UKC

I know there have been various discussions on this before, but looking for opinions based on what happens in the real world, rather than ones based on manufacturers' recommendations. Are the materials and process involved in manufacturing a half and a skinny single of the same diameter so very different, or is the only difference the testing? They certainly look and feel the same.

For example, when a single rope has to pass a particular test five times, and a half rope only twice, what is it that happens (or significant risk of happening) after the second fall on the half? Is it really being suggested that the rope may "fail" on fall number three? Does "fail" mean snap? Are there any documented cases of this actually happening?

Climbers routinely climb trad on the same pair of halves for some years, and even if they don't fall off much, the ropes are likely to have taken several falls - and in most if not all of these falls, the impact will be taken on one rope.

In reply to bpmclimb:

Yes, fail means snap. Here' an example of a "fail", albeit a single rope in this case.

https://www.youtube.com/watch?v=K9Wzx-9JzsI&t=13s

The established wisdom is that a 1/2 has less cut resistance (although there isn't a universally agreed definition on testing that) than the equivalent single rope. Also the 1/2 will be boingier (technical term) due to the scenario when the fall starts to be arrested by a second rope so as to try to avoid spinal damage etc. Look at the maximal force ratings on the ropes

In reply to bpmclimb:

They are are still kernmantle ropes, made from similar materials using similar weave patterns etc but they are designed for different uses/performance characteristics?

I'm not sure what test you are referring to but the Fall Test from UIAA 101/EN 892 involves 5 off FF1.7 falls prior to failure, using an 80kg mass (Single)/55kg mass (Half) with a limit of 12kN (Single)/8kN mass (Half) for the peak impact force during the first drop

In reality, the force is rarely only seen on one rope, you are unlikely to be in FF1.7 fall and ropes are cut, they don't snap. However, using a single half to lead increases your risk exposure.

In reply to bpmclimb:

Id have thought you'd snap before a half rope does.

High fall factors only happen when leaving the belay at least one pitch up a multipitch. Therefore higher forces tend not to be experienced by ropes on most lead falls without hitting the ground first. 

As a trad climber, I regularly will clip one rope to the extent that the fall will load only one half rope. I think yes. Should be willing to lead on a half rope only. If not, you're using the wrong gear and dont have the faith needed for an unfettered lead - so are handicapping yourself. 

K

In reply to bpmclimb:

People who have used these triple rated thin ropes as singles have told me it can be a problem belaying, as there's not much to grab. No experience myself though.

In reply to Mike Stretford:

Most of the falls I have ever held have been on a half rope.  Certainly all the real whippers, and mostly the other rope has not played much of a role.  On that empirical evidence, you should be fine.   You bet on that, every time a route starts on one side before swapping over to the other.

An awful lot of falls in this country are caught on one half rope in circumstances in which the second rope would not intervene before the faller abruptly stopped falling.

In reply to nniff:

I was told that even if the other isn't going to hold it still helps to hold the live one. I couldn't picutre my self belaying on doubles ropes while having this convo so didn't argue. 

Not arguing with you, I was puzzled at the time, main reason I thought I'd bring it up here.

In reply to CantClimbTom:

That is not a snap, that is a cut. Ropes never snap.

In reply to Mike Stretford:

I can't imagine how the other rope would play a part if it's slack?

In reply to bpmclimb:

When I first learned to climb we had an instructor who would solo alongside with a half rope on his back just in case. In the occasion when he did tie in and have us belay him for a section I asked him about the fact that it wasn't rated for what he was doing. He simply said that the rope would do exactly what it was needed in the unlikely event of a fall compared to not having the rope and that it was the same scenario as only having 1 rope clipped at the moment of a fall.

In reply to bpmclimb:

I wouldn't routinely lead on a single strand of skinny half-rope, just because the abrasion resistance is less. If you pay attention, you really can quickly start to notice abrasion damage. So, if I had a scenario where the rope was running tightly over abrasive rock (esp grit, in my mind!) and I took a lead fall, then tried again and fell again; then tried a third time... and fell again... I'm starting to get worried on one half rope about the effects of that on the rope. The same applies in the context of top roping.

However, I have quite happily led short sections of easier rock on a single half rope to save time during the course of a long day on mountain crags and have used one strand of 8.6mm half rope to belay seconds (not on grit!) without concern.

The ropes do feel very different, though: all my single ropes seem significantly less stretchy. This can have pretty important practical effects, especially when close to the ground.

