I think the DMM Revolver is one of the more underrated climbing inventions of recent times. Though this specialty carabiner has been on the market for the last five or so years, it deserves another look for its multiple applications to a wide array of climbing situations.
The Revolver, simply put, is a carabiner with a pulley wheel built into the carabiner. Its usefulness to climbing can basically be distilled to helping out in rope-drag situations. You’d never carry an entire rack of these puppies; but it’d be worth picking up one or two Revolvers, whether you’re into sport, trad, aid or even alpine climbing.
The carabiner itself is beautifully made. The DMM hot-forging process—all completed at their home base in Wales—results in high-quality hand-made carabiners that feel more like works of art than hardware, and this ‘biner is no different.
The first question is: does the Revolver actually reduce rope drag when properly placed? The answer is, a BIG yes! When the Revolver is used properly, it can make a huge difference in rope drag.
The next question is, where and when should I use a Revolver? That answer gets trickier. But let’s explore some situations in which it might be helpful:
At the first bolt. The best place to use a Revolver for a sport climb is at the first bolt, especially in situations where the belayer has to stand out away from the wall. Using a Revolver here will reduce rope drag while you’re climbing. The reduction in friction will also make it easier for you to work a project—hangdogging, boinking up, etc.
That said, less rope drag and less friction isn’t always a good thing. If you there’s a crux low on the project, and you often take fall that are uncomfortably close to the ground, then more friction in the system might be preferable. Likewise, if you’re a heavy climber with a light belayer, you may not want less friction because your belayer will be pulled up more easily. Use your judgement.
Using a Revolver in a trad-climbing situation is a little trickier since you have to have a really great sense of rope-drag dynamics in order to place the Revolver in the correct spot.
Sometimes this is obvious (the pitch doglegs left at this one obvious point). Other times, it’s not.
I prefer to NOT use the Revolver with shoulder-length slings. I’ve found that after simply clipping a single Revolver to a sling, often what happens is that the Revolver flips around so that the pulley wheel is against the sling, not the rope, thereby defeating its purpose. Instead, I prefer to keep my Revolver clipped to a long quickdraw, which holds the carabiner in place.
What’s so interesting about this situation is that it’s actually OK to have a shorter draw (as opposed to using a full shoulder-length sling) because the pulley does such a good job of reducing friction. This might be ideal in situations where A) you will have rope drag but B) you’d rather have a shorter quickdraw because you’re climbing into a crux and don’t want to make your potential fall any longer than it needs to be.
DMM also makes the Revolver as a locking carabiner, which would be better suited for a clean, easy top-rope.
In a pinch, you can use a Revolver to help you haul a bag. However, I’d say if you’re planning on doing any hauling (say, of a day pack), then you’d be much better off using a Petzl MicroTraxion because that actually cams the rope in between pulls and it weighs next to nothing.
Some people like to jug ropes using a GriGri and one ascender, with the rope running like a Z back through a carabiner clipped to the eye hole of the ascender. In this situation, you’d be much more stoked to have a Revolver instead of a regular carabiner.
In a big multi-pitch situation, especially one in which you’re using twin ropes, a Revolver can really come in handy in reducing rope drag. The worst rope drag of my life came on the North Face of the Cime Grande in the Dolomites. Darkness was coming. I was trying to link two pitches. And I was climbing on twin ropes. Even though I only had three pieces clipped in the last 45 meters, I felt as if I were lugging an elephant up the wall with me. Had I just used a Revolver for that first clip (with both twin ropes), I would’ve been fine.
If you’re interested in this carabiner, I’d recommend getting one; maybe two. But you honestly wouldn’t ever need more than that. Clip one to a quickdraw, and keep the other one free for contingencies. And climb on without the drag.