Slackline Frequently
Asked Questions
Here's where we answer some of the questions regarding
the sport of Slacklining we've received.
For FAQs on our gear, our
company or us see our Company FAQs
"What is a
slackline?" / "What is slacklining" / "Why would you do it?" / "Where did it come
from?"
The premise of slacklining is that it is a fun balancing
activity. It's easy enough to learn, loads of fun and has lots
of nice physical benefits. It is a lot like tight rope walking
but is almost always done close to the ground and the line is
bouncy and to the observer looks like a rope with slack in it.
In reality it's springy webbing set tightly between two points
and it stretches once your on it, but the concept is the same,
but it feels a lot different than rope.
A typical
slackline setup is consists of a line of webbing (usually
tubular 1" nylon) pulled
tight between two upright and sturdy objects, preferably
trees but telephone poles and vehicles are frequently used
as well. There are lots of variations on how to get the line
tight and some creative minds have found interesting ways of
setting up slacklines without trees as well. The basic idea
is walking it like a tight rope. It behaves differently
since the nylon webbing stretches and bounces under the
slacker's weight and has a very "live" feel.
Besides being
incredibly fun, walking on webbing was used for a new type
of concentration and balance exercise. Some people use it
for meditation or to bring their balance and concentration
to a new level for performance in sports. Others just find
it relaxing yet exhilarating as a sport it itself. Most
importantly though, it was for fun. The sport has evolved
a lot since the beginning of just a handful of slackers
being in the loop to lines popping up around campfires and
climbing gyms across the world. Our goal is to push it one
step even further by introducing non-climbers to the sport
as well.
Slacklining has its origins
the rock climbing arena. For days off or evenings after a
hard days climb, climbers in Yosemite
Camp 4 were walking chains between posts just for fun as
a balancing trick. Eventually someone came up with the idea
of walking nylon webbing usually associated with climbing. It provided a more "live" feel
and instead of being a static balancing act, it would bounce
and recoil against your moves making for a really fun
dynamic ride. That idea spawned into a sport of it's own and
there are now slackers all over the world.
The sport is strongly linked to
rock climbing but it is starting to grow to include non-climbers
as well.
For the most comprehensive
history of slacklining that we've seen, see
Scott Balcom's post on RockClimbing.com
"How hard is it to slackline?"
To get started, not very
hard at all. More accurately, just about everyone who wants to,
barring some physical disability, can get the basics down. With
good instructions and good spotters average is standing
confidently and taking a step or two in five to fifteen minutes.
If they keep at it within an afternoon most people can walk at least most of a 25
foot line. Your basic balancing skills have a lot to do with how
quickly you can pick up the sport, I've witness pure naturals
able to take steps on the line on their first try more than
once but also those that took all day to stand up. However, in
the end they all got it down. The real thrill is that you can constantly bring your
skills further as there is almost no end to the
tricks you can do on a slackline. Heck, we even play Frisbee
between two lines.
"What are some of the ways
to rig a slackline?"
Rigging a slackline basically includes rigging the two
anchor points to study places and somehow putting tension on the
line. You will almost always want the slackline tighter than
what you'll be able to pull by your own hands so the idea is to
resort to some type of mechanical advantage.
On the basic physics front, we
have four main ways of amplifying force (mechanical advantage):
pulleys, levers, gears and hydraulics. Since hydraulics are very
heavy by nature and more suitable for extreme pressure but small
movement, they aren't used on slacklines. A gear box is usually
ruled out since it is so heavy and relatively expensive but
people have done it before with things like boat winches. Pulley systems are the
most common and can be made using climbing gear and
levers are used in the form of a
ratcheting device. Currently all of our main kits we sell use
leverage but we'll make you a pulley style system if you certain
you want one.
We're working on a page dedicated to many of the
different rigging techniques and real world comparisons. The
ones we have tested and done photos on so far are on our Rigging Types
page.
For a reference guide:
Primitive setups (pulley style except pulling webbing over
biners) ** Please check out why
pulley style systems aren't for everyone
How
mechanical advantage works, pulleys, levers, gears and
hydraulics
**Autolocking
3:1 slackline that uses webbing and carabiners
(scroll down)
**Ellington
3:1 system that uses thinner webbing for the tensioning
system to reduce friction
Pulley style systems that use
more than just webbing and carabiners
**3:1 slackline that uses webbing,
carabiners
and rope
**9:1 slackline that uses webbing, carabiners and rope and a
release hitch
Using actual pulleys to tighten a slackline (scroll down)
and of course:
A list of all of the major commercial slackline makers out there
If you want more information on
advanced pulley systems, piggy backing and large go get a
roped rescue book - they have a wonderful selection of good
books out there that can describe the physics and proper
selection of techniques for each scenario.
