@QuantumBrick You here?

@imsodin Yep. Just got here.

Cool. So yes, I completely ignored the low temperature side, because I think the two issues are different and should thus be treated separately. Also I just stumpled over that resource, so I wanted to use it.

My reasoning is, that the way the core is woven should not change at higher temperatures. I just don't see why a macroscopic property should change in that range (Nylon isn't melting).

Ok, maybe the "friction" between single strands is changing with temperature, but I would assume it gets lower with higher temperature as well. But that might obviously wrong, as it is just a gut-feeling, nothing I actually read up.

@imsodin I liked your answer. It does provide links to info I've never heard of, so I'm pretty happy with it on a side. On the other side, you're quite right to say that the webbing doesn't change with temperature, but I ask you to think about what elasticity is: it is a property of atomic movements inside a chain. If temperatures are low enough, the chain almost doesn't unfold, which means there's almost no entropy change, which by itself means there's almost no elasticity to provide,

because elasticity is derived from a derivative of entropy.

My guess is, as I commented, that the elastic properties of the rope make it become stiffer with cold and looser with heat. Both are dangerous, but cold seems to be worse.

It seems to be worse because the rope will never break. That I can assure you. It won't break unless you're climbing on Venus. But taking a fall on a stiff rope can, and most of the time will, break you up.

If it's a factor > 1 fall it might easily kill you.

But that's pure speculation

Afternoon all :-)

@imsodin You're right to question what I said. I didn't express myself very well, but I still this that the the drastic decrease in Young's modulus in the pictures I attached to the OP should provide significant changes in rope properties. One other thing that is bothering me greatly is that some ropes do have some info about the temperature range they should be used at (normally from -35ºC to 50ºC), but no one freakin' says how the fu#! they arrive at these results, because they're not present

in any fu!@#!@# norm.

I think this matter is serious enough to send an email to Petzl or something, asking for clarification.

@WedaPashi Hi Weda

@QuantumBrick Good idea, but not petzl. 10 years ago I would have said Mammut, today maybe Beal. Heard a lot of good things about their customer support and their ropes are great.

@imsodin: Thanks for adding the bounty?

-35 to 50 sounds like a statement by a lawyer, exactly because there is no norm.

@imsodin "-35 to 50 sounds like a statement by a lawyer, exactly because there is no norm." I want to give a +100 to this comment.

@QuantumBrick You are not per chance living in or close to Switzerland? Getting to know a physics grad student liking sketchy trad routes would probably be a whole lot of fun xD

@QuantumBrick Sounds good. Tough we don't really have much clean stuff, and the sketchy stuff is mostly sketchy because of rock quality :P

@imsodin Don't get me wrong. I like any kind of climbing... Even the ones where death doesn't look you in the eye.