In reply to Mike Stretford:

IIRC if only one of the ropes holds the fall the braking force that can be applied is significantly reduced. Which in theory means that it might sometimes be better to only belay with one rope until a runner is placed for the other (same situation might occur if protection points are infrequent). One wouldn't choose to brake with a single rope while holding a short length of rope beside. I'll see if I can find the figures.....I think Jim Titt may have posted them.

In reply to Mike Stretford:

IIRC if only one of the ropes holds the fall the braking force that can be applied is significantly reduced. Which in theory means that it might sometimes be better to only belay with one rope until a runner is placed for the other (same situation might occur if protection points are infrequent). One wouldn't choose to brake with a single rope while holding a short length of rope in the hand beside it. I'll see if I can find the figures.....I think Jim Titt may have posted them. Obviously using an ATC-XP type device.

In reply to bpmclimb:

Iirc Ben Moon's first ascent of hubble used a half rope to save on weight. However, half ropes then were thicker than the skinniest singles now.

The limiting factor is probably belay plates, can they provide sufficient friction given that the reduced diameter rope is more difficult to hold. And can they do this without impeding paying out.

Petzl used to manufacture a reverso specific to skinny ropes but it disappeared from the market quite a while ago. 

In reply to Kevster:

Or if your gear pulls out, on a pitch above the first, and you don't hit the deck.

In reply to oldie:

https://www.mountainproject.com/forum/topic/112357901/the-deadly-atc?page=1...

Above may be what I was looking for. Histogram type representation near bottom of page.

In reply to bpmclimb:

Half ropes tend to have less material in the sheath (more easily abraded/ cut through) and are designed to meet the requirements of a different set of test falls (less weight, same factor, not sure of how many).

For what it is worth I cut through to the core in one fall while seconding a traverse on grit (leaving the top of tower crack at Stanage). 

In reply to Presley Whippet:

I think there's an ATC Alpine Guide now, specifically designed for thinner ropes.

In reply to bpmclimb:

I think there are quite a few posts on this thread which are somewhat illogical. 

Construction methods are no different from a Single to a half. For example a thin single (8-7-9.0) is really not substantially different to a double rope of a similar diameter. What changes is the tests to which it is subjected.

I feel as a group we are somewhat undereducated in the simple mechanics of how ropes work. It is utter guff that a fat rope is less able to absorb impact than a thin rope. Infact I would say in many cases this is actually completely untrue. A rope absorbs impact by extension and it achieves that extension by the twisted cores pulling straight. The tighter the twist of the core, the more it is able to extend. So a semi static rope for example will have more static properties not because the materials of construction are particularly different, but because the cores have less twists in them. Of course the sheath also has to extend to match the core and this is where different manufacturers vary the properties of their rope. In general a looser, more acute weave on the sheath allows more extension and a lower impact force to be observed. It also means more wear. 

For a thin rope to support a fall, generally it means that the number of twists in the core structure is reduced simply because there is less space for a given volume of fibre because of the smaller diameter. A thin single will generally have a higher impact force rating than a fat single rope. The same is true of double ropes. It is difficult to achieve a good triple rating for this reason - the impact of a thin rope is high in the single rope test for the above reasons, so you have to employ the best fibre, the best construction methods, superior fibre coatings etc. to allow for the required extension. 

Are you going to snap a double rope if used single? Hell no - ropes DO NOT snap under normal loads. The UIAA have as far as I am aware NEVER recorded a snapped rope. The danger presented by using a double rope as a single is that you are exposing your anchor to maybe a higher load than if you used a rated single rope, especially a fatter one. So the question you need to ask is whether that is an acceptable risk to you.

Cut ropes is different and this is the main failure mode and IS a real danger. So you need to again be aware of a thinner ropes limitations. Abrasion is different and is yet again not as simple as x rope is fat therefore it is more abrasion resistant whereas y is thin so is rubbish for abrasion. It comes down to sheath percentage. As sheath percentage increases, abrasion resistance also increases. You could in theory have a 9mm with a thin sheath which would be less resistant than an 8mm rope. Of course core size also decreases as sheath thickness increases to maintain diameter, which means less twists and higher impact. 

