Edelrid MegaJul Belay Device

bearbreeder wrote:folks ... first of all Jim's tests who that generally the alpine smart is generally no worse than the reverso3 and in certain situations better ... no one is going to stop using their reversos because of these tests, nor should they here jims tests again the other thing is that we, on da intrawebz, really dont know how the devices AND belayers behave in real world large falls ... sure we know from Jim's test they slip at a certain point .... however they dont have an "inertial" phase where the hand moves up towards the device when braking .... in the case of the smart the hand should move DOWN onto the rope fully how much of the impact force is absorbed by the initial braking is unknown ... youll notice that with a hand belay method (munter, ATC) the maximum force occurs at the when the hand actually starts grabbing the rope ... with the smart the rope is grabbed to a certain extent from the get go ... until some body comes out and tests it with belayers in the system for high factor falls and publishes the results we wont really know Jims tests are valuable in that they reinforce the point that NONE of these devices are hands free and should not be treated a such... even if they do lock in certain circumstances but the smart anyways will do its job if you do yours ... it just isnt a "hands free" device ... no commercial climbing device is what one should worry about is not so much the devices themselves ... but the belayers and the folks who promote them as substitute for basic belaying skills and proper brake control (with gri gris as well) ;)

The maximum force for all kinds of belay devices is just as the rope begins to slip, we´ve enough drop test results to be sure of this and it is in fact logical since the dynamic coefficient of friction is lower than the static one.
The hand inertia theory was junked about 20 years ago or to put it better just ignored. The obvious questions which should have been asked when the theory was produced is if that´s the part of the curve caused by hand inertia what does it look like if the inertia is removed or infinitely high? Manin for the CAI and Ratzenberger for the DAV built inertialess systems and also tested with GriGri bolted to the ground so infinite inertia and the curve remains the same.
All subsequent tests have either been with an inertialess system, infinite inertia systems or good old humans. All give the same curve which comes from rope stretch, not hand inertia.
It´s also slightly irrelevant since we know that everybody is capable of gripping the rope sufficiently to lift off, unless you are belaying the leader from a fixed anchor above then belayer body inertia is relevant but not their hand movement. I´m strong enough to resist the pull against my gripping ability on a climbing rope (I train levering myself out of my armchair) and would hazard a guess most of us are otherwise we´d hear more about peoples hands jammed in belay plates.

so jim

then pages 23-29 from this are bunk and disproven?

A Simulation of Climbing
and Rescue Belays -2006 International Technical Rescue Symposium

CMT Conclusions on Belaying
•Hand acts as an inertial load for the first few hundred
milliseconds.
•Slip distance is proportional to fall height, not fall factor.
Confirmed.
•Peak force occurs at maximum hand acceleration, not
at lowest climber position.
•Only a small amount of belayer lifting is helpful (~20
cm). More lifting increases fall distance and does not
decrease peak force. Confirmed.

user.xmission.com/~tmoyer/t…

as a side note we DO hear about folks jamming their hands in belay plates in large falls ... thats one way to lose control, have the webbing of your hand pulled up into the device and let go for inexperienced climbers

which is why experienced belayers have enough separation between the ATC and their hand

bearbreeder wrote:NONE of these devices are hands free and should not be treated a such... even if they do lock in certain circumstances but the smart anyways will do its job if you do yours ... it just isnt a "hands free" device ... no commercial climbing device is

I am curious though... I have a Mammut Smart which I rather like, and I have found that while it won't *catch* every fall, it seems to behave like an autobelay a lot of the time if you don't brake. That is, climber takes a fall, device applies friction, rope slips a bit and climber is slowly lowered.

(I fiddle with it frequently to get comfortable with its behavior, and giving a foot or two of slack on the brake side lets me observe the autoblock in action without dropping anybody)

I don't count on that right now, and there are a lot of circumstances where being lowered would not be all that great. Still, it would be nice to know if this or that device can be trusted to prevent free-fall in the event the belayer is knocked out. Not necessarily lock- but even gentle rope slippage is vastly preferable to free-fall!

