double ropes - interchangeable with twins?
ant
hundred pitches of anecdotal experience. i always thought it was best
to clip double ropes separately. in the very unusual circumstances in
which i want both doubles into one piece, i use a biner for each rope.
for the second time in two months, ive been climbing with an
experienced climber who uses 8.5mm mammut doubles just like i would use
twins. i can think of pros and cons, but more cons spring to mind. i
have (had?) strong and complex technical reasons for the way i used
doubles, but maybe it just doesnt pan out the way i imagined.
assuming normal, steep, fifth class climbing:
Q1) just how bad is it to use doubles like twins?
(partners claim increased fall forces negligible)
Q2) is glazing a myth?
(even when different lengths of rope out, partners clip both ropes
through one biner)
come on, euros. ante up!
Chiloe
> Q1) just how bad is it to use doubles like twins?
> (partners claim increased fall forces negligible)
increases when doubles are used like twins -- link,
anyone? Is it really negligible? If not, I'd want a
good reason before doing this.
As for rope-on-rope damage, the risk of that seems
greatest if you clip your ropes as doubles at some
point on the lead, then as twins somewhere else --
so they could stretch differently and be sliding past
each other in a fall.
What's the upside of using doubles as twins? Seems
like you'd be combining the disadvantages of doubles
with most of the disadvantages of singles. Other
systems (doubles as doubles, twins as twins, single
plus a tag line) all make more sense for most of the
two-rope scenarios I can picture.
melissa
we'd end up using them as both within the same pitch. It's just less
hassle to clip them both in and keep on moving, but every so often we
have an issue of traversing or somesuch that makes us want to clip them
singlely. It always seemed to me that no matter how careful we were,
there'd be a twist or twenty in the ropes, so I figured we were getting
glazed in the event of a fall anyway. We're not big fall takers, so as
long as I didn't think they were at actual risk of getting burned
through, I guess I didn't stress about the twist too much (or the risks
of having them slide past each other). When stuff like that happens, I
don't mind saying "thank you" to my gear, and retiring it.
Lord Slime
> I haven't seen figures for how much the impact foce
> increases when doubles are used like twins -- link,
> anyone? Is it really negligible?
From experience, I'd say it's within the UIAA limits. Compare
this to the impact forces designed into those skinny (<10mm)
sport ropes they're selling now. They're HIGH, but still below
the UIAA limit. Since most double/twin belay devices slip
(no Gri-gri), or can be slipped, this seems quite reasonable.
> As for rope-on-rope damage, the risk of that seems
> greatest if you clip your ropes as doubles at some
> point on the lead, then as twins somewhere else --
> so they could stretch differently and be sliding past
> each other in a fall.
Yup, and it seems like a Catch-22. You'd only do this is you
had to, but that's when you're most likely to fall...
> What's the upside of using doubles as twins?
It calms the scary voices inside your head? You get really
strong hauling all that rope?
- Lord Slime
Dll
"melissa"
> When stuff like that happens, I
> don't mind saying "thank you" to my gear, and retiring it.
I think the issue is that there possibly wouldn't be a next time. This is
more or less how Dan O died, no? Rub two ropes together and make fire?
Climbed with a brand new pair of Genesis ropes a few days ago on a route I'd
done just a few days before with a single 10.5. What a contrast. So much
more drag and weight with the two ropes. Nevermind the CF factor. The one
and only advantage I see to two ropes is redundancy in alpine rock/ice fall
situations - but I question that, too, given the beating with ice tools,
crampons and sharp rocks I've seen my thicker ropes take. Even then, Ice
Floss is about the heaviest rope I'd want - which is still heavier with more
drag than a single rope. Packing a 7mm for hauling and raps, when you
actually need to haul and/or make long raps, is far more efficient in all
respects, IMO.
- Nate
Chiloe
> The one
> and only advantage I see to two ropes is redundancy in alpine rock/ice fall
> situations
near North Conway called Flight of the Falcon. It's about equal
parts 5.10d finger crack, 5.9 face traverse, then more 5.10 up
short finger cracks and an arete (115'). To do this smoothly
w/single rope you'd have to pass up protection opportunities
that IFO just don't wanna pass up. The gear's not all bomber
and the falls aren't all clean. I don't doubt that someone else
could be fine with one rope up there, though.
This is a great route, BTW, a one-pitch adventure that for
some reason hasn't made it onto most "classics" lists.
Dll
"Chiloe"
> Flight of the Falcon. [...] To do this smoothly
> w/single rope you'd have to pass up protection opportunities
> that IFO just don't wanna pass up.
Someone always cites some such exception, but I have yet to find one. Also,
is that exception worth the overhead the other 99.99% of the time?
> I don't doubt that someone else
> could be fine with one rope up there, though.
It's amazing what a few full length runners can do. Worst case is breaking
a pitch in half or dealing with probably the same rope drag I'd get on a
straight pitch with 2 ropes.
- Nate
krish...@myrealbox.com
Dll wrote:
> Someone always cites some such exception, but I have yet to find one. Also,
> is that exception worth the overhead the other 99.99% of the time?
>
comes immediately to mind - where i makes more sense to use a double
than not. But as always, YMMV.
Dawn Alguard
> Dll wrote:
> There are some areas where many routes zig-zag a log - 'Gunks
> comes immediately to mind - where i makes more sense to use a double
> than not. But as always, YMMV.
>
I climb at the Gunks and find doubles more of a nuisance than a help.
For one thing, you don't need the second rope to get down. There are
places where it might save you a rap or a short walk but you can always
get down with one. For another, doubles don't save you rope drag caused
by features, which tends to be the issue at the Gunks. If the ropes are
running against the lip of a roof or across ledges or around an arete,
you just get more drag from there being more of them.
One thing about climbing at the Gunks with one rope is you learn how to
use your runners.
Dawn
rgold
In the end, it is mostly just a matter of taste (or perhaps religion),
though of course the type of rock you are climbing on matters. But the
focus on the advantages, such as they are, for "wandering" routes
always seemed to me to miss an important point. On certain types of
rock, doubles increase your protection options. The pro can wander
even if the route doesn't. If you climb with doubles and don't notice
the new options available, then of course you aren't likely to find
doubles advantageous. So maybe there really is no benefit in using
doubles on this or that climb or in a certain area, or perhaps, on the
other hand, there is some benefit if you manage to exploit their
possibilities.
The increase in options, by the way, is more important when you don't
know much or anything about the route. If you have it wired, you may
know how to arrange for pro in a straight enough line, but if you are
groping your way in unkown territory, I think the ability to spread
your placements over a wider swath, make desperate high clips without
risking a much bigger fall, and employ manky overhead protection
without penalty for its failure can be a useful advantage.
Finally, some speculative considerations: the work of the CAI on more
realistic models for rope systems suggests that friction in the system,
even that caused by relatively shallow angles at the carabiners,
reduces the amount of rope available to stretch and so increases the
effective fall factor. If doubles can be made to run significantly
straighter than a single rope, then they might be more effective in
reducing anchor loads by keeping the effective fall factor closer to
its theoretical value. I've always wondered whether this wasn't
involved in the conventional wisdom about the "softer catch" afforded
by doubles, rather than the "extra stretch" they're assumed to have.
Simon Isbister
"rgold" <rms...@aol.com> wrote in message
news:1147735871.3...@j73g2000cwa.googlegroups.com...
>
> In the end, it is mostly just a matter of taste (or perhaps religion),
> though of course the type of rock you are climbing on matters. But the
> focus on the advantages, such as they are, for "wandering" routes
> always seemed to me to miss an important point. On certain types of
> rock, doubles increase your protection options.
I've always liked not having to debate if clipping a dubious piece was worth
the extra rope I was pulling into the system; the other rope is still nice
and snug to the gear at my waist while I am clipping the piece at my head
;-)
-s-
melissa
This is
more or less how Dan O died, no? Rub two ropes together and make fire?
"
I'd actually like to see the data on this. My assumption is that the
amount of friction from sliding due to uneven stretch is in a whole
'nother world than the friction experience when DanO's ropes got
crossed as he was in free fall. It's also been my assumption that if
twins sliding past each other was sufficient to melt the ropes, then on
account of their tendency to twist all by themselves, a lot of people
would be dead from such an occurrance. When I said that I didn't mind
retiring gear if need be, I was thinking of a little gloss on the
sheeth. If I thought they'd burn through, I'd think differently. I'd
love to hear why my assumptions are wrong, if they are, as I do
appreciate my life.
The main reasons why we use two ropes is that climbing with something
on your backside is a pain in wide cracks, and also so that I can get a
more plumb belay when I follow my bf on very traversing climbs where my
probability of lobbing is high. Otherwise, I prefer the lower weight
(real and perceived) and the easier handling of a single as well.
melissa
worth
the extra rope I was pulling into the system; the other rope is still
nice"
This theoretical sense of security with double ropes is usually
canceled by my assumption that my partner is probably instinctively
feeding both ropes out when I pull for slack.
ant
> This theoretical sense of security with double ropes is usually
> canceled by my assumption that my partner is probably instinctively
> feeding both ropes out when I pull for slack.
maybe. depends on the partner. i probably climb about 1/3 with doubles
and 2/3 with singles. thats a lot of pitches on doubles, so i consider
myself pretty handy with 'em.
when i climb with doubles, and a partner is climbing something cruiser,
i feed as if a normal single rope. if they're doing something hard,
gripping, scary, or are whimpering audibly, i feed separately. its a
lot more work, and i would never expect a dedicated singles climber to
figure it out without shortroping me, but it can work nicely.
the one thing i note is that my doubles (midline, mammut genesis, i
think. 8.5mm) stretch a lot more than a single. i think that for almost
all the climbing i do (assuming an experienced separate-rope doubles
belayer, which is rare) the additional stretch negates the advantage of
being able to blow a clip.
that doesn't sound clear in print.. i mean: if i blow a clip with a
single, i fall with six extra feet of slack in the system. if i blow a
clip on doubles, that extra slack isn't there (assuming the last piece
is clipped into the other rope), but the rope will stretch and ill end
up six feet lower than the same fall on a fatter rope.
and anyways, i rarely do the 'clip alternate ropes' thing. this means
that most of the time, the last piece is clipped into the same rope im
clipping the high piece with, so for my climbing: i get the danger of
botching the clip, *and* the extra stretch.
if the line is straight, i rarely use doubles. but for face climbing or
wandering routes, or mountaineering with raps, or ice, they are the
bee's knees. more work, but one learns real quick-like, i find.
OT: there is little i find funnier than canadian mountaineers using
doubles at indian creek. endless laughs there.
ant
> I haven't seen figures for how much the impact foce
> increases when doubles are used like twins -- link,
> anyone? Is it really negligible? If not, I'd want a
> good reason before doing this.
i would assume that if you are consistently clipping both doubles as
twins the whole way, then the fall force would effectively double.
because doubles are a lot stretchier than normal singles, i dont think
its going to be like climbing on a static rope, but its undesirable.
i find it particularly surprising that these two experienced climbers
ive traded belays with also clip doubles as twins on ice and with shit
trad pro. those are both situations where i am delighted to be climbing
on a stretchy half rope.
> As for rope-on-rope damage, the risk of that seems
> greatest if you clip your ropes as doubles at some
> point on the lead, then as twins somewhere else --
> so they could stretch differently and be sliding past
> each other in a fall.
exactly. which my partners do occasionally. but my question is- what
does it take to glaze a rope badly enough to have to retire it? ive
never fallen on twin-clipped doubles so i have no anexcdotal experience
to fall back on.
> What's the upside of using doubles as twins? Seems
> like you'd be combining the disadvantages of doubles
> with most of the disadvantages of singles.
with both of the climbers who spring to mind, i think they are just
ignorant of the existence of twin ropes. i suspect they would buy twins
next time if they did a little reading.
an upside i can relate to is the ease. if you are climbing a straight
section of a route, where there is no obvious 'clip red on right, blue
on left' trend, then it takes a bit of extra work to figure out what to
do with the ropes. if you fuck up and clip the wrong on, you can
quickly get debilitating rope drag. i think it takes inexperienced
doubles climbers only a few times to decide that they would rather clip
as for twins than risk the progress-stopping drag.
of course, used correctly, this doesn't happen, but like i said.
doubles take some time to get used to.
i do clip doubles as twins when im doing easy mountaineering type
climbing, or running it out so much that i can no longer tell easily
which rope to clip. in those circumstances, i am happy to take the
tradeoff in fall force for increased redundancy for rope-cutting and
not having to decipher which rope to clip.
when climbing with doubles in normal terrain, i clip both ropes into
one piece when i am worried that i might hit a ledge on the extra rope
stretch of doubles, or if there is a rock feature that might cut the
rope below me so i want both for redundancy.
ant
> I think the issue is that there possibly wouldn't be a next time. This is
> more or less how Dan O died, no? Rub two ropes together and make fire?
the manufacturer manuals and rock climbing manuals never say that
clipping doubles through a single biner could result in a catastrophic
failure as you describe. they say you can glaze the sheath, in some
instances enouhg to have to retire the rope.
i thought the osman (sp?) death was because of a rope running over
another rope, not inline with another rope. not sure though.
given the high-liability-awareness of climbing companies, im pretty
sure they would tell you if there was a chance of a failure from
twin-clipping doubles.
mammut's rope isntruction book doesnt even say you *have* to retire a
rope if it gets glazed. just that you should if it's glazed *badly*. i
guess you have to decide what 'badly' means.
ant
> Someone always cites some such exception, but I have yet to find one. Also,
> is that exception worth the overhead the other 99.99% of the time?
nate, ive done countless pitches where i was delighted to have doubles.
when you've got the system wired, it takes about the same amount of
mental effort as using a single, except you dont have to plan your pro
ahead, you dont have to pack/haul a rap line, you get no rope drag,
etc. in many instances, you dont even have to extend pro at all. its a
softer catch for bad pro. its twice as many ropes for redundancy and
more options in the mountains (i can make a lot of rap slings out of a
60m!).
i think the cited 'overhead' dissipates as one gets more experienced
with doubles. i dont want to step on your toes, boss, but i generally
think that rope drag with doubles is a primary symptom of incorrect
use.
