UKC

A common test to check whether a bit of rope is damaged or not is to try bending it to see if it folds back on itself easily in a V sort of shape or whether it forms more of a U shape ( youtube.com/watch?v=IMdgD9SDlQo& BMC video demonstrating the idea, with very obvious damage points, I'm thinking about more subtle 'failure' points where the rope just feels soft but looks ok). The idea being V shape bad, U shape ok. All the ropes I've used would make a U shape when new.

As far as I'm aware this is supposed to reveal core damage in the rope (maybe this is an incorrect assumption?), but I'm skeptical that it does. It seems to me that the test could be very influenced by the sheath condition - after all if you remove a short section of sheath on a new rope and bend that bit it won't make a U shape, it'll just fold easily. If it is just revealing sheath condition why would I care? I can look at the sheath and decide if it's ok or not.

Does anyone know of any evidence, have any experience or any theory as to whether the test works or is meaningful. E.g. has anyone ever cut the sheath off a section that failed the test and compared the core to a bit that passed the test?

Quite a few years ago I had a rope that developed a soft spot. The sheath was in good nick still but it felt almost like there was no core inside it for a length of an inch or two. I ended up having to cut it, and on inspection all that had happened was that the woven core had become loose at that point. All strands were still undamaged and there's no reason to think the strength would have been significantly impaired at all.

Thankfully ropes seem to do this less often nowadays, but even knowing this is almost certainly what I would find were I again to have a rope that was completely floppy at a single point, I'd still chop it to make sure.

Not sure what this test is really supposed to show up, soft spots/V-folds happen where the structure is a little rucked up allowing the core strands to flatten out when bent. That does tend to happen right where the rope takes the most beating (~3m from the end if you're falling a lot sport climbing) but I've never seen a broken core strand resulting from that.

One of my old climbing partners had a totally battered skinny sport rope back when shinny singles were new. It was as flacid as overcooked spaghetti for several meters each end, more like tape to handle than rope and totally uninspiring to climb on. It was completely intact internally.

Trimming an end down is no great cost most of the time if it gives you confidence back.

jk

Thanks both. Good to hear some experience from people who've cut the floppy bit open.