Slackline equipment is constantly developing to ever greater technological finesse. Gear is now lighter, stronger and shinier than ever before. However, there’s one piece of equipment that hasn’t changed much:
The industrial round sling.
And technically, that’s not a bad thing. Industrial round slings are inexpensive, versatile and very reliable. Unfortunately, there are also terribly heavy and they aren’t very wide, which limits their overall tree-friendliness. In the times of ever decreasing tension, industrial round slings become less and less suited for your everyday 20-minute bicycle commute to your slackline park.
There are some alternatives to round slings, most of them are well known and all have their own downsides and it’s always a compromise in one or the other way.
The adjustable slings from Slackline-Tools are a great light-weight low-tension option, but they are relatively expensive and fairly flimsy (~30kN).
Slings out of tubular nylon are really cheap, a little stronger, but also thinner and thereby less tree-friendly and not adjustable.
A more disputable option is the use of dyneema rope in combination with carbon-fibre reinforced tree protection. This is a very expensive and potentially very dangerous method. As of now, we don’t know whether the carbon fibre actually helps in distributing the pressure on the tree.
Another, almost unknown, option is using boa-slings. They are made from hollow braid polypropylene rope (cheap as f***) and plastic inserts that give the rope a wider surface area. It’s a system that is used by arborists to secure tree crowns. Here you can find more info on the tree cabling system. In slacklining, this could be used as a normal eye-to-eye sling, which is fairly inexpensive to make or as a whoopie sling, which would give you some adjustability. Depending on the rope you use, you can get different strengths for your slings (from 40kN to 160kN in basket).
The slings are pretty light, decently strong, adjustable and reasonably priced. Biggest downside is the fact that they are rather stiff and cannot be stuffed in a backpack, only rolled up.
So, if you’re a slackliner tired of carrying around heavy slings or a slackline company in need of some new product, have a go at the boa-sling!!