TRS - choosing the safer rope in spite of stock advise

The stock advise for a TRS rope is get static. 

Many posts state that a dynamic rope is somehow unsafe. That it will drop you long distances and you could hit ledges or deck hard. I don't agree. A TRS fall is the same as a follower's fall who is being belayed from above.
Do followers drop huge distances onto ledges or deck hard? No. Are the first meters of a route especially treacherous so that a static rope should be the default choice? No. A dynamic rope hardly stretches any longer than a static rope. The static elongation values for both static and dynamic rope are almost the same, 5% vs 8%. Where the rope types vary is in their dynamic elongation values. The reason to choose dynamic rope is for situations when slack has built up unnoticed or unintentionally. Things will go wrong sometimes and your system should allow for that.  

When you TRS using an MT it is analogous to being belayed from above with an MT. Which I don't do, but Petzl has tested it. The positions swap, but the physics is the same.

Belaying the second with a MICRO TRAXION

Calculate the impact forces for static rope vs dynamic rope, especially close to anchors or re-belays, the values are sobering.

Basic Fall Force Calculator

This seems like a strawman, who says only use a static rope? Go on any top rope solo thread on here and you will see dozens of people using static and dynamic ropes and combinations of the two. No body says you must use a static. 

I've used both. I now use a mostly static canyoneering rope.

Falling in the first half of a climb on a dynamic was a mess and slightly dangerous, contrary to your flat earth math above. 

Can't you just delete all that crap you wrote and rerurn to the subject when you know a bit more?

The world would be a better place if the first rule of toprope solo club club was that you don't talk about toprope solo club.

OP's starting premise is that STR on a dynamic rope is considered unsafe. LOL  If there's anything in that post that's unsafe, it's the notion of folks using a MT as their belay device.

How about you do use both... and just buy a semi-static? Thats the best of both worlds.

Noel Z wrote:

A dynamic rope hardly stretches any longer than a static rope. 

lol. 

Noel Z wrote:

The static elongation values for both static and dynamic rope are almost the same, 5% vs 8%. 

Citing sources usually makes claims more credible.

Here are static elongation numbers for a few Sterling ropes, with urls linking to published spec sheets -

Static, 3/8 HTP - elongation 1.4% at 300lb
https://sterlingrope.com/store/climb/ropes/static/htp/3-8-htp

Semi-Static, 3/8  WorkPro - elongation 3.5% at 300lb
https://sterlingrope.com/store/climb/ropes/static/workpro-climb/10mm-workpro

Low-Elongation Top Rope, ReVO 9.8 mm - elongation 4.1% at 150kg ( ~330lb)
https://sterlingrope.com/store/climb/ropes/gym-ropes/revo-9-8-mm

Dynamic, T-10 10.0 mm XEROS - elongation of 8% at 80kg
https://sterlingrope.com/store/climb/ropes/dynamic/t-10-10-0-mm-xeros

Notice that elongations are listed for different weights, the dynamic rope would have ~14% elongation for similar weight as static and semi-static ropes listed above.

TLDR - your elongation numbers are wrong.

OP: If there is such a thing as stock advice for such a niche activity, I'd be wary of it. Context matters here.

I think the best argument for using static for TRS is that a dynamic rope is more inclined to rub against edges or choss under repeated weighting. There are scenarios where the stretch in a dynamic line could result in a bad deck, but I avoid such scenarios. 

If you whip much on lead, you probably have a dynamic rope that's lost most of its bounce. Assuming sheath is still good and rope doesn't run over edges, this is my choice.

I'm no guru, but if you're experimenting with any system that is new to you, I suggest using a backup knot well above the deck. This saved me when I was refining my system.

Dynamic vs static doesn't matter much if you do your due diligence in padding any edges of concern... Theoretically.

... but in practice... For the chance that something messes up and you fall with some non-trivial amount of slack in the rope... would you rather be falling onto a static or dynamic with your progress capture devices?

Logan Peterson wrote:

OP: If there is such a thing as stock advice for such a niche activity, I'd be wary of it. Context matters here.

You're right. Context matter.

In the OP I said that the "stock advise" was to use static. It is the most common recommendation for a TRS rope.

I'm taking about falling. What rope is best to fall on when your at your limit.

I think static is probably best if you don't fall a lot and can rule out slack every single time. I started out that way five years ago, but very quickly bored of doing laps and falling rarely. When I started climbing at or over my limit on all kinds of terrain I felt I had to move to a dynamic rope. That conclusion stems from experience (lots of falls) and not because I'm new. I weigh 65kg so my dynamic ropes don't stretch a lot under my weight. I like a soft catch and am used to it.

Is anyone disagreeing that a TRS fall is analogous with a follower/second fall?

Id be willing to bet most people here have never even had an actual static rope. Most climbing brand's "static" ropes are actually semi-static. The first time you use a proper static, you know immediately; zero stretch, even 80 feet away from your last connection point. 

I personally wouldn't want to TRS on a pure static line. Semi-Static, like the Black Diamond 65m Static, or the Mammut Performance Static, id be totally fine falling on that.

Noel Z wrote:

"You're right. Context matter.

Is anyone disagreeing that a TRS fall is analogous with a follower/second fall?"

Yes, if I am following on a route with a ankle breaker under me and a hard start I tell my belayer to take in very tight so they take out half the stretch. 

I weigh 90+ kg and often top-rope solo on a 45m high cliff, with a dynamic rope a fall in the first 10m or so is going to be a ground fall so it's a static rope for me thank you very much. Context matters indeed!

P.s. Restricting who can reply to you because they disagree with what you wrote because it was incorrect and bad advice is childish.

Matthew Jaggers wrote:

I personally wouldn't want to TRS on a pure static line. 

Why the heck not? Theres a reason static lines are used on big wall. They are the most efficient, safest way to ascend a rope. Guess what top rope soloing is.....

LOL. This isn't even a thing.  When using a dynamic rope, you simply clove into a few pieces or bolts along the way and voila, no worrisome stretch issues, ever.  

Erroneous Publicus wrote:

LOL. This isn't even a thing.  When using a dynamic rope, you simply clove into a few pieces or bolts along the way and voila, no worrisome stretch issues, ever.  

Doesn't make much sense on TRS...

If you're :LRS sure, you rebelay, but of course you're on a dynamic rope. (one hopes)

Are you talking TRS or LRS? I do both and use a dynamic rope in both situations.  Although I rarely TRS without leading the pitch first. Are folks saying there is more or less forces generated in a fall climbing solo vs with a partner? To me, it seems the same relatively the same,  so I have a hard time seeing how a static rope is safer. Thoughts FB massive?

Doesn't make much sense on TRS...

Let's say you rap nearly a full rope length to the bottom of a crag, and start TRS back up from there. There are some difficult moves right off the deck. You're worried about rope stretch and decking. How to minimize? Note this could also be a ledge halfway up, with some hard moves above it, doesn't have to be on the ground.

As you rap down, place a piece or clip a bolt let's say, Oh whateverville, 30, 40, 50 feet above the ground and clove you rap rope onto that piece. Now you'll only have that amount of rope to stretch, instead of the full length. Remove the piece when you climb back up past it.

I see a lot of folks talking about rapping down to a bolted belay anchor and then getting all fancy about building an equalized anchor, despite the fact their rope is till tied to what ever it is they are rapping from. Mind boggling. I would clip a biner and clove the rope to it, one bolt, for a redirect; done. Rap on. I routinely use this "re-direct" concept.

Still doesn't make much sense but situationally in a blue moon, sure. You do you. Most of us TRS guys are just here to do laps ime.

Fuck off