Patrick Shyvers wrote: I am curious though... I have a Mammut Smart which I rather like, and I have found that while it won't *catch* every fall, it seems to behave like an autobelay a lot of the time. That is, climber takes a fall, device applies friction, rope slips a bit and climber is slowly lowered. I don't count on that right now, and there are a lot of circumstances where being lowered would not be all that great. Still, it would be nice to know if this or that device can be trusted to prevent free-fall in the event the belayer is knocked out. Not necessarily lock- but even gentle rope slippage is vastly preferable to free-fall!

it may or may not .... its not something i would depend on especially with thinner slicker ropes

but if your partner gets konked its better than an ATC where you KNOW you will bite the big one

the gri gri is still tops if your belayer goes kaput

bearbreeder wrote: it may or may not .... its not something i would depend on especially with thinner slicker ropes but if your partner gets konked its better than an ATC where you KNOW you will bite the big one

Right, that's kind of where I'm at. I love my ATC, but regardless whether an autoblock can be trusted 100%, I bet it can be trusted more than an ATC.

My ATC is still my primary device, but I mull over this regularly.

bearbreeder wrote:the gri gri is still tops if your belayer goes kaput

And I look at the grigri occasionally, but the places I'm most concerned about rockfall & lightning are the places where I'm most likely to double-rope rappel & belay two followers at once.

Which is not necessarily to say I want a two-rope grigri. That would be a heavy beast.

No perfect answer. Oh well :)

Patrick Shyvers wrote: And I look at the grigri occasionally, but the places I'm most concerned about rockfall & lightning are the places where I'm most likely to double-rope rappel & belay two followers at once. Which is not necessarily to say I want a two-rope grigri. That would be a heavy beast. No perfect answer. Oh well :)

for climbing with two seconds ... just get one to belay while the second keeps feeding the rope to that person nice and neat ... prevents tangles when using twins/doubles and the feeder acts as a belayer backup in case of rock fall (unless they both go kaput)

for autoblock usage, especially with two seconds, nothing short of a gigi beats the alpine smart ... even pulling 2 10mm+ old fuzzy stiff ropes at the same time is like BUTTAH

which incidentally makes it the best ascending devices on double ropes if you miss your rappel station as well ....

i think we need to make it clear that there are 2 different modes (well 3) in an alpine smart

- asssited locking (normal belaying) ... what some folks call autolock ... may or may not "lock" depending on the rope, biner, weight, etc ...

- autoblock ... bringing up seconds ... locks reliably all the time IME with the ropes i use

bearbreeder wrote:so jim then pages 23-29 from this are bunk and disproven? A Simulation of Climbing and Rescue Belays -2006 International Technical Rescue Symposium CMT Conclusions on Belaying •Hand acts as an inertial load for the first few hundred milliseconds. •Slip distance is proportional to fall height, not fall factor. Confirmed. •Peak force occurs at maximum hand acceleration, not at lowest climber position. •Only a small amount of belayer lifting is helpful (~20 cm). More lifting increases fall distance and does not decrease peak force. Confirmed. user.xmission.com/~tmoyer/t… as a side note we DO hear about folks jamming their hands in belay plates in large falls ... thats one way to lose control, have the webbing of your hand pulled up into the device and let go for inexperienced climbers which is why experienced belayers have enough separation between the ATC and their hand

The first bit is just ignored.
The second is so (as long as the FF is high enough to cause slip in the first place though there is always a certain amount of take-up through the device).
Third:- Peak force of what, Top anchor, T1, T2, belayer hand? The peak top-piece force is when T1+T2 are maximum which varies for the device used. It´s never (as far as I know) when either T1 is at it´s maximum or when T2 is at it´s maximum but somewhere between. Got nothing to do with hand speed since we don´t use hands anyway!
Fourth-Undecided, the CAI tests are done in a way not many people belay and the relevance to belaying off the harness is doubtful..

