There is a rather common (and problematic) situation in climbing that occurs when thereâ€™s a significant weight difference between climbing partners.
All is well when the heavier climbing serves as the belayerâ€¦but that all changes when the lighter climber takes the belay, particularly if the heavier partner climbs first: the belayer can be lifted off the ground trying to arrest a fall.
Edelrid offers a solution to this problem with its OHM, a device that, honestly, no one really misses until itâ€™s needed.
The device is attached to the harness and is installed to the first bolt or placement as if it were a quickdraw. During a fall, the device acts an assisted braking device and engages to balance the weight between climbers.
It works perfectly when climbing partners have anywhere from a 10 to 40 kg (22 to 88 lb) weight difference. The OMS is not recommended for smaller weight differences because it pulls up the gear when braking, loading the climbers and safety chain with more force than usual; the system works for bigger weight differences, but less efficiently than with differences in the 10 to 40 kg (22 to 88 lb) range.
At weight differences closer to 10 kg (22 lb), say 12 kg (26.5 lb), the OMS dynamically adds friction but may pull the climber towards the wall a bit. This is easy to get used to and is not an issue for most. Everything worked flawlessly for bigger weight differences.
In short, a device that makes for safer, more controlled descents and is worth the redundancy in sports climbing, particularly in the common situation of a significant weight difference between partners on artificial and natural climbing walls.