|
8flood8
Nov 25, 2007, 4:52 PM
Post #1 of 20
(8208 views)
Shortcut
Registered: Nov 10, 2004
Posts: 1436
|
is this the same as accessory cord?
i got my #4 big bro from the mail man.
Is PMI 5mm or 6mm accessory cord the same thing as tech cord??
or do i need to buy something that has kevlar in it to make it tech cord? i've seen both and the kevlar action is really really stiff.
another question, for those of you that sling the knots inside the bros, how do you fit the big ass knot in there? just all bunched up and what not?? anyone think it would be bad to have the knot resting over the top of the big bro between the top two sling-holes?
and... what kind of knot? are we talking double fisherman's end-to-end?
anyway.. yes i read the directions... they weren't that specific!
|
|
|
|
|
vegastradguy
Nov 25, 2007, 5:14 PM
Post #2 of 20
(8197 views)
Shortcut
Registered: Aug 28, 2002
Posts: 5919
|
tech cord is not accessory cord. tech cord needs kevlar in it- titan or gemini cord are two types- i think there's a couple more out there. expensive and stiff, but MUCH stronger than standard accessory cord of the same diameter.
i dont sling the knot inside the bro- put it on one side of the sling outside the bro. i'm actually not sure you could put the knot in any bro except the biggest one....
i wouldnt put it on top of the bro- seems like that'd be a good place to create some weird forces.
knot- double fishermans- just like you would tie a pruisk or cordlette.
watch trango's video on how to use a big bro for a good look at the sling that Mal has on his bros- they should look just like that when you're done.
|
|
|
|
|
8flood8
Nov 25, 2007, 5:39 PM
Post #3 of 20
(8184 views)
Shortcut
Registered: Nov 10, 2004
Posts: 1436
|
excellent, thanks for the reply!
|
|
|
|
|
maldaly
Nov 25, 2007, 6:15 PM
Post #4 of 20
(8168 views)
Shortcut
Registered: Oct 31, 2002
Posts: 1208
|
Hey 8flood8,
Use this stuff:
http://www.mountaingear.com/pages/product/product.asp/imanf/BlueWater+Ropes/idesc/Titan+Spectra+Cord+%2D+5.5+mm+x+6+m/Store/MG/item/640554/N/1055
Your local shop may be able to get it to you in less than 6M lengths.
Other manufacturers have similar stuff as well. PMI, Sterling, etc. Whatever you use ought to have a tensile strength of 14-16kN.
Mal
|
|
|
|
|
poedoe
Nov 25, 2007, 6:23 PM
Post #5 of 20
(8165 views)
Shortcut
Registered: Mar 25, 2005
Posts: 107
|
Um actually double fishermans shouldn't be used on tech cord, much has been written about this. Use a triple fishermans, I think the instructions that come with the big bro say this as well. Also the instructions tell you how much tech cord to use to sling them and I felt like it wasn't enough after tying the knots and all. Go with an extra 6 - 12 inches and it will work better.
|
|
|
|
|
8flood8
Nov 25, 2007, 6:30 PM
Post #6 of 20
(8159 views)
Shortcut
Registered: Nov 10, 2004
Posts: 1436
|
so as long as the cord is strong enough, kevlar is not necessary?
|
|
|
|
|
maldaly
Nov 25, 2007, 6:48 PM
Post #7 of 20
(8153 views)
Shortcut
Registered: Oct 31, 2002
Posts: 1208
|
Worry less about what's in it and more about its strength and knotability. I believe that anything you find in 5.5mm x 14kN will have kevlar, vectran, spectra or dyneema in it.
|
|
|
|
|
8flood8
Nov 25, 2007, 6:58 PM
Post #8 of 20
(8145 views)
Shortcut
Registered: Nov 10, 2004
Posts: 1436
|
sweet thanks!
|
|
|
|
|
ja1484
Nov 25, 2007, 7:44 PM
Post #9 of 20
(8125 views)
Shortcut
Registered: Aug 11, 2006
Posts: 1935
|
poedoe wrote: Um actually double fishermans shouldn't be used on tech cord, much has been written about this. Use a triple fishermans, I think the instructions that come with the big bro say this as well. Also the instructions tell you how much tech cord to use to sling them and I felt like it wasn't enough after tying the knots and all. Go with an extra 6 - 12 inches and it will work better.
