Top belay with Revo?

So I recently picked up a used Revo for cheap to at least give it the ol college try. It's fine for its intended use, that is, single pitch redpoint attempts with little hanging, or for beginner belayers. That being said, I'm looking for other applications.

I recently started to do more multi pitch and trad stuff, and in my quest for the best/most efficient top belay (I know, this has been beaten to death in the forums), I got to thinking a pulley design would make things super easy, though I worry about having enough friction to catch a follower. In my research, I see that the Revo is not to be used in this fashion, but I can't find a decent conclusion as to why. I did a quick test rig on my wall set up as you would a direct belay off an anchor, and went to town yanking the rope and testing all the function, which it seems to work just fine, though I didn't test it with a climber-equivalent load.

From test reports with Petzl, you can't use progress capture devices in this fashion, as the teeth may shred the rope from higher than expected fall factor due to traverses or not keeping up with slack. However, this isn't an issue with the Revo, as there are no teeth that bite the rope. I know in that other forum post there's discussion on de-sheathing the rope, but that seems unlikely in this scenario as well.

Other than the obvious not wanting to carry this ten pound brick up the wall, is there a good reason not to use a Revo to belay a follower? Is it a YGD scenario?

Are you planning on redirecting the rope and belaying off your harness?  Sure, its fine for that.

But it sounds like:

Are you wanting to put the device directly on the anchor like an atc in guide mode?  The problem here is you have to lift the brake strand above the device for it to lock immediately.  If you are not lifting the brake strand, then you are relying on the centrifugal "safety" mechanism (intended as a backup not the primary) to do the locking which doesn't engage until some rope zips through and reaches a certain velocity. Your follower may fall unnecessarily far by top rope standards.

Are you planning on belaying directly off you harness or off the anchor?  The lack of fast lockup and honestly mediocre friction would make the device poor for the function in guide mode.  You would have to drop you partner fast like 3+ feet to have a chance of even getting it to lock. If you are harness belaying it should work ok but why bother for the weight?   A gri gri is much more versatile and lighter.   The Revo is a one trick pony for the most part.  I have used it while simuling directly on gear as a stop anchor in case my second fell but I was most just messing around as I'm not sure it would have been all that useful

As Nick B said, it needs actual fall that reaches certain speed (I can't remember the number, see their website) in order to engage the locking mechanism. It works great for soft catching the leader with Revo but I don't think it's great for top belaying the second as it won't lock right away. I own and use both Grigri+ and Revo (and in the past Grigri2 and Cinch) but I end up using Grigri 99.9% of time and I've mostly used Revo for lead rope soloing. (That application is another can of worms) 

YGD my dude

I'm curious about using it for rope solo, but that's another thread.

The speed to lock is 4m/s, which seems to be ~2-4' of freefall. I understand the auto lock is a backup, but you're pretty much doing the same thing when you use a Grigri on the anchor.

I just tested it by attaching a pretty heavy tool bag and dropping it. Locked up every time around 3'. It's a pretty harsh lock up, so I think a dynamic anchor would be smart (though in my test rig, I barely have any rope in the system to stretch). But it seems like a pretty reliable system.

I realize a Grigri is the way to go here, but I don't own one, and the ease of feeding rope is the real draw. The Revo could also pretty easily be locked manually as well. In fact, it almost works like a progress capture if you find a way to keep tension on the locking lobe, maybe with a bungee to the belayer's harness.

Nate Mech wrote: maybe with a bungee to the belayer's harness.

When you lock it manually the engagement is into an area in the wheel not designed for this. It fails at a fairly low force. As this is only aluminium and is damaged each time I can't imagine this is a reliable long-term solution.
Also, the 3 feet drop before it locks is free- fall, in a typical seconding scenario this could be much further, especially if you are providing some resistance holding the brake strand.
Grigri if you must.

Jim Titt wrote: When you lock it manually the engagement is into an area in the wheel not designed for this. It fails at a fairly low force. As this is only aluminium and is damaged each time I can't imagine this is a reliable long-term solution.
Also, the 3 feet drop before it locks is free- fall, in a typical seconding scenario this could be much further, especially if you are providing some resistance holding the brake strand.
Grigri if you must.

Interesting, I was not aware of this. Seems like an odd design choice to make such a component a weak point. So does that mean it is unsafe/unreliable to manually lock the device, even when belaying normally?

For multi-pitch you can do no better than an ATC-XP and a Munter hitch. Spend some time researching this and you’ll know why.

Start your quest here: Should you change the way you belay?

Climb safe,
Mal

Nate Mech wrote:

Interesting, I was not aware of this. Seems like an odd design choice to make such a component a weak point. So does that mean it is unsafe/unreliable to manually lock the device, even when belaying normally?

Whether it's safe or not is up to you, Wild Country don't say to use it that way either, no-where in the instructions does it mention you deliberately locking the device. It isn't badly designed, the cut-out in the wheel is specially designed to take the nose of the centrifugal weight which then trips the jaw which blocks in another cut-out further around the wheel. The weight cut-out forces the nose of the jaw outwards damaging the wheel and releasing it. After the wheel has regained speed the Revo then locks properly. I explained this with pictures in my previous testing posts.

Thanks for the input Malcolm, that's how I typically belay, though that's not the purpose of this thread.

Jim, I'll have to look at that post. I've gone through most of those discussions, but must have missed that. Thanks. I think I saw a review post from Matt Samet on climbing mag talking about manually locking the device, so it seems folks are using it this way.

Nate Mech wrote: Thanks for the input Malcolm, that's how I typically belay, though that's not the purpose of this thread.

Jim, I'll have to look at that post. I've gone through most of those discussions, but must have missed that. Thanks. I think I saw a review post from Matt Samet on climbing mag talking about manually locking the device, so it seems folks are using it this way.

Why don't you ask him if it's safe? One assumes he examined how it functions and tested it before recommending a use not given by the manufacturers. Alternatively it could be typical magazine review i.e. worthless.