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Is there a reason that most leashes are only rated to 2-3kN? i.e. are they purposely designed to break in case of a fall on to them?
1
In reply to mmmhumous:
Don't know if it answers your question but I have taken a fall above gear directly on to grivel springer leashes which held, surprisingly, this no obvious signs of damage. I probably weigh about 73kg.
Don't know if it answers your question but I have taken a fall above gear directly on to grivel springer leashes which held, surprisingly, this no obvious signs of damage. I probably weigh about 73kg.
1
In reply to mmmhumous:
They're designed to be elasticated so they don't get in your way and also don't limit your reach. I imagine 2-3kn is about the best you'll get from elasticated cord.
That said, I've also fallen on leashes and they held. 2-3kn is plenty to hold a slip in reality. Its not enough to hold a large dynamic fall but that's never going to be the case for a slip onto leashes.
Not to be relied upon but assuming your axe placement is good, they'd probably hold 9 out of 10 times.
They're designed to be elasticated so they don't get in your way and also don't limit your reach. I imagine 2-3kn is about the best you'll get from elasticated cord.
That said, I've also fallen on leashes and they held. 2-3kn is plenty to hold a slip in reality. Its not enough to hold a large dynamic fall but that's never going to be the case for a slip onto leashes.
Not to be relied upon but assuming your axe placement is good, they'd probably hold 9 out of 10 times.
In reply to mmmhumous:
Sometimes they break, sometimes they hold. They're not designed for holding falls - if they were they would be less effective for their primary purpose.
Sometimes they break, sometimes they hold. They're not designed for holding falls - if they were they would be less effective for their primary purpose.
In reply to mmmhumous:
(I think) they are made to break for one reason. In case of a slip/fall where an ice axe is in quite solid placement the sling is supposed to break. If it does not, it will eventually rip out the ice axe which is... attached to you! Although sling is not very elastic, it might spring back to you with quite a lot of force. You might be okay if another axe is not placed somewhere lower so you just fall into space and you might be able to avoid an ice axe flying into you.
(I think) they are made to break for one reason. In case of a slip/fall where an ice axe is in quite solid placement the sling is supposed to break. If it does not, it will eventually rip out the ice axe which is... attached to you! Although sling is not very elastic, it might spring back to you with quite a lot of force. You might be okay if another axe is not placed somewhere lower so you just fall into space and you might be able to avoid an ice axe flying into you.
In reply to mmmhumous:
I would hazard two or three reasons in the mind of the manufacturers: i) a short high fall-factor could do the climber a lot of damage ii) shock loading the tool could rip it out and insert the pick in your eye (according to Black Diamond). iii) some clip-in holes in tools (ie Grivel Matrix, or the piddly hole in Nomics) aren't very strong.
I've made a homemade rig with 22kn tubular tape with shockcord though it and and a screamer to attach to harness
I would hazard two or three reasons in the mind of the manufacturers: i) a short high fall-factor could do the climber a lot of damage ii) shock loading the tool could rip it out and insert the pick in your eye (according to Black Diamond). iii) some clip-in holes in tools (ie Grivel Matrix, or the piddly hole in Nomics) aren't very strong.
I've made a homemade rig with 22kn tubular tape with shockcord though it and and a screamer to attach to harness
Post edited at 11:28
1
In reply to iksander:
I have the same DIY leaches made from tubular webbing and bungy cord. Work great and I love the fact you can easily "add" your tools to your belay by taking a good swing and then hanging on them.
I like the idea of adding a screamer but doesn't it make the leashes long and unwieldy? I take it your using one of the really short Yate's ones?
I have the same DIY leaches made from tubular webbing and bungy cord. Work great and I love the fact you can easily "add" your tools to your belay by taking a good swing and then hanging on them.
I like the idea of adding a screamer but doesn't it make the leashes long and unwieldy? I take it your using one of the really short Yate's ones?
