

No. It's not. I own the evidence.

That's like me interrupting you every three seconds and saying "prove it....show me.... Where does it say that ?" And so on....

Although you may not have found anything that says it is in fact "sheath heavy", doesn't mean it isn't. If by sheath heavy you mean that more than half of the rope's fibers are found in its sheath, this rope fits that definition. I own some of it and if you were to examine a cross section of this rope you'd see what I mean.

Hmmm. Interesting.

What's the ratio?

Easiest way to measure is to cut some length, pull the core out of the sheath and weigh the two parts. Gotta have enough material to produce good results on your scale.

I'm still saying "prove it!", in case you haven't figured it out.

Tom

[rrv]

Just to be clear, your "Really?" is limited to the discussion of price, correct?

REI.com cheapest New England 10.2 x 60m = $ 144.00
Sierra Trading Post: Tendon 10.4 x 60m = $ 150.00
Summit Hut.com: Mammut Supernova 10mmx60m = $ 160.00

So I will claim equal exaggeration:
A. No, a dynamic 60m climbing rope does not cost twice what canyoneering rope does; and
B. While on-sale dynamic 60m climbing ropes may occasionally be on sale for only a hundred bucks, the normal SALE price would be more like $ 150.00

Let's call it a draw!

Tom

Yes, I was referring to price and his statement that you could buy 2 static ropes for the price of one dynamic.

If by a draw, you mean that static and dynamic ropes are basically the same price, then yes, I agree.

[Bootboy]

Hmmm. Interesting.

What's the ratio?

Easiest way to measure is to cut some length, pull the core out of the sheath and weigh the two parts. Gotta have enough material to produce good results on your scale.

I'm still saying "prove it!", in case you haven't figured it out.

Tom

I separated the sheath and core fibers. More in the sheath than in the core volume wise. I'd call it 55/45. There are obviously different ways to measure, volume, weight, tensile strength, this could vary simply by the materials used in the respective parts of the rope

[ratagonia]

I separated the sheath and core fibers. More in the sheath than in the core volume wise. I'd call it 55/45. There are obviously different ways to measure, volume, weight, tensile strength, this could vary simply by the materials used in the respective parts of the rope

Again, interesting... I cannot find a Technora sheath / Polyester core on their website - can you direct me to the product you are suggesting? I am genuinely interested in this item.

You could weigh it, but as you suggest that is not the most natural way to consider the "amount of material". Weighing it and dividing by density would tell you the volume, if you want to go to that much trouble.

(Technora: 1.39 g/cc - http://www.matweb.com/search/datashe...aa93229&ckck=1 ;
Polyester: 1.38 g/cc - http://gestis-en.itrust.de/nxt/gateway.dll/gestis_en/530566.xml?f=templates$fn=default.htm$3.0 )

So Technora and Polyester have the same density, thus a weight comparison also gives a volume comparison.

Tom

[Bootboy]

I'll find it for you. I had trouble finding it on their website too.

I had no idea that technora and polyester were so similar. But you see the point I was trying to make, right?

The only weakness I can find in the rope is that the sheath is not woven as tightly as other canyon specific ropes.

[ratagonia]

I'll find it for you. I had trouble finding it on their website too.

I had no idea that technora and polyester were so similar. But you see the point I was trying to make, right?

The only weakness I can find in the rope is that the sheath is not woven as tightly as other canyon specific ropes.

Found it under new products... http://www.pelicanrope.com/low-angle...cue-ropes.html

As Technora Prusik line... A cord for Prusik would be made soft to have more grip, might not be suitable for rappelling. I asked for a quote, might get a sample to look at.

I'm unsure how this makes your point, but I am also not very clear on what point you were trying to provide evidence for.

As far as sheath-heavy - an 8mm rope with a polyester core and a 6000 lb rating would have a core 1/5th larger than my Canyonero... unless the sheath is so amazingly strong that the sheath is way stronger than the core (which very well could be true in this case) so that the rating comes off the sheath (which is counter to the way most static ropes function).

