DMM revolver + ATC: any experiences with this?

I think Nate has a point. If I understand Jim, the Revolver isn't going to significantly affect the braking "power" of the ATC because the revolver pulley doesn't really function under high loads.  It does work under low loads, so might make feeding slightly easier.  So if "he just likes using this one," but isn't sacrificing braking power for the kind of handling ability he ought to have acquired anyway, its no big deal and we should all get over ourselves as instructed.

I'd question why anyone would use a $30 locker with an ATC when they could use a $10 one, but it seems like the safety issue isn't a problem. 

This whole thing is much ado about nothing. Making the proverbial mountain out of a molehill.

slim wrote
i'm kind of surprised rgold was only lukewarm on this one.  i thought he was fully convinced a person can't belay with a regular ATC unless they have a 1/2" thick leather glove and a 13mm rope.

OK, I'l fix that for you.  95% of all belayers will experience rope burns using a regular ATC with ropes at or under 10.5mm and no gloves if the the leader falls past the belay stance.  (Of course I made up the 95%.  It should probably be 99%.)  How many of those belays will totally fail I do not know.  How many of those burns will be severe enough to leave lasting damage I also don't know.  I do know that both these unpleasant outcomes have happened.

Señor Arroz wrote: I'd question why anyone would use a $30 locker with an ATC when they could use a $10 one, but it seems like the safety issue isn't a problem. 

sure, it SEEMS ok.  based on literally zero actual data points, one kind-of related test based on a vaguely defined "heavy load", etc.  the question is WHY would somebody really do this?  i think one of the posters above nailed it when they pointed out that if the belayer is so weak they can't yard a bit of rope through an ATC you might want to puzzle over it a bit.   i can only hope this is some sort of troll, but based on the typical stuff i see on a weekly basis anymore i don't have high hopes....

I have better things to do with my life than go along with being belayed with a revolver in the brake system.

Jonathan Croom wrote: I've always wondered about using a Revolver in guide mode; in the case of guide mode some friction comes from the rope pinching itself, which increases with an increased load, so reduced friction around the carabiner might not matter. Anyone try it?

I just tried it out on the ground with an ATC-guide.  Even when I perfectly positioned the rope over the pulley, the carabiner shifted the moment weight was put on the rope, moving towards the end of the red lines I drew on the picture.  The pulley makes the interior and exterior angle of the biner different.  I still would use a different carabiner for guide mode.

slim wrote:

sure, it SEEMS ok.  based on literally zero actual data points, one kind-of related test based on a vaguely defined "heavy load", etc.  the question is WHY would somebody really do this?  i think one of the posters above nailed it when they pointed out that if the belayer is so weak they can't yard a bit of rope through an ATC you might want to puzzle over it a bit.   i can only hope this is some sort of troll, but based on the typical stuff i see on a weekly basis anymore i don't have high hopes....

I don't disagree that it's a stupid use of the technology, especially if the stated purpose was to make feeding through an ATC "easier" since it's already easy. But it's not hugely dangerous. The bottom "twist" of the rope through an ATC could be over just about anything that's not going to cut the rope or break itself. 

Adam Fleming wrote:

I just tried it out on the ground with an ATC-guide.  Even when I perfectly positioned the rope over the pulley, the carabiner shifted the moment weight was put on the rope, moving towards the end of the red lines I drew on the picture.  The pulley makes the interior and exterior angle of the biner different.  I still would use a different carabiner for guide mode.

I don't think I understand what you're getting at...I can imagine the biner will move around a bit...did it make it easier to pull slack?

Jonathan Croom wrote:

I don't think I understand what you're getting at...I can imagine the biner will move around a bit...did it make it easier to pull slack?

I'm pretty sure he meant that when the ATC brakes the rope isn't even over the pulley. Thus no decreased friction. 

Señor Arroz wrote:

I'm pretty sure he meant that when the ATC brakes the rope isn't even over the pulley. Thus no decreased friction. 

Nailed it. 

rgold wrote:

OK, I'l fix that for you.  95% of all belayers will experience rope burns using a regular ATC with ropes at or under 10.5mm and no gloves if the the leader falls past the belay stance.  (Of course I made up the 95%.  It should probably be 99%.)  How many of those belays will totally fail I do not know.  How many of those burns will be severe enough to leave lasting damage I also don't know.  I do know that both these unpleasant outcomes have happened.

Why would a belayer get rope burn if a leader falls past the belay stance?

eli poss wrote: In theory, the braking power comes from friction over the edges of the ATC and less from the biner but considering that the differences between using a round stock biner and an I-beam biner are noticable, using a pulley would probably make me squirmish.

What theory are you referring to?

To much of this thread is conjecturing, which is the problem. Don't belay people with conjecture to overcome some trivial annoyance.

