UKC

Looking at my wires, it's noticable that quite a few of them are now slightly bent. Manufacturers reccomend replacing bent wires immediately, question is does a bend in the wire significantly weaken it, or is this just the gear companies covering themselves?

In reply to JackM92:

Don't worry about 'slightly bent' wires. They take a huge amount of abuse before failure, and don't forget the weakest point is likely to be the bend through the nut itself. I've got a couple with the odd frayed filament and I'm not too bothered about that either.

Maybe someone will come along and tell me to get worried though....

In reply to JackM92:

As far as I'm concerned, the only issue with slightly bent wires is that they are more fiddly to place.

In reply to JackM92:
From a technical point of view, a wire (strand) being bent back and forth across a 'kink', is a series of fatigue cycles, which would eventually break it.

What this means in practice I couldn't say.

In reply to Timmd:


If they're bent, then don't straighten them, perhaps?

In reply to JackM92:

There's bent and there's mangled. Considering the bend they go through to pass through the nut I'd not worry about it unless it's definitely seen better days.

In reply to humptydumpty:

I dare say repeatedly placing and removing and falling upon them may cause them them to flex at any kinks?

Which is probably why the companies recommend replacing them, so they can know they've done all they can to ensure people are safe...

In reply to nniff:
There's a bend and there's a kink, too. A kink is more likely to flex at the angle created, resulting in fatigue cycles, where as a bend is smooth and nice

One can't guess at how many cycle it'd take for a strand or multiple strands to snap at a kink, but the theory behind it is well understood, which is why they recommend replacing nuts with bent wires.

In reply to Timmd:

Indeed. But, and it's a big but, how often do you actually fall onto wires so as to stress them in this way (i.e. with enough force to straighten a kink?). Unless you're a serial dogger, not often I suspect. If you do fall repeatedly, then your wires will a) enter the 'mullered' category for early retirement and b) you'll have probably have worked out what's what by then anyway.

I think I can safely say that i have very few wires that do not have a bend where they exit the nut and those that do not shortly will (assuming that we get something that I have people call 'summer').

In reply to nniff:
Was just pointing out the difference between bends and kinks really. A kink wouldn't need to fully straighten out and contract again for a fatigue cycle to happen by the way - just flexing at the point where the kink is would be enough, which is why I thought it was worth pointing out. If you sit with a piece of wire and flex it at a kink or flex it back and forth at the same point, depending on what it's made from it can be surprising how little back and forth movement it can take for it to snap. I guess it's possibly less applicable to kind of wire used for climbing nuts, but it's worth knowing about I think, and maybe worth being cautious about given the cost of a climbing nut (depending on your assessment of the risks attached).