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Half Rope Size Recommendations??

Original Post
JasonSH · · unknown · Joined Apr 2015 · Points: 90
Seth Kane · · Bozeman, Montana · Joined Sep 2013 · Points: 113

the revelation is a single rope. IMO 8.5 should be the far upper limit of diameter for half ropes. I own a pair of 7.5s (mammut twilight) and a pair of 8.1s (PMI Verglass) and I cant imagine ever wanting to use anything bigger. Its also worth noting that half ropes that are not rated as singles are more durable then those that are (ie mammut genesis is more durable then the serenity).

BigB · · Red Rock, NV · Joined Feb 2015 · Points: 340
Ed Schaefer · · Centennial, CO · Joined May 2014 · Points: 35

My half ropes are 8.5mm and they're pretty big for half ropes. Mammut Genesis. I chose these because I use them primarily in alpine environments or for ice climbing and wanted the heavier sheath to improve abrasion resistance and durability.

When I get another set in the future I will likely go thinner.

I don't see how the weight of you and your partner is relevant to this question. It's far more important to understand why you think a set of half ropes will be useful to you and what situations and conditions you will be using them.

Ryan Hamilton · · Orem · Joined Aug 2011 · Points: 20

Jason I have some awesome Tendon 7.8 half ropes for sale for $200 for the pair. Plenty of life in them, they barely look used at all -

Even if you don't buy my ropes. I second what others are saying if you're going half rope the 7.7 - 8.0 range is where you want to be.

Kyle Tarry · · Portland, OR · Joined Mar 2015 · Points: 162

9.2 is really big for half ropes, I would not want to be on the sharp end of that.

I have Beal Cobras (8.6) and I would definitely not go any bigger.  However, the ideal size depends a lot on the specific size and your usage.  For example, I would go way smaller on ice (<8.0 mm) but probably not so much on sharp rock.

JasonSH · · unknown · Joined Apr 2015 · Points: 90

Ed Schaefer wrote:

I don't see how the weight of you and your partner is relevant to this question. It's far more important to understand why you think a set of half ropes will be useful to you and what situations and conditions you will be using them.

wandering routes, and routes with potential for rockfall.  

Jonathan Lagoe · · Boulder · Joined Aug 2011 · Points: 5

I use a serenity 8.7 as a single and would not want to drag two up a climb. 8.5 is more than adequate and the Mammut Genesis is industry standard in the the UK where double ropes are the norm for trad, winter etc. I'd also probably go thinner next time.

Nick Sweeney · · Spokane, WA · Joined Jun 2013 · Points: 666

For pure ice: As skinny as you can get.  I use Mammut Twilight 7.5mm.

For rock: I think 8.5mm is great, and would not go any bigger.  You can go a bit smaller, but I don't like to do so.  There is just too much abrasion on the rope in an alpine environment, where I normally would be using half ropes.  

beensandbagged · · Unknown Hometown · Joined Oct 2013 · Points: 10

8.5 Mammut Genesis. I climb with these and they have handled well and held up well. There is certainly no reason that I can see to go bigger, skinnier would be nice when hitting (real) slabs since the friction between the rope and the rock towards the end of a long pitch is a bit of a bitch. But I think the 8.5mm feels pretty good when belaying from either end of the rope.

Don Ferris · · Eldorado Springs · Joined Nov 2012 · Points: 175

For an all-rounder setup, I think 8mm half ropes are the way to go. I have a pair of flycatchers (6.8mm) twins that are crazy light but I really prefer to not fall. Very stretchy and sketchy looking but I'm sure it's mostly in my head. 

climber pat · · Las Cruces, NM · Joined Feb 2006 · Points: 215

I like my mammut phoenix ropes (8.0 mm) half/twin rated.  They are fine and I don't see any reason to go bigger for half/twin ropes.  I use a mammut serenity as my single rope and it is very nice.  I strongly recommend twin/half ropes over only half ropes belaying paradigm is more similar to single ropes and easier for belayers to pick up.


Nick Goldsmith · · Pomfret VT · Joined Aug 2009 · Points: 440

depends on what you intend to use them for. 8.8 marathon 60m for  multi pitch rock. 7.8mm 70m for ice. YMMV

tallguy · · Unknown Hometown · Joined Sep 2010 · Points: 0

Thin ropes used as half ropes can wear fast.  I think companies like to emphasize thin and light characterstics because they know they will sell more ropes, not because those are the best general purpose ropes for climbers.  I prefer to not go "as thin and light as possible" just so i am not buying new ropes all the time.  For applications like yours, i like 8.2 mm or so twins, and slightly fatter, 8.5 or so, halfs.  But i love the twins for alpine rock, never have to worry about how you will take care of big raps. Plus a little fat helps with the cut potential, which i think is a significant danger in alpine type climbs.  I like the peace  of mind, and i dont think that last pound or two of weight tradeoff matters much.

Jonathan Steitzer · · West Lebanon, NH · Joined Feb 2010 · Points: 1,960

Sterling Duetto is the way to go.

JasonSH · · unknown · Joined Apr 2015 · Points: 90

Jonathan Steitzer wrote:

Sterling Duetto is the way to go.

Wondered how those were

Z Winters · · Mazama, Washington · Joined Aug 2014 · Points: 207

I like my Trango Amphibians (8.1mm) for alpine rock. They're the just rebranded PMI Verglas. Did a lot of research and thought they were a great value based on price and reviews. Almost went for the Genesis because everyone loves them, but I decided on a little lighter and a little less expensive. 

anotherclimber · · Unknown Hometown · Joined Apr 2016 · Points: 70

I'm still in my first season of using my half ropes, so I only have experience on what I bought. Went with Mammut Genesis 8.5mm, 60m as a lot of people seem to like them and I figured thicker would be more ideal for my first half rope set until I get more experienced with them. I like them. Yes, the rope bag is heavier than my single 9.2mm, 70m. So far on the wall I don't notice it all while climbing. 

If you and your partner have never done half rope belaying before, make sure to make plenty of time on the ground to figure it out and do practice runs with clipping as it is really different than single rope belaying. 

Benjixxx · · Unknown Hometown · Joined Aug 2015 · Points: 0

When climbing in a group of three on half ropes (leading on doubles with two seconds following tied into a rope each belayed in guide mode)  what diameter rope would you recommend in this instance?  Is an 8mm rope enough for a 200lb man following to be belayed on.?

Z Winters · · Mazama, Washington · Joined Aug 2014 · Points: 207

Benjixxx wrote:

Is an 8mm rope enough for a 200lb man following to be belayed on.?

Yes. Anything rated as a half rope can catch a lead fall essentially on its own, so TR falls are no problem, you just want to be careful of ledges as they are very stretchy, and watch out for sharp edges. This is common for stuff in the 7.8 range

jdejace · · New England · Joined Sep 2013 · Points: 5

There's about a zero percent chance any half rope will spontaneously fail on a TR fall (barring sharp edge freak accidents etc..), but as with any dynamic rope a 200lb dude is gonna end up farther down than a lightweight climber as the rope elongates, especially if he's just starting a long pitch. Probably twice as far as if he were tied into both ropes. It's not really about the diameter, you can look at the static elongation specs if you like such as

Static Elongation (%) Half | Twin 11.7 | 6.5

Sterling's 8.4mm and 8.8mm have about the same static elongation (11%). I doubt that 0.7% on the super skinny amounts to much in the real world.

Guideline #1: Don't be a jerk.

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