A regular ATC is a weak with todays ropes to begin with. Working in the belayers favour is that the revolver is a shit pulley. But that's all besides the point, if you are going to innovate and come up with newer lower friction belay device setups I expect you to have done some testing that didn't involve a falling person. I would be impressively surprised if that happened in the OPs case.

What next, an ultralegere on the belay biner?

rockklimber wrote:

Why would a belayer get rope burn if a leader falls past the belay stance?

I'm generalizing all over the place, but here am assuming a fall factor greater than 1.  For most climbers using an standard-sized, the threshold load they can hold is only about 600 lbf with a regular ATC.  Double that for an ATC-XP.

rgold wrote:

I'm generalizing all over the place, but here am assuming a fall factor greater than 1.  For most climbers using an standard-sized, the threshold load they can hold is only about 600 lbf with a regular ATC.  Double that for an ATC-XP.

Thanks for clarifying.  I lead with the mantra "early and often". Very seldom do I put myself at risk for a factor 1 fall.  

Thanks all for the opinions and inevitable YGD's so far. I had reasoned something along the lines of what Jim Titt described, but yes, probably not something I'll expose myself to again without experimenting in a controlled way first. In any case, that's not high on my list of priorities since the setup seems to introduce more uncertainty than necessary, but I'll post up if I ever do. Not trolling, just curious: I figured I'd ask the community to see if I was missing something.

To clarify, my belayer's feeding technique was fine -- I don't think anyone gets pumped feeding slack into an ATC, or that she had any issues using one with a normal biner. Her guide school is a well-known one (but of course what you learn there and what you actually do are different stories, I know). Perhaps this was a bad habit that was not yet stamped out, but if I was in the mood to speculate (like some of you seem to be  ), I'd say that the use of the revolver was most likely just related to the fact that she had only brought the bare minimum gear for a morning TR solo, it was on her harness, and she had used the setup before and was comfortable with it. I'm happy to take the rest of the onus for my safety and recognize when I took an unnecessary risk, though.

sourisse wrote: Thanks all for the opinions and inevitable YGD's so far. I had reasoned something along the lines of what Jim Titt described, but yes, probably not something I'll expose myself to again without experimenting in a controlled way first. In any case, that's not high on my list of priorities since the setup seems to introduce more uncertainty than necessary, but I'll post up if I ever do. Not trolling, just curious: I figured I'd ask the community to see if I was missing something.

To clarify, my belayer's feeding technique was fine -- I don't think anyone gets pumped feeding slack into an ATC, or that she had any issues using one with a normal biner. Her guide school is a well-known one (but of course what you learn there and what you actually do are different stories, I know). Perhaps this was a bad habit that was not yet stamped out, but if I was in the mood to speculate (like some of you seem to be  ), I'd say that the use of the revolver was most likely just related to the fact that she had only brought the bare minimum gear for a morning TR solo, it was on her harness, and she had used the setup before and was comfortable with it. I'm happy to take the rest of the onus for my safety and recognize when I took an unnecessary risk, though.

I wonder if her guide school would endorse her "technique".

Nate Tastic wrote: I really can't argue with that. I believe it will catch fall. I don't know that it will, however. Beliefs are like opinions and opinions are like...whatever that asshole saying is.

I'm cool with people saying, "I think this works, it's a bit unconventional but it worked the first 3 times we tried it! How do you feel about being belayed with this? "

But that's quite a different thing from it working the first 10,000 times. What happens 99% of the time is uninteresting, but that 1%, now that's the meaningful part!

Recently linked to another thread, it's a bit of an extreme example but these guys invented their own means of belaying - which worked the first few times - http://caves.org/section/vertical/nh/45/ivyaccrpt.html

Now like you guys, I'm *guessing* this revolver+atc isn't instadeath. But I have reservations about such experimentation for such an inconsequential upside.

I wish I had a revolver so I could attach a Nalgene to my backpack with it, troll you guys hard when I’m out hiking... “Like how do you get the rope up there and where’s Diana’s Baths?!?”

rgold wrote:

I'm generalizing all over the place, but here am assuming a fall factor greater than 1.  For most climbers using an standard-sized, the threshold load they can hold is only about 600 lbf with a regular ATC.  Double that for an ATC-XP.

An interesting side note....  As I'm sure you are aware the number of really hard catches is pretty damn low.  Two quick examples:

Today I managed to catch a fall on a grigri without even the grigri engaging.....  AKA I gripped with my brake hand and my feed hand and it was the feed hand that seem to stop the fall!  Light climber, short fall..  Still it did surprise me a little.   But short fall and a bunch or quickdraws to add friction probably was a big part of it.

A month or so ago I had a partner take a fall with only one piece between him and the deck and he was a decent stance above it.  I twinged my tricep catching that one.  Me yarding in half an armful of slack before it came tight might not have helped my tricep.   Minimal/no rope slippage on the catch but it was a hard catch, pretty close to FF1.