This comes up often in the forums, so I figured I’d outline how I do it. The quad is described in Climbing Anchors by Jonh Long and Bob Gaines. I’ve taken to using this every time I have two bolts to work with.
Here’s what you need to remember:
- If using on top rope, use two locking carabiners at the power point
- Just so that it’s out of the way, make sure the fisherman knot is in one of the arms, and not in the power point
- I use a 6 meter, 6mm cordelette, but JL says that 5.5 high-tensile cord is enough
- Most importantly: Clip into only 3 strands and never all 4. This is so that if one side blows, you won’t go down as well (see end of video)
I’ve whipped up a very quick and dirty video to demonstrate.
(Edit: Here’s what it actually looks like at the bolts)