Suspension Equipment Recommendations [Level 3]
This article lists some of the specific models of hardware I find most useful, and offers a few pointers on what to consider when choosing equipment for suspension. There's generally no single right answer when it comes to choosing equipment, however; your habits and preferences may be different than mine. At the end of the day, whatever you like is the right thing, so long as it's safe.
The single decision with regard to suspension equipment which is likely to make the biggest difference in your life -- and be most costly to change -- is your choice of carabiner.
For the vast majority of suspension applications, there is no reason to consider anything except an aluminum climbing carabiner. However, that still leaves hundreds of models to choose from. The factors you want to consider are:
- Width at the wide end; the wider it is, the more rope you can pass through it without jamming.
- Flatness at the wide end; extra width doesn't help much if it's at an angle that shoves all the rope down into the center, or up against the spine.
- Cross-sectional shape; a circular cross-section reduces friction and puts less wear on your rope; most climbing biners are only smoothly rounded over a small section of the inside.
- Locking mechanism; locking carabiners are not strictly necessary in most bondage situations, from a safety perspective, but they offer extra peace of mind and flexibility. Personally, I find screw gates abominably inconvenient in suspension work. Auto-lock carabiners are my preference, but there are many different mechanisms available; you ideally want to find one that you can easily open with one hand.
You could spend weeks researching different carabiners trying to find the perfect combination of traits, but let me save you the trouble: there is exactly one carabiner I have ever seen which is ideally designed for rope suspension, and it is the Black Diamond Rocklock TwistLock. The only reasons I've ever heard of for not liking this model are trouble operating it one-handed for people with very small hands, or that it doesn't come in black. The Rock Exotica Pirate Auto-Lock Black is black and has nearly as good a shape, but is much harder to open one-handed due to the 3-stage action, a great safety feature for climbing but a giant pain for bondage.
I stopped using rings years ago. They are heavy, bulky, and use up a ton of vertical space when working under a low hardpoint.
If you want to use a ring, the three things you have to decide on are diameter, thickness, and material. A larger diameter ring is easier to reach through and allows you to stack more support lines through it without jamming, but takes up more vertical space. A thicker ring is heavier, and there is some evidence it may increase friction. There is no actual evidence I've seen that an extra-thick ring decreases the chance of rope breaks, as claimed by some proponents. Wooden rings -- a recent trend -- produce substantially more friction than metal rings, and thus make lifting more difficult and increase the chance of rope breaks if using weak support lines.
While it is possible to simply chain one carabiner off another, I find that putting more than 1 support line + 1 additional biner on any given biner tends to be a recipe for jams. When working without a ring, this means that you extend your rig downward by one carabiner per support line, thus doing my least favorite thing -- squandering vertical space.
The solution to this is the rigging plate -- a device which holds several carabiners spaced out horizontally at the same height. My preferred model is the Petzl PAW Small; it has a shape which promotes stability, good spacing, and comes in black. I find a 3-hole plate to be the right size for the majority of single-person suspensions. Occasionally I will clip additional biners in, extending down onto a second level; but now I can get up to 6 support lines in 2 carabiners of vertical space, a 3x improvement over without the rigging plate.
I've noticed that when getting their first rigging plate, many people tend to assume bigger is better -- it can't hurt to have extra spots for more biners, right? Wrong. The problem is that the wider the rigging plate is, the more it tips back and forth as you're using it. Also, even in situations where you need 5 or 6 lines tied off, having that many biners all right next to each other at the same level can become too crowded. I can't recommend strongly enough going for a small rigging plate. The only situation I've ever found larger ones useful in was doing highly complex multiple-bottom transition stunts.
I use the Rock Exotica Shackle Swivel, which I keep permanently installed on my rigging plate; this type of setup saves the height of a carabiner between your swivel and your plate (or ring). However, the newer Petzl Swivel Open is probably actually a better design, and I now would generally recommend that instead (although be aware it has a smaller opening). Either way, be sure to read the manual and understand the limitations and risks of these special-purpose products.
For use with a carabiner, almost any normal climbing swivel is fine; however I find Petzl and Rock Exotica to have lower friction, and thus enable longer spinning, than the Black Diamond models.
In addition to safety scissors (never as a substitute), I like to carry a rigging knife with a marlinspike when suspending. While the knife portion is only useful for cutting near the ring, which the safety scissors could do just as well, the marlinspike can help unjam a knot without cutting. In truth, I'm not sure I've ever used it in the air -- there are often other ways to undo jams, and cutting is always faster -- but I like to have an option available other than cutting for a jammed knot. The knife I have is the Fury Tactical Spike Folding Tool, which is currently unavailable; but this Myerchin appears identical in design and has at least one good review. What makes a good marlinspike is that it should lock open, and taper for its entire length; a surprising number of supposed rigging knives fail on one or both these counts.
It turns out that hardware made for swingsets is great for building suspension frames out of. My frame at home is built from these inexpensive corners; just add lumber and you've got a frame of whatever dimensions you want for around $200, that's as or more stable than any custom-designed-for-bondage frame I've ever encountered. Some trigonometry required.
I was asked about how to calculate the footprint of one of the A-frames I link to above; here are the dimensions for my setup:
- Floor to Bottom of Beam: 90"
- Footprint of Frame, Parallel to Beam: Length of beam + 48"
- Footprint of Frame, Perpendicular to Beam: 97"
- Length of Legs: 103"
All those numbers should scale linearly with each other, assuming you get a bracket identical to mine. However I don't think they're all identical (or they changed at some point) -- a different bracket I had of the same model, I measured 10" of clearance for every 12" of leg length, which would have been 4" shorter than listed above. It might also partly depend on the size of the setup, since the elements are not perfectly rigid. Speaking of sizing, here's what the manufacturer says about max specs:
4x4 legs should not exceed 8'. If you do choose to exceed this length we do recommend setting each foot in concrete. 4x6 Swing Beam should not exceed 12' and not have any more than 3 swings on the beam. Anything past this length is not recommended. The maximum load on the swing set should not exceed 500lbs.