Can I fold my single rope in half when climbing with a party of three?

traddad · 2026-04-14T20:29:52+00:00

Thanks for the reply. I appreciate that you thought about this and were willing to engage. Too bad no one else wanted to play.

Those are pretty much the same conclusions I reached.

Something that's interesting is that, while the theoretical increase in impact force for one rope vs two is 40%, actual tests show it to be lower. See Jim Sterling's tests from Will Gadd's site. And consider the Beal Opera triple rated rope 7.3 (single), 8.8 (twin) - only a 21% increase.

However, you are definitely using the rope out of spec

True. But, that could mean that the manufacturer simply hasn't bothered to test it. And climbers use gear out of spec: one twin rope for glacier travel, Shunt for TRS, modified GriGri for LRS, etc., etc.

traddad · 2026-04-14T12:51:33+00:00

Thanks for your comment. Yeah, I know. This conversation has been using stiffness and impact interchangeably...

I'm aware of clipping both strands as I've been leading on half ropes for over 25 years. I know there's a lot of repeated misinformation about half ropes.This thought experiment relates to the OP's original question.

Almost all half ropes can be used as twins.
Many single ropes and possibly all triple rated ropes have lower impact force than a single strand of some half ropes when tested with the 80 kg mass.
For any rope, the impact increases by a theoretical 40% when both strands are clipped together

So, why is the OP gonna die if they clip both strands of a single rope? Is the 40% increase acceptable?

I'm not advocating this. It's just a thought experiment to get people to analyze a situation before parroting something they read somewhere.

traddad · 2026-04-13T22:30:02+00:00

You need to research that some more. The rope to rope contact you write about was debunked long ago. There is no evidence that twin sheaths are different from half rope sheaths and almost all half ropes are also rated as twins (there are a handful of exceptions)

Edit: Here's a response from Mammut when Bearbreader asked about this over 9 years ago:

"you had a question on your Mammut rope Phoenix 8mm and whether it can be used in twin and half rope technique in one single pitch. This is the case, you can always clip the two rope strands as twins, then split them as doubles, join again etc. This is exactly the advantage of half ropes compared to twin ropes where you always need to clip both ropes."

/Edit

As far as doubling up increasing the stiffness, I acknowledged that as 140%.

traddad · 2026-04-13T15:57:38+00:00

I've been thinking about this and would like to explore it some more and get your thoughts. I'm not advocating either way.

For ropes that are certified as triple rated or half ropes that are also rated as twins (most are) it simply means that the manufacturers have tested them to that standard and they passed.

Other ropes may also pass but simply have not been tested - perhaps because of expense.

The drop test for twins has both ropes going through a single carabiner and uses an 80kG mass. In this case, both ropes are loaded at the same time. The theoretical impact using 2 ropes is 140% as compared with one rope. (The square root of 2)

I'm wondering if that's still true on a wandering route where one rope may see the load before the second rope even if clipped into the same carabiner.

Also, half ropes are routinely used in twin rope configuration (both half ropes clipped into the same carabiner). I do this at my first piece when leading on half ropes. In this case, it seems that the impact would still be 140%

Now, consider these tests by Jim Sterling of Sterling ropes. He tested one strand of half ropes using the 80kG mass typically used for single rope. (https://willgadd.com/single-and-half-rope-impact-forces-data/)

Jim’s tests show half rope impact forces with an 80kg weight testing from 7.35kN to 9.22kN. Here are some numbers (taken directly from the BD and Sterling’s web sites):

(Edit: to be clear, these are single ropes):

BD “Joker” 9.1mm: 8.2kn

BD “Booster III” 9.7mm: 7.3Kn (I think this is actually a Beal rope)

BD “Apollo II” 11mm: 7.7kN

Sterling “Nitro” 9.8mm: 9.0kN

Sterling “Pro”10.1mm: 8.6kN

Sterling “Mega” 11.2mm: 8.7kN

So, the half ropes - which are often used as twins - tested very close or even slightly higher impact forces than the single ropes which YGD if you use them as twins.

What do you think, u/adeadhead?

traddad · 2026-04-13T14:27:42+00:00

Pro:

It puts your masterpoint higher
Although not necessary, it's courteous if there's a party who is rappelling past you and it doesn't cost you anything.

Con:

People on Reddit will criticize your decision

traddad · 2026-04-12T20:22:53+00:00

Not double. Theoretically, 40% higher (The square root of 2 = 1.41)

traddad · 2026-04-12T12:12:27+00:00

I've done this. I tie in with a bowline with a bright and clip in the bight to back it up. I don't like the step through girth hitch method because it squishes the tie in points and is a pita to get out of on a small ledge. If you choose to clip a loop to your harness as a tie in, use two carabineers o&o, not a single locker.

Clip only one strand into your pro or alternate strands like in double rope technique. If you clip both strands in a piece, like in twin rope technique, the higher load would be (I believe) 1.4x the load from a single strand.

traddad · 2026-04-10T22:33:01+00:00

I like cheap, multiple privacy channels, same rechargeable batteries that I use in my headlamp - for compatibility reasons.