"What is the cheapest and easiest way? / "What
is the bare minimum I need to make my own slackline?" / "Where
can I buy slacklines at?"
Those terms are more or less
mutually exclusive (contradict each other). See a decent
explanation of why along with basic minimum ingredients for different
setups on Rockclimbing.com's
Slackline FAQs It also includes a series of links to the
major companies.
"What are these primitive slacklines I keep
hearing about and how can I make my own?"
A primitive slackline is a slackline using nothing but
webbing and carabiners for the main line and tensioning system.
Refer to What are some of the ways of
rigging a slackline for lots of ways of making them. The term primitive isn't something we made up, it's just a
common name for the method and it doesn't imply that it's less
powerful or anything, just that it uses very basic components to
do the job.
Variations that turn it into a more powerful pulley system include items such as using static rope, ascenders,
prussic knots and other climbing related tricks of the trade but
for the most part primitive means just carabiners and webbing.
The typical system uses anywhere from 2 to 6 carabiners and uses
some of the webbing in the tightening system. One end is tied
off to the tree the other is ran through the tightening system
which requires pulling on the webbing to create tension.
While this is the most commonly
used technique, most climbers agree that it can take a good deal
of pulling to set one up, especially with new stretchy webbing.
Most people cannot set up anything except short lines without
help pulling using this method. The setup is based on looping the webbing back and forth through
carabiners which provide a mechanical advantage. The more
carabiners used in the looping back and forth (which act as a pulley), the more mechanical
advantage. For each extra pass through the carabiners it almost
doubles the amount of pull that is created. For instance if you
can pull 100lbs and you have three carabiners in a Z style 3:1
mechanical advantage, it would theoretically equal 300lbs. I say
theoretical because that would be in a frictionless setup, in
reality it is closer to 125 lbs of pull due to the
friction drag of the webbing, that's a lot of inefficency. The only real
guarantee is that for every 1 inch you pull, it only tightens
1/3 of an inch - that usually equates to an easier to pull setup
but friction becomes a big problem to overcome with the more
turns in a system.
Webbing creates a lot of friction
when it is ran over carabiners and by adding more carabiners it
increases the conglomeration of webbing which can be overlapping
and increase friction. Using pulleys with climbing rope
drastically reduce the friction involved in the system. The main reason everyone doesn't use pulleys is because they are fairly
expensive, not many people have them, they require other gear you may not have and they can be a
bit cumbersome if your not experienced with setting them up.
If your interested, we can sell you the
gear you
need to make one. Even though we don't use them ourselves on a
regular basis, we
still understand that there are people out there who want to
make their own, and still get a good price on it. The list
pretty much goes like, 40-80 feet of webbing and 3 to 8 oval
carabiners. We sell the tree slings pre-made so you can have nice
sewn slings with adjustment gear if you'd like as well.
Before you get too hyped up and
buy all of the stuff, read on to see
why
we don't recommend pulleys for everyone.
"How much of a
difference does friction really make?"
Short answer: a whole bunch. Long
answer: read
Technical Analysis of Friction in Hauling Systems
"Ok that primitive setup doesn't sound so
bad, why don't you guys recommend it?"
We sell them because they can work, but they don't work well for
the majority of people. For some people, especially climbers and
river guides we do strongly encourage at least knowing
how to making a primitive tightening system (Z
system/3:1/whatever you call it). It's a useful tool for lots of
things but when it comes down to ease of
use and cost effectiveness other options can be very worthwhile
to look into while your at it. Hey, more techniques and
knowledge just mean a free new tool for your
mental toolbox so why not learn all of the methods and pick the
right one for your needs.
If you are a climber who wants to learn all about
rigging techniques and think you might need to set a haul line
for an injured climber or do multipitch with lots of gear, then you'll want to spend the time to at least try the pulley style types of mechanical advantage.