rgold wrote: [Emphasis is mine.] Brian, your willingness to just make stuff up is impressive. EVERYONE (I count 19 posters) who commented on the MegaJul, with the SINGLE EXCEPTION of me, indicate that they own and use the MegaJul (and, by the way, are almost entirely positive about the experience). The vast mob of ignorant armchair engineer posters is something you just invented and are now apologizing to. As far as my post, I've already explained myself and won't add anything to what I've already said very clearly. Since I am not an engineer, you are welcome to call me an "armchair engineer" without apology if that tickles your fancy. Greg, Jim's graphs have pretty much every device slipping once the load to the belayer exceeds about 2.5 kN, a level around 1/3 of the maximum possible load one might conceivably get, and in some cases a lot less. The take-away is that the tested "assisted locking" devices are not going to "lock" for extreme falls and, moreover, might provide less stopping friction than the good old ATC XP. I haven't tossed my assisted locker (one that Jim hasn't tested) yet, but I have gone back to using it with gloves, as I would with an ATC.

I counted 24 people commenting on this thread that didn't say they use a MegaJul and 13 that stated that they did. That is a majority. Of course it is hard to tell because some commented solely on other devices like a Mammut Smart or just made comments on catching falls, or how smart Jim Titt is, or how dumb I am because I dare to question Jim Titt.

I believe that something you said above sums it up... "might provide less stopping friction than the good old ATC XP." The crux of the debate is "might" and until someone tests it then it is all a bunch of speculation by armchair engineers.

One should always have your break hand on the rope when belaying, so the fact that the Edelrid Mega Jul isn't certified for Factor 2 falls in "assisted braking" (eg. hands free) mode is rather meritless. Get a Mega Jul....they're great belay devices.

Brian wrote:I climb with a lot of inexperienced climbers who I don't have totally confidence can hold me in a fall. So I like them using an assisted braking device.

I'm curious what aspect you are worried about. Are you concerned they are not strong enough? Not fast enough? Not... what?

Second-hand anecdote, but the owner of my local climbing gym has related to me that his observation has been that the traditional tube-style device (e.g. the ATC) is the most natural for new climbers to learn how to use. They master the device more quickly and easily, and basic human instincts work better with the tube-style devices.

You just have to watch a few people mis-using the GriGri to understand what he means. For example, a popular way to pay out slack is to pinch the cam with your thumb. However, when your climber falls, the natural instinct is to tense- which leads to clamping your hand down on the cam, and preventing it from locking! This is an example of one of the ways a GriGri is less compatible with our instincts.

Personally, I'm much more concerned about my belayer mis-using their device or not paying attention, than being too weak to catch my fall. Even the old, standard toothless ATC has plenty of bite for a 90lb high-schooler to catch me. As for paying attention- I prefer to holler at my belayer when they start ignoring me, than depend on an autolocker.

Patrick Shyvers wrote: I'm curious what aspect you are worried about. Are you concerned they are not strong enough? Not fast enough? Not... what? Second-hand anecdote, but the owner of my local climbing gym has related to me that his observation has been that the traditional tube-style device (e.g. the ATC) is the most natural for new climbers to learn how to use. They master the device more quickly and easily, and basic human instincts work better with the tube-style devices. You just have to watch a few people mis-using the GriGri to understand what he means. For example, a popular way to pay out slack is to pinch the cam with your thumb. However, when your climber falls, the natural instinct is to tense- which leads to clamping your hand down on the cam, and preventing it from locking! This is an example of one of the ways a GriGri is less compatible with our instincts. Personally, I'm much more concerned about my belayer mis-using their device or not paying attention, than being too weak to catch my fall. Even the old, standard toothless ATC has plenty of bite for a 90lb high-schooler to catch me. As for paying attention- I prefer to holler at my belayer when they start ignoring me, than depend on an autolocker.