> It's amazing what a few full length runners can do. Worst case is breaking
> a pitch in half or dealing with probably the same rope drag I'd get on a
> straight pitch with 2 ropes.
ive climbed wandering face pitches and been able to put pro in a 25'
swatch the whole way up the climb with zero rope drag. ive watched
experienced climbers try the same routes and been distressed when they
were shut down with drag, or unable to use the outlier pro that i
could. long runners are great. but they dont give you the same options
doubles ropes do. breaking a pitch up? ugh. not a selling point for
single ropes, i figger'.
of course, there are routes which are ridiculous to do with doubles. if
dedicated double-rope aficionados insist on lugging both cords up a
straight line, then they may reap what they sow.
Dll
"melissa"
> I'd actually like to see the data on this.
Good luck.
> If I thought they'd burn through, I'd think differently.
Ant's probably right. I've never paid close enough attention.
> The main reasons why we use two ropes is that climbing with something
> on your backside is a pain in wide cracks
One can haul with a zip line, and the leader can clip that anywhere on their
harness. If you're packing everything with the second, easiest to use a 2-4
ft runner attached to the top of the pack (or just clip gear to the runner
if no pack) - let the thing dangle down below in the wide stuff. Even with
your arguement, you still have to do something with all your other gear
anyway - unless you're talking about cragging.
> , and also so that I can get a
> more plumb belay when I follow my bf
>on very traversing climbs where my
> probability of lobbing is high.
Takes a special pitch to get any benefit here. Just as many tricks with a
single.
- Nate
Dll
"ant"
> i think the cited 'overhead' dissipates as one gets more experienced
> with doubles.
Ant - I'd wager I've owned and used doubles for longer than you've been
climbing. 9mm Blue Water Rock Serpants bought in 1992. They probably
stopped making them before you started. I finally threw them away last
fall. Somewhere in there I believe I might have even figured out how to
climb with them, but thanks for your helpful tips anyways. I also have a BW
Ice Floss collecting dust in my closet. I've decided for myself they
provide no advantage and many significant disadvantages, especially in
contrast to the thinner and thinner single ropes these days. Hence my post.
- Nate
rgold
Melissa:
> This theoretical sense of security with double ropes is usually
> canceled by my assumption that my partner is probably instinctively
> feeding both ropes out when I pull for slack.
Ant:
> maybe. depends on the partner.
Does it ever. An incompetent belayer can negate several doubles
features, and as Ant says, a belayer, no matter how experienced, who
has only used single ropes is probably not going to do it right at
first. And feeding both ropes out when you pull up slack to clip is
just one of the noob errors. Another is failing to take in the rope
from the higher piece while paying out the rope to the lower piece.
This does require more attention than some belayers have to give. In
such cases, stick with singles.
Ant:
> if i blow a clip with a single, i fall with six extra feet
> of slack in the system. if i blow a clip on doubles, that extra
> slack isn't there (assuming the last piece is clipped
> into the other rope), but the rope will stretch and ill end
> up six feet lower than the same fall on a fatter rope.
I don't get it. Take the single rope first. S'pose you have a piece 40
feet up, your waist is 8 feet above the piece, and you're stretching to
clip a piece 4 feet above your waist. Blow the clip and you've got 16
feet of rope out from the last piece; you fall 24 feet plus the rope
stretch in the single. Now take the double rope alternately clipped
(surely you arrange for an alternate clip if you know a desperate clip
is coming up?) You are caught on the other rope which only has 8 feet
out, so you fall 16 feet instead of 24 feet plus the rope stretch in
the double. Even if the double stretches so much that the total fall
distance is the same as with the single (I wonder if this is really
true), with the double you are being decelerated for 8 feet during
which you're still accelerating with the single. If there's a ledge 24
feet down, you hit that with full gravitational acceleration with the
single rope; the double rope has already stretched 8 feet and absorbed
some fall energy when you hit. Even if the fall distances seem the
same, the fall impacts will not be.
Karl P
Dll wrote:
> Ant - I'd wager I've owned and used doubles for longer than you've been
> climbing. 9mm Blue Water Rock Serpants bought in 1992. They probably
> stopped making them before you started. I finally threw them away last
> fall. Somewhere in there I believe I might have even figured out how to
> climb with them, but thanks for your helpful tips anyways. I also have a BW
> Ice Floss collecting dust in my closet. I've decided for myself they
> provide no advantage and many significant disadvantages, especially in
> contrast to the thinner and thinner single ropes these days. Hence my post.
The thinner and thinner ropes these days, like the 10.5mm you were
proudly talking about being far superior earlier? My, how far you've
come.
Cheers,
Karl P
Dawn Alguard
> This does require more attention than some belayers have to give.
It seems to require more coordination than I have to give. Or more
fingers. When I try to feed the ropes separately I never feel like I've
got a good enough grip on either of them. It makes me nervous.
Dawn
Simon Isbister
"ant" <dummya...@electricant.net> wrote in message
news:1147748693.5...@i39g2000cwa.googlegroups.com...
> melissa wrote:
>> This theoretical sense of security with double ropes is usually
>> canceled by my assumption that my partner is probably instinctively
>> feeding both ropes out when I pull for slack.
>
> maybe. depends on the partner. i probably climb about 1/3 with doubles
> and 2/3 with singles. thats a lot of pitches on doubles, so i consider
> myself pretty handy with 'em.
Yeah, thats the thing- I don't own doubles, so the only time I am using
them, I am with someone who owns them and has had lots of practice. And I
am never taking mine out, and using them with a partner who has never
belayed doubles before.
> that doesn't sound clear in print.. i mean: if i blow a clip with a
> single, i fall with six extra feet of slack in the system. if i blow a
> clip on doubles, that extra slack isn't there (assuming the last piece
> is clipped into the other rope), but the rope will stretch and ill end
> up six feet lower than the same fall on a fatter rope.
I think in that scenario you are still somewhat better off with doubles.
With the single rope, you fall the extra 6 feet, then the rope catches,
stretches, etc, etc. With the doubles, the rope catches your fall before
you have dropped the extra 6 feet, and begins absorbing your force earlier
than with the singles. In fact, the very fact that you are still travelling
the extra 6 feet is only a result of what a nice soft catch you will get,
which is nice if you are in any way unsure about your gear.
> OT: there is little i find funnier than canadian mountaineers using
> doubles at indian creek. endless laughs there.
I always thought it was the brits- I met a guy in Tuolumne who was pissed
that no one he was meeting had a single line of double rope to pair up with
his single line of double rope, which apperently is what he always did at
home.
-s-
ant
> I always thought it was the brits- I met a guy in Tuolumne who was pissed
> that no one he was meeting had a single line of double rope to pair up with
> his single line of double rope, which apperently is what he always did at
> home.
ah ha! i've bumped into a number of foreign roadtrippers who were doing
this and i could never figure it out. kept wondering why travel with
half a double. its an overkill tag line, no one uses doubles over here,
etc.
thanks for clearing that up.
ant
> I don't get it. Take the single rope first. S'pose you have a piece 40
> feet up, your waist is 8 feet above the piece, and you're stretching to
> clip a piece 4 feet above your waist. Blow the clip and you've got 16
> feet of rope out from the last piece; you fall 24 feet plus the rope
> stretch in the single. Now take the double rope alternately clipped
> (surely you arrange for an alternate clip if you know a desperate clip
> is coming up?) You are caught on the other rope which only has 8 feet
> out, so you fall 16 feet instead of 24 feet plus the rope stretch in
> the double. Even if the double stretches so much that the total fall
> distance is the same as with the single (I wonder if this is really
> true), with the double you are being decelerated for 8 feet during
> which you're still accelerating with the single. If there's a ledge 24
> feet down, you hit that with full gravitational acceleration with the
> single rope; the double rope has already stretched 8 feet and absorbed
> some fall energy when you hit. Even if the fall distances seem the
> same, the fall impacts will not be.
rgold, and simon, you're right, of course. there is an advantage to the
double ropes when botching clips. i guess i dont dwell on it as a
personal selling-point because of two reasons.
the first is the one i half-assedly tried to explain away. you guys
pointed out my incorrect logic there. i guess in the moments of fear
during tough clips, i am, for some reason, more excited about a long
fall than a hard fall. and despite the safer fall provided by a doubles
system, i find it hard to forget ill still go a long way on a stretchy
line.
the second prob trumps the first, for me, though. as i mentioned
before, i infrequently end up clipping alternate lines, so the
advantages of the clip-botch-protection-system don't often apply. ah
well.
ant
> Ant - I'd wager I've owned and used doubles for longer than you've been
> climbing.
i had a funny feeling you'd have something like that going on. i cant
wait to be 40 so i can tell people the same thing.
anyways, i was having a rope-drag-with-doubles conversation with a
friend a while back. he felt the same way you did. he wasn't a very
good doubles climber, which could have been the problem, but was also a
much bolder climber than i am.
if one is willing to put a lot of distance between placements, and
extend crux pieces with double length runners, then there are very few
routes that will show the marked drag-reduction i find with doubles.
perhaps that is your style, in which case doubles are probably not
worth the extra weight.
OT: the logic 'ive been doing it for centuries' doesnt really mean
anything, though. if i had a nickel for every time an experienced
climber didnt understand some basic part of the system, i'd be.. well,
i'd be able to splash out for a couple casino buffet dinners...
i no longer place any weight on partners' 'years ive been climbing'.
its not a good indicator of competence or safety.
just a comment. dont take it personally, you just brought it to mind.
please limit flames to less than two pages.
GOClimb
> of course, there are routes which are ridiculous to do with doubles. if
> dedicated double-rope aficionados insist on lugging both cords up a
> straight line, then they may reap what they sow.
I love climbing with doubles on many routes, for the reasons cited
above. But of course, on other routes, a single line is often a better
choice. So here's my compromise:
My "doubles" are one half rope (the technical term for a rope designed
for doubles), and one sub-10mm single. Then for that hard toprope at
the end of the day, or for the straight-up route, I'll just use the
single. Alternately, for that single pitch route that requires a
longer than 60m rope to get down, I'm ready. The weight difference
between this method and two half ropes is negligible.
And on-topic: I think the time when clipping doubles into a single
biner could really bite you in the ass is if you fall, and one of the
ropes which is clipped way out of line with the other, rips out the
piece that's out of line (not unlikely, as the piece is probably
getting pulled up or sideways). You now have two tensioned ropes, and
one of them suddenly slips several feet. I think you could get worse
than bad glazing from this - I think you could probably get a rope you
might not feel good about finishing the climb with. I don't think
you'd likely destroy both ropes though, since the running rope would
only get lightly glazed. So you'd probably live to tell the tale.
Just the same, I'd rather avoid the whole issue and simply add another
biner.
GO
melissa
biner."
Or by not falling!
Martin Carpenter
"Simon Isbister" <simoni...@telus.net> wrote:
> I always thought it was the brits- I met a guy in Tuolumne who
> was pissed that no one he was meeting had a single line of double
> rope to pair up with his single line of double rope,
Mmmm. Could be.
"Where's the other rope?"
"You said bring *a* half rope"
"But isn't that half a half rope?"
Paulina
In which case you really don't need any ropes at all.
Cheers
Paulina
rgold
> I think the time when clipping doubles into a single
> biner could really bite you in the ass is if you fall, and one of the
> ropes which is clipped way out of line with the other, rips out the
> piece that's out of line (not unlikely, as the piece is probably
> getting pulled up or sideways). You now have two tensioned ropes, and
> one of them suddenly slips several feet.
But when the out-of-line piece rips, the rope through it is no longer
under tension. If the other rope is still stretching, then the falling
climber will pull the slack rope along. One rope will be stretching
and absorbing fall energy, the other will just be pulled along, but
both will be going through the biner at the same rate. I find it hard
to imagine how this will produce catastrophic damage to one of the
ropes.
It seems to me that in order to have even a chance for serious damage,
one rope should be running through the carabiner and one should not.
In order for this to happen, you'd need unequal rope lengths from the
carabiner catching the fall to the falling climber. This could happen
if, after clipping both ropes to one biner, the climber places a higher
piece, clips just one rope to it, falls when still below the piece, and
the piece pulls. Even if all these things happen, I wonder if you'd
get much damage in the slack rope unless it somehow got pinched
underneath the tensioned rope.
The scenario just mentioned is presumably the source of the
conventional wisdom that once you clip both doubles, you should
continue to do so.
Personally, I've never found a need to clip both ropes to a single
piece, with or without extra biners. In cases where I feel I need the
higher security of two clipped ropes, I usually just place two pieces.
Lord Slime
> So here's my compromise:
> My "doubles" are one half rope (the technical term for a rope designed
> between this method and two half ropes is negligible.
> biner.
Well GOClimb, I think your "compromise" sucks. And I find it
amusing that you think you're smarter than the UIAA and the
millions of climbers who've come before you.
First of all, the weight difference is NOT negligible. Your 8mm
and 9.5mm are, generally, 45% heavier than a single 10.2mm.
So for 60m ropes, this is about 4lbs. Now, add a biner for each
clip, lets say 10 clips, so add another pound. (I won't even go
into the added bulk and wasted time.) Find a 5lbs dumbell,
GOClimb in the gym with it hanging from your harness for a
couple hours, and then try to tell me it's negligible.
Secondly, all those sub-10 single ropes have very high impact
forces, and you are combining it with a rope with a very low one.
If you are clipping both to each piece, the 9.5mm will take all
the force every time (less stretch). So what's the point of having
the 8mm? If you're alternately clipping, why not two 8mms? DOH!
I'd say you should leave your paranoia and the 8mm at home
and take that single sub-10mm rope climbing. It'll wear out soon
enough, and you can buy another 8mm to match the one at home.
