Relative "dyamicicity" of various belay devices

[catbirdseat]

Here's a total tech nurd question. Is there any test data out there on the relative amount of slippage of various types of belay devices, such as the ATC, GriGri, Reverso, Sticht Plate, etc. I had to make up the word "dynamicicity" for want of a better word, to describe how dynamic the belay would be in catching a leader fall with the respective device. I am interested to know the effect of "dynamicicity" on impact force.

[erik]

CBS

 

CAN I ASK WHY? WOULD IT INFLUENCE YOU TO THE POINT WHERE YOU WOULD GO OUT AND BUY A NEW ONE?

 

I HAVE SEVERAL BELAYS DEVICES AND ALL THE TUBERS WORK THE SAME. THE GRI GRI IS UNTO ITSELF.

 

 

[Sphinx]

There is certainly data, I remember reading about this very issue in some book or magazine, but I don't remember which. Use common sense: Grigri gives max impact force, hip belay least. I think Munter is harder than plate/tube. All the plate and tube type devices are about the same. I tend not to use a Grigri on trad, but for sport it's the shit. I use an ATC all-around.

[chucK]

ERIK! The most dynaminitic belay will produce a very high impact force (though it would be on the ground, not the usually discussed impact force on the pro).

 

CBS! You spelled "nerd" wrong.

[Bronco]

if you use a figure 8 in rappel mode it's pretty soft

[catbirdseat]

I am concidering a GriGri for sport climbing (only). I am considering switching from an ATC to a Reverso for Trad climbing. Mainly, my interest is of an intellectual nature. Probably the practical aspects would outweigh other factors.

[catbirdseat]

chucK said:

ERIK! The most dynaminitic belay will produce a very high impact force (though it would be on the ground, not the usually discussed impact force on the pro).

 

CBS! You spelled "nerd" wrong.

NERD is an acceptable form of the word. Both NURD and NERD are right. Why do I get called on spelling. Others are far worse.

[chucK]

A "nerd" is a guy who asks techy questions. A "Nurd" is a children's confection made by Wonka Company. You know I'm right and you're wrong. Stop trying to shift the blame! If Dave Shuldt jumped off of a cliff, would you do it too?

[catbirdseat]

I have a pretty good qualitative sense of relative dynamicicity, I want quantitative data.

 

So qualitatively it goes like this, right?:

 

hip belay >> figure eight (rap mode)> ATC=Reverso=GiGi=tuber>Sticht Plate=Munter>GriGri

[catbirdseat]

chucK said:

A "nerd" is a guy who asks techy questions. A "Nurd" is a children's confection made by Wonka Company. You know I'm right and you're wrong. Stop trying to shift the blame! If Dave Shuldt jumped off of a cliff, would you do it too?

If Dave jumped off a cliff I wouldn't, but I might if it were Erik.

 

[ Go look it up.

[Winter]

catbirdseat said:

I am concidering a GriGri for sport climbing (only). I am considering switching from an ATC to a Reverso for Trad climbing. Mainly, my interest is of an intellectual nature. Probably the practical aspects would outweigh other factors.

 

I recently switched from an ATC to a reverso, and have not noticed any difference, but what the hell do I know? It seems to work. Its really just a fancy looking GiGi - the Euros seem to love them. Doesn't fuck up the rope as much as a munter when belaying off the anchor, and its easier to use with two ropes.

[Dr_Flash_Amazing]

chucK said:

A "nerd" is a guy who asks techy questions. A "Nurd" is a children's confection made by Wonka Company. You know I'm right and you're wrong. Stop trying to shift the blame! If Dave Shuldt jumped off of a cliff, would you do it too?

 

What? No, the Wonka candies are 'Nerds', aren't they? Not 'Nurds'?

 

Get the Grigri, catbirdseat (deconstructing your name renders the moniker "cat birds eat", or a bird eaten by cats. Amusement ensues.). You'll be loving it next time your partner commences a half-hour flail-a-thon on their proj' of choice. Then you can put on your down jacket, put on sunscreen, eat a burrito, or whatever while they thrash about like a gaffed marlin. Excellent!

