Stop style bobbin question

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Re: Stop style bobbin question

Postby chh » Jul 6, 2011 7:34 pm

GroundquestMSA wrote:This was more than just faster, it was dangerously fast, thoughts of doing a leg wrap fast, maximum effort on the braking hand fast. I dont weigh anything at all and have never had the slightest trouble slowing myself down before. I also haven't used a braking carabiner. Any intructions?

Are you sure you had the rope installed correctly? FWIW I weigh about 165 and I would want a braking carabiner with a bobbin on a 10.5 dynamic line. I also don't usually need it on a stiff 11mm pit rope, though I always install it anyway at first. Also, I've used just one braking carabiner with a stiff 9mm line. Different makes of rope are different. It's always good to start out with more friction than you need, as I'm sure you know. With a bobbin that means keeping a braking carabiner on your harness at all times. Trust me, you won't even know it's there.
Your words of caution are no match for my disaster style!
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Re: Stop style bobbin question

Postby GroundquestMSA » Jul 6, 2011 8:08 pm

chh wrote:Are you sure you had the rope installed correctly? FWIW I weigh about 165 and I would want a braking carabiner with a bobbin on a 10.5 dynamic line.


I'm not very bright but I'm pretty positive I have it installed properly. There's a diagram drawn on the device and I checked several online sources to be sure. I weigh about 130 and after adding a braking carabiner I was able to stay under control but with more effort than when using any other of my descenders (fig. 8, atc, rack). I also tried it on an 8mm static rope and got about the same results (don't everyone panic I don't normally use 8mm in cave).
I think the rope must be mostly to blame. I know little about rope but it seems that my climbing rope (Mammut Flash) is extremely flaccid. I suppose I'll
LukeM wrote: try the device with some stiff caving rope before passing judgement on it.


Cavemud wrote:My offer still stands brother!

And will hopefully be soon accepted.

Thanks everyone.
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Re: Stop style bobbin question

Postby Chads93GT » Jul 6, 2011 8:17 pm

rope enters the bottom and leaves the top coming down to the brake biner.
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Re: Stop style bobbin question

Postby GroundquestMSA » Jul 6, 2011 8:25 pm

Chads93GT wrote:rope enters the bottom and leaves the top coming down to the brake biner.


Yessir.
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Re: Stop style bobbin question

Postby paul » Jul 7, 2011 6:13 am

Chads93GT wrote:rope enters the bottom and leaves the top coming down to the brake biner.

Image
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Re: Stop style bobbin question

Postby GroundquestMSA » Jul 7, 2011 2:15 pm

paul wrote:
Chads93GT wrote:rope enters the bottom and leaves the top coming down to the brake biner.

Image



Are you taking to extremes my claims of personal stupidity or are you chastising Chads93GT for his redundancy?
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Re: Stop style bobbin question

Postby chh » Jul 7, 2011 4:37 pm

I don't think anyone thinks you're stupid, but that's the problem with solving problems on the internet. I always start with the simplist solution and work from there, no judgement on your experience or intelligence intended. Heck, I threaded a bobbin wrong the first time I did it. It happens.

Is your lead line new? I'm surprised that you had trouble with it. I don't have much of a problem with my lead line in a bobbin (the few times I've done it), but it's an older 10.2 and been drug up quite a few miles of rock, so it feels more like an 11.5 now :laughing: Newer ropes, especially those with dry treatments, which are common nowadays in lead lines, can be especially slick. However, I have the sneaking suspicion that at 130 pounds, when you load a used pit rope into that bobbin, you won't need the braking carabiner. But like I said before, install it anyway at the pitch head so you won't be surprised. Bobbins are great devices. Don't give up yet...
Your words of caution are no match for my disaster style!
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Re: Stop style bobbin question

Postby gdstorrick » Jul 7, 2011 11:07 pm

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Re: Stop style bobbin question

Postby NZcaver » Jul 7, 2011 11:25 pm

gdstorrick wrote:Now we should know what the subject of the conversation is.So why are there so many pictures here of Petzl stop bobbins, an entirely different device? Why not talk about the device that GroundquestMSA asked about?

