UKC

/ Belay plates and sub 8mm ropes

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Stuart the postie - on 24 Jun 2018

Hi,

Currently I use a Reverso 4 and looking to buy new rope. Have seen 7.3, 7.5 & 7.8mm ropes within my price range, would these be suitable to be caught 'guide mode' ?

Stuart

Wayne S - on 24 Jun 2018
In reply to Stuart the postie:

Petzl state:

Rope compatibility: - for half ropes (8 mm or greater diameter) and twin ropes (7.5 mm or greater diameter) and on single ropes (8.9 mm or greater diameter).

I would go for the 7.8mm or buy a different plate.

Blackcountrybill - on 24 Jun 2018
In reply to Stuart the postie:

I've been using a pair of tendon 7mm twins for the last year. I've had no problems catching falls in both regular and guide mode with a reverse 4 and a grivel master pro.

I'm happy with both belay devices but make of that what you will.

GarethSL on 24 Jun 2018
In reply to Stuart the postie:

When you say 'rope' are you looking for a skinny single or a pair?

My tuppence, so far I've had no problems with my Edelrid Skimmers (7.1) on a Petzl Reverso 4, but did invest in an Edelrid Micro Jul just in case.

Have also just replaced my mountain ropes with the Beal gully (7.3) and fear no real issues using them with the DMM Pivot, Reverso 4 or Micro Jul.

But obvious advice would be get a belay plate with a rope diameter range that suits the rope/ ropes you end up with.

Stuart the postie - on 24 Jun 2018
In reply to GarethSL:

Thanks, that's what I expected to hear. A friend just got a pair of Gully 7.3mm, he uses a Pivot and said it was fine too.

Kinda wanted to hear others experiences, which have concluded........

Stuart

GarethSL on 24 Jun 2018
In reply to Stuart the postie:

No worries! But just to add, so far I've not witnessed any slip in guide mode when weighted by a second, nor when bringing up two seconds. But it pays to be attentive.

Also I haven't found abseiling on super skinny ropes with any of those devices to be less controlled either. In fact quite the opposite as it's much smoother. This is with dry, wet and icy ropes, so the gear seems to do its job quite well!

rgold - on 24 Jun 2018
In reply to Stuart the postie:

I think it is wrong to worry about guide mode first.  A much more critical question is whether you're equipped to hold leader falls.

My standard response to the leader fall question is to do a single-strand free-hanging rappel with your device.  If there is even a hint of a control issue, you won't be able to hold a big fall.

I think a lot of people say their devices are "fine" with thin ropes based on evidence that comes nowhere near the kinds of loads that happen in a high-fall factor scenario with low system friction. If so, that "fine" comes with a giant asterisk: device only known to be reliable in restricted circumstances. (Maybe ok for gym and closely bolted sport climbing.)

I'm also perplexed when a manufacturer rates a device for 8mm half ropes but requires 8.9 mm single ropes.  Half ropes catch falls on a single strand.  It can't be 8mm if it has to be 8.9mm! I've never heard an explanation of this discrepancy that makes any sense.

Getting back to guide mode, the locking mode can fail if the rope(s), when loaded, are thin enough to swap places in the slot.  You want to be sure this isn't a possibility with the device and diameters considered; I don't think there is any way to know except by carefully conducting a test and observing what the strands are doing.

Belaying is the most critical aspect of roped climbing.  I'm continually surprised at the level of complacency people bring to the use of belay devices in situations outside the manufacturer's recommendations, which as I've noted above already seem inexplicably lax.

A final word: if you're going to run thin ropes through a device that isn't rated for them, at the very least make sure you've got a good pair of belay gloves.

1
oldie - on 28 Jun 2018
In reply to rgold:

> My standard response to the leader fall question is to do a single-strand free-hanging rappel with your device.  If there is even a hint of a control issue, you won't be able to hold a big fall. <

I once abbed down an impending wall with large pack, new shiny skinny rope and original ATC. Eventually completely lost control and was very lucky to be able to aim for a widish ledge below me (no backup prusik). Hand deeply burnt. 

> I'm also perplexed when a manufacturer rates a device for 8mm half ropes but requires 8.9 mm single ropes.  Half ropes catch falls on a single strand.  It can't be 8mm if it has to be 8.9mm! I've never heard an explanation of this discrepancy that makes any sense. <

When Sticht plates became popular in the 1970s most ropes were either 11 or 9mm (if my memory is correct) and different plates were made for each. I had one for single 11, one for two 9mm and one with different size holes to mix 11 and 9. Because they were for specific ropes I would never have envisioned using, say, a 9mm rope in an 11mm device. Nowadays manufacturers provide devices claimed to cover a wide range of diameters: it is very hard to see how there can be sufficient braking for thinner ropes in severe falls especially as ropes differ in flexibility, and smoothness (especially if new and shiny and if dry treated... I've read somewhere that the latter can reduce braking force by up to 40%). Not to mention other variables such as krab dimensions 

The only reasons I can think of for quoting a higher safe diameter when using a double rope are either thinking that a thin rope is hard to grip and its easier if a hand is "fuller" with a second rope even if its stationary (but one can easily imagine the reverse being true) or that the manufacturer assumes that the second rope will always start taking some strain during a fall (obviously wrong).