[Dru]

Gri Gris are the shit for hard aid. Your partner uses one so he can read his book on UFOs safe on the ledge and basically ignore you . You have to climb harder cuz you know if you fall, the Gri Gri "hard catch" (static belay) will ENSURE you rip that string of beaks and smashies.

[catbirdseat]

[daler]

catbirdseat,

 

More important than the device is the rope, and how you place your gear. The least amount of rope drag you can create the smaller the impact force, because it allows the rope to do its job.

The idea of reducing impact force via device slippage is foolish to me. To much going on during a fall to icrease or decrease slippage.

Also not fighting the fall(move into the catch not away from it) will be your best solution. people argue this fact in trad climbing, I feel its more important in trad vrs. sport because the gear is way more suspect(obviously) than bolts.

My vote is almost always for the Gri Gri!!!!

 

dale

[catbirdseat]

Daler, you make an interesting point. I've been told many times the importance of limiting rope drag, but have always thought of it in the context of the rope hindering your progress, not in terms of it limiting the stretch of the rope. It makes sense totally. Very good.

[pms]

I would think since the rope is dynamic, it's the belay device's job to not be dynamic. the munter is very good btw. For situations near the belay where there is less rope stretch (dynamic), that the belayer being lifted up will provide a dynamic component.

[thol]

[catbirdseat]

By Jove, the Good Doctor was right.

[Off_Route]

 

A proper evaluation of the comparative dynamisstitcity of belay devices may compell the nurdy nerd to consider multiple variables...

 

Today I saw a huge stack boxes, presumably full of donuts, hover through the doorway of the new shop on Aurora North. Fall factor one, fall factor two, fall factor Krispy Kreme...

 

That reminded me... I was thinking about swapping out the old ATC...

 

Now this, FWIW--

 

Quantitative data on the braking force required to stop a fall with various braking devices on fat and skinny ropes:

 

"The Trango Pyramid required 24.7 pounds of force for a 10.7mm rope and 36.9 for an 8.4mm rope. The ATC required 22.3 and 36.7 pounds of force...

 

...test calculated that the Petzl Reverso required 25.9 pounds of force for a 10.7mm rope and a whopping 46.5 for a single 8.4mm rope...

 

...the B52 required 19.2 pounds of force for a 10.7mm rope and only 23.2 for an 8.4mm rope."

 

http://www.traditionalmountaineering.org/FAQ_Belay_device.htm

 

-mC-

 

 

 

[Lambone]

Yep you don't get much friction with skinny ropes and the Reverso...this is pretty evident when rappeling, especialy on a single 8 mil! Using two biners helps.

[catbirdseat]

The whole idea of using a reverso was to climb with double or twin ropes and to be able to belay two followers at the same time. If you are on twins and you fall, the load is shared between each at the device. Likely, the friction would be similar to one large diameter rope. If you are on doubles and you fall, all the load is on one strand and you have to deal with that fifty-plus pounds of force to stop the fall. That doesn't sound too good. Your belayer would want to wear gloves, certainly.

 

So has anyone used the Trango B52? They make it out to be the greatest thing since sliced bread.

[ctuller]

With the reverso if you are belaying up two followers on doubles than you want to spin the reverso around and set it up off the anchor in 'reverso' mode. That way it is self locking and you do not need to worry about the 40 lbs stopping force.

The reverso can also be thread on the harness 'backward' so that there is greater breaking force.

I like the reverso a lot, and I climb on doubles. Although I've not found the need to rap on a single 9 yet.

[Dru]

B52 is a pain and kluged to belay off the anchor with. purported self locking aside, it looks like to do it you need two locking biners.

[catbirdseat]

Okay, how about the Trango Jaws? I have one, and I like it for skinny ropes up to 9.8 mm. I have to turn it around for rappelling on 9.8 mm so it works like an ATC.