Post edited at 12:38
In reply to Tom F Harding:
I have long arms, so I actually need to extend them a bit - I find having a short screamer between my harness and the centre point of the leashes less unweidely than having longer leashes going straight to the harness.
> I like the idea of adding a screamer but doesn't it make the leashes long and unwieldy? I take it your using one of the really short Yate's ones?
I have long arms, so I actually need to extend them a bit - I find having a short screamer between my harness and the centre point of the leashes less unweidely than having longer leashes going straight to the harness.
In reply to mmmhumous:
I fell onto my Grivel Leashes just two days ago (gladly, as the runout was not appealing). No signs of damage what so ever. If they were to pop I'd imagine a nomic to the face would be far from ideal.
Ollie.
I fell onto my Grivel Leashes just two days ago (gladly, as the runout was not appealing). No signs of damage what so ever. If they were to pop I'd imagine a nomic to the face would be far from ideal.
Ollie.
In reply to OllieF:
My Grivel springer leashes survived two factor one falls without damage.
The 6mm maillon connecting them to the axes was not done up properly ( only one thread engaged ) and ended up almost failing in gate open mode. It had to be hammered shut to finish the route.
Someone with a test rig could find out the force generated, my guess is 4 kN.
My Grivel springer leashes survived two factor one falls without damage.
The 6mm maillon connecting them to the axes was not done up properly ( only one thread engaged ) and ended up almost failing in gate open mode. It had to be hammered shut to finish the route.
Someone with a test rig could find out the force generated, my guess is 4 kN.
In reply to Jamie B:
The only time I fell on to a leash, it broke. But I was placing gear at the time to only had one axe in. So all my weight came onto one axe. Actually, as well as the leash breaking, it pulled the bottom hook section of the axe off too, so maybe I'm heavy.
The only time I fell on to a leash, it broke. But I was placing gear at the time to only had one axe in. So all my weight came onto one axe. Actually, as well as the leash breaking, it pulled the bottom hook section of the axe off too, so maybe I'm heavy.
In reply to Andy Nisbet:
I'm surprised, I fell on one last year and it held, I'm fairly sure I'm about 50% heavier than you!
I'm surprised, I fell on one last year and it held, I'm fairly sure I'm about 50% heavier than you!
1
In reply to iksander:
I was assuming it was the axe pinging off into head scenario, but hadn't crossed my mind that the axe tie in point might not be rated higher. I'm currently rocking 7mm cord on mine, but was deciding weather to switch to leashes or a home-made tube/bungee combo. ( I too like being able to add my axes quickly to an anchor).
For those discussing holding falls and their weight. the 2-3kN is the strength when new... and their harmonica design looks suspiciously like that of the via-ferata sets that resulted in the series of recalls (due to strength loss with repeated use)... might it be that the leashes which broke had seen more use... or our sample size is not statistically significant and we need more volunteers to fall on their leashes, to see how many break (or get DMM to make another 'informative yet terrifying' product testing video).
Thanks all.
I was assuming it was the axe pinging off into head scenario, but hadn't crossed my mind that the axe tie in point might not be rated higher. I'm currently rocking 7mm cord on mine, but was deciding weather to switch to leashes or a home-made tube/bungee combo. ( I too like being able to add my axes quickly to an anchor).
For those discussing holding falls and their weight. the 2-3kN is the strength when new... and their harmonica design looks suspiciously like that of the via-ferata sets that resulted in the series of recalls (due to strength loss with repeated use)... might it be that the leashes which broke had seen more use... or our sample size is not statistically significant and we need more volunteers to fall on their leashes, to see how many break (or get DMM to make another 'informative yet terrifying' product testing video).
Thanks all.
In reply to mmmhumous:
My Grivel lanyard ripped yesterday after an unexepected fall. Like Andy i was leaning over to get gear and one axe ripped so i fell onto the other one. Reckon they were 10 years old and were getting a bit furry anyway!