Abrasion resistance on a double will NOT be significantly higher whether you use it as a double or a single in the right circumstances, namely that you appropriately extend pieces and keep it away from sharp edges, as you should already be doing. I can vouch for that because I have only just decided to stop using my Mammut Serenity 8.9 after 18 years - I cannot tell you how many metres of climbing that rope has done - 800m rock routes, Yosemite granite trips, ice climbing, grit, trad at home, used single, used double. It was my main rope for 10 years probably and it still is IMO serviceable. I replaced it with an Alpine Sender and I hope I will get similar service out of it.

The one thing that really cannot be denied is the point about being able to stop a fall. Small diameter, especially with a slick dry coating makes for a slippery rope. So make sure you adjust the way in which you belay - use a specific belay device designed for small ropes. Or add an extra carabiner. 

I guess the take home is do not make stupid, lame assumptions. Sit down with the label and read the ratings a few times. Get to understand what they mean - big numbers are not always better. The sooner people realise that it is a blend of compromises and that your rope needs to suit the individual and that it's up to the individual to educate themselves what it all means, the better. Just ask if you're not sure...

In reply to BeardtMike : - question on this 'The danger presented by using a double rope as a single is that you are exposing your anchor to maybe a higher load than if you used a rated single rope, especially a fatter one.'.  I always assumed that a double (used as a single) would be 'bouncier than a single of similar diameter else things can get very 'unbouncy' when the pair act together.  Wouldn't this reduce peak force, at the disadvantage of more stretch for comparable falls?

In reply to Presley Whippet:

It was called a Reversino, I still have mine, great bit of kit.

In reply to beardy mike:

Given you a like , Mike, but 

I wish you had not used the term  "double  rope " .   There are half, twin and singles .

Its also difficult to compare single and half use  from the data sheets as the test weight varies .

I stand to be corrected but some of your remarks are counter intuitive , good if you could check your wording.

Regarding holding falls , R Gold , an incredible source of knowledge and experience on here, has suggested trying a long free abseil on your rope/ plate combo. If its not comfortable on the ab , it probably will be problematical holding a harsh fall.

In reply to wbo2:

My point is this - fatness is actually not related to impact absorbtion. Just because something is thinner, that does not make it more stretchy - think about a Dyneema sling versus a Nylon sling. The materials have been changed and nylon is inherently more stretchy than Dyneema, but its widely accepted that a fat nylon sling has more stretch than a thin Dyneema one. 

Think of a rope like a spring. A thin rope would be represented by a spring with fewer fatter windings. The spring will extend and take the weight but it will not extend as far. A fat rope would be represented by a spring with more, thinner windings - the spring takes the load just the same but extends more. The point being that the one with more windings will bring the mass to rest over a longer period of time (even if that is a fraction of a second) and the mass will come to rest more gently. It's the same principle broadly speaking as a car crumple zone.

Proof is in the pudding:

Mammut Alpine Sender 8.7, single rope test 10.2 kN

Mammut Crag Classic Dry 9.8, single rope test 9.3kN

Mammut Crag Classic 10.2, single rope test 8.4 kN

Now to your point about acting as a pair. Lets say that you place parallel pieces with draws exactly the same height and you land on the ropes perfectly evenly. You of course halve the impact on each piece. That is why the test is conducted with 50kg, not 80kg. It's the fact that you are halving the impact by sharing the load which is protecting the piece of protection, not some magic fairy dust which makes the ropes more stretchy. If you look at the Mammut sender, the half rope impact stat is 6.7kN. I.e. it's no different to a half rope of the same diameter. So if you invert this, you can more or less make a guess at the impact of an 80kg mass on the top piece if you were to use a half rope as a single... namely that the impact would be 10.2kNish or maybe a bit more. Do you see what I mean? And I am going to place a fairly solid bet on the impact absorption stats of one of the fatter ropes above, having lower impact figures than a half rope if you were to use them as a half rope in the scenario illustrated above. The reason we use half ropes is because the reduce rope drag, allow you to share load between pieces more effectively, allow for 50m abseils, give you a redundancy factor to protect against a rope cutting, are lighter to carry than two single ropes, plus any others you can think of. But not really because they are stretchier - that is simply a misconception based upon our primitive brains equating thin to stretchy...

In reply to Rick Graham:

Sorry - I somewhat use those terms interchangeably. I will pay more attention!

I know all of this is counterintuitive, maybe my second answer helped? If not grill me brah...

