Im I using my rack wrong?

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Im I using my rack wrong?

Postby Oddball » Oct 30, 2014 12:51 pm

To sum it up quickly i have a micro rack with two hyper bars. From what I read a micro (depending on who you ask) is not good for long descents. Have also read about adjusting the bars, which in my many descents have never done. I still have to feed rope to my rack and is the primary way I control speed. I understand the factor of rope weight but that is the basis of a "bottom bellay" (i think that is the term... you just add more weight to the rope.)
So the main question is using my hyperbars am I actually adjusting the first 2 bars by the way I feed rope in? And if i'm not planning on descending 200 ft a min where heat could become an issue, why do i need a long rack instead of my mirco?
I did not sum this up quickly as I said I would, but I have done 200 ft plus pits with no problem with my mirco when others may say use a long. any insight and knowledge will be helpful.
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Re: Im I using my rack wrong?

Postby GroundquestMSA » Oct 30, 2014 1:27 pm

Oddball wrote: From what I read a micro (depending on who you ask) is not good for long descents.

Micro racks have been used successfully for very long descents.
Oddball wrote:Have also read about adjusting the bars, which in my many descents have never done.

There's really no room to adjust bars on a micro rack, and it's impossible anyway if you're utilizing the hyperbar.
Oddball wrote: I still have to feed rope to my rack and is the primary way I control speed.

If by "feed" you mean manually push the rope through the descender, be careful, and read this. If you mean that you are primarily controlling your speed with your brake hand, then that's fine. Friction on the hip and/or brake hand as well as the angle of the rope as it exits the rack are how it's done.
Oddball wrote:So the main question is using my hyperbars am I actually adjusting the first 2 bars by the way I feed rope in?

How are you using the hyperbars? I haven't been using them at all lately, and I can't imagine a need to use them both unless you're locking off. Using the top hyperbar adds a lot of friction since it adds another surface, another bend, and it mashes the four bars together more tightly.
Oddball wrote:And if i'm not planning on descending 200 ft a min where heat could become an issue, why do i need a long rack instead of my mirco?

You don't.
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Re: Im I using my rack wrong?

Postby caver.adam » Oct 30, 2014 1:40 pm

I agree with what was said above.

Feeding rope can be dangerous in some situations. If you are feeding rope there are a number of factors you can adjust. Is your body positions correct (legs perpendicular to the rock face) or are you leaning too far forward? Do you have too many bars set? By using your hyperbar are you adjusting your bars automatically closed (the rope pulls the bars upwards toward the hyperbar as you brake)?

I have one hyperbar on my mini-rack and often rappel without using the hyperbar. Especially at the top of a tall drop. This lets me control my speed by moving my bars and by putting tension on my control/brake hand.

Issues with micro racks are two that I'm aware of. The first is that it is not possible to safely adjust the number of bars you are using and is harder to lock off your rack (unless you have double hyperbars). The second is that there is less metal to dissipate the heat. This heat can cause the rope sheath to be glazed. This decreases the life of the rope and can cause dangerous situations. I've even known 1 person to do a 400 foot pit with a micro rack and a squirt bottle to watercool his rack. But in general, if your rack is getting hot enough to glaze the sheath on the rope....it's too hot and you need another rack.
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Re: Im I using my rack wrong?

Postby caver.adam » Oct 30, 2014 1:41 pm

(Ok...there are a lot more than 2 issues I'm aware of...but they also apply to full sized racks so I'm not including them).
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Re: Im I using my rack wrong?

Postby rlboyce » Oct 30, 2014 5:44 pm

I made the mistake of purchasing an aluminum micro back when I first got into caving. I had to feed rope all the time, unless I was heavily weighted with gear. Even then, it was still slow progress. Using the hyperbar was almost a joke. I finally wised up and bought a stainless steel rack. Big difference. I still have to occasionally feed rope, but that's only if I'm rappelling very dirty rope and have little gear. I don't weigh much as others, so it'll probably always be an issue for me when using a rack.
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Re: Im I using my rack wrong?

Postby yvonnedroms » Oct 30, 2014 7:20 pm

If you weigh under 150 lbs or so, you need the longer version of the microrack, so you can spread the bars more. It feels counter-intuitive (longer rack for shorter, lighter people), but that's the way it works. If you're feeding rope into the rack in order to move down, beware! You could open a bar and then suddenly lose two bars, causing an out-of-control rappel. Get the proper descending gear for your weight and for your purposes (length of descent)...
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Re: Im I using my rack wrong?

Postby Oddball » Oct 31, 2014 7:49 am

I will clarify what I meant when said said I have to feed the rope as it seems to have been a common topic in the replies.I meant I use my brake hand as the main means of controlling decent speed, either by increasing friction or angle of the rope as it approaches the rack.
I do use my top hyperbar and the second when tying off.
I believe just through the replies I have received, I just had some misperceptions that I'm not really sure how I picked up.
I weigh 160 pounds and routinely will not use the hyper bar in this particular cave (it is not a 90 degree drop, but closer to a 45 degree slippery slope that my feet are always planted on. The accent is actually achieved by just using my frog's main hand ascender and my QAS's hand ascender instead of my foot loops.) For this drop I do not use the hyperbar because my full body weight is not put onto the rope and tends to be difficult to descend at all (and the decent is only around 15 foot.) For a free fall I feel more confident with using my hyperbar.
Thanks for the responses. Cleared up some things for me. Seems my Miro is not as limited to its uses as I thought.
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Re: Im I using my rack wrong?