My Grivel lanyard ripped yesterday after an unexepected fall. Like Andy i was leaning over to get gear and one axe ripped so i fell onto the other one. Reckon they were 10 years old and were getting a bit furry anyway!
Post edited at 09:26
In reply to mmmhumous:
It's real simple - don't fall onto spring leashes as it's not what they're designed for.
It's real simple - don't fall onto spring leashes as it's not what they're designed for.
In reply to Jamie B:
Sure, but why aren't they. I have seen lots of theories and discussions, but I haven't seen anything from the manufactures. Its such a universal thing that I presume there is evidence based design here ? or is it the problems of maintaining that strength in an elasticated cord as someone said above?
For the record I fell on a older Blue Ice one when my "good axe" ripped, and it saved me . Since then I note they have changed the design and the strength is down graded....
Sure, but why aren't they. I have seen lots of theories and discussions, but I haven't seen anything from the manufactures. Its such a universal thing that I presume there is evidence based design here ? or is it the problems of maintaining that strength in an elasticated cord as someone said above?
For the record I fell on a older Blue Ice one when my "good axe" ripped, and it saved me . Since then I note they have changed the design and the strength is down graded....
In reply to steveshaking:
Here's Black Diamond Europes thoughts:
"Surely lots of controversy surrounding this topic. If the leash were to be built to a higher load rating this might lead to a false sense of security. Even if it were built to withstand higher loads, the ice axe cannot be thought of as an anchor as it is clearly not an anchor. A leash could be built like a via ferrata leash, but this comes back around to the ice axe not being a good anchor point. Other arguments could be that the via ferrata leash is heavier and bulkier, much!"
Here's Black Diamond Europes thoughts:
"Surely lots of controversy surrounding this topic. If the leash were to be built to a higher load rating this might lead to a false sense of security. Even if it were built to withstand higher loads, the ice axe cannot be thought of as an anchor as it is clearly not an anchor. A leash could be built like a via ferrata leash, but this comes back around to the ice axe not being a good anchor point. Other arguments could be that the via ferrata leash is heavier and bulkier, much!"
In reply to mmmhumous:
But surely all folk want is:
For the axe to remain attached to them
For the axe not to split in two
The axe not to whiplash into you if the placement fails
The shock loading be as low as practical.
Not really so out of order to be dissed by the climbing gear manufacturers.
But surely all folk want is:
For the axe to remain attached to them
For the axe not to split in two
The axe not to whiplash into you if the placement fails
The shock loading be as low as practical.
Not really so out of order to be dissed by the climbing gear manufacturers.
In reply to mmmhumous:
And Now DMM have got back to me too:
" There are a few reasons that we rate the freedom leash to 2kN:
Having a low rating, allows the leash to be of a lightweight, user friendly design.
In the event of a leader fall that may generate high impact forces, if the axe is in a solid placement, the leash may break, absorbing some impact from your fall onto your protection system. If the leash had a high kN rating, there is a possibility of generating high impact forces directly onto the climber’s harness.
In the event of a fall (rather than a slump onto the axes) with the axes in a very good placement, the leash is more likely to break, meaning you’re less likely to be hit by a falling ice axe on your way down."
> Here's Black Diamond Europes thoughts:
> "Surely lots of controversy surrounding this topic. If the leash were to be built to a higher load rating this might lead to a false sense of security. Even if it were built to withstand higher loads, the ice axe cannot be thought of as an anchor as it is clearly not an anchor. A leash could be built like a via ferrata leash, but this comes back around to the ice axe not being a good anchor point. Other arguments could be that the via ferrata leash is heavier and bulkier, much!"
And Now DMM have got back to me too:
" There are a few reasons that we rate the freedom leash to 2kN:
Having a low rating, allows the leash to be of a lightweight, user friendly design.