Also, to note, the weight is 40.2 grams per meter, which is considerably less than my 8mm polyester (50 grams per meter) and even less than the Canyon Pro (42 g/m) - so if it is really an 8mm in size, then they are not packing it very tight!

Tom

[Bootboy]

I don't know that I ever really tried to make specific point, I just mentioned this cord as a curiosity. Something to fiddle with. You're the one who has belabored and knit picked it.

P.s. Here is a pick of the sheath and core fibers on a fairly accurate, tunable balance scale. To zero it, you get an average difference of about .3 grams /inch. After re-zeroing the scale and remeasuring several times. The sheath fibers are heavier every time, on both sides of the scale. That's a weight difference of almost 12g/m. 40g/m is what you said right? That's 65% in the sheath if I did my math right. That's pretty "sheath heavy"

[Bootboy]

...

As far as sheath-heavy - an 8mm rope with a polyester core and a 6000 lb rating would have a core 1/5th larger than my Canyonero... unless the sheath is so amazingly strong that the sheath is way stronger than the core (which very well could be true in this case) so that the rating comes off the sheath (which is counter to the way most static ropes function)....

"sheath heavy"

Wouldn't that also be the way your own designs of ropes function?
How does the design of your own ropes explain the paltry 3600lb MBS of your canyon fire rope?

[Bootboy]

Pictures next to my C-IV


It's on sale from my tree supply folks

http://www.wesspur.com/Prusiks/bulk-prusik-cord.html. It's the technora cord that's $.84/ft

If they'd make it in a 2 end per carrier braid at a higher braiding tension we'd have one heck of a canyon line, especially at that price. That, I think we could agree on.

[ratagonia]

"sheath heavy"

Wouldn't that also be the way your own designs of rope function?

How does the design of your own ropes explain the paltry 3600lb MBS of your canyon fire rope?

Nope. And Nope.

"Wouldn't that also be the way your own designs of ropes function?"

Nope.

When you put a static rope on the testing machine, it loads up and extends, and then the core breaks; and then it loads up again, extends further and the sheath breaks. The core fibers are straight, so those are the ones that take the load first. The sheath fibers are criss-crossed at a 45 degree angle (roughly, at rest) so before they can be really loaded, they have to align straight.

For a standard 50-50 static rope, once you align the sheath fibers by pulling them straight, you find your bundle of fibers is 1.4* longer than it started, and therefore 1/1.4 * (71 %) of the size (diameter) of the core, so it would not be as strong.

Ah, but if the inside was Polyester and the outside was Technora, you change the equation substantially because the Technora, when new, is 3X as strong as the Polyester. However, we also need to be concerned about how the criss crossing interacts, so it is hard to say what the result it, but it is entirely possible for the outside braid to be stronger than the inside core.

My ropes do not work that way - the core carries the strength.

And even if they did, I am not sure I would feel good claiming a strength based on the sheath, because the sheath becomes worn. In a kernmantle rope, there is the assumption that the sheath (mantle) takes the wear while the core (kern) retains its strength. If you are relying on the mantle for strength, then what is the strength after it has been rappelled on? (Answer: uncertain, and unlikely to be the full rated strength).

"How does the design of your own ropes explain the paltry 3600lb MBS of your canyon fire rope?"

You making stuff up?

Not sure where you got the figure you quote, but it is inaccurate.

http://imlaycanyongear.com/ropes2.php

The current rating is 4100 lbs. The rating used to be 3900 lbs (for the 8mm and the Canyon Fire), but after collecting several years of data, it became clear that the data set supported a rating of 4100 lbs. (It is not uncommon for products to come onto the market with one rating and then have the data set support a higher rating down the road. When setting an initial rating, the engineer would want to build in some "just in case" headroom, just in case some variable in manufacture creeps in that causes a loss of strength.)

And it is not MBS or Mean Breaking Strength, it is a 3-sigma rating. MBS is kind of a poor-man's rating; a rating without statistics behind it tells you very little about the actual strength of what you hold in your hand. I want both a respectable Mean breaking strength and a low sigma (variance). A low variance tends to indicate that the manufacturing processes are well-understood and well-controlled. In batch testing, you really want a low sigma, because outliers indicate something is not right.

