A slackline is a thin elastic cable hung between two anchor points. Unlike most non-elastic tightropes seen in circuses, a slackline isn't pulled completely taut and has a bit of slack as the name implies. The elasticity combined with just the right amount of tension lets a slackline stretch, sway, and bounce, allowing for a much more dynamic experience for the person walking the line. This elasticity causes the line to move along with the user and can be somewhat more forgiving than a static walking surface. The elasticity also allows the line to act as a trampoline at times, making huge jumps and flips possible.
At the same time, walking the slackline is great for building balance and working muscles that rarely get used in normal walking. In less time than you think, you will be able to stand or even walk on a inch wide cable like it's nothing. While building balance in general is great on it's own, the skills you learned on a slackline will lower the learning curve if you're interested in other circus skills that involve balance. If you've worked on your balance with a slackline, learning to walk on stilts or ride a unicycle will come much easier.
Besides building balance and all that, slacklines are a whole lot of fun. In this Instructable, I will outline some of the basics that I discovered while learning to slackline. Good luck...
Step 1: The Line
There are several different slacklines on the market. The slackline that I use was bought from a company called Webster-Maroon. I have a kit that they make called The Highway. It's a 50 mm wide line which is easier to use than narrower lines, although I would start on a 1 inch line if I was to do it all again. I'd rather take a little longer to learn on a narrow line in the beginning rather than relearn how to slackline on a narrow line later on. On the plus side, I really like the lizards printed all over the Webster-Maroon line.
Gibbon is another big slackline company out there that sells all sorts of kits.
Technically, you can make your slackline. Doing it yourself may or may not be cheaper than buying a prepackaged slackline kit and may not be as safe. If you're thinking DIY, here are two other Instructables on putting together your own line:
Step 2: Setting Up
Although setting up a slackline is pretty simple, different lines that are sold work differently. Some use ratchets to add tension to the lines. Others rely on you pulling the line nice and tight. For this reason, I am keeping this pretty general. What is discussed on this step applies to almost all slacklines, but refer to the instructions that go with your particular slackline when setting up.
Trees work best in my opinion as anchor points for slacklines. Any sort of post in the ground will work, but I trust the root systems of most trees to support the tension and weight involved with slacklines more than a pole cemented into the ground. Find two medium size trees, big enough to hold a decent amount of weight, but small enough to easily wrap a line around. Palms, oaks, and pines generally work pretty well. It will be easier to keep your balance on shorter distances, so I'd look for two trees about 10-15 feet apart to start out. Technically, the trees can be as far apart as the slackline will reach, although there will be much more wobble in the line at longer distances.
Get some sort of tree protection before hanging the line. If you bought a slacklining kit, the included tree protection will probably be a couple of long strips of felt. Towels, cardboard, or carpet also work. The main purpose of the tree protection is to keep the tension of the slackline from damaging the tree bark. If you're slacklining in a public park, the rangers/police will appreciate this...
Experiment with different heights as well. With different lengths and tensions, the distance above the ground will vary. When you're learning, try and get the center of the line to stay about one foot off the ground when in use.
Step 3: Getting Up
Once the slackline is setup, perhaps the hardest part is getting onto the line. Place your dominant foot onto the slackline with the line going diagonally across your foot from around the big toe to the outside of your heel. Putting pressure on the line initially will cause a horrible wobble in the line that is extremely intimidating at first. Do your best to ignore the wobble and just step up into a standing position on the line. With time, the wobble will eventually go away.
Step 4: Balance
You will be tempted to start walking right away, but I recommend taking it slow and learning how to stand before you walk. Once you're standing, keep your arms anywhere from completely vertical to slightly above horizontal. Let them flail everywhere as you try to stay up on the line. Attempt to stand on only one foot at first, using the second foot as a third extremity to help keep your balance. Learn to stand on one foot with both your dominant and non-dominant foot. Then finally, learn how to get your second foot on the line, either in front or behind your dominant foot and use only your hands for balance.
Holding onto two peoples shoulders on either side of the line will help initially. This is sort of like a security blanket as your getting your bearings of what it's like to stand on a narrow elastic strap suspended above the ground.
There are two techniques that I discovered that helped me a whole lot with keeping my balance at first. Don't know if these work for everyone, but they helped me. First is something I call magic fingers. For some reason, I found that if I constantly wiggled my fingers as I tried balancing, I was able to stay on the line much longer. This also worked for walking, that is until I reached a plateau in my learning process and I was able to balance and walk with or without wiggling my fingers.
Hand extensions were also helpful. You know how in the circus you see tight-rope walkers hold a large pole for balance? I tried that and it made slacklining much harder. What did help was holding two individual objects in each hand. I used juggling clubs while learning and it made a big difference. At times, I even found myself wiggling my fingers while holding the clubs.
Step 5: Walking
Once you have standing and balancing on the slackline figured out, you're ready to take a couple of steps. The first few will be really intimidating, but it's as simple as you would think it would be. Look ahead rather than looking down and put one foot in front of the other. Take it slow and don't rely on your momentum from the previous step to keep on moving. You should be able to easily stop and go back to standing still after every step.
The middle of the line is the most difficult place to walk due to the line having the most wobble and sway there. If you start at one end and make it past the middle, getting to the other end of the line isn't bad.
Step 6: Tricks
I juggled long before I slacklined. To me, combining the two skills was only natural. I started with balls and pretty much just went for it. Clubs came next, followed by knives. I have yet to try torches while on the line, but it will happen one day. The problem with juggling fire on a slackline are the flammable trees that are generally close by.
I find it easiest to juggle on the slackline while balancing on one foot, using the opposite foot for balance. Since both arms are occupied with the juggling, the second foot is providing most of the counterweight to keep balanced. Unlike learning to juggle on other balance skills like unicycle, I did not follow the whole process of relearning to juggle starting with one ball, moving to two, and then finally three. Standing still on the line is similar enough to standing on the ground with one foot where I was able to get a pretty good run of juggling pretty quickly.