I'm not that worried about a factor 2 fall. We are debating an extreme use of any belay device. I try at all cost to avoid putting myself in a factor 2 situation. As Rgold mentioned not many belayers even know how to hold a factor 2 fall (pull the rope up not down or to the side) as the force is downward. What I'm postulating is that an assisted locking device is better than a tuber-style device because its default is to lock off even if the belayer is knocked unconscious by a falling rock. AND even in a factor 2 fall because it will at least initially and momentarily catch by squeezing the rope giving the belayer a chance to hold the fall before it goes ripping through the belay device. Of course this is just speculation on my part as another Internet armchair engineer because no one has tested this. I sent an email to Edelrid but they said "Yes we did fall tests, nothing that will stand the comparison to a 20m factor 1,9 fall though due to a lack of falling tower height... well...
So we don´t have any relevant data for this discussion.

Brian wrote:I'm not that worried about a factor 2 fall.

Me neither

Brian wrote:What I'm postulating is that an assisted locking device is better than a tuber-style device because its default is to lock off even if the belayer is knocked unconscious by a falling rock.

If I could have an assisted locking ATC Guide, I would agree that would likely be strictly better. Unfortunately nobody has come up with an assisted locking tube-style, and as I discussed in my previous post the tube-style have some important advantages! It's a difficult apples-to-apples comparison to make. Do you prefer the easy-to-operate, lightweight, inexpensive, do-it-all device that works well when people act on instinct? Or do you prefer the counter-intuitive, heavy, pricey, single-function device that is easy to mis-use - BUT is autolocking?

Basically what I'm getting at is the autolockers are wonderful in specific environments for skilled operators, were things like "heavy" are meaningless, because you get the benefit (autolocking) at little cost (e.g., you didn't have to carry the device for miles)

Now, in fairness the MegaJul fixes a lot of those problems. It is very similar to a tube-style device. It is light, inexpensive, and can double-rope rappel! Paying out rope is not as simple though, and conspicuously enough, that was the #1 complaint about the Mammut Smart- that paying out rope was annoying.

I'm curious Brian, you have a vested interest in the MegaJul? Because your personal attacks have seemed to be directed at those who question its use.

Before you reacted to Jim's statement about his and Richard's experience and went off spewing:
"There are lots of self-proclaimed expert engineers and people with 100 years of climbing experience on here that will give you untested opinion which may or may not be relevant for your unique situation."

You might want to figure out who those two guys are and just what their qualifications and experience are. You might find they actually know a boat load about what they're talking about. In Jim's case, quite literally.

need another hint?
www128.pair.com/r3d4k7/Gold…

The point is not that one doesn't debate with the experts but that if you are going to step into the debate, you do so with some meaningful contribution. And spew against competent, experienced climbers with backgrounds in engineering and mathematics isn't meaningful. Nor is a test with a sample set of 1 where your buddy jumps off the cliff and wow, you held the fall. Too many degrees of freedom there Brian.

Your observations of your experience with the device are possibly meaningful to the OP. That's for them to decide, to take it or leave it. But in terms of attacking the integrity and knowledge of others, it just doesn't cut it.
It gets you called out with the age old cry of BS.

Doesn't really help your case either to make a false statement about armchair engineers and then indicate you can't follow the charts and graphs.

It is true that Jim and I have some expertise in both climbing and the technical issues involved in equipment decisions. As Brian has been very quick to note, that by itself doesn't mean one should believe anything we say. Our separate professional fields both demand that claims be justified with clearly logical arguments and/or data given with enough information to allow others to reproduce the experiment, and I think both of us have honored those requirements here---most especially Jim, who has been more than generous in sharing his results---even though MP is about as far from a professional environment as it is possible to get.

If my thinking is faulty, I've done my best to give you the basis for my conclusions and so the means for explaining why I've gone wrong. I think Jim has had to correct me several times in this thread, for example. I also do my best to never play the "I'm an expert so you have to believe me" card---I certainly never consciously make this assertion, even when I am in some sense an expert (which would not be in this discussion), because I don't believe it. I also really try to avoid the ad hominen attacks and straw man arguments that turn up the temperature while muddying the discussion, but of course there is no way to prevent others from doing this and it is part of the sport of internet posting, to the amusement of some but the detriment of understanding anything important.

Paul Davidson wrote:I'm curious Brian, you have a vested interest in the MegaJul? Because your personal attacks have seemed to be directed at those who question its use.