> A final word: if you're going to run thin ropes through a device that isn't rated for them, at the very least make sure you've got a good pair of belay gloves. <

IMHO most people don't wear gloves perhaps partly because they almost never hear of falls sufficiently severe to cause burns with modern belay devices (although many didn't wear them even when waist belays were common and leader falls quite often did cause burns).

The latest British Mountaineering Council magazine, Summit, discusses belay devices and in a "Top Tip" says wearing gloves can be useful to prevent burns but may make it more likely that one cannot hold falls in the first place. Later the article states that wearing gloves can be one cause of too low hand force when belaying. To effectively discourage gloves seems rather unwise, particularly as there are cheap, dextrous and grippy industrial ones available. However the article must be based on experiences/testing (possibly influenced by use of mitts etc in winter?) and is written by the BMC technical officer. I have little technical knowledge but my gut feeling would be that it is often a good idea to use them. I think in a recent thread you said you always do so. Perhaps people with a weak grip might not brake well with gloves even with low severity falls, but in that case they would not hold a bad fall anyway and might be best with an assisted device.
 

 

danm on 28 Jun 2018
In reply to oldie:

That's a thoughtful post, and I guess some explanation is in order seeing as I was the author of the Summit article. When we started researching the performance of belay devices and ropes a few years back, one of the things we wanted to study was the range of different hand forces different people could apply. Use of gloves had always been recommended for climbing where a high fall factor might occur, for belaying a heavy climber, or if the belayers grip was weak. So, it came as a bit of a surprise when we did some test measurements and found that most of the time, the hand force was lower if the subject wore gloves. Of course, there's more to it than that, some gloves seem to be grippier than others, and they may change as they get used and worn in the same way that the grippyness of a rope changes. In general though, it's fair to say that using gloves will give most belayers a weaker hand force. But, and it's a big but, the protection the gloves give the hand against rope burn do mean that the rope may still be controlled by the belayer despite it running through the hand. So, I'd agree with you that in many situations wearing gloves is a good idea. We're planning on getting more data on hand forces this year as it's a subject worth getting more knowledge about.

One other point I'd add, is that if using ropes towards the lower end of the recommended diameter, be careful especially in guide mode. A weakness in the rope standard is that rope diameter can be reported as +/- 0.2mm the measured diameter. If I manufactured a rope with diameter 7.75mm, I could sell it as anything between 7.6mm to 8.0mm, so your rope may be thicker or thinner than you think. Worst case is that it isn't compatible with your device despite technically being in the acceptable range of diameters.

TobyA on 28 Jun 2018
In reply to Stuart the postie:

I'll post you an Edelrid Micro Jul in return for a vague promise that you'll buy me a pint should our paths cross at some future date. Message me an address and you can give it go and see if you get on with it. I really like the Mega Jul (same but for just slightly thicker ropes) but lots of people don't.

rgold - on 28 Jun 2018
In reply to oldie:

> The only reasons I can think of for quoting a higher safe diameter when using a double rope are either thinking that a thin rope is hard to grip and its easier if a hand is "fuller" with a second rope even if its stationary (but one can easily imagine the reverse being true) or that the manufacturer assumes that the second rope will always start taking some strain during a fall (obviously wrong).

Well, according to tests by Jim Titt, you can't exert as much braking force on half ropes, one of which is running and one of which isn't,  as you can on a single thicker rope.  This makes the rating discrepancy more bizarre.  If you can't go below 8.9mm with a single rope, and will, according to testing be able to provide less braking force in the half rope situation, then how will you be able to brake an 8mm strand?

> The latest British Mountaineering Council magazine, Summit, discusses belay devices and in a "Top Tip" says wearing gloves can be useful to prevent burns but may make it more likely that one cannot hold falls in the first place. Later the article states that wearing gloves can be one cause of too low hand force when belaying. To effectively discourage gloves seems rather unwise, particularly as there are cheap, dextrous and grippy industrial ones available. However the article must be based on experiences/testing (possibly influenced by use of mitts etc in winter?) and is written by the BMC technical officer. I have little technical knowledge but my gut feeling would be that it is often a good idea to use them. I think in a recent thread you said you always do so. Perhaps people with a weak grip might not brake well with gloves even with low severity falls, but in that case they would not hold a bad fall anyway and might be best with an assisted device.

I've heard from Jim about lower braking force with gloves.  I don't recall what the percentage decrease is.  Of course, hands don't get weaker when you put on gloves, so the lower braking force must be a consequence of the gloves being more slippery than skin and/or the gloves actually obstructing the gripping contraction.  It does seem that both those possibilities could be addressed with the right fit and material.  In any case, I'd settle for a little more rope running but maintaining control and walking away with all my skin still on my hand over possibly not having a strong enough grip anyway and suffering the possible control and injury consequences.