- Lord Slime
Julie
>
> First of all, the weight difference is NOT negligible. ... Find a
> 5lbs dumbell, GOClimb in the gym with it hanging from your harness
> for a couple hours, and then try to tell me it's negligible.
Straw man: very few of us climb with the entire rope hanging directly
from us.
Further: for the routes where doubles are useful, proper use of them
mitigates rope drag of singles. You may find yourself "weighing" LESS
at the top of a route, leading it with doubles. Speaking of weight -
to lead the same (wandering) pitch with a single, you'll need more
runners and draws to extend pieces.
Gabe's setup does offer him a lot of flexibility, having a
full-strength single around for when it's appropriate, doubles for
when they're appropriate, and 2 ropes to rap.
JSH
Simon Isbister
parties of 3. You can lead with doubles, then take each second up on
separate lines. In some situations, you can even have them come up at the
same time, and speed things up a little. This is a situation where you need
to have 2 ropes anyways, so bringing doubles is lighter than using 2
singles.
-s-
Lord Slime
news:4d176rF...@individual.net...
> Lord Slime wrote:
> > First of all, the weight difference is NOT negligible. ... Find a
> > 5lbs dumbell, GOClimb in the gym with it hanging from your harness
> > for a couple hours, and then try to tell me it's negligible.
>
> Straw man: very few of us climb with the entire rope hanging directly
> from us.
So? You gotta carry it, and it seems that most approaches are at least
an hour and all uphill. GOClimb carries extra biners, here, put them in
YOUR pack. Then hang 3/4 of the rope off you for several pitches, and
don't forget the extra biners.
> Further: for the routes where doubles are useful, proper use of them
> mitigates rope drag of singles. You may find yourself "weighing" LESS
> at the top of a route, leading it with doubles.
It seems to me that improper use of either system results in
rope drag.
> Speaking of weight -
> to lead the same (wandering) pitch with a single, you'll need more
> runners and draws to extend pieces.
Runners are WAY lighter and smaller than biners.
> Gabe's setup does offer him a lot of flexibility, having a
> full-strength single around for when it's appropriate, doubles for
> when they're appropriate, and 2 ropes to rap.
Yeah, and you can take the kitchen sink to wash up.
- Lord Slime
Lord Slime
> There is one other advantage I find for double ropes- I quite like it for
> parties of 3.
You can do this with twins too.
- Lord Slime
GOClimb
Lord Slime wrote:
> "GOClimb" <gost...@gmail.com> wrote in message
> > So here's my compromise:
> > My "doubles" are one half rope (the technical term for a rope designed
> > for doubles), and one sub-10mm single...The weight difference
> > between this method and two half ropes is negligible.
> > Just the same, I'd rather avoid the whole issue and simply add another
> > biner.
>
> Well GOClimb, I think your "compromise" sucks. And I find it
> amusing that you think you're smarter than the UIAA and the
> millions of climbers who've come before you.
Huh? Where'd I say that?
> First of all, the weight difference is NOT negligible. Your 8mm
> and 9.5mm are, generally, 45% heavier than a single 10.2mm.
Read what I said Mr. Slime: When I want a single, I use the single.
And when I want doubles: the 1/2 rope Genesis 8.5mm is 48g/m. The
Infinity 9.2 weighs 58 g/m. So the difference between this and two
Genesis ropes is 10g/m x 60 m = 600g total. A bit over a pound.
That's acceptable to me.
> So for 60m ropes, this is about 4lbs. Now, add a biner for each
> clip, lets say 10 clips, so add another pound. (I won't even go
> into the added bulk and wasted time.) Find a 5lbs dumbell,
> GOClimb in the gym with it hanging from your harness for a
> couple hours, and then try to tell me it's negligible.
I don't know where all your extra biners come from. If I were to climb
on two official 1/2 ropes, that would use fewer biners somehow? Or
maybe I'm required to place twice as much pro because I'm carrying an
extra rope? Makes no sense! I place about the same amount of gear
whether I'm climbing with a single or two doubles. I do use somewhat
fewer runners when climbing with doubles, though. As for clipping two
biners to a piece so as to clip both ropes to it, I've maybe done this
once? Maybe never? I wouldn't want to do it, merely because of the
impact it would have on that one piece - main reason I can think of
might be to keep the rope from being swallowed behind a flake or
running over a nasty edge or something.
> Secondly, all those sub-10 single ropes have very high impact
> forces, and you are combining it with a rope with a very low one.
> If you are clipping both to each piece, the 9.5mm will take all
> the force every time (less stretch). So what's the point of having
> the 8mm? If you're alternately clipping, why not two 8mms? DOH!
Why would I clip both ropes? Perhaps you're thinking of twins
technique, rather than doubles? I know it's confusing - thus the
subject of the original post.
> I'd say you should leave your paranoia and the 8mm at home
> and take that single sub-10mm rope climbing. It'll wear out soon
> enough, and you can buy another 8mm to match the one at home.
No paranoia - don't know where that comment comes from. It's true,
though, that the thin singles wear out quickly, especially as it gets
more use. But I simply replace them when the sheath wears out, and as
I get a good deal from mammut, I can swing it.
GO
GOClimb
> GO:
> > I think the time when clipping doubles into a single
> > biner could really bite you in the ass is if you fall, and one of the
> > ropes which is clipped way out of line with the other, rips out the
> > piece that's out of line (not unlikely, as the piece is probably
> > getting pulled up or sideways). You now have two tensioned ropes, and
> > one of them suddenly slips several feet.
>
> But when the out-of-line piece rips, the rope through it is no longer
> under tension. If the other rope is still stretching, then the falling
> climber will pull the slack rope along. One rope will be stretching
> and absorbing fall energy, the other will just be pulled along, but
> both will be going through the biner at the same rate. I find it hard
> to imagine how this will produce catastrophic damage to one of the
> ropes.
Well what I was imagining is this: Climber falls. At near peak force,
an out-of-line piece on one of the ropes rips, releasing several feet
of tension on that rope. Just for the sake of argument, lets say for
the moment that the climber has fallen to the end of the rope-stretch.
So neither rope is moving, but there is a lot of tension on both. Now
with several feet worth of tension released on the belayer side of the
rope, naturally the tension is going to want to equalize over the
entire length of the rope, and so some of the rope must slide through
the biner toward the climber. Whether it's pinched under the other
rope or not, both ropes will be forced together quite hard in the
basket of the biner from all the tension in them. Now let's say that
instead of the the climber being at the maximum tension (bottom of
their fall), they're still in the middle of it. Both ropes will be
moving, but that *difference* in speed of the two ropes will still
manifest.
As to whether the amount of rope that runs through the biner as the
rope equalizes tension will be significant enough to cause light
glazing, or to burn halfway through the other rope, I don't know. Of
course a lot depends on how much rope is released by the piece ripping,
and the ratio of rope on the belay side versus the climber side of the
biner. So, for example, in high fall-factor falls, where there's not
much rope on the belayer side, most of the tension in the released side
of the rope *must* run through the biner, since most of the rope is on
the climber side of the biner.
Does this make sense? It is late, and I may have overlooked something.
> Personally, I've never found a need to clip both ropes to a single
> piece, with or without extra biners. In cases where I feel I need the
> higher security of two clipped ropes, I usually just place two pieces.
Like you, I don't recall ever having clipped both ropes to a single
piece, though I can imagine a reason for doing so. I have clipped both
through a power-point at an anchor when bringing up a second, but in
this case the ratio of rope on my side versus the climber's side makes
this seem like a pretty safe bet to me.
GO
GOClimb
Julie wrote:
> Gabe's setup does offer him a lot of flexibility, having a
> full-strength single around for when it's appropriate, doubles for
> when they're appropriate, and 2 ropes to rap.
>
> JSH
Yes!
Of course this setup is only of any benefit if you're one of the weird
individuals like me who values both single and doubles, and is not
staring malevolently over the battlements at the stupid
(single/doubles) users in the other camp!
GO
GOClimb
Which probably makes more sense - it's hard to get much benefit from
doubles technique when you're trying to properly protect the followers
on both ropes individually!
GO
Emil Briggs
> So? You gotta carry it, and it seems that most approaches are at least
> an hour and all uphill. GOClimb carries extra biners, here, put them in
> YOUR pack. Then hang 3/4 of the rope off you for several pitches, and
> don't forget the extra biners.
>
As an aside one of my climbing partners is a fairly big guy. He's been
climbing for about 30 years now and doesn't see any reason to throw away
perfectly good gear even if it is ancient. I hate using his rack! None of
the new lightweight stuff. He still has a lot of gear racked on ovals. The
weight doesn't seem to bother him that much probably due to his size but I
can sure feel it.
ant
> From experience, I'd say it's within the UIAA limits. Compare
> this to the impact forces designed into those skinny (<10mm)
> sport ropes they're selling now. They're HIGH, but still below
> the UIAA limit. Since most double/twin belay devices slip
> (no Gri-gri), or can be slipped, this seems quite reasonable.
im still really in it for my original two questions. first- is the
increase in fall force negligible/acceptable? second- how easy is it to
glaze a rope badly enough to consider retiring it?
specs from mammut/UIAA websites:
mammut genesis double ropes 8.5mm:
9% elongation
6.4 kN impact force
mammut single ropes:
6.4 - 8% elongation
8.8 - 9.5 kN impact force
UIAA single rope specs:
impact force < 12 kN
elongation < 10%
this would suggest (if my amateur guess that climbing on doubles
clipped as twins would effectively double the forces.. rgold?) that
using my double ropes as a a twin system would put it barely above the
UIAA accepted range. however, perhaps more interestingly, it would put
it well above the actual single rope range, and it would be hard to
argue that the difference is 'negligible', as my partners have told me.
this relies on the doubled-force assumption. someone with physics
background care to chip in?
i accept that in certain situations, this would be an acceptable margin
for me, but then, as other posters have stated- why would you do that
anyway?
regarding glazing:
who has glazed their rope? and how did it happen?
David Kastrup
> Lord Slime wrote, regarding fall force with twin-clipped doubles:
> > From experience, I'd say it's within the UIAA limits. Compare
>> this to the impact forces designed into those skinny (<10mm)
>> sport ropes they're selling now. They're HIGH, but still below
>> the UIAA limit. Since most double/twin belay devices slip
>> (no Gri-gri), or can be slipped, this seems quite reasonable.
>
> im still really in it for my original two questions. first- is the
> increase in fall force negligible/acceptable? second- how easy is it to
> glaze a rope badly enough to consider retiring it?
>
> specs from mammut/UIAA websites:
>
> mammut genesis double ropes 8.5mm:
> 9% elongation
> 6.4 kN impact force
Tested as half ropes, or as twins?
> mammut single ropes:
> 6.4 - 8% elongation
> 8.8 - 9.5 kN impact force
>
> UIAA single rope specs:
> impact force < 12 kN
> elongation < 10%
>
> this would suggest (if my amateur guess that climbing on doubles
> clipped as twins would effectively double the forces.. rgold?) that
> using my double ropes as a a twin system would put it barely above the
> UIAA accepted range. however, perhaps more interestingly, it would put
> it well above the actual single rope range, and it would be hard to
> argue that the difference is 'negligible', as my partners have told me.
>
> this relies on the doubled-force assumption. someone with physics
> background care to chip in?
The factor is more like 1.4 rather than 2. It would be double if the
elongation was the same, but of course, if every rope is weighted with
half the weight, the elongation will be shorter. However, if they
were tested as half ropes, they were tested with different weights,
too, so that comes into account as well.
--
David Kastrup, Kriemhildstr. 15, 44793 Bochum
ant
> Tested as half ropes, or as twins?
this is confusing. i assumed the specs cited are for a single half
rope, but i suppose it doesnt actually say on the mammut website. but-
it would make sense based on the numbers and my experience with them.
> The factor is more like 1.4 rather than 2. It would be double if the
> elongation was the same, but of course, if every rope is weighted with
> half the weight, the elongation will be shorter.
forgive me, i dont follow.
impact force is ultimately the spec i am most interested in. elongation
is, i assumed, a parallel (and interesting) spec that matters less to
me. so- are you saying that if you clip both half ropes into one piece,
the force will be 1.4X the force with a single half rope? why?
> However, if they
> were tested as half ropes, they were tested with different weights,
> too, so that comes into account as well.
the specs on the mammut website gave elongation with 80 kg as the unit
for both half and single ropes, so i was assuming (big assumption) that
the impact forces were also from analogous situations.
David Kastrup
> David Kastrup wrote:
>> Tested as half ropes, or as twins?
>
> this is confusing. i assumed the specs cited are for a single half
> rope, but i suppose it doesnt actually say on the mammut website. but-
> it would make sense based on the numbers and my experience with them.
>
>> The factor is more like 1.4 rather than 2. It would be double if the
>> elongation was the same, but of course, if every rope is weighted with
>> half the weight, the elongation will be shorter.
>
> forgive me, i dont follow.
>
> impact force is ultimately the spec i am most interested in. elongation
> is, i assumed, a parallel (and interesting) spec that matters less to
> me. so- are you saying that if you clip both half ropes into one piece,
> the force will be 1.4X the force with a single half rope? why?
Because the ropes, sharing the load, will not stretch as much. Since
the impact force is proportional to the stretch, it is not doubled.
>> However, if they were tested as half ropes, they were tested with
>> different weights, too, so that comes into account as well.
>
> the specs on the mammut website gave elongation with 80 kg as the
> unit for both half and single ropes, so i was assuming (big
> assumption) that the impact forces were also from analogous
> situations.