I do find vitriol & aggression is more commonly the armaments of "fanboys" rather than creators (if that is what you were suspecting). A common enough phenomenon; the owner of a certain product seeks social validation of his purchase, and feels any suggestion to the contrary is an attack on himself & his choices. PC vs Apple is a classic example.

Brian wrote: I'm not that worried about a factor 2 fall. We are debating an extreme use of any belay device. I try at all cost to avoid putting myself in a factor 2 situation. As Rgold mentioned not many belayers even know how to hold a factor 2 fall (pull the rope up not down or to the side) as the force is downward. What I'm postulating is that an assisted locking device is better than a tuber-style device because its default is to lock off even if the belayer is knocked unconscious by a falling rock. AND even in a factor 2 fall because it will at least initially and momentarily catch by squeezing the rope giving the belayer a chance to hold the fall before it goes ripping through the belay device. Of course this is just speculation on my part as another Internet armchair engineer because no one has tested this. I sent an email to Edelrid but they said "Yes we did fall tests, nothing that will stand the comparison to a 20m factor 1,9 fall though due to a lack of falling tower height... well... So we don´t have any relevant data for this discussion.

Belayers being knocked out and dropping the climber seems to be a fairly rare occurance. I knew a climber who was hit by a rock while belaying, the combined weight of the rock and his body lying on the rope were enough to hold the climber though.
The default is NOT "to lock off even if the belayer is knocked unconscious by a falling rock" and this has been tested, the default is it MAY lock off. In a factor 2 with an unconcious belayer it will not lock, this is the UIAA/EN test.

Jim Titt wrote: With the MegaJul the self locking is removed but if you lock it up by hand the resistance is the same as a single karabiner. With the Smart it moves into the locked position on it´s own but has virtually no self-generated resistance whatsoever.

Sorry Jim, I meant 2 carabiners with the reverso and the black diamond as a function of rope diameter.

rgold wrote: As Brian has been very quick to note, that by itself doesn't mean one should believe anything we say. Our separate professional fields both demand that claims be justified with clearly logical arguments and/or data given with enough information to allow others to reproduce the experiment, and I think both of us have honored those requirements here---most especially Jim, who has been more than generous in sharing his results---even though MP is about as far from a professional environment as it is possible to get.

Of this we agree. Another huge factor in any test is the most unreliable, unpredictable variable in the test: a human. You can rig up all the test equipment you want but a human is always the critical variable in a real-life situation. Results without humans as variables are, or should be, meaningless. Engineers/scientists hate these messy variables. There will always be a human in a real life situation. So the question shouldn't be will the angle of the cut in an ATC equation most likely hold a fall better than the lesser angle in a device like a MegaJul. It should be whether a human is more likely to hold a fall with an assisted locking device than a regular tuber style device. The only way to test that is with human beings continually holding falls. The variables are whether they are wearing gloves, how much they weigh, how much experience they have, etc. And even then the results may not be consistent because one time the person may hold the fall and the next time they don't. That is why I like assisted locking devices, in most cases, they lessen the variability of the human intervention.

I consider anyone who makes claims on a climbing forum about gear without verified test results to be an armchair engineer, myself included, so don't anyone get all hurt. This is a climbing forum. There are a few people jumping in to enthusiastically defend Jim, who seems to have a cult following. Jim doesn't need defending, I'm sure he is very knowledgeable.

But we know this already, that is why belay devices are not included in the PPE legislation and receive no CE marking. They require human intervention to function and this is outside of the remit of the European Norms which are industrial standards.
We can however measure the relative strength of the holding power of different devices and measure the capabilities of a broad section of the climbing community to achieve a reasonable picture of under which circumstances and with which device most belayers are capable of holding a fall without injury. You can do what you like with this information.

Brian wrote: You can rig up all the test equipment you want but a human is always the critical variable in a real-life situation. Results without humans as variables are, or should be, meaningless.

Your assertion is the exact opposite of reality and the scientific method.

You HAVE to eliminate the human variable in testing. Without a controlled baseline, results are meaningless.