 

oldie - on 30 Jun 2018
In reply to danm:

> ...... In general though, it's fair to say that using gloves will give most belayers a weaker hand force. But, and it's a big but, the protection the gloves give the hand against rope burn do mean that the rope may still be controlled by the belayer despite it running through the hand. So, I'd agree with you that in many situations wearing gloves is a good idea. We're planning on getting more data on hand forces this year as it's a subject worth getting more knowledge about. <

Many thanks for your reply. When I first read the original article I had interpreted it as discouraging gloves rather than more as a point to consider in any situation.

Winter climbers can relax knowing they need not risk frostbite to protect their leader.

 

Jeff Ingman - on 30 Jun 2018
In reply to Stuart the postie:

I've been using Beal gullies (7.3mm) with a Reverso 4 for 3 years now but only for winter/ice/alpine. I did a full test at the climbing wall and local crags to confirm in my own mind that the combination would be OK to hold a leader fall, or in guide mode. It's worked fine, and I've held a full on leader fall with the combination. If I was climbing with someone significantly heavier than me, and the ropes were covered in sticky snow or ice I would probably add an additional crab to change the run through and increase friction. Hope this helps..........Jeff

pass and peak - on 13 Jul 2018
In reply to Stuart the postie:

I changed my old WC atc to a Climbing Technology BE UP, after testing with new 8.5mm ropes in Guide mode left me on my arse at the bottom of my loft hatch! As already stated, in guide mode if the slot in the brake side is not narrow or more important deep enough then the ropes can cross over in the slot! This was happening often when using (all be it with back up) the device in guide mode on your belay loop as a clutch when jumaring up a fixed line. Remember ropes diameters are measured unloaded, under load that stretches the rope say 15% then I would have though that elongation would correspond to the same loss of diameter. 8mm minus 15% and all of a sudden your rope when holding even a light fall could be 6.9mm!!

1
Toerag - on 13 Jul 2018
In reply to Stuart the postie:

I'd like to see some edge cut tests before starting to use skinny ropes for anything.

3
MFB - on 13 Jul 2018
In reply to Toerag:

Climbing on double 7.9 and 8mm for about 10 yrs, modest grades, fairly regularly and never seen any damage or felt concerned about chopping, only didn't go thinner recently because of belaying/abseiling  fear. Great to carry, great to climb on.

David Coley - on 14 Jul 2018
In reply to rgold:

Belay gloves are often leather and well used. Which can mean polished. I tried abseiling once with my well used aid gloves on a 8 mm rope and reverso. I had a real job controlling it. No way I could have held a lead fall  

rogerwebb - on 14 Jul 2018
In reply to danm:

When you were testing belay devices and skinny ropes what was the weight of the test subject?

At 93kg plus winter gear I wonder if I am simply too heavy to risk skinny ropes much though I would like to save pack weight on the walk in. Any thoughts? 

 

wbo - on 14 Jul 2018
In reply to Stuart the postie:we climbed 12 pitches today then rapped the route using a 7,5 and a 7,3 , both using pivots. Seemed to work ok, didn't use gloves.

 

rgold - on 15 Jul 2018
In reply to David Coley:

> Belay gloves are often leather and well used. Which can mean polished. I tried abseiling once with my well used aid gloves on a 8 mm rope and reverso. I had a real job controlling it. No way I could have held a lead fall  

I must be recycling my gloves sooner.  I don't doubt that they can get really slippery, but I've never had a pair that made a difference in gripping that I could detect, which is not to say that a proper test would not have revealed reduced gripping ability, but it was never enough to be noticeable for things like rappelling.

In any case, my real point is that a number of manufacturers are making gloves specifically for belaying, and yet I'm not sure any of them have really worked on enhancing the gloves' grip properties.

oldie - on 05 Aug 2018
In reply to pass and peak:

> Remember ropes diameters are measured unloaded, under load that stretches the rope say 15% then I would have though that elongation would correspond to the same loss of diameter. 8mm minus 15% and all of a sudden your rope when holding even a light fall could be 6.9mm!! <

Not sure it would be as extreme....if one assumes the volume of rope stays constant then a 15 percent increase in the length of a "cylinder" of rope would give a decrease the diameter to 7.46mm as the formula for the volume of a cylinder involves the square of the radius. I may be wrong: recent GCSE students please advise.

 

Jim 1003 - on 05 Aug 2018
In reply to oldie:

Mammut smart alpine....dogs bollocks...semi auto and for Trad

 

 

Martin Haworth on 06 Aug 2018
In reply to Stuart the postie:

Ropes seem to have got thinner to acheive the same role over recent years but I don't think the belay plate market really has kept pace. There are some skinny rope belay devices but I'd like to see petal re release the Reversino which is just a miniaturised version of the reverse and was available until about 10 years ago. It was specifically for thinner ropes. I have one and it's ideal for ropes between about 7mm and 8mm, not sure what it's official size range is, I'd have to go and look at it.


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