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rgold
Trad climber
Poughkeepsie, NY
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Jul 28, 2014 - 09:55am PT
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Have a look at http://www.mountainproject.com/v/edelrid-mega-jul/108052298 but especially http://www.mountainproject.com/v/edelrid-megajul-belay-device/109133730__10#a_109256747
The latter thread has Jim Titt's tests, which lead to the surprising result that none of the assisted locking devices is a powerful as an ATC-XP when it comes to holding falls with high belayer loads. It appears that there is a tradeoff between everyday performance holding the relatively low-load typical leader fall and performance under extreme circumstances when the load to the belayer is very high. You'll also read a lot of sometimes heated debate about whether performance under extreme circumstances matters, given the rarity of such events and the possibility that the belayer may not be able to control the fall with any device.
My sense is that among the MegaJul, the Alpine Smart, and the Alpine Up, the MegaJul is the least effective performer and the Alpine Up is the best; in particular, it looks as if the MegaJul really shouldn't be used with ropes at the low end of its recommended range. There are, of course, other considerations such as weight, bulk and cost that might enter into the decision, not to mention the questions about holding really big falls with low system friction.
The fact that a major climbing publication named the MegaJul "Gear of the Year" suggests, in case anyone didn't already know it, that such "tests" need to be taken with many grains of salt.
One take-away: if you are going to use one of the assisted lockers, you should (still) be wearing gloves, because the rope will start to slide through the device when the loads get high.
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rgold
Trad climber
Poughkeepsie, NY
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Jul 28, 2014 - 10:36am PT
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The tests show that you had better know exactly what you (and the companies) mean by "safe and effective." You are paying for something, but it may or may not be what you want or need.
All the devices are pretty easy to use. I think the Alpine Up is the easiest to use if you are going to be using half-rope technique.
None of the devices is great for rappelling, but they are all adequate.
It turns out that performance depends to some extent on the carabiner you are using, as well as the rope diameter, condition, and treatment.
The Alpine Up is sold with a carabiner, thereby eliminating that performance variable. The other devices are not and you may have to experiment with different carabiners.
None of the devices are autolocking---you absolutely cannot assume the device will lock up under a fall load if your hand isn't on the brake strand.
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JimT
climber
Munich
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Jul 28, 2014 - 11:42am PT
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that's why we pay the companies the big bucks, to engineer safe and effectiv egear Optimism rules!
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BrassNuts
Trad climber
Save your a_s, reach for the brass...
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Jul 28, 2014 - 12:40pm PT
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I've been using the mega jul for almost a year now and like it pretty well. Good things; easy to lock off in any mode, stainless steel stays cooler on raps, extremely wear resistant, doesn't blacken your rope as much as aluminium devices. Bad things; locks up too easily if your rope is slightly fat or fuzzy, too much drag in the high resistance rap mode depending on rope - a little hard to get the right rap resistance depending on rope and rap angle.
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rgold
Trad climber
Poughkeepsie, NY
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Jul 28, 2014 - 04:53pm PT
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I accidentally listed the same thread twice; that has now been corrected. The second thread is the one with the important information I mentioned. Here is some sample engineering banter (ignore the unlabeled graph) that led to my comment that the MegaJul should not be used with ropes near the lower end of its rated range.
All these devices (with the possible exception of the MegaJul on thin ropes) are going to perform adequately in normal climbing situations. You can expect the "in use" reports to say the device locked up on the user's leader fall catches, and the main discussion will be about rope-handling characteristics.
The question about how the device might behave under some bad if not worst case scenario falls is typically not part of the "in use" reports, because the users didn't have that type of incident.
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rgold
Trad climber
Poughkeepsie, NY
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Jul 28, 2014 - 05:04pm PT
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The credit goes to Jim Titt, not to me. There are other graphs from Jim's tests using different ropes in the (now correctly) referenced thread.
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donini
Trad climber
Ouray, Colorado
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Jul 28, 2014 - 05:09pm PT
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Lot's of threads on ST aboult belay devices. I'm pushing the classic hip belay.....no extra gear and nothing to lose. Wait, I'll amend that....when it comes to hips, a lot of posters on ST have considerable inches to lose.
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rgold
Trad climber
Poughkeepsie, NY
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Jul 28, 2014 - 05:42pm PT
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Depends what you mean by "fall." Normal climbing situations involve falls with relatively low fall-factor and substantial system friction, so the loads transmitted to the plate are not particularly high. All the assisted-locking devices seem to work fine for such situations.
In a multipitch climbing situation in which there is a chance the leader can fall past the belayer, and this with little or even no protection in and so little system friction, holding a fall means controlling the belay even though the rope has started running through it. Once the rope starts to run, the belayer's chances of controlling the fall depend on how much frictional assistance they are getting from the device.
According to Jim's tests, none of the assisted locking devices provides as much assistance to strong grippers in such situations as an ATC-XP, which however does not "lock" for modest falls. The results depend on the rope diameter (and no doubt on several other rope characteristics) and may also depend on the type of carabiner employed. I posted the graph of the situation in which the MegaJul performs the worst; you should visit the referenced thread for the other graphs.
Donini was sorta joking, but in fact a hip belay might well be the most effective belay if the belayer suddenly has to hold a factor-2 fall. Most of the device manufacturers have warnings in their manuals that their devices are not up to that type of load. I've held one real factor-2 fall on a climb and a whole bunch of factor 1.8 falls with weights with a hip belay, so I know for sure it works even in these very extreme situations.
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blahblah
Gym climber
Boulder
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Jul 29, 2014 - 11:19am PT
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. . . Most of the device manufacturers have warnings in their manuals that their devices are not up to that type of load. . . .
Really? I've never seen such a warning, and I've at least skimmed the manuals for several devices.
It's possible I've just missed them, but let's just say I'm a little skeptical that "most" device manufactures have any warnings that their belay devices are "not up to" any particular load that one could encounter in recreational climbing.
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rgold
Trad climber
Poughkeepsie, NY
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Jul 29, 2014 - 06:07pm PT
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Yeah, "most" reflects manuals I've seen and this is hardly a sampling of the majority of device manufacturers. Bit of hyperbole there.
Look for a statement or cartoon indicating the device won't hold a factor 2 fall and requiring that the rope be redirected through the anchor, for example (from the Reverso manual)
From Edelrid MegaJul Manual
I don't think there is anything about this in the ATC-XP manual though.
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Salamanizer
Trad climber
The land of Fruits & Nuts!
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Jul 29, 2014 - 06:19pm PT
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All I know is one of my climbing partners got one of those several months ago. And sense then he hasn't been able to stop short roping me at every slight tug on the rope. Never used to be a problem.
Personally, I wish he'd throw that piece of sh#t away!
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