Postby Adam Byrd » Oct 31, 2014 10:29 am

Oddball » Fri Oct 31, 2014 7:49 am
For this drop I do not use the hyperbar because my full body weight is not put onto the rope and tends to be difficult to descend at all (and the decent is only around 15 foot.)


To negotiate a 15' slope, consider a Munter hitch on a pear-shaped 'biner or another device with less friction like a Figure 8. An arm rappel might also suffice on low angle terrain.
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Re: Im I using my rack wrong?

Postby yvonnedroms » Oct 31, 2014 12:12 pm

Another option for descending a 15-foot slope (or a longer one, as long as it's angled, and not vertical) is to use 2 bars plus the hyperbar on a microrack. You'll find it works very smoothly. Make sure no part of the slope is fully vertical, though, or you may not have enough friction in that case.
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Re: Im I using my rack wrong?

Postby Oddball » Oct 31, 2014 12:39 pm

yvonnedroms wrote:Another option for descending a 15-foot slope (or a longer one, as long as it's angled, and not vertical) is to use 2 bars plus the hyperbar on a microrack. You'll find it works very smoothly. Make sure no part of the slope is fully vertical, though, or you may not have enough friction in that case.
Adam Byrd wrote:
Oddball » Fri Oct 31, 2014 7:49 am
For this drop I do not use the hyperbar because my full body weight is not put onto the rope and tends to be difficult to descend at all (and the decent is only around 15 foot.)


To negotiate a 15' slope, consider a Munter hitch on a pear-shaped 'biner or another device with less friction like a Figure 8. An arm rappel might also suffice on low angle terrain.


Thanks for the input but 20 feet from the drop I was talking about is the 250ft pit.... So while i am in my gear may as well use it. although I do know another cave that may be useful for an arm reppel or Munter hitch (war eagle)...
thanks for the input
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Re: Im I using my rack wrong?

Postby Claff » Oct 31, 2014 7:03 pm

Oddball wrote:
Thanks for the input but 20 feet from the drop I was talking about is the 250ft pit.... So while i am in my gear may as well use it. although I do know another cave that may be useful for an arm reppel or Munter hitch (war eagle)...
thanks for the input


Are you referring to the entrance drop in War Eagle? If so, I would strongly recommend you do not use a Munter Hitch or arm rappel. I don't recall the exact distance, but there's somewhere around 130ft of free hanging vertical after the flowstone slope. If it's some nuisance drop I don't know, please disregard.

Cave safely,
Chris
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Re: Im I using my rack wrong?

Postby Chads93GT » Nov 1, 2014 9:56 pm

You can do 800' on a micro rack. It was done two weeks ago in west Virginia. However. Not recommended.
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Re: Im I using my rack wrong?

Postby GroundquestMSA » Nov 2, 2014 5:19 pm

Chads93GT wrote:You can do 800' on a micro rack. It was done two weeks ago in west Virginia. However. Not recommended.


Did you do it on a micro?

Micro-racks have been used, reportedly, to do Golondrinas (1000+'). One individual who did so wrote an article for the Texas Caver in which he called the micro a bad idea for 150 meter or more pits if you're a light caver. Like Chad, I'm not recommending anything. It seems though, that the mounting evidence suggests that micro-racks may be an adequate choice for most pits. Given appropriate skill and experience of the operator, of course.
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Re: Im I using my rack wrong?

Postby Chads93GT » Nov 2, 2014 6:58 pm

Oh hell no, I will use an 18" long rack any day of the week on that drop. Its the difference between riding in an Escalade and a Pinto with 400,000 miles on it and 3 wheels.

If I did a micro on a large drop (with new rope) I would be over the hyperbar in no time, if not all of the way.

I would rather haul ass on an 18" rack and not glaze the rope.
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Re: Im I using my rack wrong?

Postby Oddball » Nov 2, 2014 10:47 pm

Claff wrote:
Oddball wrote:
Are you referring to the entrance drop in War Eagle? If so, I would strongly recommend you do not use a Munter Hitch or arm rappel. I don't recall the exact distance, but there's somewhere around 130ft of free hanging vertical after the flowstone slope. If it's some nuisance drop I don't know, please disregard.

Cave safely,
Chris


Thanks for the advice but no, the entrance drop to War Eagle is not the drop in War Eagle I was talking about. Thanks for the concern, because that would be a truly dangerous situation.
I was actually talking about a flowstone drop in the downstream(from the entrance) horizontal part. Glad someone has got to experience such a great cave. One of the best caves I know that offers so much (but I haven't experienced enough). I wrote down a caving journal entry about it Id be happy to share. PM if you would like. It has some "sensitive" information I will need to edit. But that is not the topic of the thread. If someone would like me to post it in another thread I can, but its brief and wouldn't actually call it a "trip report".
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