A rabbit runner is a terrific and underutilized piece of gear. It’s simply a bit of webbing about 4 feet long, with loops in the end, either sewn (or tied by you). The loops in the end look a bit like rabbit ears, get it?
Photo below, sweet rabbit runner made by Black Diamond.
(Note the two different sizes of loops, a nice design feature. The small loop is designed to pinch a carabiner so it doesn't flop around and maybe get cross loaded. The larger loop is big enough to easily tie a girth hitch.)
Why are rabbit runners cool?
You get the utility of a double length 120 cm sewn loop, with less weight and bulk.
You can put it over your shoulder, clip each loop with a carabiner, and then easily deploy it by unclipping one loop and pulling it off. (Try this with several normal sewn loop slings, you'll probably strangle yourself.)
You can pass it entirely around a tree, icicle or chockstone that's up to about 3 feet in circumference; can’t do that with a 120 cm double runner.
You can make a quick and strong equalized anchor, with two pieces of gear and either a clove hitch or an overhand knot at the master point.
What's not especially cool about the rabbit runner is the price. A nice new one from Black Diamond, admittedly beautiful gear made with burly Dyneema and with an end-to-end pull rating of 22 kN, runs about $17, ouch!
Now, if you’re already sold on rabbit runners, this is still a fair price for a very useful bit of gear. But, if you're new to this kind of sling and want to give it a try before you pay for a new one, or if you’re a frugal climber and would rather spend your money on that sweet new set of Camalots, then read on, because it's easy and fast to make your own rabbit runner for about $2.
What you need:
Six feet of 9/16 inch tubular webbing (as of spring 2019, this costs about $0.30 a foot)
Flame source (optional)
Measure 18 inches from the end of the webbing. Pinch that spot with one hand, and bring the end of the webbing to that 18 inch mark. With this doubled 9 inch section, tie an overhand knot making a loop in the end. Take your time, make it tidy, with no twists. When you're done, you should have a tail of at least 2 inches or so, and the loop itself should be about 2 inches. It should look something like this.
Repeat this at the other end of the webbing. You should now have a loop in each end. Stretched out, it should be a bit under 4 feet from end to end.
Now, two more things to tidy it up.
If you cut the webbing yourself from a longer piece you had around, you might have an end(s) that looks a little ragged. Hold it over a flame source, candle, lighter, whatever, and melt it. (Do this outside, it stinks.)
Crank down those knots to really tighten them. You're never going to untie them again. I like to soak the webbing in water, then (carefully) crank on the webbing with pliers, then let it dry.
Here’s a good way to rack it: over one shoulder, loops clipped with one carabiner. To deploy, unclip one loop and pull one end around your neck. Our model here is a bit under 5 feet tall, so for her the sling is hanging a little low. For me at about 5’ 10”, it fits perfectly.
If you want to make the rabbit runner shorter, untie one of the overhand loops (before you set it with pliers) cut off about 1 inch of webbing, and retie the loop. Don’t get over enthusiastic with cutting off too much webbing, or you’ll cut too much and ruin the entire thing! Just shave off 1 inch at a time, retie it, and stop when the length feels about right for you.
If you're taller than about 5’ 6”, you probably won't need to make any adjustments to this at all.
When was the last time you made a handy piece of gear like this for under $2? =^)
And, if you use it a few times and decide you like it, I recommend springing for the Black Diamond version. It's lighter, stronger, and racks more easily.