I climb a lot with my wife and we spend much of our time at the local sport crag or the gym. Like many couples, she and I have a large weight difference between us. She’s about 105 pounds and I weigh about 170. That much difference can create some dangerous climbing situations when there’s not much friction in the system.
I’m excited about the Edelrid Ohm. This device is designed to add friction into the system during a fall or when lowering, but not when climbing normally or pulling up slack to clip. The Ohm works kind of like a auto-engaging ATC. When climbing normally or pulling slack, the Ohm rests in a position where it’s braking slot doesn’t engage. When a fall occurs, the tightening rope causes the Ohm to flip over and engage the braking slot onto the rope, adding friction. Like an ATC, the braking slot isn’t active, so it doesn’t clamp down and stop the rope like a GriGri does. Instead, it adds some friction to the system, compensating for a portion of the weight difference between a heavy climber and light belayer.
To use the Ohm, you clip it onto the lead rope as though it was the first quickdraw on your rack. Be careful to thread it the correct way. This is pretty straight forward and akin to loading a GriGri. The Ohm has clear graphics that show the correct threading method. Upon arriving at the first bolt, clip in the Ohm instead of a quickdraw. You can fall directly onto only the Ohm and it will behave like a quickdraw, though the additional breaking power is diminished vs when at least one more draw is used.
I’ve used the Ohm a few times now with my wife belaying me. I was using the device indoors at a climbing gym almost exclusively on about a 20° overhanging wall. We were tentative at first, and used the Ohm in conjunction with some other weight-difference compensation techniques we’ve used in the past, including skipping the first bolt, clipping the first clip out of line and using some additional ballast weight attached to my wife’s harness. As we grew more comfortable with the Ohm, it became clear that it did a great job of assisting with the catch and we didn’t need the other methods (though I still think skipping the first clip is good if it’s not too high up)
Our first night of using it, I started with small falls then slowly graduated up to larger ones. By the end of the night, I was taking 25-30 footers without concern over doing any damage to my wife or having her belay device jammed into the first draw. Even on the largest of falls, her feet only came off the ground perhaps 4 feet.
So the Ohm does a great job with the catch, but how about feeding slack? For us, that’s still a bit of a work in progress. The Ohm is more prone to engage when the angle between the rope going into and out of the Ohm is smaller. Essentially that means that the further away from the wall the belayer is, the more likely the Ohm is to flip over and engage. So far, we’ve used it primarily on overhanging walls, which naturally result in a smaller rope angle and hence a quicker engagement. As a result, I’ve had some issues with being short roped while trying to clip too quickly.
When you experience a short rope, Edelrid suggests you jiggle the rope up and down like a stuck seat belt. I’ve found that if you’re on easy holds and close to the belay, that’s easy to do, but if you’re higher up with some friction in the system and/or you’re on challenging holds and a sketchy clip it’s a lot harder. Of course, it’s those challenging holds that are exactly the ones that are going to make you want to yank rope really fast, so there’s a bit of a catch 22.
In spite of some issues with short roping, I still highly recommend the Ohm. I’ve climbed cautiously for years not wanting to stretch things out and take a fall that might put my wife into a harm’s way. It was liberating to feel like I could push the envelope and risk a larger fall. Just like that new pair of tennis shoes that made me run faster as a kid, the Ohm is going to add a letter grade or two to my top end—for sure! And it’s going to keep my wife from getting injured, which of course is more important.
I give the Ohm 4 out of 5 stars. I’ll bump up this rating if we figure out the beta on where to stand, how to feed and how to jiggle the thing properly so we eliminate the short rope issue.