Strange. Usually 55kg are used for testing half ropes. If that was
the case, then the impact force for doubling the ropes and using 80kg
instead of 55kg differs by a factor of about sqrt(2*80/55) = 1.7.
ant
> Because the ropes, sharing the load, will not stretch as much. Since
> the impact force is proportional to the stretch, it is not doubled.
i thouht the more stretch, the lower the impact force. i thought that
the more elongation, the more time taken in movement for energy to be
dissipated, and the more shock absorption, and therefore the lower
impact force. if this guesswork is absolutely wrong, i clearly have
some reading to do..
on my dubious assumption, i assumed that because the ropes would
stretch, say, half as much, the impact force would be, say, double.
> Strange. Usually 55kg are used for testing half ropes. If that was
> the case, then the impact force for doubling the ropes and using 80kg
> instead of 55kg differs by a factor of about sqrt(2*80/55) = 1.7.
while the UIAA uses the 55 weight for the drop testing, it makes sense
to me that the rope specs are consistent units across the board.
ie: use the 55 weight to make sure its safe (arbitrary, i suppose,
but..) and use the 80 weight so that you can make true comparisons rope
to rope.
Peter
<http://www.uiaa.ch/web.test/visual/Safety/SafComPictorials/PictUIAA101-EN892DynamicRopes.pdf>
The weight used depends on both the type of rope and the type of test.
I would think you have to assume that they were tested according to UIAA
standards.
55kg is used for fall testing a half rope, 80kg for a single or twin.
The UIAA elongation specs guoted in the OP (<10%) is a static elongation
test, which uses 80kg for all 3 types, but with different specs for each.
David Kastrup
> David Kastrup wrote:
>> Because the ropes, sharing the load, will not stretch as much. Since
>> the impact force is proportional to the stretch, it is not doubled.
>
> i thouht the more stretch, the lower the impact force.
You are using "stretch" here as "relative elongation per force" (a
material constant of the rope), whereas I was using "stretch" as
"relative elongation" (the current geometry of the situation,
proportional to the current force).
> i thought that the more elongation, the more time taken in movement
> for energy to be dissipated,
Time is irrelevant for dissipating energy. Energy is distance times
average force (peak force is twice the average force when the force
varies linearly over distance).
> and the more shock absorption,
"more shock absorption"? Are you making up terms as you go? What do
you call "shock" here and what "absorption"?
> and therefore the lower impact force. if this guesswork is
> absolutely wrong, i clearly have some reading to do..
Appears so.
> on my dubious assumption, i assumed that because the ropes would
> stretch, say, half as much, the impact force would be, say, double.
So that when one drops half the weight, one gets half the stretch and
the impact force doubles?
Cough cough. Or do you think that the stretch is independent from the
weight?
ant
> Time is irrelevant for dissipating energy. Energy is distance times
> average force (peak force is twice the average force when the force
> varies linearly over distance).
>
> > and the more shock absorption,
>
> "more shock absorption"? Are you making up terms as you go? What do
> you call "shock" here and what "absorption"?
i know that time is irrelevant for dissipating energy. that statement
was a possibly bogus one born of the screamer-theory i've browsed in
the past, where it is hypothesized that the additional time the system
is in motion allows a greater amount of energy to be dissipated.
the term 'shock absorption' as i used it was meant as 'energy
dissipation'.
i wrote:
> > on my dubious assumption, i assumed that because the ropes would
> > stretch, say, half as much, the impact force would be, say, double.
>
> So that when one drops half the weight, one gets half the stretch and
> the impact force doubles?
this is how i imagined it (and it really does look like i imagined it):
if i drop a 100kg weight with a factor 1 onto a 30' section of rope,
lets say it stretches to 35' and the peak force at the anchor was 8 kN.
i was guessing that if i dropped the same weight, with the same fall,
onto two 30' ropes in parallel, then the ropes would only stretch 32.5'
(apx) and the impact force would be 16kN (apx).
it was a guess. a wild assumption.
im sorry to have been so scientifically wrong, but im glad that you are
taking the time to set me right. i started this thread for just that
reason- to learn.
so in that invented example above, would the second fall be more likely
to generate 12 kN of force? or 9 kN?
David Kastrup
That would mean that each rope would still deliver a force of 8kN, yet
be stretched only half as far. How does the rope know that it should
deliver the same force even when stretched just half as far?
> so in that invented example above, would the second fall be more
> likely to generate 12 kN of force? or 9 kN?
Something like 11.3kN.
rgold
consequence of linearity is that the energy absorbed by stretching is
proportional to the square of the amount of elongation for a given
fixed length of rope.
If you have two ropes to absorb fall energy and, assuming equal sharing
of the load, each absorbs half the energy, then the single rope absorbs
twice the energy of one strand of the double rope and so the square of
the elongation of the single rope is twice the square of the elongation
of either strand of the double ropes. It follows that the elongation
of the single rope is sqrt(2) times the elongation of a single strand
of the double ropes, or that each strand of the double ropes has
elongation 1/sqrt(2) times the elongation of the single rope.
Since (again by linearity) the tension in a strand of given length is
proportional to its elongation, The total tension developed by two
strands of the double rope is thus 2 X 1/sqrt(2)=sqrt(2) times the
tension in the single strand. Approximating sqrt(2) by 1.4, the linear
model predicts that clipping two ropes will result in a 40% higher
anchor load than clipping a single rope.
It is not clear how useful rough linear estimates are, especially in
view of rope manufacturers' efforts to engineer useful non-linearity
into rope performance. For example, the Beal Joker used as a single
rope has a UIAA impact force rating of 8.2 kN, while used as a twin it
has a UIAA impact force rating of 9.5 kN. (See
http://www.bealplanet.com/portail-2006/index.php?page=cordes_escalade&lang=us)
This is a 16% increase as opposed to the 40% increase predicted by the
linear model.
I do not know whether tensions for moderate fall factors deviate as
much from the linear prediction.
ant
> Since (again by linearity) the tension in a strand of given length is
> proportional to its elongation, The total tension developed by two
> strands of the double rope is thus 2 X 1/sqrt(2)=sqrt(2) times the
> tension in the single strand. Approximating sqrt(2) by 1.4, the linear
> model predicts that clipping two ropes will result in a 40% higher
> anchor load than clipping a single rope.
thank you rgold, and kastrup, and others.
this thread has completely redeemed rec.climbing for me.
so it sounds like the answer to my first question is: forces could rise
up to 40%, but there is a lot of uncertainty and it will probably rise
less.
the second question doesn't seem to generate that much excitement,
which is probably a vote for 'glazing is rarely a big deal'.
thanks again,
anthony
Lord Slime
> Lord Slime wrote:
> > "GOClimb" <gost...@gmail.com> wrote in message
designed
> > > for doubles), and one sub-10mm single...The weight difference
> > > between this method and two half ropes is negligible.
> > > Just the same, I'd rather avoid the whole issue and simply add
another
> > > biner.
> >
> > Well GOClimb, I think your "compromise" sucks. And I find it
> > amusing that you think you're smarter than the UIAA and the
> > millions of climbers who've come before you.
>
> Huh? Where'd I say that?
The UIAA certifies single, double and twin ropes to be used
in specific ways. Combining the equipment and techniques
in some weird way is.... weird, provides little to no advantage,
and is not recommended.
Also, millions of climbers have used the three methods with
great success. So I guess you're smarter than all that amassed
experience.
> > First of all, the weight difference is NOT negligible. Your 8mm
> > and 9.5mm are, generally, 45% heavier than a single 10.2mm.
>
> Read what I said Mr. Slime: When I want a single, I use the single.
Bullshit. What you said above (go look) is that you use a single and
a double for double-rope technique. Doh, read what YOU wrote.
> And when I want doubles: the 1/2 rope Genesis 8.5mm is 48g/m. The
> Infinity 9.2 weighs 58 g/m. So the difference between this and two
> Genesis ropes is 10g/m x 60 m = 600g total. A bit over a pound.
> That's acceptable to me.
And the extra biners? Also, what's the impact force of the two ropes?
Have you considered that?
> > So for 60m ropes, this is about 4lbs. Now, add a biner for each
> > clip, lets say 10 clips, so add another pound. (I won't even go
> > into the added bulk and wasted time.) Find a 5lbs dumbell,
> > GOClimb in the gym with it hanging from your harness for a
> > couple hours, and then try to tell me it's negligible.
>
> I don't know where all your extra biners come from. If I were to climb
> on two official 1/2 ropes, that would use fewer biners somehow?
You said that, instead of mixing twin and double technique, you'd
add an extra biner so the ropes don't grind on each other in a fall.
This is the correct method but takes extra biners.
> Makes no sense! I place about the same amount of gear
> whether I'm climbing with a single or two doubles.
You said it, not me.
> > Secondly, all those sub-10 single ropes have very high impact
> > forces, and you are combining it with a rope with a very low one.
> > If you are clipping both to each piece, the 9.5mm will take all
> > the force every time (less stretch). So what's the point of having
> > the 8mm? If you're alternately clipping, why not two 8mms? DOH!
>
> Why would I clip both ropes? Perhaps you're thinking of twins
> technique, rather than doubles? I know it's confusing - thus the
> subject of the original post.
Don't flatter yourself, I'm not confused.
> > I'd say you should leave your paranoia and the 8mm at home
> > and take that single sub-10mm rope climbing. It'll wear out soon
> > enough, and you can buy another 8mm to match the one at home.
>
> No paranoia - don't know where that comment comes from.
Then why not climb on a single? Or doubles? Why the weird
combination?
- Lord Slime
ant
> Then why not climb on a single? Or doubles? Why the weird
> combination?
far be it for me to intervene in the beginnings of another quality
sub-thread, but personally i dont find the GOclimb 'double' setup quite
as personally offensive as LS does.
when i climb on doubles, i am generally using them like two single
ropes. one is over there on the left, one out right. one protects the
traverse, while the other flaps in the wind. i have rarely fallen on
doubles, or caught climbers on doubles, but none of those few times did
more than one rope take the load and that does not bother me.
with that said, with my use i might as well use two 10.5mm ropes and
see no changes in the safety of hte system. if i used a 9.5 single and
a 8.5 double as doubles, there would be about an additional pound or
two, and no more. increased impact forces would not be an issue because
rarely are two ropes taking load at the same time.
the advantages of the GO system, as i see it, is that for only the
price of two ropes you have the functionality of two systems. you only
have to pack two ropes into basecamp. you can get to the base of hte
crag and decide, instead of committing at the car.
regarding an earlier point:
i do not believe that climbing with a used 5 pound rope is markedly
different than climbing with a used 3 pound rope. IMHE, the great part
of rope 'weight' is the drag (which dissapears almost completely when
i use doubles).
at the top of long pitch, i do not feel like i have a 5 pound dumbell
hanging off my harness when climbing with a five pound rope. the
friction against the rock and biners supports some of hte weight of hte
rope when i am not moving. the drag makes up most of hte perceived
weight when i am clipping and moving.
if one is climbing straight-bolted sport lines on new frictionless
dry-treated ropes, then sure, you feel the actual weight of hte rope.
and it sucks. but in my normal trad life? dont feel it. the rope feels
infinitely heavier when i am trailing it, and there is no friction
throguh the gear.
Dawn Alguard
> i do not believe that climbing with a used 5 pound rope is markedly
> different than climbing with a used 3 pound rope. IMHE, the great part
> of rope 'weight' is the drag
I don't know. I used to think that back when I sucked at rope
management and was always hosing myself with drag, but these days I can
climb 200 feet and keep the rope in a straight line and you know what?
200 feet of rope is heavy, drag or no drag.
And I have to say that your overall argument doesn't make much sense.
You're claiming that rock friction and biners support the weight of the
rope and then you say the weight of the rope is caused mostly by drag.
Guess what? Friction and biners are what's causing the drag. A little
circular there.
That said, I don't worry about the weight of my rope. I don't leave my
belay device on the ground either.
Dawn
melissa
I sure do. I worry about the weight of everything. I'm not usually
climbing hard enough to get shut down by it in one pitch, but towards
the end of a long day whether or not I had a few extra pounds on board
starts to really make a difference. I love that skinnier singles have
gotten so commonplace.
Lord Slime
> when i climb on doubles, i am generally using them like two single
> ropes. one is over there on the left, one out right. one protects the
> traverse, while the other flaps in the wind.
Excuse me, but that's how you use double ropes. There isn't a
practical method to use two single ropes. Doh.
> with that said, with my use i might as well use two 10.5mm ropes and
> see no changes in the safety of hte system.
Ant, you are so dense. Why do you think double ropes are smaller
and lighter than singles? Because two singles addes up to extra
weight and drag for no increase in safety (and possibly less safety).
Doh!
> if i used a 9.5 single and
> a 8.5 double as doubles, there would be about an additional pound or
> two, and no more. increased impact forces would not be an issue because
> rarely are two ropes taking load at the same time.
Okay, remedial time. Low impact forces are good, especially for
trad climbing where gear/rock may not be bomber. Although still
within UIAA specs, these recent thin ropes with high impact forces
are targetted for sport climbing and modern bolts. Double rope
technique is uniquely for trad climbing, especially on bad rock,
where high impact forces may blow a placement.
Thus, to *choose* to use a thin single rope in a situation that
is appropriate for double ropes is a poor choice.
> the advantages of the GO system, as i see it, is that for only the
> price of two ropes you have the functionality of two systems.
No, you don't.
> you only
> have to pack two ropes into basecamp. you can get to the base of hte
> crag and decide, instead of committing at the car.
And this is a tough decision for you, eh?
> i do not believe that climbing with a used 5 pound rope is markedly
> different than climbing with a used 3 pound rope. IMHE, the great part
> of rope 'weight' is the drag (which dissapears almost completely when
> i use doubles).
Sorry, that's not true.
> at the top of long pitch, i do not feel like i have a 5 pound dumbell
> hanging off my harness when climbing with a five pound rope. the
> friction against the rock and biners supports some of hte weight of hte
> rope when i am not moving.
What bullshit. Try climbing something besides 5.7 slabs, like a
50m, vertical pitch. Guess what? That rope is hanging on you
like a dead weight.
> the drag makes up most of hte perceived
> weight when i am clipping and moving.