Quoted for truth. Triple fishermans. Double's are considered too slippery with tech cord. I myself just make it quads for symmetry.
|
|
|
|
|
vegastradguy
Nov 26, 2007, 6:37 AM
Post #10 of 20
(8064 views)
Shortcut
Registered: Aug 28, 2002
Posts: 5919
|
poedoe wrote: Um actually double fishermans shouldn't be used on tech cord, much has been written about this. Use a triple fishermans, I think the instructions that come with the big bro say this as well. Also the instructions tell you how much tech cord to use to sling them and I felt like it wasn't enough after tying the knots and all. Go with an extra 6 - 12 inches and it will work better.
my bad- i get the double/triple thing confused....it should be triple fishermans....
|
|
|
|
|
8flood8
Nov 26, 2007, 7:33 PM
Post #11 of 20
(8000 views)
Shortcut
Registered: Nov 10, 2004
Posts: 1436
|
i always "say" double fisherman (meaning two fisherman's knots butt to butt) but i always "tie" a triple - at minimum.
|
|
|
|
|
knudenoggin
Nov 27, 2007, 4:09 PM
Post #12 of 20
(7950 views)
Shortcut
Registered: May 6, 2004
Posts: 596
|
8flood8 wrote: i always "say" double fisherman (meaning two fisherman's knots butt to butt) but i always "tie" a triple - at minimum.
Huh? "double" = "butt-to-butt", so that implies that
"triple" = "butt-to-butt-to-butt" ??!
There is some twisted nomenclature that has (mis)guessed that the
name "Double Fisherman's (knot)" derives from there being two of
something and that something is what is tied in each rope--nope.
The "double" comes from the component--an Overhand with a 2nd
tuck, essentially. One sees this mis-thinking esp. w/arborists, who
condoundingly call the noose hitch with a Dbl.Oh. a "Fisherman's
knot" ("Strangle Noose" would be better).
.:. A better name set is "Grapevine", "Dbl. G.", Trp. G.", ... ;
here, the number can be seen in the overwraps of the component.
*kN*
|
|
|
|
|
8flood8
Nov 27, 2007, 5:43 PM
Post #13 of 20
(7933 views)
Shortcut
Registered: Nov 10, 2004
Posts: 1436
|
agreed i like grapevine knot much better.
|
|
|
|
|
vegastradguy
Nov 27, 2007, 5:59 PM
Post #14 of 20
(7922 views)
Shortcut
Registered: Aug 28, 2002
Posts: 5919
|
knudenoggin wrote: 8flood8 wrote: i always "say" double fisherman (meaning two fisherman's knots butt to butt) but i always "tie" a triple - at minimum. There is some twisted nomenclature that has (mis)guessed that the name "Double Fisherman's (knot)" derives from there being two of something and that something is what is tied in each rope--nope. The "double" comes from the component--an Overhand with a 2nd tuck, essentially. One sees this mis-thinking esp. w/arborists, who condoundingly call the noose hitch with a Dbl.Oh. a "Fisherman's knot" ("Strangle Noose" would be better). .:. A better name set is "Grapevine", "Dbl. G.", Trp. G.", ... ; here, the number can be seen in the overwraps of the component. *kN*
i usually confuse it because when i visualize the knot, i think of a double fishermans as having two full wraps around the cord, where it really only has one. so, when i think of a 'double' fisherman's, i'm really thinking about a 'triple fishermans'. i've actually never used a double fisherman's in practice- not enough knot for me if i'm actually going to use the fishermans for anything....
|
|
|
|
|
knudenoggin
Nov 28, 2007, 1:58 AM
Post #15 of 20
(7886 views)
Shortcut
Registered: May 6, 2004
Posts: 596
|
vegastradguy wrote: i usually confuse it because when i visualize the knot, i think of a double fishermans as having two full wraps around the cord, where it really only has one. so, when i think of a 'double' fisherman's, i'm really thinking about a 'triple fishermans'.
BINGO! --exactly why I like going w/"Grapevine" (which is also an old
name), and "Dbl.Grapevine" (has extra, 2nd wrap), et cetera.
And "Grapevine" doesn't have any "Grapevine Bend" denoting a hitch,
as "Fisherman's Bend" (aka "Anchor Bend") does. That all still
leaves "Fisherman's knot" around, to denote the "single" version,
which is much used in commercial fishing (producing an efficient,
abrasion-resistant, ends-aligned joint). But then as for most
kernmantle-rope users, climbers won't miss this reference so much.
|
|
|
|
|
moof
Nov 28, 2007, 2:46 AM
Post #16 of 20
(7872 views)
Shortcut
Registered: Oct 17, 2003
Posts: 400
|
To clarify. There are several formulations of "tech cord" around, often generically called spectra cord. They are not all created the same.
1. Kevlar. Do NOT buy kevlar cord. Kevlar self abrades under load much worse than the rest (fibers are abrasive to each other). It is actually pretty hard to find kevlar cord these days, and this is why.