Hi Gary. We are talking about the Kong. The "so many pictures" of the Petzl Stop are all the same photo (my photo) and other people quoting it in their posts. When the question of insufficient friction led to discussion on the standard use of braking carabiners with bobbins, I used the photo as a generic example to differentiate between a braking carabiner and a breaking carabiner (correcting my earlier typo). I was showing how a braking carabiner can be used in conjunction with virtually any model of bobbin, including the model Groundquest has. My old Kong is currently tucked away in storage, and I don't have any photos of it rigged with a braking carabiner. So I substituted this shot of my old Petzl, which was already posted on the forum.

Clear as mud?

PS - for what it's worth, your assessment of the Kong is in line with my previous experiences using it. Of course it's possible we both might be wrong. :doh:
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Re: Stop style bobbin question

Postby paul » Jul 8, 2011 6:14 am

GroundquestMSA wrote:
paul wrote:
Chads93GT wrote:rope enters the bottom and leaves the top coming down to the brake biner.

Image


Are you taking to extremes my claims of personal stupidity or are you chastising Chads93GT for his redundancy?


Neither. A picture is worth a thousand words. I have been using "Bobbin-type" descenders for over twenty-five years and I have seen many instances of incorrect usage. And the cave rescue team I belong to have had to assist several badly injured cavers when they've had an accident caused by misuse, so I think it's important to get it right.
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Re: Stop style bobbin question

Postby Chads93GT » Jul 8, 2011 6:44 am

GroundquestMSA wrote:
paul wrote:
Chads93GT wrote:rope enters the bottom and leaves the top coming down to the brake biner.

Image



Are you taking to extremes my claims of personal stupidity or are you chastising Chads93GT for his redundancy?



I only said it because you said you weren't sure that you threaded the rope through right. I wasn't poking fun at you.
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Re: Stop style bobbin question

Postby gdstorrick » Jul 10, 2011 6:53 pm

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Re: Stop style bobbin question

Postby Jeff Bartlett » Jul 10, 2011 8:26 pm

Chads93GT wrote:You clip the rope into the biner, then you pull up on the rope. this makes a zig zag. The reason I dont like it, is using a bobbin/stope wears your gloves down. I can rap with a rack and not wear my gloves out at all.


Weird. I use a Simple almost exclusively on pitches <150ft, and I just use cheap nitrile gloves from home depot; general caving wears out the fingertips before rappelling does anything to them. It's just like a rack, really, where your right hand loosely encircles the rope and directs the angle of it; the difference is that with a rack, your left hand adjusts the friction of the device, whereas with a Simple or Stop the friction isn't adjustable beyond the angle it exits the brake carabiner. You shouldn't actually be applying any braking force with either hand unless you're unable to control your speed with the maximum angle being applied to the brake carabiner already.

On 11mm pit rope, I very rarely need much of an angle through the brake carabiner at all.
"Although it pains me to say it, in this case Jeff is right. Plan accordingly." --Andy Armstrong
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Re: Stop style bobbin question

Postby Chads93GT » Jul 11, 2011 11:16 am

for some reason I wear out my right hand glove even when using a rack. Im thinking I hold my hand on teh rope more than I actually think I do?
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Re: Stop style bobbin question

Postby TennEagle » Jan 3, 2012 12:16 pm

Gee, novitiate hesitates to offer any advice, but I do have the Petzl Stop manual, and it does have diagrams showing the addition of a carabiner for braking and an explanation of its use. I don't see how to attach a .pdf here, but this link should work for you: http://wesspur.com/images/pdfs/petzl-stop.pdf "Additional Braking" is on Page 4, Figure 3A, with the description on Page 6. I think you might also find some of the rope data (Dynamic Slippage) helpful for your questions about rope diameter.
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