Stop style bobbin question

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Stop style bobbin question

Postby GroundquestMSA » Jul 5, 2011 3:39 pm

I just bought an old Kong single brake descender. My dear and only caving rope is being borrowed in a land far away and so I gave it a go on my 10.5mm Mammut climbing rope. Having no experience with this type of a thing, I rigged it according to the instructions given in "On Rope" for a Petzl Stop. Here's the problem;
I went very fast, struggling to keep myself under control. So, Is it the rope, or am I doing something horribly wrong? Is there normally another means of adding friction? I could wait until I get my rope back and try again, I suppose, but that may be a while. I have read that these things can be used with small diameter ropes (8 or 9mm), are they going to be slower than a 10.5 dynamic?
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Re: Stop style bobbin question

Postby Anonymous_Coward » Jul 5, 2011 5:17 pm

Smaller diameter ropes are almost always faster, so I wouldn't necessarily go that route looking for more friction.

Are you using a braking carabiner? You will get a lot more control with one than without. Some of the biners that are made especially for this like the Freino have a pinch point that adds lots of friction. IMHO, bobbins are not worth using without a braking carabiner. YMMV.

(First time ever use of IMHO and YMMV, sort of a milestone for me. I just learned how to text last year...)
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Re: Stop style bobbin question

Postby NZcaver » Jul 5, 2011 7:24 pm

Anonymous_Coward wrote:(First time ever use of IMHO and YMMV, sort of a milestone for me. I just learned how to text last year...)

:rofl: Nice.

I agree with Andy's advice.

Groundquest, is your bobbin one of these? My first descender (unless you count a figure 8 - which I don't) was the Kong Speleo. It's version A on the left in the photo on Gary's website. I regularly used it on 10.5mm and 11mm static rope. It seemed to do just fine, but I was a little slimmer back in those days. I would certainly recommend adding a breaking carabiner.
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Re: Stop style bobbin question

Postby Scott McCrea » Jul 5, 2011 8:14 pm

NZcaver wrote: a breaking carabiner.

:yikes:
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Re: Stop style bobbin question

Postby NZcaver » Jul 5, 2011 8:33 pm

Scott McCrea wrote:
NZcaver wrote: a breaking carabiner.

:yikes:

:laughing: Got me! :doh: Typing too fast for my brain again. :oops:


To clarify, I meant braking carabiner...
Image

... not breaking carabiner.
Image
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Re: Stop style bobbin question

Postby chh » Jul 5, 2011 8:38 pm

Scott McCrea wrote:
NZcaver wrote: a breaking carabiner.

:yikes:

:laughing: watch out for those!

Dynamic climbing lines will always feel faster than static lines, but do learn how to use a breaking carabiner(s). Just because a descender has an assisted braking mechanism does not make it suitable for smaller lines, braking biners do though.
Your words of caution are no match for my disaster style!
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Re: Stop style bobbin question

Postby Amazingracer » Jul 5, 2011 8:55 pm

I recommend a Steel biner. Its a little heavier but wont groove out as quickly as an aluminum one. I use a steel Oval with my Stop.
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Re: Stop style bobbin question

Postby NZcaver » Jul 5, 2011 8:58 pm

Amazingracer wrote:I recommend a Steel biner. Its a little heavier but wont groove out as quickly as an aluminum one. I use a steel Oval with my Stop.

Agreed. The Raumer Handy was designed for this, but they're a little difficult to find in the US. It would be nice if Petzl made a steel version of the Freino.
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Re: Stop style bobbin question

Postby GroundquestMSA » Jul 5, 2011 9:18 pm

NZcaver wrote:Groundquest, is your bobbin one of these?


Yes it is. Exactly the same except red.

Anonymous_Coward wrote:Smaller diameter ropes are almost always faster, so I wouldn't necessarily go that route looking for more friction.


I know that small ropes are faster. My question concerned different rope types. How much faster is dynamic rope? Is a 10mm climbing rope as fast as a 9mm static, etc.?

chh wrote:Dynamic climbing lines will always feel faster than static lines, but do learn how to use a breaking carabiner(s). Just because a descender has an assisted braking mechanism does not make it suitable for smaller lines, braking biners do though.


