You know, you could do that too, instead of using somebody else's (totally unsubstantiated) picture of said failure. In fact, do that now.

That picture from the BD website is misleading. Nice touch to make the text too small to be readable. This is ancient fixed gear with weak spring tension and Kolin clearly states that he believes the failure is from gate flutter. It's worth noting that gate flutter never happens in a static pull like most biner loading, you need a drop test to see it. Which is exactly what BD did.

Anyone reading the patent on the keylock gate will notice that one of the stated benefit of that design is that a partially open gate can still lock into the groove.

Nitpick: The biner on the BD page is actually an OP biner, not BD.

The biner is anything but new and drop tested. I don't know about you but I've had to manually close gates on fixed biners because the spring couldn't do it. I hardly believe that this case is representative of a production biner in good condition.

Show me an example of a new biner with solid gave and hook nose (like a quicksilver) being tested in a drop test. Then you'll have something to take about. I've bent open-gate biners with short body weight falls before but not a biner who's gate was properly closed when loaded.

I see that you're an idiot. It matters that the biner spent the last few years hanging around someone's project and being rained on and so on. Because that biner is not representative of an average biner in good mechanical order. You attack my nitpick because you've got nothing substantive to say to back up your claim.

If you want your idiotic assertion (that the pin does nothing) to have any credibility at all, it's a really easy test to run. Take a set of identical carabiners, cut the pins out of half of them, and pull test them. I can gauran-goddamned-tee that the ones with the pin will hold larger loads before breaking.

Just because the failure mode doesn't usually involve breaking the pin does NOT mean that the pin is useless.

STFU

is that clear ?

Majid

Most of us think that the reason that pictures of broken carabiners around only show intact pins is because it is very, very difficult to create enough force in a climbing situation to exceed the measured carabiner closed gate strengths. 'All' of the field failures are open gate failures - bad springs, gate flutter, rock pressure, .... And so they have intact pins.

It should be pretty easy for you to show whether the pins engage or not - grab a couple of volunteers, jumars or prussics, and by the time you get the third guy on the line, you will be able to see the pin engage or pass the hook. Use an assortment of connections - biners, 8mm, 15mm, 25mm tape, cord... Tell us if you can get it to miss, and how.

Thanks.

The pin does not interlock with the hook under tension period.

Yo majid a cursory google revealed this link on the 2nd hit. You may be interested in this:

http://web.mit.edu/...gue_Presentation.pdf

They even have some majid-like illustrations! They even speak to your specific topic. This study seems to conclude that plastic deformation of biners occurs in low-load scenarios early in a biner life, and that plastic deformation can cause the pin to misalign later, during a fall.

Very interesting piece. Some new stuff in there for me personally.

As to the persistance of the pin/notch design, for many years Kong owned the patent on keylock designs and licensed that technology to Petzl, Spirit biners. No other mfg. had license to make them. My cursory understanding is the patent expired and now nearly ever mfg produces keylock designs.

I would not buy new pin/notch biners as my primary biner anymore. I prefer keylocks and wiregates. The prices aren't so much of an object anymore either, due to competition. Used to be that keylocks were TWICE what pin/notch designs were. For 50 biners that was a shitload of money. A SHITLOAD.

There's your why's. Enjoy!

DMT

DMT

Yo majid a cursory google revealed this link on the 2nd hit. You may be interested in this:

http://web.mit.edu/...gue_Presentation.pdf

Listen
If you do not have mechanical engineering background of some sort nor you understand how metal work and react during taking load then I would suggest you to keep your unwanted comments out of LAB and allow someone else who has the knowledge or the background to come forward in to this serious discussions.

You should take your own advice. I'm a physicist with quite a bit of experience backing my claims up with real data. You never do anything that would pass as even remotely meaningful in a scientific publication. Posting a bunch of pictures out of context and pretending like they support your ludicrous assertions is at best naive and at worst maliciously misleading.

You're a tool and should stay FAR, FAR away from the lab.

thanks DMT!
just as i said, majid you are onto something, but try to stay a bit more friendly, mkay?

qwert

Yo majid a cursory google revealed this link on the 2nd hit. You may be interested in this:

http://web.mit.edu/...gue_Presentation.pdf

They even have some majid-like illustrations! They even speak to your specific topic. This study seems to conclude that plastic deformation of biners occurs in low-load scenarios early in a biner life, and that plastic deformation can cause the pin to misalign later, during a fall.

there are few people here in RC who continuously keep calling me names when they can not prove their points .

So rather than the gate pin being useless (Majid) it is actually one of the stronger parts of the biner.