May 1st, 2008 Posted in Do-It-Yourself Articles | No Comments »
I realize that this series might actually cause a few people to make their own slacklines rather than buy pre-made kits but I get really discouraged at the number of really poorly made or even dangerous homemade slacklines out there. A quick glance at YouTube instructional videos shows a lot of various methods of rigging a line (which is good) but a lot of them have critical flaws that the beginner may not understand the trade offs involved in the system and could get hurt (not good) or otherwise have an unpleasant experience with the system such as not being able to get it tight enough. Often times a new slacker will try one system, not like it and assume all methods that have anything to do with them is bad. Thankfully it’s usually a small issue that can be corrected with small tweaks that make life easier for the slacker.
I also realize that some people will disagree with my assessment of the trade offs presented here. There are many schools of thought regarding rigging and sometimes these schools directly conflict with each other. For instance, some people believe there should be no metal left in a slackline while under use, others feel that nylon-on-nylon is evil and should be avoided so hardware is completely acceptable. Unfortunately lots of people focus solely on how the line is tightened so much they neglect the rest of the overall system so it’s flexibility and overall performance is hindered greatly or at least not up to it’s potential. It is also important to realize when working with other people in the slackline community that they will often swear by whatever method was taught to them rather than evaluating other options objectively. Basically the below are good guides that should apply to almost every type of slackline system. If you have special needs or paranoid obsessions with rigging then you may need to adjust appropriately or seek clinical evaluation.
Where appropriate I have linked to some do-it-yourself items that we carry but you could easily use the same concept to make your own tools.
Rule 1: Your line should be flat. If it isn’t flat, figure out why it isn’t and correct it. Even for a 100 percent homemade line there is simply no excuse to have a twist. Usually the culprit is knots but not always.
There are wonderful techniques at removing knots. Lately the Internet forums are abuzz with “line lockers” which are just 3/8″ chain links used to tie the line off where it is flat. They have their trade offs though as if they are not perfectly smooth they can tear the line. They are also usually a pain to secure as places like Ace hardware and Home Depot generally really dislike cutting them as they are a lot of work to cut out the other chain links. There are other easier to use methods. I personally prefer Harness Buckles and Cam Buckles for this purpose as they are easier to adjust and strength rated for that use. Also filing down chain links isn’t always easy depending on the hardness of the metal. One of the perks to removing knots is that it will increase the strength of the slackline as knots usually reduce the system strength by around 50%.
If your line is twisted because of your method of securing the fixed end of the mainline to the tree, consider using a different method. A lot of people just tie a knot at the end of their line and make a giant slip knot around the tree. While it works it has issues of twisting the line as well as some wear issues as mentioned in rule 5. Instead, consider using a separate piece of webbing for each tree sling. If tied in a “rabbit runner” fashion it will let the line lie perfectly flat, even if you did tie knots in the system. The Zip Sling is an excellent example of this technique that can be replicated at home, albeit in a non-adjustable fashion. If however you want to go the next step and eliminate some additional hardware while avoiding nylon-on-nylon wear issues the Primo Sling uses a abrasion pad to provide a unique approach. Either of these methods also lets you replace just a small piece of webbing when your slings get worn through instead of taking a large chunk out of your mainline.
Rule 2: Remove weight or move weight close to your anchors. This isn’t a problem for everyone and it is more noticeable on surf lines than others. If you have metal or other additional weight from knots or additional slings on the line while slacking moving it closer to the anchors or removing it all together will make the line feel better due to less interference. If you are using pulleys or a ratchet, make sure they are secured as close to the tree as possible to reduce their swing weight. If you are using carabiners make sure the system is adjusted so they are as close together as possible which is as tight as possible for your pre-adjusted length. This will take a lot of practice to get down but you will have far less interference if they are close to the anchors and together than having one of them further down the line. Do however pay attention to how hardware is being loaded. We’ve seen commercial products out there that recommend using their hardware in a way that places a dangerous sideways load against your trees.
Rule 3: Softpoint/Hardpoint Responsibly. Consider using a system to remove your tensioning system if you can still feel its weight even after you moved it closer to the anchors and it bothers you. Using something like a Soft Point Sling attached to the mainline will provide a point to tension the line with and let you tie off the actual main line using another method, thus letting you softpoint or hardpoint the line leaving no tensioning system behind while slacking. Soft point slings are a possibility or take a look at the tensioning widget or tensioning add-on pack which can be used to tighten the line and hold it in place while you remove your tensioning system. One of the perks of this method allows you to use tensioning systems which would otherwise be too bulky or heavy to leave on the line as they won’t be there during your slack session. Do not softpoint/hardpoint if it will introduce excessive nylon-on-nylon wear (See Rule 5).
Rule 4: Do Not Tri-Load or Cross Load Carabiners! This is a major safety consideration. Lots of the instructions floating around show tree slings coming off at large angles (greater than 60 degrees) which can cause dangerous levering against the carabiner’s gate. Ideally this angle should not exceed 45 degrees. This angle is more important than your swing weight considerations mentioned in rule #2 and if not followed it can possibly break the carabiner. People have been hurt for exactly this reason.
Rule 5: Avoid Nylon-On-Nylon Friction. Any point that moves, wiggles or otherwise will have friction against something else will be a wear point on your slackline. It is very important to avoid nylon items from rubbing against other nylon points as this can wear through the slackline with surprising speed. At early stages it actually melts and fuses the webbing together as shown here. We have melted through a line completely in only an afternoon of surfing it back and forth.
Rule 6: Simplicity in Rigging Counts. If you can’t glance at your system and tell if it is rigged correctly your eagerness to experiment with rigging is probably exceeding your knowledge to do so safely. Slacklines do not have to be complicated to work. Even things like multipliers on pulley systems do not have to obscure what is going on. If you cannot easily identify your mechanical advantage ratios or things just look too confusing I strongly suggest you read up more on how to rig efficient anchors that allow for “at-a-glance” checking.
Rule 7: Choose the right tensioning system for your application. Notice I’m just now getting to tensioning systems. That’s because when they work, it really doesn’t matter which method you choose. Do however understand the limitations of the methods you choose so you have realistic expectations. Don’t expect a primitive to be able to tighten a 100 foot slackline and don’t expect a ratchet or a large sheave pulley system to be compact enough for a 6 day backpacking trip. More on this later in the series.
Balance In Life,
Joe Kuster