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?
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Re: Stop style bobbin question

Postby NZcaver » Jul 5, 2011 11:09 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?

Try using a braking carabiner? :shrug: If it's still too fast, tie a Munter hitch in the braking carabiner. Can't imagine you'd need to do that, even with a 10.5mm dynamic.

Hard to say how much faster a dynamic rope should be compared with a static/low stretch rope. Besides being stiffer and being more resistant to bending, caving ropes tend to acquire surface fuzz and dirt more than the average climbing rope. All these factors contribute to increased friction. Abuse your nice climbing rope, and you probably won't descend quite so fast. :big grin: Or get your old rope back. Or try a rack instead.
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Re: Stop style bobbin question

Postby GroundquestMSA » Jul 6, 2011 2:54 pm

I'm having a bit of difficulty learning exactly how to use a braking carabiner (slow internet connection = no video). How does the arrangement in the above photo add friction? Can someone give me some basic directions? I'm very, very slow of wit.

On the other hand, why do I want a device that requires additional parts to work properly? Is there any advantage to using a stop or any other bobbin rather than a rack? I bought the thing with a lot of other equipment and I already own and use a rack, so if there are no situations where a stop will benefit me I'll sell it. I would still love to know how to use it properly though, just in case I someday need to.
Thanks for the help so far.
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Re: Stop style bobbin question

Postby Chads93GT » Jul 6, 2011 3:22 pm

GroundquestMSA wrote:I'm having a bit of difficulty learning exactly how to use a braking carabiner (slow internet connection = no video). How does the arrangement in the above photo add friction? Can someone give me some basic directions? I'm very, very slow of wit.

On the other hand, why do I want a device that requires additional parts to work properly? Is there any advantage to using a stop or any other bobbin rather than a rack? I bought the thing with a lot of other equipment and I already own and use a rack, so if there are no situations where a stop will benefit me I'll sell it. I would still love to know how to use it properly though, just in case I someday need to.
Thanks for the help so far.


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.
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Re: Stop style bobbin question

Postby LukeM » Jul 6, 2011 3:28 pm

Groundquest, if you hold the rope upward while it's through the braking carabiner it effectively acts as a braking bar. I would try the device with some stiff caving rope before passing judgement on it. Your climbing rope is surely very supple.

There are all sorts of reasons for using a bobbin style descender over a rack, just as there are reasons for doing the opposite. I would say the main arguments for using a bobbin are that it's simple, lightweight, and quick/easy to use. In the case of a 'stop' style bobbin, you have an extra safety in case you become incapacitated while rappelling. Some would consider this a huge benefit. In my experience a rack excels when negotiating larger drops, when on crusty, thick rope, and when carrying a heavy person.
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Re: Stop style bobbin question

Postby NZcaver » Jul 6, 2011 4:50 pm

LukeM wrote:Groundquest, if you hold the rope upward while it's through the braking carabiner it effectively acts as a braking bar. I would try the device with some stiff caving rope before passing judgement on it. Your climbing rope is surely very supple.

There are all sorts of reasons for using a bobbin style descender over a rack, just as there are reasons for doing the opposite. I would say the main arguments for using a bobbin are that it's simple, lightweight, and quick/easy to use. In the case of a 'stop' style bobbin, you have an extra safety in case you become incapacitated while rappelling. Some would consider this a huge benefit. In my experience a rack excels when negotiating larger drops, when on crusty, thick rope, and when carrying a heavy person.

:yeah that:

Groundquest, there are dozens of previous topics on the forum discussing bobbins and stops and how they compare with racks etc. Check out a couple of recent ones here and here.
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Re: Stop style bobbin question

Postby MUD » Jul 6, 2011 5:10 pm

GroundquestMSA wrote:I'm having a bit of difficulty learning exactly how to use a braking carabiner (slow internet connection = no video). How does the arrangement in the above photo add friction? Can someone give me some basic directions? I'm very, very slow of wit.

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