And this is *worse* that a 5lbs dumbell! It's like being short-roped
all the time. You're more dense than I thought.
> if one is climbing straight-bolted sport lines on new frictionless
> dry-treated ropes, then sure, you feel the actual weight of hte rope.
> and it sucks. but in my normal trad life? dont feel it. the rope feels
> infinitely heavier when i am trailing it, and there is no friction
> throguh the gear.
Get a clue Ant. I have some for sale. Send a SASE and $19.95
for and authentic, autographed Lord Slime Clue. Allow two weeks
for delivery
- Lord Slime
Lord Slime
Dawn wrote > "That said, I don't worry about the weight of my rope"
>
> I sure do. I worry about the weight of everything. I'm not usually
> climbing hard enough to get shut down by it in one pitch, but towards
> the end of a long day whether or not I had a few extra pounds on board
> starts to really make a difference.
Yup. It really does.
> I love that skinnier singles have gotten so commonplace.
Just beware their downsides for trad climbing. Yes, they are
light-weight, but they don't wear very well, I suspect they cut
more easily that a 10.5mm, and the high impact force can be
a factor in less-than-bomber rock (use a device that slips).
- Lord Slime
melissa
safe with a big fatty. I rationalize this choice though my telling
myself that if a 10.5 is what is considered bomber for a 200 lbs guy,
then I must be doing comparably well on a 9.7. I understand that all
bets are off over edges...and try to avoid them (and falls) no matter
what size the cord. If I'm jugging, I tend to bite the bullet and use
a big rope...usually.
I haven't had many ropes (of any size) show visible wear that required
retirement in advance of the point where I just figured that it was
prudent to retire them due to age.
Brian in SLC
Lord Slime wrote:
> Just beware their downsides for trad climbing. Yes, they are
> light-weight, but they don't wear very well, I suspect they cut
> more easily that a 10.5mm, and the high impact force can be
> a factor in less-than-bomber rock (use a device that slips).
I'm looking at impact force amongst the ropes and, seems to me, some
skinny cords have a lower impact force than some fatties. Seems to
vary from rope to rope.
See:
http://www.bluewaterropes.com/home/usechart.asp
http://www.neropes.com/climbing/dynamic_ropes.htm#Specs
http://www.bealplanet.com/portail-2006/index.php?page=cordes_escalade&lang=us
I've been really enjoying my BW 9.4 Dominator...nice hand. Low bulk
and weight. Purty color.
Brian in SLC
ps: Ant, fyi, I sent Lord Slime a check, he tore it up, and I still
don't have a clue...ha ha...
Julie
>
>>the advantages of the GO system, as i see it, is that for only the
>>price of two ropes you have the functionality of two systems.
>
> No, you don't.
Slime, I feel like you're deliberately ignoring the value of this
point, so let me be pedantic:
Gabe puts two ropes in his pack at the start of a day.
Route #1 is wandering and best protected with doubles. For Route #1,
Gabe uses his double system, of 1 single and 1 half rope. He gets to
the top, and gets back down in one convenient rap.
Route #2 is straight up, and at his limit. Here, Gabe uses his single
rope.
Route #3 has one pitch of straight-up, one pitch with a big traverse,
and one pitch of straight-up. On Route #3, Gabe uses his ropes
differently on every pitch!
For the price of carrying his extra pound, Gabe indeed has two unique
systems at his disposal.
---
Speaking of impact force: one arguement thus far neglect in this
thread is that with two, straighter-running ropes, more length of each
rope is available to absorb the impact of a fall.
JSH
David Kastrup
> Speaking of impact force: one arguement thus far neglect in this
> thread is that with two, straighter-running ropes, more length of
> each rope is available to absorb the impact of a fall.
Since when is a straighter-running rope longer? At best you can talk
about some measure like "equivalent length" which would refer to the
same resilience at tie-in point for a drag-free rope. This equivalent
length might be shorter in case of rope drag, but the real length is
longer, even though it gets engaged less.
ant
> > when i climb on doubles, i am generally using them like two single
> > ropes. one is over there on the left, one out right. one protects the
> > traverse, while the other flaps in the wind.
>
> Excuse me, but that's how you use double ropes. There isn't a
> practical method to use two single ropes. Doh.
slime, take everything i say within the context of hte thread, hey?
> Ant, you are so dense.
LS, you are proud king of a village.
> > with that said, with my use i might as well use two 10.5mm ropes and
> > see no changes in the safety of hte system.
>
> Why do you think double ropes are smaller
> and lighter than singles? Because two singles addes up to extra
> weight and drag for no increase in safety (and possibly less safety).
> Doh!
i did not contradict anything you say here. you are interpreting
statements out of context in an effort to.. what?
> > if i used a 9.5 single and
> > a 8.5 double as doubles, there would be about an additional pound or
> > two, and no more. increased impact forces would not be an issue because
> > rarely are two ropes taking load at the same time.
>
> Okay, remedial time. Low impact forces are good, especially for
> trad climbing where gear/rock may not be bomber. Although still
> within UIAA specs, these recent thin ropes with high impact forces
> are targetted for sport climbing and modern bolts. Double rope
> technique is uniquely for trad climbing, especially on bad rock,
> where high impact forces may blow a placement.
>
> Thus, to *choose* to use a thin single rope in a situation that
> is appropriate for double ropes is a poor choice.
so, LS, are you saying that the only time you would climb on doubles is
where there is poor pro. and that it would be unsafe to use a
'high-impact' single there. therefore, it is unsafe to use a single as
one half of a 'double' rope system.
i think you have a problem with using a 'high impact' single for trad
climbing, and that is why you are going out of your way to smack down a
reasonable compromise. im not saying thin ropes are ideal for trad, but
plenty of people are happy with the margin, and should therefore be
comfortable with the GO system.
> > i do not believe that climbing with a used 5 pound rope is markedly
> > different than climbing with a used 3 pound rope. IMHE, the great part
> > of rope 'weight' is the drag (which dissapears almost completely when
> > i use doubles).
>
> Sorry, that's not true.
> > at the top of long pitch, i do not feel like i have a 5 pound dumbell
> > hanging off my harness when climbing with a five pound rope. the
> > friction against the rock and biners supports some of hte weight of hte
> > rope when i am not moving.
>
> What bullshit. Try climbing something besides 5.7 slabs, like a
> 50m, vertical pitch. Guess what? That rope is hanging on you
> like a dead weight.
first off, im no hardened rock god like you, but from time to time i
move beyond the 5.easy slab, and i stand by what i say. im not saying i
dont get the dead-weight feel ever. im saying its not hte norm. when
pitches turn roofs, the angle kicks back, you climb past features and
ledges, you're in cracks, or the pitch doesnt happen to be straight,
you get drag no matter how insightful your pro slingage.
second, even if all i did was laps on whitehorse ledge, it's still a
valid context. in fact, what portion of hte climbing world is actually
ever doing a 50m vertical pitch?
> > the drag makes up most of hte perceived
> > weight when i am clipping and moving.
>
> And this is *worse* that a 5lbs dumbell! It's like being short-roped
> all the time. You're more dense than I thought.
and you're just as abrasive as i remembered you. yes, it can be worse
than a dead hanging weight. yes, it could feel like being short-roped
all the time. but thats not hte point. im not saying light ropes arent
things of delight and wonder, and that i cant feel the difference. all
i'm-a-sayin' is that my general impression is that drag is a bigger
part of the perceived rope weight equation than actual rope weight.
> Get a clue Ant. I have some for sale. Send a SASE and $19.95
> for and authentic, autographed Lord Slime Clue. Allow two weeks
> for delivery
need cash for anger therapy? there are other ways.
ant
> And I have to say that your overall argument doesn't make much sense.
> You're claiming that rock friction and biners support the weight of the
> rope and then you say the weight of the rope is caused mostly by drag.
> Guess what? Friction and biners are what's causing the drag. A little
> circular there.
i dont think its circular. its the difference between static and
kinetic friction. there is drag that is always present (dead hanging
weight feel) and there is drag that you only feel when moving upwards
or clipping above you.
and im talking about perceived weight (my invented term), as in- the
weight/drag i actually notice.
melissa
good...although it's only really mattered a couple of times in my
experience (belaying someone else on them)...I can think of one time
that boyfriend would have decked from a considerable height if he'd
fallen and all he had was a single. The route had a huge traverse in
between pro opportunities and then headed up roughly centered between
the peices. With two ropes he'd get suspended somewhere between the
peices when the rope came taught (assuming they held) instead of going
his distance out plumb below either peice. Scariest belay I've ever
given.
melissa
your crap every time the second changes out. Everyone carries their
own water and shoes, the leader carries the lead rack, the cleaner
carries the cleaned gear, and that is everything. I put my shoes and
my water bottle on my shoulder sling for chimneys so they're easier to
swing out of the way. There are other ways of dealing with them, but
this is what I prefer. If I need a pack to do a climb, then I pick
another climb or haul. Generally, I don't haul unless I'm spending the
night out. If the weather looks iffy, I crag. I just get no pleasure
out of climbing with a pack on. Everyone has their own sense of what
is aesthetic, and this is mine.
For the extra weight, I'd rather have a second rope that can be used as
a lead line if and when the raps hang.
As for getting a plumb belay, I followed many such special
pitches....run out traversing slabs and faces where you only get pro
where the bolts are. The only "trick" that I can think of, short of
getting brave about the fall potential, for giving a good TR belay to a
follower would be to rig some sort of tramming back belay using a
leaver biner. I've actually done this before, and it's lame beyond
words...right up there with getting butt hauled with a pulley...as you
end up under so much tension from the back belay.
GOClimb
I've been in the same situation. This is exactly the point RG was
making about using protection possibilities with two ropes that would
be inconceivable with a single rope - two points separated by more than
a few feet on the horizontal plane. In one case I recall, it was two
good points separated by about 20 feet. I was looking for the best
place to get through a roof, and tried a number of possibilites before
finding one that worked. Had I fallen in the middle somewhere, without
both of those ropes, I would have taken a nasty swinging fall.
GO
Dll
"melissa"
> Everyone carries their own water and shoes,
> the leader carries the lead rack, the cleaner
> carries the cleaned gear, and that is everything.
Sounds heavy, unequal and slow for the leader for anything that requires
more than a few cups of water.
> If I need a pack to do a climb, then I pick
> another climb or haul. Generally, I don't haul
> unless I'm spending the night out. If the weather
> looks iffy, I crag.
Spoken like a true Californian! There are places to climb where a person
really needs more than a t-shirt.
> I just get no pleasure
> out of climbing with a pack on.
Few do - but leading heavy is worse.
> Everyone has their own sense of what
> is aesthetic, and this is mine.
I think the truth is that our systems change depending on where we are
climbing, and/or where we came from.
- Nate
GOClimb
First off, glad to see you're still alive and kicking, when I shot back
and didn't hear from you in a couple of days, I began to worry!
Lord Slime wrote:
> "GOClimb" <gost...@gmail.com> wrote in message
> > Lord Slime wrote:
> > > "GOClimb" <gost...@gmail.com> wrote in message
> > > > My "doubles" are one half rope (the technical term for a rope
> designed
> > > > for doubles), and one sub-10mm single...The weight difference
> > > > between this method and two half ropes is negligible.
> > > > Just the same, I'd rather avoid the whole issue and simply add
> another
> > > > biner.
> > >
> > > Well GOClimb, I think your "compromise" sucks. And I find it
> > > amusing that you think you're smarter than the UIAA and the
> > > millions of climbers who've come before you.
> >
> > Huh? Where'd I say that?
>
> The UIAA certifies single, double and twin ropes to be used
> in specific ways. Combining the equipment and techniques
> in some weird way is.... weird, provides little to no advantage,
> and is not recommended.
Well I guess it's up to you, me, and others to decide whether it
provides an advantage. The UIAA specs for ropes merely guarantee
within some reasonable probability that those ropes are certified to
behave within certain guidelines when used in certain ways. I do not
believe I am trying to use any of my equipment in ways that will stress
the equipment in radically unanticipated ways, so I feel confident that
it will behave predictably. Or, put more succinctly, my gear does not
use me, I use it.
> Also, millions of climbers have used the three methods with
> great success. So I guess you're smarter than all that amassed
> experience.
Fortunately for me, I don't have to assume such hubris - the climbing
gods would certainly strike me down. I actually heard about the
technique from someone else, and decided I liked it. As for whether it
provides an advantage for those other millions of climbers - again,
that's for them to decide.
> > > First of all, the weight difference is NOT negligible. Your 8mm
> > > and 9.5mm are, generally, 45% heavier than a single 10.2mm.
> >
> > Read what I said Mr. Slime: When I want a single, I use the single.
>
> Bullshit. What you said above (go look) is that you use a single and
> a double for double-rope technique. Doh, read what YOU wrote.
In my first post to this topic I said:
"I love climbing with doubles on many routes, for the reasons cited
above. But of course, on other routes, a single line is often a
better
choice. So here's my compromise:
My "doubles" are one half rope (the technical term for a rope
designed
for doubles), and one sub-10mm single. Then for that hard toprope
at
the end of the day, or for the straight-up route, I'll just use
the
single. "
You can find that post here -> http://tinyurl.com/mdote
> > And when I want doubles: the 1/2 rope Genesis 8.5mm is 48g/m. The
> > Infinity 9.2 weighs 58 g/m. So the difference between this and two
> > Genesis ropes is 10g/m x 60 m = 600g total. A bit over a pound.
> > That's acceptable to me.
>
> And the extra biners? Also, what's the impact force of the two ropes?
> Have you considered that?
I'm still not quite sure where these extra biners come in. As I said
earlier, I cannot recall ever having clipped both ropes to a single
piece, though it may have happened once. I certainly don't carry extra
biners for such an unlikely occurrence.
