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Rapping issues with 9.1 and 7.8?


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Hobo Greg · · My Van · Joined Mar 2016 · Points: 175

Been reading a lot about halfs vs a skinny single with either a tag or a lightweight half for backcountry climbing where the raps are longer than 30 or 35m. If I use a 9.1mm and a 7.8mm, can I rappel like I normally would with two ropes, or do I treat it like a tag and only rap on the thicker line? If the difference in diameter is too great to rap on both at the same time, what would the lower end need to be bumped up to? I'd rather have the lightweight half instead of a tagline for the sake of not being hosed if the main line gets stuck on the pull.

Scott E · · Unknown Hometown · Joined Oct 2015 · Points: 50

I use a 7mm static paired with one of my single ropes which range from 9.2 to 9.8mm. I treat the rappel system how I normally would with 2 ropes and don't use a biner block like you would with just a tag line/pull cord. I would recommend rapping with a backup and possibly gloves because there is a lot less friction with the skinny rope so it is harder to maintain control of the rappel. Another thing to consider is that a dynamic half rope stretches a lot so it will sometimes be difficult to pull the ropes after a rappel. The combo of the single rope and skinny 2nd rope is sometimes nice but if I need two ropes for a rappel, I prefer to use 2 half ropes on the climb

John Wilder · · Las Vegas, NV · Joined Feb 2004 · Points: 1,535

I regularly rappel with a 9.4mm and an 8mm tag line. It's fine.

Buck Rio · · MN · Joined Jul 2015 · Points: 0

I agree with previous two posters: use a static tag line in either 7-8mm and rap both ropes like normal. I have never used a biner block. With a thicker rope, like 10mm and above, the tag line does like to creep a bit, since it passes through the ATC more freely than the thicker rope. I carry a right hand fingerless glove on bigger climbs if there is going to be any free hanging rappels. Tie knots in the end before you throw your rope down if you are worried about losing control, and a klemheist on the leg loop trick isn't a terrible idea. I pull the lead rope, and use the EDK with the tag line stopper knot...FWIW

Taylor Krosbakken · · Duluth, MN · Joined Nov 2008 · Points: 340

I will echo the above and say that I normally rappel on a 7.8 half rope combined with a 9.2 or 9.5 single with out a problem. I have never noticed much unevenness while rappelling with a DMM pivot or BD atc.

I usually set it up so I am pulling my skinnier rope with my rational being that if the skinnier rope does slip through faster my flat over hand will run into the rap rings. now I could see not setting it up this way if you were combining with a static line since you could put yourself in a situation where your lead line is stuck and you only have a static line. but with my set up I at least have a half rope.

I also combine the two uneven ropes with a flat overhand, having the skinnier rope away from the tales in the knot, making it harder to roll. 

Buck Rio · · MN · Joined Jul 2015 · Points: 0
TKrosbakken wrote: I will echo the above and say that I normally rappel on a 7.8 half rope combined with a 9.2 or 9.5 single with out a problem. I have never noticed much unevenness while rappelling with a DMM pivot or BD atc.

I usually set it up so I am pulling my skinnier rope with my rational being that if the skinnier rope does slip through faster my flat over hand will run into the rap rings. now I could see not setting it up this way if you were combining with a static line since you could put yourself in a situation where your lead line is stuck and you only have a static line. but with my set up I at least have a half rope.

I also combine the two uneven ropes with a flat overhand, having the skinnier rope away from the tales in the knot, making it harder to roll. 

This is the way I did it for years: 9.7 lead rope and a half rope tag line. The half rope(s) got old/retired and I don't ice climb anymore so I just got the tag line for cheap. Plus if I have to make a bail anchor, I don't mind chopping the tag line nearly as much as an actual climbing rope. The reason I always pull the climbing rope first is that it seems to get stuck less that way. Anecdotal only, I don't keep track.  But having a static line stuck is much less traumatic to pull, and they seem to come unstuck easier.

Jim Titt · · Germany · Joined Nov 2009 · Points: 490

Why bother to carry the 9.1 rope? Just use two 7.8´s like normal people do (myself for instance).