In the event of a leader fall that may generate high impact forces, if the axe is in a solid placement, the leash may break, absorbing some impact from your fall onto your protection system. If the leash had a high kN rating, there is a possibility of generating high impact forces directly onto the climber’s harness.
In the event of a fall (rather than a slump onto the axes) with the axes in a very good placement, the leash is more likely to break, meaning you’re less likely to be hit by a falling ice axe on your way down."
In reply to mmmhumous:
"the ice axe cannot be thought of as an anchor as it is clearly not an anchor" sounds like advice from the company counsel, IIRC that's not what Jeff Lowe said...
"the ice axe cannot be thought of as an anchor as it is clearly not an anchor" sounds like advice from the company counsel, IIRC that's not what Jeff Lowe said...
In reply to Jamie B:
That's a bit like saying don't fall but sometimes people do. If your climbing with leashes and your axe placements are good, your placing gear and crampons slip, your going to load the leashes, whether they're designed for it or not.
> It's real simple - don't fall onto spring leashes as it's not what they're designed for.
That's a bit like saying don't fall but sometimes people do. If your climbing with leashes and your axe placements are good, your placing gear and crampons slip, your going to load the leashes, whether they're designed for it or not.
In reply to Steve Perry:
At least we are getting some feedback on why they are building them at that strength.
Personally I would like to know if there has been much testing on this or if its based on the conjuncture that we are getting up to on this forum. Its right to say people will find themselves losing footing or the axes placement they thought was bomber from time to time, so what is the fall length 2kn will support? Is it only a slump? Have there been injuries from people bringing down their axes with them, how does the injuries compare with falling without your axes etc., very hard to then compare this to the non event of the number of climbers who have been held by leashes and thus not sustained injuries from falling or clattering axes.
I wonder what led to blue ice reducing the strength of their leashes when they had light weight and affordable system rated at 4kn?
At least we are getting some feedback on why they are building them at that strength.
Personally I would like to know if there has been much testing on this or if its based on the conjuncture that we are getting up to on this forum. Its right to say people will find themselves losing footing or the axes placement they thought was bomber from time to time, so what is the fall length 2kn will support? Is it only a slump? Have there been injuries from people bringing down their axes with them, how does the injuries compare with falling without your axes etc., very hard to then compare this to the non event of the number of climbers who have been held by leashes and thus not sustained injuries from falling or clattering axes.
I wonder what led to blue ice reducing the strength of their leashes when they had light weight and affordable system rated at 4kn?
2
In reply to Rick Graham:
So lets get this straight.
My reading of the manufacturers blurb above is that the axes/leashes are designed to fail to minimise damage to the climber??
In my dreams I am mixed climbing on Cerro Torre, an axe is torqued in a good granite crack, one slip and my axe breaks or is lost. FFS
Most axes weigh about 600 grams. A Rock 3 weighs 32g and is rated at 10Kn.
Surely something can be designed to cope.
> But surely all folk want is:
> For the axe to remain attached to them
> For the axe not to split in two
> The axe not to whiplash into you if the placement fails
> The shock loading be as low as practical.
> Not really so out of order to be dissed by the climbing gear manufacturers.
So lets get this straight.
My reading of the manufacturers blurb above is that the axes/leashes are designed to fail to minimise damage to the climber??
In my dreams I am mixed climbing on Cerro Torre, an axe is torqued in a good granite crack, one slip and my axe breaks or is lost. FFS
Most axes weigh about 600 grams. A Rock 3 weighs 32g and is rated at 10Kn.
Surely something can be designed to cope.
In reply to steveshaking:
I am pretty sure the Salewa axe promo video on here the other week, called something like the nord x(?) Had a 5/6 kn leash and one of the selling points was it could be built into a belay.
If one company starts, others will follow I'd imagine.
> At least we are getting some feedback on why they are building them at that strength.
I am pretty sure the Salewa axe promo video on here the other week, called something like the nord x(?) Had a 5/6 kn leash and one of the selling points was it could be built into a belay.