The impact force of the two ropes... on what? In general, only one
rope will catch a fall, and in such cases, both are rated by the UIAA
to be sufficient to hold a lead fall without imparting too much force
on the top piece. Occasionally, though, both pieces might feel some of
the force of a fall, in which case each is likely to feel less force
than either would, had it held the full fall on a single rope.
>
> > > So for 60m ropes, this is about 4lbs. Now, add a biner for each
> > > clip, lets say 10 clips, so add another pound. (I won't even go
> > > into the added bulk and wasted time.) Find a 5lbs dumbell,
> > > GOClimb in the gym with it hanging from your harness for a
> > > couple hours, and then try to tell me it's negligible.
> >
> > I don't know where all your extra biners come from. If I were to climb
> > on two official 1/2 ropes, that would use fewer biners somehow?
>
> You said that, instead of mixing twin and double technique, you'd
> add an extra biner so the ropes don't grind on each other in a fall.
> This is the correct method but takes extra biners.
>
True, but again, I can't recall ever having done so. I would, if I
needed to, but don't carry any extra biners for such a case.
> > > Secondly, all those sub-10 single ropes have very high impact
> > > forces, and you are combining it with a rope with a very low one.
> > > If you are clipping both to each piece, the 9.5mm will take all
> > > the force every time (less stretch). So what's the point of having
> > > the 8mm? If you're alternately clipping, why not two 8mms? DOH!
> >
> > Why would I clip both ropes? Perhaps you're thinking of twins
> > technique, rather than doubles? I know it's confusing - thus the
> > subject of the original post.
>
> Don't flatter yourself, I'm not confused.
You are if you believe - as you said above, that I'm "clipping both to
each piece". As I understand it, that's twin-rope technique, not
double-rope technique. But as I've never used twin rope technique, I
won't claim to know anything beyond that.
> > > I'd say you should leave your paranoia and the 8mm at home
> > > and take that single sub-10mm rope climbing. It'll wear out soon
> > > enough, and you can buy another 8mm to match the one at home.
> >
> > No paranoia - don't know where that comment comes from.
>
> Then why not climb on a single? Or doubles? Why the weird
> combination?
For the reasons I, and others here, have stated: it combines the
benefits of each, and adds flexibility in my choices. I recently took
a one-month road trip, and needed to bring only two ropes. In IC, for
example, the 1/2 rope never left the car, while in Red Rocks, some days
it did, and others it didn't, depending on our objectives for the day.
Used this way, the thin single will wear out fairly quickly (by its
nature, as well as by the fact that it is used on every outing, while
the 1/2 rope is not). But I can live with this drawback.
As for this repeated insistence that the thin singles are have too high
a force to be appropriate for trad use, I disagree. The Mammut
Infinity 9.2mm Single I use is rated at 9.1kN. Compare this to other
ropes they make: the Eternity 10 mm - 9kN; the Flex 11mm - also 9kN, or
the Flash 10.5mm - rated at 9kN. This last they actually advertise as
"low impact force" on their website.
If The Flash, with an impact force of 9kN is considered to have a "low
impact force", then that Infinity, rated at 9.1kN is "high impact"?
Seems like a stretch to me (no pun intended).
GO
GOClimb
> Route #3 has one pitch of straight-up, one pitch with a big traverse,
> and one pitch of straight-up. On Route #3, Gabe uses his ropes
> differently on every pitch!
Right on for your hypothetical Routes #1 and #2, but I'd probably use
both ropes on the straight up pitches of Route #3. Simply because
someone has to carry that extra rope, and typically the easiest way to
do so is to trail it. If I'm going to be trailing it, I may as well
allow myself extra protection options for shits and giggles. If this
seemed troublesome, I'd just climb on the single from the outset and
leave the half in the pack/car.
> Speaking of impact force: one arguement thus far neglect in this
> thread is that with two, straighter-running ropes, more length of each
> rope is available to absorb the impact of a fall.
I think the argument has been made, and made well, that the person
using the single rope may be just as capable of making it run in a
straight line as the person using the set of doubles. Of course the
choices that the person climbing on a single line will make in order to
get such a straight line may create other concerns (like using longer
runners (more weight, longer fall potential), forgoing protection
possibilities, etc). But in trad leading, compromises are simply part
of the game. You make your decisions and live (hopefully!) with the
consequences.
GO
x15x15
"Dll"
> Spoken like a true Californian! There are places to climb where a person
> really needs more than a t-shirt.
Spoken like the true, ignorant and angy nate that I have come to love. One
day happiness may find you..... and maybe knott!
yours truly,
the burger flipper,
x15x15
David Kastrup
> "melissa"
>
>> If I need a pack to do a climb, then I pick
>> another climb or haul. Generally, I don't haul
>> unless I'm spending the night out. If the weather
>> looks iffy, I crag.
>
> Spoken like a true Californian! There are places to climb where a
> person really needs more than a t-shirt.
I would not want to visit other places. I consider it a basic measure
of mental comfort to see trousers protecting me from the bodily
functions of a preceding party.
Martin Carpenter
"rgold" <rms...@aol.com> wrote:
[snip a fine post]
If tradgirl is still collecting tid bits, then this bit of tid should be
collected.
Which brings me to another thing: clipping the first piece/bolt with doubles
(not twins). Always both strands, or just one?
Martin Carpenter
"Lord Slime" <jbyr...@SPAMfriiPLEASE.com> wrote:
[on skinny singles]
> I suspect they cut more easily that a 10.5mm,
Less chance of getting hit from rockfall though :)
GOClimb
> Which brings me to another thing: clipping the first piece/bolt with doubles
> (not twins). Always both strands, or just one?
One strand. Honestly, I don't quite get where the desire to clip both
strands comes from when you want more safety. I guess I just never saw
it done, so I don't associate it with anything positive. On the
contrary - I associate it with more force on that piece, and potential
burning of the rope.
The only time I ever clip both strands is in order to redirect the
belay off my harness - and that would be through a big Jake (pear
shaped) biner. I can *imagine* clipping both strands to a piece in
order to keep them out from behind a rope-eating flake or something,
but don't think I've ever needed to do so yet.
GO
Lord Slime
> Lord Slime wrote:
> > Just beware their downsides for trad climbing. Yes, they are
> > light-weight, but they don't wear very well, I suspect they cut
> > more easily that a 10.5mm, and the high impact force can be
> > a factor in less-than-bomber rock (use a device that slips).
>
> I'm looking at impact force amongst the ropes and, seems to me, some
> skinny cords have a lower impact force than some fatties. Seems to
> vary from rope to rope.
I just read an article in R&I (I think) were they reviewed the
latest generation of sub-10 singles. This is where I noticed
the overall high-impact forces and I think they mentioned it
in the article too.
> ps: Ant, fyi, I sent Lord Slime a check, he tore it up, and I still
> don't have a clue...ha ha...
True enough.
- Lord Slime
Lord Slime
> > > ropes. one is over there on the left, one out right. one protects
the
> > > traverse, while the other flaps in the wind.
> >
> > Excuse me, but that's how you use double ropes. There isn't a
> > practical method to use two single ropes. Doh.
>
> slime, take everything i say within the context of hte thread, hey?
Okay, how *do* you use two single ropes then? Keep in mind
that the definition of "single rope". Doh!
> > Ant, you are so dense.
> LS, you are proud king of a village.
It's good to be the king.
> > > with that said, with my use i might as well use two 10.5mm ropes and
> > > see no changes in the safety of hte system.
> > Why do you think double ropes are smaller
> > and lighter than singles? Because two singles addes up to extra
> > weight and drag for no increase in safety (and possibly less safety).
> > Doh!
>
> i did not contradict anything you say here. you are interpreting
> statements out of context in an effort to.. what?
An effort to make you think. Alas, the Socratic method isn't
for everyone.
> > Okay, remedial time. Low impact forces are good, especially for
> > trad climbing where gear/rock may not be bomber. Although still
> > within UIAA specs, these recent thin ropes with high impact forces
> > are targetted for sport climbing and modern bolts. Double rope
> > technique is uniquely for trad climbing, especially on bad rock,
> > where high impact forces may blow a placement.
> >
> > Thus, to *choose* to use a thin single rope in a situation that
> > is appropriate for double ropes is a poor choice.
>
> so, LS, are you saying that the only time you would climb on doubles is
> where there is poor pro. and that it would be unsafe to use a
> 'high-impact' single there. therefore, it is unsafe to use a single as
> one half of a 'double' rope system.
I didn't say unsafe. In fact, I don't see that word anywhere in my text.
What I'm trying to say is that a rope system should be chosen for the
climb(s) in mind and that a good choice will produce better results
for several different aspects of the climb: weight, speed, safety and
descent.
> i think you have a problem with using a 'high impact' single for trad
> climbing, and that is why you are going out of your way to smack down a
> reasonable compromise. im not saying thin ropes are ideal for trad, but
> plenty of people are happy with the margin, and should therefore be
> comfortable with the GO system.
Fine, let them. That doesn't mean there aren't better choices.
> > > at the top of long pitch, i do not feel like i have a 5 pound dumbell
> > > hanging off my harness when climbing with a five pound rope. the
> > > friction against the rock and biners supports some of hte weight of
hte
> > > rope when i am not moving.
> >
> > What bullshit. Try climbing something besides 5.7 slabs, like a
> > 50m, vertical pitch. Guess what? That rope is hanging on you
> > like a dead weight.
>
> first off, im no hardened rock god like you, but from time to time i
> move beyond the 5.easy slab, and i stand by what i say. im not saying i
> dont get the dead-weight feel ever. im saying its not hte norm.
Well of course it's not the norm it's "time to time". This of course
in no way supports your argument, because lots of people climb
steeper rock.
> second, even if all i did was laps on whitehorse ledge, it's still a
> valid context. in fact, what portion of hte climbing world is actually
> ever doing a 50m vertical pitch?
I don't know. All I know is that I've done a lot of them.
> > > the drag makes up most of hte perceived
> > > weight when i am clipping and moving.
> > And this is *worse* that a 5lbs dumbell! It's like being short-roped
> > all the time. You're more dense than I thought.
>
> and you're just as abrasive as i remembered you. yes, it can be worse
> than a dead hanging weight. yes, it could feel like being short-roped
> all the time. but thats not hte point. im not saying light ropes arent
> things of delight and wonder, and that i cant feel the difference. all
> i'm-a-sayin' is that my general impression is that drag is a bigger
> part of the perceived rope weight equation than actual rope weight.
Dear Ant, drag is caused by the rope's weight! Friction
is directly proportional to weight. The total drag has two
significant terms: one proportional to weight, and the
other due to its path. (And varies static vs. dynamic.)
Time to send for that clue.
- Lord Slime
Lord Slime
> > Which brings me to another thing: clipping the first piece/bolt with
doubles
> > (not twins). Always both strands, or just one?
> One strand. Honestly, I don't quite get where the desire to clip both
> strands comes from when you want more safety.
It's obvious that you don't "get" it.
Double ropes have low impact forces and lots of elongation.
Clipping both strands on the first piece, or above a ledge,
makes it less likely that you'll ground out in a fall.
> I guess I just never saw
> it done, so I don't associate it with anything positive.
I.e. you don't get it.
- Lord Slime
Lord Slime
Congratulations, this stirred up the anthill pretty good.
> We don't pack everything with second b/c then you need to change out
> your crap every time the second changes out.
What? I don't follow this at all.
> Everyone carries their
> own water and shoes, the leader carries the lead rack, the cleaner
> carries the cleaned gear, and that is everything. I put my shoes and
> my water bottle on my shoulder sling for chimneys so they're easier to
> swing out of the way.... If I need a pack to do a climb, then I pick
> another climb or haul. Generally, I don't haul unless I'm spending the
> night out. If the weather looks iffy, I crag. I just get no pleasure
> out of climbing with a pack on. Everyone has their own sense of what
> is aesthetic, and this is mine.
I disagree. There are lots of situations where changing weather, sun
vs. shade, length, difficulty, etc. make your method a poor choice.
> For the extra weight, I'd rather have a second rope that can be used as
> a lead line if and when the raps hang.
Since you don't like climbing with a pack (I hate it too), use that
second line to haul a light pack. Put the water, jackets, hats, food-
bars, etc. in the pack, but keep it light enough to haul by hand (fast).
Then, both climbers are unencumbered while they climb, which is
important if you're climbing near your limit.
- Lord Slime
Lord Slime
news:4472df4c$0$22411
> "Lord Slime" <jbyr...@SPAMfriiPLEASE.com> wrote:
> > I suspect they cut more easily that a 10.5mm,
>
> Less chance of getting hit from rockfall though :)
Ha!
- Lord Slime
Lord Slime
> Slime, I feel like you're deliberately ignoring the value of this
> point, so let me be pedantic:
I'm not ignoring it, I just think that it's overkill.
> Gabe puts two ropes in his pack at the start of a day.
> Route #1 is wandering and best protected with doubles. For Route #1,
> Gabe uses his double system, of 1 single and 1 half rope. He gets to
> the top, and gets back down in one convenient rap.
> Route #2 is straight up, and at his limit. Here, Gabe uses his single
> rope.
> Route #3 has one pitch of straight-up, one pitch with a big traverse,
> and one pitch of straight-up. On Route #3, Gabe uses his ropes
> differently on every pitch!
>
> For the price of carrying his extra pound, Gabe indeed has two unique
> systems at his disposal.
1) It's unusual to find routes like 1, 2 and 3 at a single crag, on a
single
type of rock. I can't think of one, but they might exist.
2) For ALL three routes, he could have used double ropes, eh?
On the straight up pitches, he could have used them as twins.
3) Many, many people use single ropes on wandering pitches
with good results.
4) My personal opinion is that doubles are best in certain situations,
and a pain in the ass otherwise. Places where there is loose/falling
rock (lower impact forces, less chance of both ropes being cut),
zigzagging pitches, no hauling and it's nice to have two ropes
to rap with. The Dolomites comes to mind, Canadian Rockies, etc.