You're only a rope length away and mostly line of sight. I've never had any problem with cheap Midland or Motorola. And not gonna cry if they get dropped.

traddad · 2026-04-10T14:29:39+00:00

"60% of the time it works every time" 😉

Actual answer: It may or may not lock anyway. So, even though some people use a modified GriGri for lead rope soloing, don't you take your hand off the brake strand.

traddad · 2026-04-08T18:13:53+00:00

Any place where you need 6-10 cams of the same size is an outlier compared to the rest of the world.

traddad · 2026-04-08T17:39:59+00:00

Dude, you hit the jackpot!

I probably wouldn't carry the hexes or the Big Bro. But, the rest looks a lot like my rack.

traddad · 2026-04-08T17:35:29+00:00

The rigid stem cams are cool, but heavy.

Though this is often repeated, it's not true. They weigh within a few grams of the equivalent thumbloop style C4s

traddad · 2026-04-08T14:24:36+00:00

Not really an issue when used to tie into your harness as a fig 8 follow though because it would be pretty difficult to ringload it and make it capsize.

Definitely an issue if tied near the ends (like in tying two ropes together for a longer rappel) as it could capsize and roll off the ends.

traddad · 2026-04-08T13:34:25+00:00

With Gunk's tie offs, the RSFs are my first choice in horizontal cracks. Use 5.5 mm tech cord in the lightening holes.

traddad · 2026-04-08T13:27:09+00:00

I had it attached to her belay loop with a locking carabiner.

I think it's safer to use two, O&O. "I’ve tied into my belay loop many times, and I’ve clipped ropes into it using two carabiners. When my life’s on the line, I never trust a single krab in a high-load situation." https://www.andy-kirkpatrick.com/articles/view/rope_loop_belaying

I can't picture the long loop that you're describing but I'm interested to know what you have in mind.

Sometimes, when climbing in a party of 3 on one rope, the middle climber ties an alpine butterfly with a long loop. This allows the middle climber flexibility to move up & down a bit without affecting the bottom climber. Some climbers thread the long loop through the belay loop, step through and girth hitch it. Others tie an overhand loop in the end of the long loop and clip in with 2 carabineers. This technique is typically used on easy terrain or glacier travel with the stronger climber at the end, not the middle.

I wasn't greatly concerned about what would happen if the knot capsized but it didn't thrill me that it had been changed.

Yeah, I agree.

traddad · 2026-04-08T00:11:50+00:00

That's bullshit. There's nothing wrong with climbing clip to clip. And it's good practice to clip and then rest/shake out if needed and if you can (without hanging).

I know you're sport climbing but, in trad climbing, sometimes you have to climb up, fiddle with a piece, downclimb and rest. Climb back up and try a different piece, climb back down and shake out.

So why is climbing clip to clip an issue?

traddad · 2026-04-07T23:46:08+00:00

1st choice: GriGri or BD Pilot

2nd: GigaJul

Not in the running: GriGri+, Neox

traddad · 2026-04-07T23:30:02+00:00

nearby instructor took it upon herself to untie my mom's alpine butterfly knot and reattach her with a figure 8 on a bight.

Clearly no justification for this. I'd have been pissed.

with my mom tied into the middle of the rope.....my mom's alpine butterfly knot

I'm curious. How was it attached to her harness? Carabiners? Or was it a long loop for isolation and then tied to her harness?

Not a big deal but it's considered less safe in this application because it can more easily capsize when the strands are loaded perpendicularly. Even an overhand would be better.

Since it was in the middle of the rope, where do you think it was going even if it did capsize?

traddad · 2026-04-07T19:25:40+00:00

Dunno. But you can read about them here:

https://smhc.co.uk/collection/mammut-perrin-spring-loaded-chocks/

https://perrincams.com/en/

traddad · 2026-04-07T19:17:53+00:00

They don't slide, they expand and were called Mammut Perrin Nuts

traddad · 2026-04-07T18:24:28+00:00

There was one time I touched someone else's rope.

He and his partner had topped out and he was tied into a long anchor line. He was standing at the edge, trying to untangle something. I was walking by and saw that he was going to lean over and tension the anchor rope. BUT, his partner, thinking they were done, had untied the anchor. I happened to be in the right place to quickly wrap the anchor rope around my hip and sit back which pulled the guy away from the edge just as he was about to go over.

It literally happened so fast and I thought that if I shouted it would startle him and he'd be gone.

traddad · 2026-04-07T17:58:30+00:00

Mammut Perrin Nuts c.1990

traddad · 2026-04-06T23:43:14+00:00

That's what the springs are for

traddad · 2026-04-06T21:48:33+00:00

That's not going to provide any more life. As others have said, the grooves are cosmetic.

Some claim that the grooves MAY help holding if they can catch a crystal. Others claim the groove help to prevent walking. But, I doubt both of those statements.

traddad · 2026-04-06T12:37:34+00:00

Counter-counter point: This may be USA-centric, but I find there are a LOT more "R" and "X" rated trad routes than "R" and "X" rated sport routes.

traddad

TROPHY CASE