In reply to Martin Haworth:

There was also a Buggette made by DMM - similarly a really good piece of kit. Really don't know why they don't still make reversinos and alpine bugs. They did a job which is not currently covered.

In reply to beardy mike:

Thanks Mike.

Interesting test results .

Could it be that in most, less harsh,  falls on the crag  that the thinner ropes feel stretchier?

Maybe in the thin rope test , the stretch available in the construction  is utilised fully and then the stretch available in the material has to take over to absorb the fall? All a bit of a guess.

What is comforting is that the standard rope tests are to cater for the worst possible likely scenarios. In the real world its the runners and landing that's often the main concern.

Happy to climb on one half  but obviously prefer two or a single. Good that this thread has highlighted the issues.

In reply to beardy mike:

Speaking of smaller belay devices, does anyone know what the one in the pictures below is? I have a vague feeling it was HB but not sure. I bought it for my wife years ago as she struggled with skinny halfs. Probably early noughties vintage. No markings at all on it.

In reply to DaveHK:

2nd pic.

In reply to DaveHK:

Maybe HB but I don't think so. They did a plate called the sheriff which either had a plastic keeper loop or an Aluminium one depending on the model you bought. I don't remember a thin rope version but could be wrong. To me that looks like maybe an american model? Maybe SMC? 

In reply to Rick Graham:

I don't know but I reckon the seat of your pants is less accurate than a load cell I must admit to now you mention it think there is more extension when abseiling? But maybe that is just me thinking too much...

In reply to beardy mike:

Thinking about it, it's possible it was bought on a trip to the States.

The absence of markings is odd.

In reply to beardy mike:

A bit of googling reveals it is an HB Marshall. Third row 2nd from left: https://www.karabinclimbingmuseum.com/uploads/1/3/3/0/133082760/img-4678-co...

In reply to DaveHK:

Nice! Good spot!

In reply to wbo2:

Mammut Alpine sender dry 9.0 impact force 8.8/6.5/10.0
  static elongation 8.5

Mammut Alpine sender dry 7.5 impact force 6.3/9.7
  static elongation 9

Are we sure thin ropes aren't "boingier"?

https://www.mammut.com/uk/en/products/2010-04200-11236/9-0-alpine-sender-dr...

https://www.mammut.com/uk/en/products/2010-04330-11250/7-5-alpine-sender-dr...

In reply to beardy mike:

I also still have a bugette, incredibly light belay device.

In reply to beardy mike:

It's an HB Air Marshal - i've still got a few in my gear box. As far as i remember they were sold as suitable for ropes between 8 - 9 mm in diameter.

In reply to bpmclimb:

The modern and arguably improved version of the bugette, just make sure you get it the right way round, liked the symmetry of the bugette in wet or dark

https://dmmwales.com/climbing-products/belay-descent/mantis

In reply to CantClimbTom:

The half rope stat is 6.3 vs 6.5 kN. marginally boingier, but not much. Enough to be insignificant in any meaningful way and to be accounted for by different manufacturing properties, anchor strength etc. Also, inconveniently for your theory, their 8.0 half is rated 6.3, static elongation 8.7 too. The difference being sheath proportion, 42 for the 8, 34 for the 7.5. So the 8.0 has similar impact properties but will be more abrasion and cut resistant.

In reply to beardy mike:

Thanks for clarifying 

In reply to CantClimbTom:

I can confirm that Beal Icelines are disconcertingly stretchy compared to thicker ropes.

In reply to DaveHK:

I have a Chouinard device very similar to that but if anything even more minimal. It hasn't got a loop though does have holes for thin cord. I've never used it.

In reply to pancakeandchips:

Beal ropes have amongst the lowest impact forces you can find, I.e. they are super stretchy. Beal are particularly good at making a tight sheath weave which doesn't slip on the core or wear excessively quickly in most cases.

In reply to DaveHK:

Yes its defo an HB Marshal I also have one. Its a good device for half ropes I reckon. I bought mine at mile end climbing wall.

In reply to John Kelly:

I use the bugette too, but it's not quite symmetrical, it brakes better one way than the other, I've never worked out which way is which though🤔

In reply to althesin:

of course you are right, it was so slight and the effect so marginal I'd forgotten -  you know when you got it wrong with the Mantis 😲

In reply to beardy mike:

Accepted that one single rope, one half rope, or two halves are all safe for holding a leader fall regarding impact force on the climber. A question: is a danger in using a half rope as a single that there is more chance of hitting something eg ground, ledge etc? My physics is poor but in my imagination one half rope is likely to stretch more for a given height above runner/leader weight than using one single rope, so that the leader is likely to fall further (albeit while decelerating) before bouncing back a bit. Apologies if this has already been covered in the thread.