This information and experience can be critical to self rescue
and you owe that to your climbing partner and yourself. You'll also be more likely to plunk down the cash for a nice pulley
system such as the CMI Double uplift pulley and matching pulley (big bucks
$$$ but sweet gear) if your wanting to use the same techniques
for slacklines. There is a BIG IF in the equation
though - If your just wanting to slackline with as little effort or
cash as possible then leverage (ratchet) based systems are
HIGHLY effective as well and require a lot less effort and skill
from the slacker to use. If you already know the other rigging
methods then our kits still make sense since you won't have to
dedicate your climbing gear to slacking and it's still less
labor intensive to set up and almost always still just as cheap
or cheaper than making your own. The downside is you won't be
working on rigging skills.
On a side note for the lazy (that
includes us), a typical 2" ratchet unit makes a 13:1 pull
advantage that varies down to 10:1 depending on how full the
spool is and a typical primitive is a 3:1 but friction reduces
it to a 1.25:1. I know I'd rather only have
to exert 35 to 45 lbs of pressure on a comfy handle on a lever than have a friend
and I pull 225 lbs of tension on a piece of
webbing to get that 350 lbs of tension on a medium sized line
moderately tight.
***Important note you need to
know before making your own or purchasing incomplete kits from
other places*** all the carabiner companies
we've talked to specifically recommended keeping slackline
biners separate from your live saving climbing equipment, so to
be safe your looking at $15 to $30 just in dedicated carabiners.
The webbing also gets extremely stressed out and should never be
used for life saving purposes like climbing anchors afterwards.
Repeat after me "I _your name_ promise not to use my
slackline gear for climbing purposes as I will end up killing
someone due to the weakened and stressed condition of my gear."
Cost wise once you add up the
dedicated webbing and biners plus the webbing that isn't actually used to walk on and at 30
to 40 cents a foot for all of your webbing cost it adds up. If you get
a great sale or already have tons of extra equipment you can
trim that number down a lot but it's a catch 22, if you have the
climbing gear to make a good slackline system you shouldn't use
it for climbing anymore as it stresses the heck out of it.
That's part of what makes pre-made systems so nice, it comes
with everything you need and it won't be compromising your
climbing gear and it will almost always cost less but give you
more features.
"Where can I get some good trick info at?"
Our site under Slackline Tricks
Section for one and if you want even more good tips, tricks
and a good slack lining community check out
http://www.rockclimbing.com/ RC is a really great climbing
board and you should consider joining it for all of the other
information available on it; I've been known to lurk there quite
a bit. Basic getting started tips and tricks are also in the
manuals included our kits or at the links above.
"I want to make
a custom setup, what size of webbing do you recommend?" / "Why
is 1" a standard size for slacklines?"
Sorry to tell you, girlfriends lie, size does matter.
Traditionally slacklines use 1" webbing for the most part
because it is usually the easiest to find because it is used in
so many other things; so climbers usually already had extra 1"
tubular laying around. It seems to be a good flex but still not
hurt your feet.
9/16 or 3/4 work well too, but are
little bit harder on your feet - but otherwise behave about the
same. If your walking they are just fine and dandy, if your
jumping or doing tricks it might be considered a bit harsh
without shoes. 1/2" is ok to surf, bearable barefoot but leaves
big welts from whipping you if you fall. Thinner than 1/2" and
I'm not sure it'd be
fun at all. If you wear shoes while on the slackline it is a lot less
of an issue. From what I can tell most hard core super tape
fanatics wear shoes when on it.
Also worth noting is that many 1/2" webs may not be strong
enough to work for a slackline.
2" is "ok" I've tried it but it seems more like
walking rope than slacklining. It swayed but didn't really
stretch for the expected bounce. Might as well use hemp rope and
tightrope or "slackrope" since it has a much less dynamic
property to it. If you've got the 2" webbing, give it a try it
isn't "bad" or anything just different.
As for the thickness/ type of the webbing, thicker usually means
heavier duty, but not always - check the specs of the webbing as
some thick weaves are light duty. Most of the 1" webbing out
there is strong enough to slack with on a normal setup - but I'd
recommend going with proven strengths.
Polypro: very
light, cheap, not too terribly strong, water resistant, usually
feels slicker and looks a bit shiny. I've used these on quick
and dirty 30' lines and they feel pretty good - oddly I never
got them to show any wear at all, but it was slick so I didn't
spend as much time on it as the others. This stuff comes in all
types of thicknesses and strengths so don't buy it unless you
know it'll be strong enough. We use a strong variety of it for
ultra light custom lines. I've never
seen the variety we use break, but supposedly it's a bit weaker
than the flat nylon we used in the past.