Greg D · · Here · Joined Apr 2006 · Points: 877

If you are rapping different diameter ropes, there is no reason not to put both ropes in the device.  It gives you a bit more friction, you maintain control of the tag and helps to mitigate rope creep.  Rope creep is likely, but is mitigated by putting the knot on the skinny rope side of the anchor.  This is easy for the first rappel.  But, if you are doing multiple rappels, it is nice to feed your ropes through the second anchor as you are pulling it from the first anchor.  This puts the knot on the fatter rope side of the anchor. Now rope creep is more of a concern.  If you put the skinny rope onto a second biner in your rappel device, this will add friction to the skinny side and put things more in balance.  I have done this. It worked well with a 9.5 and 7.9.  

I have rapped with many different setups.  If I did a lot of routes that have many double rope rappels, I believe double ropes or twins would be the way to go like Jim said. (normal people).

You should know when a Repschnur is needed so you don't die.  

Greg Gavin · · SLC, UT · Joined Oct 2008 · Points: 766

Like Greg D said "know when to use a repschnur..."

I consistently use ropes from 8.7-10.1mm with my 7mm Petzl pull cord. There are times and rap anchors that dictate using a repschnur + biner block to ensure safety, and there are other times where simply joining the two lines via an EDK is perfectly fine.

I always use a 3rd hand friction hitch, and thread both lines through my belay device no matter my set up. This gives me added friction, and the ability to control both ropes in the event of a bad toss/windy/bushy descent conditions.

Healyje · · PDX · Joined Jan 2006 · Points: 456
Jim Titt wrote: Why bother to carry the 9.1 rope? Just use two 7.8´s like normal people do (myself for instance).
Exactly. Just climb on twins and skip the whole tagline thing.
FosterK · · Edmonton, AB · Joined Nov 2012 · Points: 43
Jim Titt wrote: Why bother to carry the 9.1 rope? Just use two 7.8´s like normal people do (myself for instance).

Money - a triple rated rope is very versatile, so you can save on purchasing a separate single if you want to use a twin/half system on occassion.

Buck Rio · · MN · Joined Jul 2015 · Points: 0
Healyje wrote: Exactly. Just climb on twins and skip the whole tagline thing.

I personally can't stand two ropes for rock, mostly because I don't trust that the belayer can handle two ropes. I climb with a lot of "acquaintances" that don't necessarily have my full trust. If they seem pretty competent or have a preference for twins, I guess I would be game, but that has never happened. In this part of the world, there are not many people that use twin ropes, or have a reason to use them. 

Strangely, all of my ice partners use either twins or half ropes, and rock climb on a single. I know a 8mm is a lot harder to hit with a crampon point than a 10.5.

A 7.8 for rock climbing would be hard to arrest with a bare hand in a tuber style device without a glove....ice climbers normally wear gloves so not as much of an issue
Healyje · · PDX · Joined Jan 2006 · Points: 456
Buck Rio wrote:

I personally can't stand two ropes for rock, mostly because I don't trust that the belayer can handle two ropes.

That's an entirely different problem. Gotta say if I didn't trust someone to manage twins I wouldn't trust them at all.
Buck Rio · · MN · Joined Jul 2015 · Points: 0
Healyje wrote: That's an entirely different problem. Gotta say if I didn't trust someone to manage twins I wouldn't trust them at all.

Welcome to my world...gotta learn to rope solo.

Greg D · · Here · Joined Apr 2006 · Points: 877

Belaying with twins is not much different than a single.  Belay halves is a different story.

And why do you think one would need to arrest a fall on a 7.8?  It would be two 7.8’s. 

Buck Rio · · MN · Joined Jul 2015 · Points: 0
Greg D wrote: Belaying with twins is not much different than a single.  Belay halves is a different story.

And why do you think one would need to arrest a fall on a 7.8?  It would be two 7.8’s. 

unless you are clipping both ropes into every piece, the top piece rope will bear the load.

Greg D · · Here · Joined Apr 2006 · Points: 877

That’s for double rope technique and double rated ropes. If you stick to twin technique on twin ropes, then it is not an issue.

Hobo Greg · · My Van · Joined Mar 2016 · Points: 175
Greg D wrote: Belaying with twins is not much different than a single.  Belay halves is a different story.

And why do you think one would need to arrest a fall on a 7.8?  It would be two 7.8’s. 

So would twins be be recommended over halves? I don't know how wandery the stuff I'll be doing is (obelisk, Charlotte dome, various 5.6-5.9 backcountry multi pitch), but I do know between things like the obelisk and the climbing I have done and want to do more off at the San Rafael swell, there are double rope raps.


The main reason I didn't wanna do two halves is I have never led on halves and only belated on em twice.
Guideline #1: Don't be a jerk.

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