UKC

I have a decently-sized stash of Dyneema slings for alpine climbs. I use the BD Dynex Runners.

The question I have is the following: What is the best nylon sling to use for an alpine anchor/top belay configuration? I've read another forum about the consensus on knotting the Dyneema slings, and that's a big no-no. However, I've seen videos where it looks like they're using them as anchors anyway.  youtube.com/watch?v=mdD4MbcE1hs&

Could someone please enlighten me as to what sling he's using? Do you have any recommendations for a nylon sling that's not super fat?

Edelrid do their 12mm "Tech Slings" in Dynema with a nylon coating. Seems a 'best of both' solution. 60, 120 & 240cm available.

eg here... https://www.climbers-shop.com/climbing-equipment/slings/edelrid-12mm-tech-w...

His looks like dyneema/spectra.

Knotting a sling reduces the strength by 50%. All slings are rated to at least 24kn, so a knotted sling is still 12kn strength (when new). A fall resulting in 7kn or more will probably cause serious injury or worse, so really the strength isn’t that much of an issue.

What is an issue is falling directly onto a dyneema sling (not really to be recommended on nylon either, but less bad). The shock load can be enough to snap the sling, especially if knotted, however this can be mitigated by the following;

If using a sling as a lanyard making sure you stay below the anchor it is clipped to, ideally with little-no slack.

If using as a belay you tie to it using the rope.

For setting up a top rope nylon has the advantage of being easier to untie, but dyneema is perfectly fine to use for this. However if weight etc isn’t an issue static rope is by far the best for setting up a top rope.

This debate has been had to death... It's completely fine to use dyneema and to knot a sewn-looped dyneema sling (i.e. almost all slings you get these days).

I think this myth comes from a host of different things, including

• dyneema being much less good if you're going to create your own slings using a tape knot (who does this anymore?)
• all slings being weakened (from 22kn!) by knots (still good for circa 15kn)
• the fact that clipping into an anchor directly with a sling to your harness, then falling onto it from above is a very good way to hurt yourself and potentially snap the sling.

People talk about melting points and so on, but they're just repeating stuff they've heard that's not really relevant in this context. If it wasn't safe to use dyneema slings with a knot in them, we wouldnt keep on using dyneema slings - because a sling is no good if it won't take a knot.

Dyneema is fine but I like having Ava couple of Edelrid aramid 120cm slings. They’re easier to undo and more abrasion resistant. Also great for poking through threads.

Yes, I see what you mean. I wasn't sure who to believe because it seems like you should still be able to use it for a circumstance like a top belay.

Thank you for the information.

22kn not 24kn, sorry.

They're just a bit too long though! I love them but they don't clip around the shoulder well so you have to double them up instead, which makes them hard to use on lead.

Very thin slings tend to tangle more easily which isn't infuriating I find, particularly when you want to be quick and efficient  as in the Alps.

Have you looked at Mammot Magic Slings, useful for using as a tether

I assume you mean pressure melting when shock loaded? If this is what you’re referring to, then don’t worry about it. If there is dynamic rope in the mix, there is 0 chance of dyneema pressure melting... only if you fall directly attatched  to the sling...

More for belays. Double up, twist into a spiral, clip the ends together with a screwgate and onto the harness. Easy enough to deploy on route though.