Flat nylon: moderately
light, a little cheaper than tubular but about half the strength
of it. If its a thin weave you'll find it curves under your
feet, so instead of contacting 1" of webbing, it makes a a kind
of upside down U so it is kind of rounded. If it's a thicker
flat weave it will only do it a little. Flat nylon is usually
fairly thin, but can still be strong, again there are varying
strengths out there ranging from very low tensile strength to
an amazing 6,000 lbs tensile strength. We used to use flat
nylon on our intro kit's main line.
Tubular nylon:
preferred for a good slackline. It is thicker and stronger,
costs a bit more but won't wear out as quickly and gives a much
more flat feel since it doesn't buckle under much at all. All of
the webbing in our kits are 1" tubular nylon (4,000
lb test) or 2" tubular nylon (10,000lb test).
Your
mileage may very, but I've set up good lines with all three.
Keep in mind that narrow webbing stretches a LOT; it's very
dynamic so plan on having high anchor points or really cranking
it down. If you'd like, we
can make you a line or even an extra for occasional use in
whatever size you'd like. We do Poly Pro 3/4" for a cheap way to
try your hand at thin and tubular nylon 5/8" for those a bit
more serious at super tape. We'll even double the line and sew
the entire length for a bit less dynamic line if you want it.
Check it out in our
Custom Kits and Accessories
"How do I know when
it's time to replace my webbing?"
Eventually the webbing will need
replaced since it is a wear item. Unfortunately, it's a pretty
hard question to answer since there are so many variables and
ways to invisibly damage the webbing. Here's the conundrum though, if
you replacing webbing too soon, it costs you more money and your
being wasteful, something which our kits are specifically design
to not do. However, if you go too long on a sketchy line, it
will break and you will fall. Now most people are used to
falling on slacklines, but by the time you wear a line out,
you'll probably be very good at it and doing some pretty wild
tricks and jumps and if it does break, it'll be during something
like that and you could seriously mess yourself up. From my
point of view, I don't want to be looked at as trying to force
feed people replacement webbing at their cost nor do I want to
let anyone get hurt.
In order
to best answer this question we've put into place a 5 year
maximum expected life time on our webbing. If it is older than 5
years even with the lightest of use, it needs to be retired as
nylon does degrade over time. For wear related damage take a
look at our Slackline Webbing Wear
& Recommendations page.
If
you stressed the line out enough to distort or break a
carabiner, I'm not sure what the heck you think you were doing
but don't do that and consider your line suspect, so inspect it
very carefully.
Remember, we don't sell highlines - so at no
point in time should our webbing be the only thing keeping you
alive.
"I don't have trees, how can I
set up a line?"
This has been answered a lot of times. You have to get
creative. See the
Slacklining Without Trees page.
"How much tension does a
slackline need?"
It varies a lot depending on how loose you like it. As just
an estimate we'll say around 400 lbs of tension for a medium
tight line that is around 30 to 40 feet, but they get much looser
and much tighter than that and the longer it is, the more
tension is required to keep from bottoming out. That is just to hold the line tight
but when
someone is on the line physics amplify that number by a good
margin, which is why it is necessary to have very solid anchors. Eric Matthes has a really interesting
Technical Analysis of a Slacklines on his site. He
calculated the amount of tension put on a slackline by the
amount of sag. I highly suggest technical info geeks check it
out. We simplified his equation into a
Slackline Force Calculator.
"How can I get my university/college to
allow us to set up slacklines?"
We
did get SMSU safety and grounds to give their official
blessing on us setting up slacklines. Here's a
Quick Facts
About Slacklining word document that worked for us. People
don't trust what they don't understand or seems too new. Give
them some information to help open their mind up first. Make
sure to emphasis that it is both safe and not harmful to the
trees. Another tip is bring in a tree sling with a tree friendly
so they can see what it's about. Also, do not try to do it all
over email or the phone, you'll probably receive a much better
acceptance in person. Whatever you do, don't act like a
rebellious punk when someone asks you to take it down. If you
act like one, they will treat you like one. We often work as a
liazon between Universities, Cities and Slackers as a
semi-official representation of the sport to help explain why it
isn't an unacceptable risk to life & limb nor will it damage
their property if properly set up.
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