Why aren't new friend cams more popular?

How is that different than just using a dyneema sling? 

Kudos for relinquishing the debate, Will. I respect that. 

Will, it might be helpful to contact somebody you trust and ask them about dyneema and whether it creates huge forces even with a dynamic rope in the system.

Midwest Will wrote:

got this from WC today .. has nothing to do with the OP but since dyneema was mentioned in the debate i thought i would share. 

And?

Midwest Will wrote:

eli poss  didn't think knots and such were a big deal .. but WC obviously doesn't recommend them.

What a manufacturer recommends is irrelevant when the raw data is out there, you make up your own damn mind at that point.

Midwest Will wrote:

eli poss  didn't think knots and such were a big deal .. but WC obviously doesn't recommend them.

They’re not necessarily a big deal.  

Edit: Let’s consider a couple things. Gear Companies error far on the side of caution. And although knotting dyneema does weaken it, the above diagram and the VIDEO posted are in the setting of worst case scenarios and factor 2 falls that cannot occur in real climbing.  Solid metal weights do not and will not replicate a falling human in a harness. Certainly not when lacking a dynamic rope in the system.  

How many stories have you heard about slings breaking due to knots. Astronomically rare when considering the frequency of knots being tied in dyneema slings.  

Knots tied in any material reduce their braking strength. Some materials (Dyneema, various aramid fibers and blends) lose a larger % of strength than other materials (nylon, polyester) but in the context of dyneema slings used for climbing this really isn't an issue. Dyneema will lose up to 60% of its strength when knotted, but since it is so strong to begin with, it is not really an issue.

Your spine will probably break at lower forces than your knotted dyneema sling.

Midwest Will wrote:

tell WC your feelings .. 

This reply keeps making me laugh. 

Here's another fact about dyneema for you to consider, will:

Because dyneema slings tend to be skinnier than your average nylon or polyester slings, they are less likely to reduce the strength of the biners used with them. When a wide nylon sling is used with you're typical D or offset D shaped biner, the sling sits much closer to the gate, which transfers a portion of the load from the carabiner's spine to the gate.

Because the gate is much weaker than the spine, this lowers the strength of the carabiner. Since most dyneema slings are 10mm or smaller, they pretty much replicate the loading conditions of the lab test (which uses a 10mm pin) which means you can count on a 20+ kN major axis strength.

It's not all black and white or as simple as saying dyneema is bad and nylon is good. You have to consider the context. 

Midwest Will wrote:

you will have to debate with WC .. 

I have not problem following their recommendations. 

"error on the side of caution" I have no problem doing that either.

I would hope that most ppl read the recommendations and not tie knots in dymeema.  

I think a better question is .. how many accidents has there been with consumers not following manufacture recommendations in general. 

Why would I debate with WC, when there is extensive empirical data on this situation? I would hope most people read the research, and come to their own informed conclusion about risk vs. usefulness for a particular climbing technique.

Say you need to connect two slings together while climbing. You're out of the other gear you could use to accomplish this task.  Do you:

a) Do nothing. Run it out/get benighted/whatever, feeling safe in the knowledge that you followed the manufacturers instructions.

b) Connect the slings using a strop hitch, knowing that this will probably hold at least 9 kN if called upon to do so. This is much less than the rated strength of a sling, but similar to the rated strength of smaller camming devices. Not ideal, but good enough in a pinch. Since I read that article I make sure all of my slings are the same type and thickness and keep my slings in good repair, in case I need to join slings. Now I have one more tool in my toolbox.

I don't know where you get the idea that this sport (or the engineering behind the gear we use and the systems we build with that gear), is so black and white.

Doing diligence and applying critical thinking >>>> manufacturers guidelines

For anybody who has read the BD QC article and wondered wtf the "climber hitch" was and how to tie it, I dug up an archived version of the page, which is longer available. Looks a bit complex for the layman climber to remember and tie without making potentially harmful mistakes, but another tool to add to the kit if you're in to geeking out about that kind of stuff.

link

Edit: okay, apparently mountain project really doesn't like links to archived pages because this is the 3rd time it's screwed with such a link. If you would like the link feel free to PM me about it. 

Alexander Blum wrote:

Why would I debate with WC, when there is extensive empirical data on this situation? I would hope most people read the research, and come to their own informed conclusion about risk vs. usefulness for a particular climbing technique.

Say you need to connect two slings together while climbing. You're out of the other gear you could use to accomplish this task.  Do you:

a) Do nothing. Run it out/get benighted/whatever, feeling safe in the knowledge that you followed the manufacturers instructions.

b) Connect the slings using a strop hitch, knowing that this will probably hold at least 9 kN if called upon to do so. This is much less than the rated strength of a sling, but similar to the rated strength of smaller camming devices. Not ideal, but good enough in a pinch. Since I read that article I make sure all of my slings are the same type and thickness and keep my slings in good repair, in case I need to join slings. Now I have one more tool in my toolbox.

I don't know where you get the idea that this sport (or the engineering behind the gear we use and the systems we build with that gear), is so black and white.

Doing diligence and applying critical thinking >>>> manufacturers guidelines

YES!  Clearly you know more than Will. Thank you. 

Midwest Will wrote:

I would hope that most ppl read the recommendations and not tie knots in dymeema.  

I think a better question is .. how many accidents has there been with consumers not following manufacture recommendations in general. 

That question is too broad.  

The better question is.. how many people have died because they knotted their dyneema? 

Probably the same number that have occured from top roping on two quickdraws clipped to bolted anchors.

Is it just me or do Will and Tut have some secret bet going on as to who can be the biggest pedant on MP?!?!

"how many accidents has there been with consumers not following manufacture recommendations in general."

Will, honestly, did something happen to you, like a friend getting hurt or dying in a climbing accident?   You are obsessed with the idea that people are doing things wrong, and are on the verge of getting injured.  How long have you been climbing?  Maybe it's not your thing, if you are so umcomfortable with the dynamics of the danger/safety game. 

I think the funniest thing about this thread is that i started it almost a year ago and forgot about it for most of that time. I read the title of the post on the board and clicked on it, thinking itd be a good read and than realized that i had started the topic.  alot of the stuff on here has been worthless and has been arguing for the sake of arguing-but such is MP

Midwest Will wrote:

i started climbing in 96

In 22 years you never discovered that you shouldn't clip a wiregate to a wiregate and you've never taken a fall on dyneema over an edge?  

Midwest Will wrote:

It's true, in 22yrs i have never taken a fall on dyneema over an edge. I don't have dyneema slings or extendable dyneema on my cams. I have taken falls on tri cams over an edge and the cable stem of a cam over an edge. 

Do you realize that you're better off taking a fall on dyneema over a sharp edge than nylon over a sharp edge? Dyneema has far better cutting resistance than nylon. Once again, not all black and white. 

Midwest Will wrote:

 I don't think it should be pictured in a Wild Country post. Just because i ask for your opinion doesn't mean i need your advice. 

It's true, in 22yrs i have never taken a fall on dyneema over an edge.  

I don't see where I offered any advice.

Midwest Will wrote:

lol ..eli loves dyneema.. gotta go light to to climb 5.10 

Apparently one doesn't need to go light to climb 5.10.  You don't.