2. Spectra cord, comes under a few names, but is very slipper inside, usually has a polyester sheath. Works great, but as stated it REALLY needs a triple fishermans with decent tails (2" or longer). Spectra has a very low melt point, but for our purposes in climbing it is rarely an issue.
3. Tech Cord from mammut. Relative to kevlar (another "aramid", whatever that means). Very stiff, good stuff. The pamphlet that came with mine says a double fisherman's is OK, but claims you get a but more strength out of a triple. Not sure if this has changed, RTFM.
4. Kevalr/Spectra blends (I forget the brand name), also hard to find as the blend didn't really help the self abrading enough to help much.
There is an excellent writeup about many of these by Tom Moyer, well worth the read. Google "high strength tech cord tom moyer" and you'll get a copy or 10, or click on http://www.xmission.com/...gh_Strength_Cord.pdf
(This post was edited by moof on Nov 28, 2007, 2:51 AM)
|
|
|
|
|
knudenoggin
Nov 30, 2007, 12:22 AM
Post #17 of 20
(7819 views)
Shortcut
Registered: May 6, 2004
Posts: 596
|
moof wrote: To clarify. There are several formulations of "tech cord" around, often generically called spectra cord.
but where only "tech" is used it's usually an indicator of Technora,
a copolymer aramid related to Kevlar.
"Spectra" is a general trade name for HMPE (hi-modulus polyethylene),
as is Dyneema; they're slightly different in detail.
And there are different types/models/grades of Spectra,
Kevlar, & Dyneema (not sure about Technora). Seldom if
ever will you see such distinctions made in climbing-rope
ads (and I just saw some hilarious mistakes about Kevlar's
"melting temp" being way less than Technoras--it isn't, and
neither melts: they char),
but if you look for info from rope makers who sell yachting rope,
you'll find it.
Beyond these are Vectran & PBO fibers.
In reply to: The pamphlet that came with mine says a double fisherman's is OK, but claims you get a but more strength out of a triple.
a Technora-cored cord that slipped out of its Grapevine,
so the Dbl.Grapevine might be a good idea here, too.
|
|
|
|
|
grampacharlie
Dec 1, 2007, 2:16 AM
Post #18 of 20
(7793 views)
Shortcut
Registered: May 25, 2006
Posts: 388
|
I agree with moof. Kevlar=bad.
To add to that, I have an independant study done shortly after tech chord was introduced (bd gemini, technora, what ever) tath said it aslo self abraided whether under load on not, meaning the more it is flexed, tied and untied, the more it weakens.
This study was centered around it's use as a cordelette, so I'm not entirely sure of it's use for slinging pro.
On a side note, I have 5 mm tech chord on my hexes, though I don't fall on/employ them much at all anymore.
so... I'd steer clear of kevlar. For the money, it's hard to beat the duribility and usefulness of good old nylon.
|
|
|
|
|
treenail
Dec 4, 2007, 12:35 AM
Post #19 of 20
(7704 views)
Shortcut
Registered: Jan 20, 2002
Posts: 68
|
See 'this...me' arborists comments:
http://www.climerware.com/dogvine.shtml
|
|
|
|
|
kylethemonkey
Apr 6, 2011, 3:59 AM
Post #20 of 20
(6981 views)
Shortcut
Registered: Oct 16, 2006
Posts: 21
|
I recently purchased two Big Bro's and wanted to do a review of the tech cord that came with them for anyone who is trying to decide what to buy for slinging their Big Bro's.
The Number 3 (Green) Big Bro was purchased from Rock & Snow along with 6 mm Sterling PowerCORD. The cord that arrived was yellow with blue and green markings which makes for an overall yellow with green cord that matches the Big Bro.
The Number 4 (Blue) Big Bro was purchase from GearEXPRESS along with 5.5mm Edelweiss Aramid Cord. The cord that arrived was blue with purple and yellow markings which makes for an overall blue cord that matches the Big Bro.
The Sterling 6.0 cord is visibly thicker but was easier to thread than the Edelweiss 5.5 cord. The sheath on the the Edelweiss cord tends to bunch up and it took over 30 minutes to thread the cord through the 4 holes in the Big Bro (no problem with the Sterling). I can visually see that the braiding pattern is different on each cord. The Edelweiss braid is a tight diamond while the Sterling braid is herring bone.
The core of both cords is tan braided fibers that appear identical, but the Edelweiss has one yellow colored braid (I'm not sure why). The Sterling cord strength is listed as 19 kN and Edelweiss at 18 kN.
Bottom line: If I buy any more Bro Bro's I will buy Sterling 6.0 mm PowerCORD which was much easier to feed.
|
|
|
|
|
|
|
|
|
