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Author

WANTED: first generation Gri Gri

Pat

31/01/2012
9:06:39 PM

Looking to get my hands on a first generation gri gri. Anyone with one they don't need anymore?

Samuel

1/02/2012
8:20:58 AM

Ebay. $60 from the states plus some postage. Fairly new ?

mikllaw

1/02/2012
9:06:08 AM

i have an old very worn one you can have, perfect for 10.5 mm ropes but not much less

Pat

1/02/2012
1:43:15 PM

Hi Mikl,

I'm wanting to modify it for solo aid - will be using 10.5 - I guess I will have to look at what diameter my mammut tusks are. Get back to you soon.

Pat

2/02/2012
8:39:26 AM

Bump

miketg

2/02/2012
12:47:33 PM

Hey I have a Mammut Tusk, its 9.8mm

Pat

2/02/2012
1:21:49 PM

Yeah, they list it as 9.8, but when you measure it its about 10.2. I read somewhere that the UIAA test for diameter is to cut a length of rope (not sure what length) and then weight it with a specific weight and then measure the diameter - so I guess that's why its 9.8 but measures 10.2.

shortman

2/02/2012
1:24:31 PM

On 2/02/2012 Pat wrote:
>Yeah, they list it as 9.8, but when you measure it its about 10.2. I read
>somewhere that the UIAA test for diameter is to cut a length of rope (not
>sure what length) and then weight it with a specific weight and then measure
>the diameter - so I guess that's why its 9.8 but measures 10.2.

What da? That just made my mind boggle!?!

Pat

2/02/2012
1:29:26 PM

I'll see if I can find the reference - it was legit, but I'm not sure if it was for UIAA or CE standard.

mikllaw

2/02/2012
1:39:38 PM

For friction you need to also consider how fuzzy the rope is, that can add half a mm or more to the effective diameter. And if there is any water it seems to be much 'stickier'.

Pat

2/02/2012
2:52:46 PM

On 2/02/2012 Pat wrote:
>I'll see if I can find the reference - it was legit, but I'm not sure if
>it was for UIAA or CE standard.

Mammut say that in the test the rope is subjected to a 10kg load. They don't say what length or rope this is done with, but I remember that a short length (2 or 3 meters?) is cut for the test.

sliamese

2/02/2012
3:49:35 PM

having used an old un-modified gri-gri a fair bit aid climbing (maybe 75ish pitches?) I've converted to using reverse/guide. no mods required, runs smoothly for free-climbing and can do your double rope raps easier. is an option if you can't find a gri-gri!!

Pat

2/02/2012
4:45:40 PM

Do you mean a BD Guide? Is there a way to use the guide so it auto-locks like the gri gri?

mikllaw

2/02/2012
7:03:59 PM

On 2/02/2012 Pat wrote:
>Mammut say that in the test the rope is subjected to a 10kg load. They
>don't say what length or rope this is done with, but I remember that a
>short length (2 or 3 meters?) is cut for the test.

Length doesn't matter, just stress (load divided by cross sectional area)

Pat

2/02/2012
7:41:32 PM

I always find the physics stuff hurts, but wouldn't the same load applied to a 50 meter rope reduce the diameter less than it would applied to a 2 meter length?

shortman

2/02/2012
8:31:41 PM

On 2/02/2012 Pat wrote:
>I always find the physics stuff hurts, but wouldn't the same load applied
>to a 50 meter rope reduce the diameter less than it would applied to a
>2 meter length?

Yeah, but a 9.8 is still 9.8 and a 10.2 rope is still 10.2....etc....etc...

Pat

2/02/2012
9:11:16 PM

yep fair enough, but my tusk is labelled as a 9.8 but because of they way they test for diameter its actually 10.2, which puts it in the ball park for the old gri gri - but I get your point.

mikllaw

2/02/2012
11:15:10 PM

On 2/02/2012 Pat wrote:
>I always find the physics stuff hurts, but wouldn't the same load applied
>to a 50 meter rope reduce the diameter less than it would applied to a
>2 meter length?
sorry but no

There are 18 messages in this topic.