In reply to oldie:

I'm not 100% certain on this as its pretty difficult to compare given that the stats are all for different weights. But my intuition is that the amount of stretch is not going to be so significantly different as to present a far greater danger. Like I said above, thin ropes stretch less which is why the impact force is generally higher and more abrupt. If comparing a thin triple rated rope to a single half rope with similar impact stats, both used to hold a single rope fall, I think there will be virtually no difference in fall distance, because the properties are nearly the same.

I think it would be far more important to look at the likelihood of your anchors failing due to the higher impact force exerted by the thinner rope in a single scenario. If we are assuming that the impact on the anchor in a factor 1 single rope fall on a typical half rope with an 80kg bloke is around 9kN based on the triple rope ratings above (quite an assumption but gives us numbers to play with), you have to assess whether an anchor will fail at that sort of level, and take steps to mitigate any risks a failure might present. For example, placing two pieces in short succession as a back up would be a good way to do this as the first if it should fail will reduce the impact on the second making it less likely to fail. And as stated, if there really is a risk of anchor failure, using pieces placed directly next to each other and using half ropes clipped in parallel would be a greater improvement as you will be looking at several kN less on each anchor, and should one fail, the other may hold, so you are introducing redundancy and reduction in the same step.

In reply to beardy mike:

Hi Mike, thanks for the detailed posts

Yes, I had been thinking that! I held off from reacting, though, because I'm not particularly up on the technicalities of rope manufacture/performance. It's been good to see so many replies.

...... I'm in the market for a 70m skinny single, mainly for sport climbing, and looking at 9.2mm or maybe 9mm, but not in a rush to buy right now, just looking at prices/options. Cheers, Brian.

In reply to beardy mike:

The mistake most punters make, they look at the rope specs to make a decision. Unless there is an inordinate amount of friction in the system the force applied by the belayer is always the limiting factor. If there IS a lot of friction in the system then the rope characteristics then play second fiddle to where and how much friction there is. The 9kN force from the rope specs is irrelevant if the belayer can only apply 2kN against it. The newest rope standard does at least adress this to some extent, mainly by making it so technical nobody can understand it!

In reply to The Pylon King:

I've snapped one. Granted it was tied to a 50t digger at the time 

In reply to Wide_Mouth_Frog:

What? The 50t digger was leading?

In reply to jimtitt:

I agree, personally I think there's far too much hand wringing about this or that. I personally climb on single  ropes most of the time just because its less faff unless I'm doing something sketchy or where I know there will be lots of drag. To me, how my belayer belays, and how I place me gear is far more important tha  whether I'm on a single or double rope, or whether it's high stretch or a bit naff. 99% of falls that's what's going ti make the difference...

In reply to beardy mike:

Things like the rope diameter changing the friction over the top karabiner make more difference than the number printed on the label. We still don't know whether low-impact ropes continue to be so through their life either, we are all familiar with some ropes turning into stiff wiry things and others becoming floppy caterpillers which surely can no longer give the same results as when tested.

In reply to Wide_Mouth_Frog:

I snapped one too. Only that was part of the twisted torsion bundle of a car-sized siege engine. Not a likely application in climbing.

In reply to beardy mike:

Thanks. I based my question on a belief that one half rope was likely to stretch far more than a single even just under body weight. I've experienced what seemed an "exciting" amount of stretch on a lone half rope when using one half to belay way back on a fence post and then holding the second's weight, and also when using the end of a half rope used for abseil as the anchor for a second abseil. Of course I didn't repeat either using a single rope so I'm probably wrong. Googling a bit however I do see that many share the same view, perhaps based on experience and misconception, that half ropes stretch a lot and some would not use them even in many top rope situations.

Well consider me nerd sniped. I have taken the time to go thru the beal rope range (my favorite rope manufacturer), data below as csv if you're interested to do your own analysis.

  -- Impact force isn't correlated to thickness but if anything, there's is a positive correlation.

 -- There is a step change in static elongation with the half ropes (difference in the UIAA requirement), which give explains the observed "but i always hit the floor top roping on a half". Static elongation and impact force aren't really correlated tho, which is interesting.

