Carabiners get punished more than any other piece of gear on my rack. This abuse has, over the decades, also caused them to magically get cross loaded or unlock in the most inopportune times, such as belaying or hauling. I’ve dropped cumbersome auto-lockers, watched screw-gates unlock themselves as I ascend the rope via Jumars, and had them freeze shut during winter storms.
Invented in 1910 by Otto Herzog, the carabiner has changed shape and size too many times since to keep track. Today’s aluminum climbing carabiners have gates that come in straight, bent or wiregate. Shapes are available in D, Offset D, Oval, and Pear/HMS shape; lockers come in twist lock or screw lock.
Rock Exotica’s (patented pending) rockD BiWire carabiner, $12.95, 2.36 oz., has two opposing wire gates to make it lock differently than any other biner on the market. In addition, it’s offset-D construction gives it one of the highest breaking strengths at 30KN.
To operate the BiWire, you drop your index finger between the gates at the nose, then pry the wires apart by pressing down. Once they’re open, you then slide the nose over the piece you’re clipping before releasing the gate. This is opposite to how 99% of other carabiners work. However, after a few rounds of practice they became easier to operate than some auto-lockers on my rack which tend to snap and lock shut while I’m getting them off a sling or my harness.
The BiWire can be used in any situation where a locker is needed and they are especially bomber on ice. There generous size makes them highly versatile at anchors, hauling, jugging and docking haulbags. One drawback is they don’t come in alpine-size, meaning extra small and light.