- Lord Slime
Lord Slime
> safe with a big fatty. I rationalize this choice though my telling
> myself that if a 10.5 is what is considered bomber for a 200 lbs guy,
> then I must be doing comparably well on a 9.7.
Not necessarily. If you take a high fall-factor fall, you can generate
more force than that 200lbs guy taking a low FF fall.
> I understand that all
> bets are off over edges...and try to avoid them (and falls) no matter
> what size the cord.
And falling rock...
> I haven't had many ropes (of any size) show visible wear that required
> retirement in advance of the point where I just figured that it was
> prudent to retire them due to age.
See how long it takes to wear out your 9.7mm and get back to
us.
- Lord Slime
x15x15
"Lord Slime"
> An effort to make you think. Alas, the Socratic method isn't
> for everyone.
But it seems the Lord Slime persona has transcended into the Real Mr. Byrnes
(sp?), thereby causing your Socratic method to come across as just another
burn and shutting down all critical dialogue.
But it is still funny.
x15x15
Lord Slime
> First off, glad to see you're still alive and kicking, when I shot back
> and didn't hear from you in a couple of days, I began to worry!
That's cool. I was climbing Thurs&Fri.
> > The UIAA certifies single, double and twin ropes to be used
> > in specific ways. Combining the equipment and techniques
> > in some weird way is.... weird, provides little to no advantage,
> > and is not recommended.
>
> Well I guess it's up to you, me, and others to decide whether it
> provides an advantage.
True, but I don't see any advantage to your system.
> > And the extra biners? Also, what's the impact force of the two ropes?
> > Have you considered that?
>
> I'm still not quite sure where these extra biners come in. As I said
> earlier, I cannot recall ever having clipped both ropes to a single
> piece, though it may have happened once.
Okay, perhaps I mis-attributed the text.
> The impact force of the two ropes... on what?
As I said, I would choose double ropes for loose rock and
wandering pitches, such as the Dolomites or Canadian Rockies.
Impact force is important on poor rock, and many of these
new sub-10mm singles have rather high impact forces.
> > > > Secondly, all those sub-10 single ropes have very high impact
> > > > forces, and you are combining it with a rope with a very low one.
> > > > If you are clipping both to each piece, the 9.5mm will take all
> > > > the force every time (less stretch). So what's the point of having
> > > > the 8mm? If you're alternately clipping, why not two 8mms? DOH!
> > >
> > > Why would I clip both ropes? Perhaps you're thinking of twins
> > > technique, rather than doubles? I know it's confusing - thus the
> > > subject of the original post.
> >
> > Don't flatter yourself, I'm not confused.
>
> You are if you believe - as you said above, that I'm "clipping both to
> each piece". As I understand it, that's twin-rope technique, not
> double-rope technique. But as I've never used twin rope technique, I
> won't claim to know anything beyond that.
What I was trying to convey is that, in case one, you'd use a single
rope and the other is superfluous, and in case two, two half-ropes
is a better choice.
> > > > I'd say you should leave your paranoia and the 8mm at home
> > > > and take that single sub-10mm rope climbing. It'll wear out soon
> > > > enough, and you can buy another 8mm to match the one at home.
> > >
> > > No paranoia - don't know where that comment comes from.
It comes from the fact that, somehow, you don't feel comfortable
with two half-ropes.
> For the reasons I, and others here, have stated: it combines the
> benefits of each, and adds flexibility in my choices. I recently took
> a one-month road trip, and needed to bring only two ropes.
Non sequitur. This is not a reason to use a single and
double, using double-technique, on a route. What would you
do if the single was damaged?
> As for this repeated insistence that the thin singles are have too high
> a force to be appropriate for trad use, I disagree. The Mammut
> Infinity 9.2mm Single I use is rated at 9.1kN. Compare this to other
> ropes they make: the Eternity 10 mm - 9kN; the Flex 11mm - also 9kN, or
> the Flash 10.5mm - rated at 9kN. This last they actually advertise as
> "low impact force" on their website.
Compare it to my Mammut Genesis half-rope with 6.0kN, or my
Beal single rope with 7.5kN. It's a LARGE difference!
> If The Flash, with an impact force of 9kN is considered to have a "low
> impact force", then that Infinity, rated at 9.1kN is "high impact"?
> Seems like a stretch to me (no pun intended).
I don't consider 9kN to be low, even if you did read it correctly
on the website.
- Lord Slime
GOClimb
> "GOClimb" <gost...@gmail.com> wrote in message
> > Martin Carpenter wrote:
> > > Which brings me to another thing: clipping the first piece/bolt with
> doubles
> > > (not twins). Always both strands, or just one?
> > One strand. Honestly, I don't quite get where the desire to clip both
> > strands comes from when you want more safety.
>
> It's obvious that you don't "get" it.
>
> Double ropes have low impact forces and lots of elongation.
> Clipping both strands on the first piece, or above a ledge,
> makes it less likely that you'll ground out in a fall.
You are right, I don't think of it that way. When I've got one piece
between me and catastrophe, the *last* thing I want to do is increase
the force on that piece by ~ 40% if I should fall. I'd rather increase
my odds of hitting a ledge at the end of the rope stretch than get
stopped short, hear that horrible ping as a piece rips, and then go for
a big one.
But thanks for adding another positive attribute to my climbing system
that I hadn't thought of: if there's a possibility of hitting
something with rope stretch (and only room for one piece), I have a
better choice than the person using standard doubles technique on two
1/2 ropes: I can choose to improve my odds by clipping the piece with
my single rope. For the person climbing with the standard doubles,
they only have the poorer choices of clipping both ropes (too little
stretch) or clipping a single rope (too much stretch).
Thanks again!
GO
Thor Lancelot Simon
Lord Slime <jbyr...@SPAMfriiPLEASE.com> wrote:
>"GOClimb" <gost...@gmail.com> wrote in message
>> Martin Carpenter wrote:
>> > Which brings me to another thing: clipping the first piece/bolt with
>doubles
>> > (not twins). Always both strands, or just one?
>> One strand. Honestly, I don't quite get where the desire to clip both
>> strands comes from when you want more safety.
>
>It's obvious that you don't "get" it.
>
>Double ropes have low impact forces and lots of elongation.
>Clipping both strands on the first piece, or above a ledge,
>makes it less likely that you'll ground out in a fall.
Also, keep in mind that in a lot of situations you really, really
want a good, solid, multidirectional piece down low to avoid nasty
outwards zipper pull on "down-only" gear higher up on the route.
When you make that first placement, if you're lucky enough that it
is, in fact, "good, solid, multidirectional", often you don't know
the *next* one will be. So it is often prudent, when climbing with
doubles, to clip both ropes to the first piece.
The same thing applies in any situation where zippering of a series
of pieces is an issue -- clipping both ropes together may be the
right thing to do.
--
Thor Lancelot Simon t...@rek.tjls.com
"We cannot usually in social life pursue a single value or a single moral
aim, untroubled by the need to compromise with others." - H.L.A. Hart
David Kastrup
> Dear Ant, drag is caused by the rope's weight! Friction
> is directly proportional to weight. The total drag has two
> significant terms: one proportional to weight, and the
> other due to its path. (And varies static vs. dynamic.)
While you are correct about friction being proportional to the weight
in theory, I consider it questionable that the woven mantle of the
rope is modeled satisfactorily by friction alone. It would take some
experimenting in "drag" situations to see whether adding weight at the
bottom influences the force of drag linearly. While the surface of
ropes is certainly not nearly as sticky as woven slings for sandstone
and chock stones, I could still imagine that its interaction with
various surfaces is not exactly linear.
Any idea whether experiments like that have been done already?
GOClimb
Thor Lancelot Simon wrote:
> In article <1276m8k...@corp.supernews.com>,
> Lord Slime <jbyr...@SPAMfriiPLEASE.com> wrote:
> >"GOClimb" <gost...@gmail.com> wrote in message
> >> Martin Carpenter wrote:
> >> > Which brings me to another thing: clipping the first piece/bolt with
> >doubles
> >> > (not twins). Always both strands, or just one?
> >> One strand. Honestly, I don't quite get where the desire to clip both
> >> strands comes from when you want more safety.
> >
> >It's obvious that you don't "get" it.
> >
> >Double ropes have low impact forces and lots of elongation.
> >Clipping both strands on the first piece, or above a ledge,
> >makes it less likely that you'll ground out in a fall.
>
> Also, keep in mind that in a lot of situations you really, really
> want a good, solid, multidirectional piece down low to avoid nasty
> outwards zipper pull on "down-only" gear higher up on the route.
>
> When you make that first placement, if you're lucky enough that it
> is, in fact, "good, solid, multidirectional", often you don't know
> the *next* one will be. So it is often prudent, when climbing with
> doubles, to clip both ropes to the first piece.
Good point, I'll think about that next time I'm out with doubles and
see whether I like the idea.
GO
GOClimb
Lord Slime wrote:
> "GOClimb" <gost...@gmail.com> wrote in message
> > Hey LS,
> > First off, glad to see you're still alive and kicking, when I shot back
> > and didn't hear from you in a couple of days, I began to worry!
>
> That's cool. I was climbing Thurs&Fri.
Excellent. Hope it went well. What'd you do?
> > > The UIAA certifies single, double and twin ropes to be used
> > > in specific ways. Combining the equipment and techniques
> > > in some weird way is.... weird, provides little to no advantage,
> > > and is not recommended.
> >
> > Well I guess it's up to you, me, and others to decide whether it
> > provides an advantage.
>
> True, but I don't see any advantage to your system.
No, clearly you don't. But others do. More to the point, the
advantages are obvious to me, and you haven't pointed out any serious
disadvantages, which is encouraging. The only serious issue you've
raised is the potential higher impact force of the single rope, and
while I believe that *some* thin singles may not be appropriate for
trad climbing, I think the force characteristics of the rope I'm using
seems okay. More on that later.
> > > And the extra biners? Also, what's the impact force of the two ropes?
> > > Have you considered that?
> >
> > I'm still not quite sure where these extra biners come in. As I said
> > earlier, I cannot recall ever having clipped both ropes to a single
> > piece, though it may have happened once.
>
> Okay, perhaps I mis-attributed the text.
No problem.
> > > > > Secondly, all those sub-10 single ropes have very high impact
> > > > > forces, and you are combining it with a rope with a very low one.
> > > > > If you are clipping both to each piece, the 9.5mm will take all
> > > > > the force every time (less stretch). So what's the point of having
> > > > > the 8mm? If you're alternately clipping, why not two 8mms? DOH!
> > > >
> > > > Why would I clip both ropes? Perhaps you're thinking of twins
> > > > technique, rather than doubles? I know it's confusing - thus the
> > > > subject of the original post.
> > >
> > > Don't flatter yourself, I'm not confused.
> >
> > You are if you believe - as you said above, that I'm "clipping both to
> > each piece". As I understand it, that's twin-rope technique, not
> > double-rope technique. But as I've never used twin rope technique, I
> > won't claim to know anything beyond that.
>
> What I was trying to convey is that, in case one, you'd use a single
> rope and the other is superfluous, and in case two, two half-ropes
> is a better choice.
So what you're trying to ask is why I would want anything besides two
1/2 ropes for doubles technique? We've been round and round on this
one - if you're not convinced that the flexibility I've described is of
any use, then you're not going to be. Everyone else has heard my say,
and will make up their own minds. I must say, I think your aguments
have not been terribly persuasive, but perhaps that's only because you
were confused by some of the things I said. If I was unclear, I
apologize, it certainly wasn't intentional.
> > > > > I'd say you should leave your paranoia and the 8mm at home
> > > > > and take that single sub-10mm rope climbing. It'll wear out soon
> > > > > enough, and you can buy another 8mm to match the one at home.
> > > >
> > > > No paranoia - don't know where that comment comes from.
>
> It comes from the fact that, somehow, you don't feel comfortable
> with two half-ropes.
Sure I do. What I don't feel comfortable doing is taking repeated
falls on only one of those 1/2 ropes, or TRing on it, or risking
cutting it when I'm only belayed on one rope. I want a full-strength
single for those applications.
> > For the reasons I, and others here, have stated: it combines the
> > benefits of each, and adds flexibility in my choices. I recently took
> > a one-month road trip, and needed to bring only two ropes.
>
> Non sequitur. This is not a reason to use a single and
> double, using double-technique, on a route. What would you
> do if the single was damaged?
It's not a non-sequitur! The whole damn point is that I can climb with
doubles or singles technique with only two ropes!!! But to answer your
question - let me ask you this: what would *you* do if you were on a
roadtrip and your single rope was damaged? Hightail it to the nearest
gear shop and buy a new one! I'd do the same. Or do you mean, what
would I do if I were on a route and the single line got chopped when I
was using it in a pair as doubles? Same thing I'd do if I were leading
on a pair of 1/2 ropes! Probably bail, but maybe try to get up with
just the other rope.
Come to think of it, if one of the ropes was chopped by rockfall while
I was in the middle of a route, 50% chance says it's be the 1/2 rope.
And given my doubles setup, that would leave me with: one
full-strength single rope to finish the route. Cool, thanks - that's
another good reason to use my technique. LS, I really must thank you
for these ideas!
> > As for this repeated insistence that the thin singles are have too high
> > a force to be appropriate for trad use, I disagree. The Mammut
> > Infinity 9.2mm Single I use is rated at 9.1kN. Compare this to other
> > ropes they make: the Eternity 10 mm - 9kN; the Flex 11mm - also 9kN, or
> > the Flash 10.5mm - rated at 9kN. This last they actually advertise as
> > "low impact force" on their website.
>
> Compare it to my Mammut Genesis half-rope with 6.0kN, or my
> Beal single rope with 7.5kN. It's a LARGE difference!
Bullshit, plain and simple. The Mammut Genesis is measured as a 1/2
rope - they don't do the same drop test! It's measured with a 55kg
weight, instead of the 80kg weight used for singles. Do you know what
it would be rated at if it were tested with an 80kg weight?