If one company starts, others will follow I'd imagine.
In reply to steveshaking:
Absolutely... and thanks to the guys at BD and DMM who took the time to reply (no response yet from Grivel).
Depends on your (and your gear's weight).... if you apply a static load e.g. very solely lower your weight onto (in this case leash) the force you apply is 10x your weight in Kg (or on average, at sea level, 9.80665 x your weight if you want to be picky )... so if you weigh 50kg you exert 0.5kN, 100kg, 1kN etc. etc. I've read somewhere (that seemed fairly reputable at the time ) that bouncing can increase that force to 2-3kN... So dependant on your weight, a small slump/ factor 0.X fall may be held by a single leash (assume axe/ice don't fail). I weigh in at ~100kg, so with gear/boots/pack etc, 2kN doesn't give me a lot of "spare change" which is why I started this post... i.e. are my ~7kN homemade leashes genius, or a very bad idea.
I'd be interested to see "a scary DMM video" of a used freedom leash, straight from the freezer and whether it still held the rated 2kN.... i.e. is the rating only straight from the box, or post reasonable use and when cold?
> At least we are getting some feedback on why they are building them at that strength.
Absolutely... and thanks to the guys at BD and DMM who took the time to reply (no response yet from Grivel).
> Personally I would like to know if there has been much testing on this or if its based on the conjuncture that we are getting up to on this forum. Its right to say people will find themselves losing footing or the axes placement they thought was bomber from time to time, so what is the fall length 2kn will support? Is it only a slump?
Depends on your (and your gear's weight).... if you apply a static load e.g. very solely lower your weight onto (in this case leash) the force you apply is 10x your weight in Kg (or on average, at sea level, 9.80665 x your weight if you want to be picky )... so if you weigh 50kg you exert 0.5kN, 100kg, 1kN etc. etc. I've read somewhere (that seemed fairly reputable at the time ) that bouncing can increase that force to 2-3kN... So dependant on your weight, a small slump/ factor 0.X fall may be held by a single leash (assume axe/ice don't fail). I weigh in at ~100kg, so with gear/boots/pack etc, 2kN doesn't give me a lot of "spare change" which is why I started this post... i.e. are my ~7kN homemade leashes genius, or a very bad idea.
I'd be interested to see "a scary DMM video" of a used freedom leash, straight from the freezer and whether it still held the rated 2kN.... i.e. is the rating only straight from the box, or post reasonable use and when cold?
In reply to Mr Trebus:
this one? http://www.ukclimbing.com/videos/play.php?i=2441
Didn't hear him mention a breaking strength though.
> I am pretty sure the Salewa axe promo video on here the other week, called something like the nord x(?) Had a 5/6 kn leash and one of the selling points was it could be built into a belay.
this one? http://www.ukclimbing.com/videos/play.php?i=2441
Didn't hear him mention a breaking strength though.
In reply to mmmhumous:
That is odd, I think it must be a different version as I have only watched one but a quick Google shows it as 5kn.
http://hikinginfinland.com/2015/02/ispo-2015-news-2.html
That is odd, I think it must be a different version as I have only watched one but a quick Google shows it as 5kn.
http://hikinginfinland.com/2015/02/ispo-2015-news-2.html
In reply to Mr Trebus:
Interesting. I hope others follow, certainly shows that the current trend isn't based on unchallengeable principles.
I don't know what the guy in this video thought would happen when he let go of his leashes, but I think it certainly shows that 2kn goes nowhere at all beyond stopping you dropping your axe.
http://www.ukclimbing.com/news/item.php?id=67789
Interesting. I hope others follow, certainly shows that the current trend isn't based on unchallengeable principles.
I don't know what the guy in this video thought would happen when he let go of his leashes, but I think it certainly shows that 2kn goes nowhere at all beyond stopping you dropping your axe.
http://www.ukclimbing.com/news/item.php?id=67789
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