>Rating: 3

Warning!! The Ohm is not magical.

Familiarity: I've used it several times

I've been climbing in the gym for about a year and a half and outside for six months. My wife and I have been using the Ohm for the past 4 or 5 months inside and out when I lead. I outweigh her by 90 pounds and am aware that the upper range of the Ohm is 40 kg or 88 pounds. A few nights ago, I decked from about 27 feet while climbing at our local gym. We were using the Ohm in our usual set-up: me on lead and tied into a fairly new Mammut Infinity Classic 9.5mm and she on belay with her GriGri+. After safety checks, I began climbing a moderately overhanging 10 that had been put up a few nights before; 5.10 is my typical lead indoors. First clip at ten feet was uneventful and I hung the Ohm in the correct position. Second clip was straight up another five feet, also easily clipped. Third clip, again five feet straight up, and also easily clipped. The fourth bolt was about six or seven feet above the third. The holds got a bit sketchy between bolts three and four and I decided to re-position myself before making the clip. I climbed about three feet above the fourth bolt such that the fourth bolt was then located at my belt line (I'm 6'6"). I might have pulled out a foot of slack to make the clip. At that point I lost footing. A second later I was on the ground wondering what had happened. My wife was pulled up ten feet into the first draw (Ohm). I was not hurt in the fall, other than some minor rope burn on my left arm, and my wife was unharmed, other than some frazzled nerves. This was the first time we'd experienced what we thought was a failure of the Ohm. I stated earlier that the Ohm was hung and threaded correctly at the first bolt. This was verified by other Ohm users and gym staff. My belay partner was not belaying from directly underneath the first draw. Our rope was within spec. Her Grigri locked up flawlessly and she caught the fall as best she could, yet I still fell to the floor. After much analysis and discussion with gym staff we've learned that the Ohm's response to that particular situation is quite common and that it is customary for belayers to be pulled into the first draw especially when their climbers outweigh them by 80-90 pounds, even when the Ohm is properly used. Apparently, up until a few nights ago, I had never tested the Ohm by taking a fall from 7+ feet above the last bolt. Needless to say my partner and I were shocked by the results. Outside, I routinely climb 7+ feet between bolts as required by the route, but have never taken a fall... I lead 8/9 outside as I am still a fairly new to it and don't push myself as hard as I do in the gym. In hindsight, it was not a failure of the Ohm but our own ignorance that was the true fault in this accident. I'm just glad we learned this lesson in the gym instead of on route at Shelf; the consequences there could have been catastrophic. The moral of this little lesson is this: check your bolt line and do the math on the amount of rope out in the system. If there is potential for ground fall, tie into an anchor or use a weight bag in addition to the Ohm, especially if you're on the extreme end of the weight differential. The Ohm is not a locking device like a Grigri. It is a friction device and will allow line to slip through, and while it certainly makes some aspects of climbing easier, it does not necessarily mitigate the risk of ground fall. Be safe.