" ...explain the paltry 3600lb MBS of your... "

You, sir, are a scoundrel. How dare you both lie about my rope, and also insult it by calling it 'paltry'. Defamation! (Mock Outrage)! Pistols at Dawn! Okay, Sabers at Sunset!

But enough of that.

I re-assert my original contention. You said this stuff is sheath-heavy rope. It is not. I concede that it is sheath-heavy - in fact, it is very, VERY sheath heavy, practically braid. But it is not ROPE. It is purpose-specific Prusik line. That is not rope. Rappelling on this stuff is not what the manufacturer intended, and would have very unpredictable results, and is likely quite dangerous. It is not rope.

Tom

[Bootboy]

Haha! I love watching the linear thinking engineering types get all up in arms and geek out on this stuff, spitting out terminology and numbers. Its kinda fun to needle you along,Tom.
Pretty sure the card that is packaged with your canyon fire rope said something about a minimum breaking strength of 3600lb. I could be wrong, in which case I would retract my statement.

I'm aware of how different rope designs work. Even in my short years I have an extensive background of rock climbing, high angle rescue with ski patrol and SAR, technical rescue with the fire department, and tree work. I've been dangling from the ends of ropes since I was old enough to walk, have made a living with them, and literally saved lives with them.


Once again I merely mentioned this cord, as it were, as a curiosity. I'm not rappelling on it any time soon. I have several real canyoneering ropes, even one of yours. Which I will continue to use.

Or maybe I'll go to the hardware store to by some polypro diamond braid for all my life safety applications, I heard it floats....

[ratagonia]

Haha! I love watching the linear thinking engineering types get all up in arms and geek out on this stuff, spitting out terminology and numbers. Its kinda fun to needle you along,Tom.

Pretty sure the card that is packaged with your canyon fire rope said something about a minimum breaking strength of 3600lb. I could be wrong, in which case I would retract my statement.

...

Or maybe I'll go to the hardware store to by some polypro diamond braid for all my life safety applications, I heard it floats....

Current hangtag says 3900 lbsF. 3900 is not the same as 3600. That's some linear thinking, right there.

Glad to provide entertainment...

Harbor Freight. Best Ropes EVER!

http://www.bogley.com/forum/showthre...d-The-Incident

Tom

[Bootboy]

I'll have to find what rope they were using so I can get one for myself....sounds fast!

What was the point of that post? I use a helmet, I rap on purpose built ropes, I carry a FA kit and warm clothes, I send the most competent rappeller down first with an auto block and use a bottom belay for everyone else. Pleas don't paint me like I don't have a clue. You've had to twist this whole discussion into a scenario in which you can be right about something. I didn't set out to prove anything but you apparently felt threatened by my comment. The self proclaimed guru and overseer of all things canyoneering and lord over all Zion, I am not worthy!

Please don't assume that I would be the type to do something that foolish. You must have missed the part where I told you that I've used ropes professionally for over 6 years in a variety of different applications. Get over yourself.

[ratagonia]

I'll have to find what rope they were using so I can get one for myself....sounds fast!

What was the point of that post? I use a helmet, I rap on purpose built ropes, I carry a FA kit and warm clothes, I send the most competent rappeller down first with an auto block and use a bottom belay for everyone else. Pleas don't paint me like I don't have a clue. You've had to twist this whole discussion into a scenario in which you can be right about something. I didn't set out to prove anything but you apparently felt threatened by my comment. The self proclaimed guru and overseer of all things canyoneering and lord over all Zion, I am not worthy!

Please don't assume that I would be the type to do something that foolish. You must have missed the part where I told you that I've used ropes professionally for over 6 years in a variety of different applications. Get over yourself.

Too serious, oh lad of the sandals... you suggested a rope from a suspect source, I riffed off your suggestion. That's all.

This horse dead yet?

Tom

[spinesnaper]

I guess I am the idiot. I thought these scales were only useful for measuring weed (for medicinal purposes of course (we have a lot of disabled 24 year olds in California)).

[Bootboy]

You may notice that my scale is dusty, been a while since I used it...