UKC

I'm trying a route that's only gear is 2 X size 1 nut, bent back in a bolthole. They're deep and great placements, but if they fail, you're probably going to die, so was just wondering if anyone knows/can reference me a test on whether there are any strange forces applied to the wire when used this way. Anyone fallen on one?

Micro tricams don't fit and I don't have any other gear with me. Those removable bolts look ideal, but I don't own one..

Thanks!

Well... a rock 1 is only rated 7kN in a perfect setup.  Bend it in half and I wouldn't want it to be my only gear for a lead fall.

vTer replyt to Franco Cookson:

It depends on the ethics of the crag. You could just find the right sized

expansion bolt and remove it after the ascent - or maybe use a hand placed peg. How big is the shot hole?

Wedge it in place with a suitably sized and tapered piece of dowling, knocked in place with a lump of rock which you can chuck down after.  Natural pro, man

I DM’d you as the gear you’re looking for might actually be borrowable!

Thanks. Any other size 1 walnut beta much appreciated in the mean time..

As Deadeye posted 7 kN in an ideal placement. This is rated strength so you may be lucky and get a slightly better result.

In a fold back the wire will be bent possibly more harshly in a tighter radius, so weaker. It will also be compressed between the rock and the nut, this will probably have a significant weakening effect.

The angle the nut jams across the hole will have a significant effect on the holding power or the stress on the rock. It is not a predictable constant camming angle like a manufactured camming unit. and will exert a point load on part of the rock, which may be close to the rock face and thus prone to exploding the rock.

The strongest option in a pre drilled hole is to glue in a piece of metal ... Oh hang on a sec

Sounds like a Rock'n'Roller #2 placement? Have you tried a slug, or whatever they are called now? If it's deep enough you might get a peg in (warthog?) and pad it out with cardboard to keep it snug.

Old ice screw? Something like the old "snarg" design maybe if you need it a bit narrower than modern screws?

ok call me thick, but if you desperately wanted to do the route but were going to die or be very badly injured if you fall and your gear failed, and there was a perfect bit of gear which you didnt own, wouldnt you think it worth the cost of buying it?  £60 to not risk life changing injury sounds like a good investment to me. 

The bend loads the wire unevenly, the tighter the bend the worse the force distribution across the strands. How bad it is will depend on the wire and the geometry. De-rating significantly would be sensible and since we're discussing nominally 7kN gear protecting your life I think it'd be reasonable to conclude it's not 'bomber'.

I'd look at removable bolts (basically a ball-bearing based slider nut) or make something to fit the hole.

jk

youtube.com/watch?v=0SXs58jEkwg&t=13

12mm Petzl Coeur Pulse removable caving/access bolt? Bomber if the hole is parallel and clean...

youtube.com/watch?v=MOGRNErTyH0&

https://www.urbanrock.com/petzl-coeur-pulse

A one Wild Country Rock is 7mm by 13mm so about 14mm square into a round hole, therefore the hole must be about 20mm (3/4 in?).

The Pink (0.5) Camp Tricam should fit but you may need to file the corners off to make it fit a perfectly round hole. 

I've done that and it fit perfectly and seemed solid, in fact it was difficult to remove afterwards!

There are also sizes 0.125 + 0.25 tricams.

Really need to know the hole  diameter depth and rock type, Franco.

...and crag.

Sounds like a job for a metolius curve nut with a weight placed on it. 

Rather than bending it back, could you use another rock 1, chop the wire off it, and use the two stacked together as you would 'normal' stacked nuts?

Or a modified ballnut, I'm sure the smallest is rock 1ish, by glueing/soldering additional bulk to the ball part

Dave Birkett might have something he'll lend you

Cheers all. Will look into those options. It's little finger sizes. Size 1 walnut. Rock is granite, so the placement is perfect. Really deep also. I regularly use micro tricams, but they don't fit. Maybe filing them down would work..

I would potentially look at buying something to fit it but a) I'm quite poor currently b) I'd like to do the route in a way people are likely to repeat. Using a removable bolt seems very close to an actual bolt!

You've basically answered the question though: bent back nuts are sketchy. Cheers.