Name,Type,Thickness [mm],Impact [kN],Ratioed Impact [kN],Dynamic elon,Static elon.,Sheath
Opera,single,8.5,7.4,7.4,37%,8.4%,39%
Joker,triple,9.1,8.2,8.2,34%,8%,35%
Stinger III,single,9.4,8.2,8.2,37%,9.5%,38%
Booster III,single,9.7,7.4,7.4,38%,9.7%,42%
Tiger,single,10,7.6,7.6,37%,10%,40%
Flyer,single,10.2,7.4,7.4,37%,7.7%,37%
Top gun II,single,10.5,7.5,7.5,37%,9.5%,40%
Apollo II,single,11,7.7,7.7,35%,9.5%,35%
Wall cruiser,single,9.6,8.2,8.2,36%,8.5%,41%
Wall school,single,10.2,8.4,8.4,36%,8.5%,40%
Wall master,single,10.5,8.4,8.4,36%,8.5%,47%
Zenith,single,9.5,7.5,7.5,38%,9.2%,62%
Karma,single,9.8,7.5,7.5,36%,8%,34%
Virus,single,10,7.8,7.8,35%,9.7%,37%
Antidote,single,10.2,7.8,7.8,35%,8%,33%
Diablo,single,9.8,8.2,8.2,36%,9.2%,38%
Diablo,single,10.2,8.4,8.4,37%,8.7%,40%
Gully,half,7.3,5.2,7.56363636363636,35%,10.1%,45%
Iceline,half,8.1,5,7.27272727272727,37%,11.5%,41%
Cobra II,half,8.6,5.4,7.85454545454545,35%,11.5%,39%
Legend,half,8.3,5.3,7.70909090909091,36%,11.2%,39%

In reply to lukevf:

What the hell use is this? Where the hell is the pretty graph? Call yourself a nerd...

In reply to bpmclimb:

Ignoring the triple, the average values are

half
8.08kN Impact
36% Dynamic Elongation
11.08% Static Elongation

single
7.84kN Impact
36% Dynamic Elongation
8.91% Static Elongation

So it seems they're pretty comparable (I didn't know that before this thread) - except notably... the static elongation is more for half (not a huge surprise)

I think my "knowledge" was either out of date going back to the days when ropes were 9mm or 11mm (except for maybe a Mammut Galaxy 10.2, how I loved my first rope) or maybe I was just always wrong. I think the stats vindicate BeardyMike that they are comparable (give or take hideous bouncy jumaring/top roping on a half and maybe reduced cut resistance of a half)

In reply to CantClimbTom:

Think the average is 7.6kN for half, 8.08mm is the average diameter.

Sorry beardy mike, can't post pictures without a supporter badge. Anyway, i'd have thought pasting raw text is on form, number 5 of the UNIX philosophy and all. (Or more sarcastically, I'll be round at 7 to chew your dinner for you)

In reply to lukevf:

If you like, PM me the pics and I can post them here. You never know, this thread may be the one that stops this question from ever being asked again. This year.

In reply to CantClimbTom:

Nit picking addition for lone half of stretch when using it for distant anchor for belaying or abbing.

Incidentally the following may be of interest to some regarding impact force. I imagine several posters are already familiar with it.

https://willgadd.com/single-and-half-rope-impact-forces-data/

In reply to all:

This thread has got me looking at different rope specs more closely, and not just basing things on rating, diameter, treatment - and price!

In particular, I was looking at the Edelrid Protect range with interest (with their addition of Aramid fibres to the sheath), and the quite dramatic improvement claimed in abrasion/cut resistance. Apparently the Swift Protect, depsite being only 8.9mm, out-performs much thicker ropes in this respect, and would appear to be a game-changer - if the manufacturers aren't exaggerating. Does anyone have experience of using this rope?

In reply to bpmclimb:

Haven't used them but have played quite a bit with kevlar and technora,  both aromatic aramids. The cut resistance is fenomenal, a bundle of 5mm kevlar wound round and round and then glued with a dot of gel superglue was all good to about 18kN if I remember right. Over a 2mm edge, we got to I think 10000 rubs and it had not substantially abraided or cut. With a pair of sharp side cutters and pressing quite hard on them, it would go. Basically aramid is what is used in kevlar stab proof and bulletproof vests, and for racing sails. 