As for the Beal single rope - yes, beal ropes seem to have lower impact
forces than Mammut ropes, _accross the board_. Let's take a look at
the thinnest rope Beal makes specifically as a single. What's it rated
at? 7.60-7.80 kN. So much for your whole argument of thinner ropes
having too high a force to be appropriate for trad climbing. I guess
that's what you get for paying too much attention to articles in R&I.
> > If The Flash, with an impact force of 9kN is considered to have a "low
> > impact force", then that Infinity, rated at 9.1kN is "high impact"?
> > Seems like a stretch to me (no pun intended).
>
> I don't consider 9kN to be low, even if you did read it correctly
> on the website.
"even if I did read it correctly"? Jeez, that's what your whole
argument leaves you with? That's it? This stuff is pretty easy to
verify! Go look for yourself, and you'll find that pretty much all of
Mammut's single ropes are rated in the range of 8.8 - 9.5 kN -
significantly over the rating of Beal's ropes. Looking at that range -
the 9.1kN one I use is slightly below average for what they sell. It's
also one of the thinnest singles they sell. So much for your whole
argument.
Of course if you want to argue that Mammut ropes are inappropriate for
trad climbing, be my guest. We'll see. I'm a big fan of the handling
and durability of Mammut ropes, but I'll consider your argument.
GO
Lord Slime
> > That's cool. I was climbing Thurs&Fri.
> Excellent. Hope it went well. What'd you do?
I didn't *do* anything. I got done. I'm working on Killer up at Sinks,
or rather, I'm getting worked on Killer.
> > What I was trying to convey is that, in case one, you'd use a single
> > rope and the other is superfluous, and in case two, two half-ropes
> > is a better choice.
>
> So what you're trying to ask is why I would want anything besides two
> 1/2 ropes for doubles technique?
Yes.
> > > > > No paranoia - don't know where that comment comes from.
> > It comes from the fact that, somehow, you don't feel comfortable
> > with two half-ropes.
>
> Sure I do. What I don't feel comfortable doing is taking repeated
> falls on only one of those 1/2 ropes, or TRing on it, or risking
> cutting it when I'm only belayed on one rope. I want a full-strength
> single for those applications.
"I don't think you understand what that word means."
PARANOIA: an irrational fear. Hey Goclimb, what is "full-strength"?
Is it the number of UIAA falls? Is it resistance to cutting? Some other
measure? Why do they test single ropes and doubles differently?
Why do manufacturers make doubles and singles, with a broad
spectrum of parameters?
> > Non sequitur. This is not a reason to use a single and
> > double, using double-technique, on a route. What would you
> > do if the single was damaged?
>
> It's not a non-sequitur! The whole damn point is that I can climb with
> doubles or singles technique with only two ropes!!!
Is your vehicle incapable of holding another rope? This
is trivial.
> ...let me ask you this: what would *you* do if you were on a
> roadtrip and your single rope was damaged?
I always take two single ropes in case one is damaged. If
I'm planning on long routes, I'll take a half-rope (or small static)
in addition for hauling. Do you take one pair of shoes on your
trips?
> Hightail it to the nearest
> gear shop and buy a new one! I'd do the same.
Not to many gear shops in Tensleep, Indian Creek, Caymans,
etc.
> > > As for this repeated insistence that the thin singles are have too
high
> > > a force to be appropriate for trad use, I disagree. The Mammut
> > > Infinity 9.2mm Single I use is rated at 9.1kN. Compare this to other
> > > ropes they make: the Eternity 10 mm - 9kN; the Flex 11mm - also 9kN,
or
> > > the Flash 10.5mm - rated at 9kN. This last they actually advertise
as
> > > "low impact force" on their website.
> >
> > Compare it to my Mammut Genesis half-rope with 6.0kN, or my
> > Beal single rope with 7.5kN. It's a LARGE difference!
>
> Bullshit, plain and simple. The Mammut Genesis is measured as a 1/2
> rope - they don't do the same drop test! It's measured with a 55kg
> weight, instead of the 80kg weight used for singles. Do you know what
> it would be rated at if it were tested with an 80kg weight?
Who cares? See below.
> As for the Beal single rope - yes, beal ropes seem to have lower impact
> forces than Mammut ropes, _accross the board_. Let's take a look at
> the thinnest rope Beal makes specifically as a single. What's it rated
> at? 7.60-7.80 kN. So much for your whole argument of thinner ropes
> having too high a force to be appropriate for trad climbing. I guess
> that's what you get for paying too much attention to articles in R&I.
You miss my point entirely, so let me spell it out AGAIN. Double
rope technique is a good choice for bad rock and overkill for
good rock. Thus, you want a low impact force.
Now, if you want to carry a lot of extra rope up every climb, be my
guest. How many people do you see using this technique in Yosemite?
Or Eldo, or .... anywhere?
> Of course if you want to argue that Mammut ropes are inappropriate for
> trad climbing, be my guest. We'll see. I'm a big fan of the handling
> and durability of Mammut ropes, but I'll consider your argument.
I've retired, and still own, several Mammut ropes. This argument
has nothing to do with brand.
GO haul whatever you want up the route. Just don't be spewing
that it's a great system, because it's not. If it were, *everyone*
would be using it, and you're the ONLY one I've heard of using
it regularly.
- Lord Slime
Lord Slime
> > Double ropes have low impact forces and lots of elongation.
> > Clipping both strands on the first piece, or above a ledge,
> > makes it less likely that you'll ground out in a fall.
>
> You are right, I don't think of it that way. When I've got one piece
> between me and catastrophe, the *last* thing I want to do is increase
> the force on that piece by ~ 40% if I should fall. I'd rather increase
> my odds of hitting a ledge at the end of the rope stretch than get
> stopped short, hear that horrible ping as a piece rips, and then go for
> a big one.
What an ass. (Even if what you wrote were true) You'd rather
hit the ground!
What's really funny is that you've managed to argue on both sides
of the question (and don't realize it). It's pretty clear that selling
you a clue won't help.
> But thanks for adding another positive attribute to my climbing system
> that I hadn't thought of: if there's a possibility of hitting
> something with rope stretch (and only room for one piece), I have a
> better choice than the person using standard doubles technique on two
> 1/2 ropes: I can choose to improve my odds by clipping the piece with
> my single rope.
Bullshit again. Hey GoClimb, compare the elongation of
my doubles to your single in this situation. Are you SURE
it improves your odds? Doesn't it depend on the specs of
the ropes? Doesn't it depend of whether the piece holds
or not? And if it pops, at what force it pops?
It's not so cut-and-dried as you seem to think.
- Lord Slime
Lord Slime
> "Lord Slime" <jbyr...@SPAMfriiPLEASE.com> writes:
> > Dear Ant, drag is caused by the rope's weight! Friction
> > is directly proportional to weight. The total drag has two
> > significant terms: one proportional to weight, and the
> > other due to its path. (And varies static vs. dynamic.)
>
> While you are correct about friction being proportional to the weight
> in theory, I consider it questionable that the woven mantle of the
> rope is modeled satisfactorily by friction alone.
True, but I was trying to keep it simple. In this discussion
we don't need to *quantify* the drag, we only need to
establish *relative* drag; heavy rope vs. light. Much easier.
> It would take some
> experimenting in "drag" situations to see whether adding weight at the
> bottom influences the force of drag linearly.
Now com'on David! What does your experience tell you?
It may not be perfectly linear, and may have many complexities,
but it's easy to see that a heavier rope has more drag, given
the same topology and similiar materials.
Thought experiment ONE: A 60 degree slab. Easy to see.
Thought experiement TWO: Horizontal ceiling. The rope
sags inbetween each piece, putting more force on each
biner. Easy to see.
Thought experiment THREE: Vertical wall, rope takes a
left-turn halfway up. The heavier rope puts more tension
on the rope, which translates to increased friction at the
turn-biner.
> Any idea whether experiments like that have been done already?
Done.
- Lord Slime
David Kastrup
> "David Kastrup" <d...@gnu.org> wrote in message
>
>> It would take some
>> experimenting in "drag" situations to see whether adding weight at the
>> bottom influences the force of drag linearly.
>
> Now com'on David! What does your experience tell you?
>
> It may not be perfectly linear, and may have many complexities,
> but it's easy to see that a heavier rope has more drag, given
> the same topology and similiar materials.
>
> Thought experiment ONE: A 60 degree slab. Easy to see.
>
> Thought experiement TWO: Horizontal ceiling. The rope
> sags inbetween each piece, putting more force on each
> biner. Easy to see.
Well, but that's not the draggiest situation.
> Thought experiment THREE: Vertical wall, rope takes a
> left-turn halfway up. The heavier rope puts more tension
> on the rope, which translates to increased friction at the
> turn-biner.
The real dragsters for me (short of the rope being pulled into
something crackish, in which case rope weight should be pretty
immaterial) is soft sandstone, rope running round a whaleback sort of
thing.
You can then arrest the rope more or less with the pinky at the belay
without belay device, which would vouch for a hefty amplification of
the forces at least at the end of the rope, due to friction. So
indeed the effect of rope weight should be similar.
>> Any idea whether experiments like that have been done already?
>
> Done.
I am just slow in thinking.
Lord Slime
> > It may not be perfectly linear, and may have many complexities,
> > but it's easy to see that a heavier rope has more drag, given
> > the same topology and similiar materials.
> >
> > Thought experiment ONE: A 60 degree slab. Easy to see.
> >
> > Thought experiement TWO: Horizontal ceiling. The rope
> > sags inbetween each piece, putting more force on each
> > biner. Easy to see.
>
> Well, but that's not the draggiest situation.
No, it's only one situation.
> > Thought experiment THREE: Vertical wall, rope takes a
> > left-turn halfway up. The heavier rope puts more tension
> > on the rope, which translates to increased friction at the
> > turn-biner.
>
> The real dragsters for me... [yadda, yadda, yadda]
I'm not trying to find the situations with the MOST drag.
I'm only trying to show that in just about every situation, a
heavy rope will produce more drag than a light one.
- Lord Slime
ant
> I'm not trying to find the situations with the MOST drag.
> I'm only trying to show that in just about every situation, a
> heavy rope will produce more drag than a light one.
and who contradicted you on that point?
i, for one, never meant to say that a light rope felt the *same* as a
heavy rope. what i'm saying is that *relatively*, the difference does
not mean much to me.
for me, perceived rope weight is far more dependent on route conditions
(angle, rock friction, pro-in-lineness, etc) than rope weight. i dont
think the fact that rope weight feedsback to friction/drag changes
much.
say im getting (arbitrary numbers) 40 lbs of drag at the top of a long
pitch, it'd be like 35 lbs were because the rock was grippy and i didnt
extend a piece, and 5 lbs because of rope weight.
and- if i had just used a lighter rope, with its subsequent reduction
of friction and weight, i'd guess it'd be more like 32 lbs of drag and
4 lbs of rope weight. big whoop.
the numbers are made up, but do you see what i'm a-sayin'?
anyways, who cares. i cant even remember how this got started. i like
light ropes. i just cant afford them.
Dawn Alguard
>
> say im getting (arbitrary numbers) 40 lbs of drag at the top of a long
> pitch, it'd be like 35 lbs were because the rock was grippy and i didnt
> extend a piece, and 5 lbs because of rope weight.
But rope drag can usually be avoided through proper planning. Rope
weight you're stuck with.
> the numbers are made up, but do you see what i'm a-sayin'?
Well, if we're allowed to make up numbers then I suppose we can prove
anything.
Dawn
David Kastrup
> Lord Slime wrote:
> > I'm not trying to find the situations with the MOST drag.
>> I'm only trying to show that in just about every situation, a
>> heavy rope will produce more drag than a light one.
>
> and who contradicted you on that point?
>
> i, for one, never meant to say that a light rope felt the *same* as a
> heavy rope. what i'm saying is that *relatively*, the difference does
> not mean much to me.
>
> for me, perceived rope weight is far more dependent on route conditions
> (angle, rock friction, pro-in-lineness, etc) than rope weight.
Rope weight factors in about linearly, so perceived weight is always
depending on rope weight.
> i dont think the fact that rope weight feedsback to friction/drag
> changes much.
>
> say im getting (arbitrary numbers) 40 lbs of drag at the top of a
> long pitch, it'd be like 35 lbs were because the rock was grippy and
> i didnt extend a piece, and 5 lbs because of rope weight.
There are features where extending pieces won't help.
> and- if i had just used a lighter rope, with its subsequent reduction
> of friction and weight, i'd guess it'd be more like 32 lbs of drag and
> 4 lbs of rope weight. big whoop.
You mean, if you climb loaded down with 32lbs of drag, you won't mind
another 8lb of drag? Come again? It is _exactly_ when you are bogged
down that heaping it on is not going to improve the situation.
> the numbers are made up, but do you see what i'm a-sayin'?
Yes, and it is not a pretty sight.
Brent Ware
> Well, if we're allowed to make up numbers then I suppose we can prove
> anything.
Pardon me in advance if I steal this from you and turn it into a group
catchphrase?
-bw
i was told we wouldn't have to do math in this 'froup.
mheyman
When I lead on double ropes, if they are not widely separated, bombr slung
trees get both ropes.
mheyman
I think LS has made an interesting point here. This is what I think he was
trying to convey - he can comment if he would like:
What we feel as rope drag is partly rope weight and partly friction.
The friction part increases with rope tension. It might even be thought of
as a factor that multiplies the tension in the rope.
where does the base tension come from? It is the weight of the rope, and
since it is being multiplied by a large factor, then a small increase in
rope weight might well create a large increase in tension when you pull
against it. After all there is nothing else creating tension on it's own, it
is only the weight of the rope that is pulling back. So, the weight of the
rope factors into what you will must pull in terms of weight, but also as a
multiplying factor in the friction component of rope drag
This means that the weight of the rope has a larger affect than lifting the
weight alone - certanly more than I would have guessed before this thread.