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Pulleys


kurthicks
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The maxi traction.

A good large frame hauler, but the wheel is slightly too small for the loads sometimes.

CMI are the pulley masters! they get all rescue freakout..

 

A good rule of thumb is the heavier the load, the bigger the wheel. ( this is true to a point )

...when the wheel gets too big, it causes more friction, but climbers specific wheels aren't that big anyway.

 

whatever...Big Wall?...Big wheel!

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Since it seems like people are getting excited about prussiks and z-systems and stuff...

what is everyone's pulley of choice? prussik minding or not? weight? other ideas (Guarda, etc)?

 

For basic glacier travel, light and fast (OK I'm too old and fat to move fast frown.gif, but light anyway), I serioulsy think a combination of the Petzel ULTRALEGERE with the Omega JC Wire Gate is the way to go.

 

At a combined total weight of 51 gms (that's 1.8 ounces blush.gif) it is hard to beat for weight. thumbs_up.gif The JC Wire gate happens to be built perfectly to allow the wheel to turn without hitting the side of the biner. thumbs_up.gif Keep in mind that you have to have a biner anyway.

 

If you are worried about strength, I agree it isn't the strongest thing out there. frown.gif But this way the biner acts as the pulley's axle, instead of some weak ass axle like on the Petzl OSCILLANTE Further, this set up elimniates the weak ass housing connecting hte axel to the biner. Tell me that is stronger than a biner... hellno3d.gif

 

Maybe I'm wrong, you engineer type feel free to chime in and tell me I'm high on crack. cantfocus.gif But it certainly seems to be to be the best "lightweight" system out there.

 

bigdrink.gif

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yup.

 

Glaciers: Produit_Image_347.jpg

 

 

Rock: minitraxion.

 

On the same subject (crevasse rescue) you people who carry mechanical ascenders on glaciers should reread your Twight. You think that's "light and fast"??? WTF.

 

The best system for crevasse rescue is to not fall in in the first place. Note the super technical rope system Kurt and I are using here

 

4707_armada.jpg

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i haven't hauled anything all that heavy with it actually. it's more like peace of mind when i head out. but i like to follow rule no. 1...don't fall in. you can always drop the pulleys out of the system and just use biners. that's why i was asking in the first place.

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Z x C (where you add a C to the pull end of the Z by threading a sling or cord through the locking prussik and then run the pull-end of the rope through that) is a 5:1, not 6:1. Geek_em8.gif

 

I say, don't fall in. If you do, prussik out. If you can't prussik out, use a 5:1 with garda. If that's not enough, use a 7:1 which is actually a pretty simple set-up.

 

Wilderness Search and Rescue by Setnicka has tons of this shizzle in it and a look at the physics involved in the systems. It's a fun read if you're interested in the technical/scientific end of it.

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I'd want to look into this a little more. I havn't seen a number in climbing related lits anywhere, but, from my work rigging 3 line diameters is the minimum size for pulleys before you start adding to the friction of the system. I'm sure it is better that a plain biner though.

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anyone rely solely on a tibloc setup?

 

I do.

 

My crevasse rescue gear:

One small basic pulley

two tiblocs

one locking oval biner

one regular oval biner

texas prusik foot loop (with smaller top loop cuz when using tibloc instead of prusik knot, you don't need as much rope)

regular prusik loop for harness

 

This gear allows me to climb the rope and setup a basic 3:1 "Z" pulley. If I need to add on a "C" I'll use slings and biners (higher friction, but it'll work).

 

 

wave.gif

 

p.s. I don't use these: Produit_Image_347.jpg because in my brief experience with them, the rope can slip off the side of the wheel and jam up in between the side of the wheel and the biner. I prefer something like this:

pe-swing-side-f01_small.jpg

 

wave.gifwave.gif

Edited by Alpinfox
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Z x C (where you add a C to the pull end of the Z by threading a sling or cord through the locking prussik and then run the pull-end of the rope through that) is a 5:1, not 6:1. Geek_em8.gif
I'm not quite sure what you are saying here at the end, but a "C" 2:1 acting on a "Z" 3:1 is a 6:1 compound system. Geek_em8.gif^2
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If someone told me to build a "batwing" I'd picture a 3:1 on 3:1 with a change of direction to make a 9:1. Maybe the term can be used for other systems? The batwing term I think comes from reed thorne's ropes that rescue course (and its graduates who are addicted to aztec kits afterwards yellaf.gif )

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