In reply to bpmclimb:ew

Am I understanding static elongation here? The UKC review of the Swift Protect Pro Dry has maker saying it's unsuitable as single for top rope yet has a 5.5 percent static elongation. From other posts this low value might make it very suitable?

In reply to bpmclimb:

With absolutely no further ado, courtesy of Luke, here are some pretty pictures.

In reply to beardy mike:

Beauty is in the eye of the beholder!

In reply to oldie:

I haven't just checked the review, but from memory they said unsuitable for top-roping and working routes. This is probably for reasons other than the static elongation figures - more to do with the Swift being a thin and a specialist rope; i.e. might as well use a cheap and clunky rope for those things rather than an expensive triple ...... maybe?

In reply to bpmclimb:

Because it (Kevlar) has poor abrasion resistance and loses strength with repeated flexing.

In reply to jimtitt:

Repeated flex I would agree, abrasion resistance is higher than Dyneema.

In reply to bpmclimb:

Maybe you're right. However the rope is sold as abrasion resistant so less reason to use a cheap rope. Earlier posts have implied top roping ropes ideally have low static elongation (makes sense, semistatic rope is often used for top roping these days....reminder of the 60s and early 70s when everyone used polyprop ropes at Harrisons) and the Swift Protect is far lower than all singles and halves in the earlier list posted. Must be OK for taking in a second which is essentially top roping, though often people do use the term as synonymous with bottom roping. 

Edit: Just crossed with Jim Titt's post which points out the rope is cut resistant NOT abrasion resistant. That explains things.

In reply to oldie:

I wrote that review and don’t remember writing that. It’s a single rope… you can tope rope with it… but it’s a bit like using a Ferrari to tow a caravan.

In reply to bpmclimb:

I have a swift protect pro dry, with the aramid sheath. Can't comment on the cut resistance, but certainly seems tough, hasn't visibly furred up at all. A bit tricky to handle though, quite easy to get a bit of a rope burn nip while flaking it out if you're rough with it. I save it for mountain routes where the lightness and abrasion resistance is more useful/reassuring.

In reply to Tom Ripley Mountain Guide:

The figures for elongation and comment on recommended uses were in the "What Edelrid says" bit at the end of your review.

In reply to beardy mike:

I suppose the important point might be "is kevlar more abrasion resistant than nylon"?

In reply to oldie:

🤔… not too sure about that. 

Best check with UKC or Edelrid.

I suspect it’s either a translation error or a typo. 

In reply to Tom Ripley Mountain Guide:

May be relevant:

dirtbagdreams.com/proview-edelrid-swift-protect-pro-dry-8-9mm
"Although Edlerid, like most manufacturers, doesn’t recommend their skinny lines for top roping or working projects."

https://gearjunkie.com/climbing/edelrid-swift-protect-pro-dry-8-9-climbing-...
"After a total of 4 days of thrashing, my verdict on the Edelrid Swift Protect Pro Dry 8.9 is an unequivocal “yes.” The Aramid does improve cut resistance and overall sheath durability, especially as a sub-9mm single rope."

In reply to bpmclimb:

I'm buying the Edelrid Starling Protect pro - cut resistant rope. 

The cut resistant ropes seem to have a higher impact forces - roughly 10% more than equivalent ropes 

My question is will that 10% be significant in real world scenario

In reply to beardy mike:

Who compared it with Dyneema?

In reply to John Kelly:

Perhaps another question: Does the cut resistance decrease with use even when lead climbing? If a reason for not top roping with this rope is indeed that aramid loses strength with repeated flexion (assuming this means with bottom roping where the rope is dragged round the top krab), then there is some, perhaps less severe, flexion when the rope passes through a belay plate/krab combination during leading and seconding. Admittedly bottom roping will have the combined effect of top krab and belaying. Perhaps nobody has tested loss of cut resistance after long use. In fact would any weakening in aramid lead to a decrease in impact force? 

In reply to oldie:

Perhaps nobody has tested loss of cut resistance after long use. In fact would any weakening in aramid lead to a decrease in impact force? 

Edelrid have their cut-test machine up and running now; it wouldn't be difficult for them to load a well used Protect rope and see how its performance compares to new. In fact, they probably already have (I would, out of curiosity) - but AFAIK haven't released any info on that (yet).

In reply to jimtitt:

Nobody did, but Dyneema is considered a fair step up from Nylon. I should have compared to Nylon...