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Frequently Asked Questions

Questions about the Slackers Ninjaline

We'd like to set up a separate line near the base of our trees/posts for feet to rest on when using the Ninjaline.  What do you recommend?

One of our Slacklines would be best for this type of set up. The Slacklines are made of the same material and feature the same ratchet system as the Ninjalines for ease of installation and adjustment.  We also offer our ropes course, which is the only kit that includes both a top and bottom line. Click Here for more info on one of our more popular Slackline sets!

What length Ninjaline/Slackline should I buy and how is this determined?

You'll need to measure the circumference of both trees in your set up and add that to the distance between the two trees.  You always want to purchase more line than necessary so that you can use the extra slack to tighten and secure your line. Too much line is not an issue as we provide special ratchet covers that fasten securely around the ratchet and excess line. Here is a helpful took to help you calculate the course:

Circumference of Tree #1 + Circumference of Tree #2 + Distance between Tree #1 and Tree #2

What do I do if I purchased a kit and the line is not long enough for my course?

Not enough line can cause you to run into issues that can sometimes be solved with the help of one of our customer service representatives, but not always. It is best to know the total dimensions of your trees and the course length before making a purchase. One solution for a Ninjaline that is not long enough is to purchase a 15' Ninjaline Extension.

What if my trees are too big for the 6' ratchet strap I got with my Ninjaline?

We offer a 10' ratchet strap (SLA.818) sold separately on our website. If the longer ratchet straps are not available, or you are in need of a quick fix, use the diagram below that shows how you are able to use excess line from the mainline to help reach all the way around the large tree:

Can the Ninjaline be set up indoors in a garage or basement? 

Yes, however, we recommend consulting with an engineer or contractor to determine the "side load" strength of your two points of attachment. Some Ninja families have even found ways to install the hanging obstacles directly into a ceiling so no line is needed! We love to see our customers become creative, but whatever your idea is for an indoor Ninjaline, remember to consult with an expert on the safest way to install.

What is the difference between the Slackline and Ninjaline?

Though the Slackline and Ninjaline are both made of the same material and feature the same ratchet system to attach to trees or posts, that's where the similarities end.  The Slackline is designed to be mounted just a few feet above the ground for the purpose of balancing on as one walks accross.  The Ninjaline is meant to be mounted higher up off the ground and features integrated sewn in pockets designed to fit the delta clips which are used to attach the Ninja obstacles.  If you are looking to create a Ninja obstacle course, we recommend purchasing the Ninjaline because of the integrated obstacle pockets. With our new Ninja Grip Clips that create pockets, you can turn your slackline into a Ninjaline!

I received a damaged/brokenproductor I am missing parts for my product.  What actions can I take to resolve this? 

Please send an email with pictures of the damaged/broken items or a list of missing parts to  Please be sure to include a photo of the damaged part or a receipt for the missing as well as your shipping address for us to send the replacement.  With this information on hand, we should be able to resolve your issue quickly and efficiently.

Can I hang a swing from my Ninjaline?

If you want to attach an obstacle that allows you to swing, or attach an actual swing, we strongly recommend that you reinforce your Ninjaline with our Ninjaline Protective Sleeves. These sleeves reduce the friction of the 2 pieces of material rubbing against each other during use.

A swinging (perpendicular) motion on the Ninjaline will combine with the lateral tension of the ratchet and create an unsafe Ninjaline. Over time, the material can fray and may break unless you protect your friction points.

Questions about my Slackers Zipline

What length Zipline should I buy and how is this determined?

You'll need to measure the circumference of both trees in your set up and add that to the distance between the two trees. It is better to overestimate the length of cable you will need as there are no extensions for the zipline as there are fort he Ninjaline.  In the case of excess cable, you can cut off the extra that you're left with or wrap it safely around the tree should you need more cable to set it up in the future in a larger space.

Zipline turnbuckle: How is it installed and what end of the Zipline does it attach to?

 The turnbuckle is a more recent addition to select Ziplines.  It has been thoroughly tested to work at both ends of the line.  To install the turnbuckle, simply attach one eye bolt to one of the looped ends of the Zipline cable (either the pre-looped end or the loop that was made from the u-bolts.  Then, attach the other eye bolt end of the turnbuckle to the 2 loops from the sling cable that wraps around the opposite tree.  Twist the turnbuckle to fine-tune the overall tightness of the Zipline course as well as adjust for stretching of the cable that will occur over time.

What if I am having trouble tightening the cable enough with the turnbuckle?

In order to tighten the zipline with ease and success, you must follow this order of installation. Set up the turnbuckle + sling cable end first, attach the U-Clamps to the loop on the opposite tree (make that loop as tight as you can!), and then use the turnbuckle to tighten even more. 

The second and easiest option, which happens to be our favorite, is the Zip Quick Ratchet Installation. This makes tightening the cable easier than ever and simplifies the installation so much that you could even do it alone!

Questions about other Slackers Items

What size tree will the Build-A-Branch work with? 
The ratchet strap for the top bracket is 7’ long which will fit a tree with a diameter between 12-24” (37.6” circumference – 75.3” circumference).

The bottom ratchet strap you will receive is 20 feet long! Keep in mind that in order to set the BAB up safely and successfully, the bottom strap must be wrapped around the tree TWO times with just a bit of strap left over to be able to tighten the ratchet securely. 

For more Information on the Build-A-Branch - check out our Tips, Tricks, and How to Blog


General Questions

What does the product warranty entail?

Our products come with a 1 year workmanship warranty.  Warranty does not cover normal wear and tear or element damage (i.e. leaving product set up outside all the time).  If you receive a defective product, please send an email with pictures and your proof of purchase to and we will look into it further.