Brian Greenstone Review
March 3rd, 2010Recently Brian Greenstone had a chance to review some of our gear. Here is the video.
ZipLineGear
your one stop shop for all zip line supplies
Zip Line Brake
February 22nd, 2010What is a Bungee brake and How Does it Work?
What:
The bungee brake consists of a high density plastic block that is assembled on the cable but is free to slide up and down. A bungee cord is then connected from the block to an anchor point (usually a tree or post) off to the side of the zip line, near the end.
How:
When the rider comes zipping in on the cable the pulley will make contact with the block and push it down the line. As the block is pushed the bungee cord is stretched and provides resistance, slowing the rider to a gentle stop near the end of the cable.
How do I know if I need a bungee brake?
A braking system is recommended if the slope of your zip line is greater than 6% of it’s length and you will be using a low friction ball bearing pulley.
What the kit contains:
-1 padded plastic block
-1 length of heavy duty bungee
-All the necessary hardware for assembling and anchoring the brake
Installation instructions:
1) Assemble the two plastic blocks onto the cable using three standard bolts and an eyebolt.
2) Attach the rubber bumper to the block, making sure the pad faces the top of the ride (so the pulley will hit the pad).
3) Using a quick link, attach the bungee cord to the eyebolt in the block.
4) Drill a pilot hole and screw your eye lag to a tree or post at least 10 feet off to the side of the zip line. Use your other quick link to connect the bungee cord to this eye lag.
NOTE: In addition to being at least 10′ off to the side of the zip line, your tree or post needs to be far enough from the end of the ride so that the bungee has room to slow down the pulley before it reaches the end. This distance is typically 175% of the cord’s original length, or 35 feet for a 20 foot cord.
Testing your brake:
Have a test rider sit on the zip line seat, and lower them down the zip line by walking or running alongside them holding a rope attached to the pulley. Increase the speed of each run until you are confident that the zip line will not stretch the bungee cord to more then 175% of it’s original length when the riders are allowed to zip freely.
FAQs:
Riders are getting tangled in the bungee cord: Move the anchor farther off to the side of the cable so it doesn’t hang in the way. This can change the amount of stretch on the cord. So be sure to test it again.
Brake does not stop riders before they reach the end: You need to shorten your cord or move the anchor farther back from the end.
Bungee stretches too much: The easiest solution is to decrease the slope or tension of your zip line to slow things down. You can also double the resistance by folding it back into two cords or purchasing a second length of bungee. A third solution is to affix something onto the cable itself to prevent the block from passing the 175% mark. Just be sure to do another speed test and make sure the stop is not too abrupt.
To view the complete kit manual, click here.
Tightening a heavy zip line cable…
August 21st, 2009
The anticlimactic maiden voyage of a 350′ Zip line.
It has been an exciting week for the team here at ZipLineGear.com! As the summer sales have tapered off a bit, we’ve had some time to work on the products you’ve been asking for. Following close on the heels of the Quicksilver and Viper zip line pulleys we’ll be rolling out some new pre-made bungee brake blocks, commercial riding kits, and a brand new line of Jumbo-size zip line kits for those of you who keep asking for the 250-1000 footers. Stay tuned!
So what’s new for this week? (drumroll please) …Cable tension kits.
One of the most difficult aspects of installing a big zip line is stretching the cable from one anchor to the other. You typically have a turnbuckle on one or both ends for minor adjustments, but that does nothing to help get your 100lb length of cable stretched to the other side. The problem is illustrated by our friends Bob and Joe, the Stick brothers…
Bob and Joe Stick have prepared their anchors and are trying to stretch their zip line cable from one pole to the other. Joe Stick soon realizes that the cable is far too heavy for him to pull it across.
Joe fumes in frustration, but his brother Bob Stick remembers an article he read on the ZipLineGear blog about using a come-along and a cable grab to tighten zip line cables.
Bob and Joe resume their work, after stopping by the ZipLineGear warehouse to get one of their new Cable Pulling kits. The $149.95 price tag seemed pretty expensive for only using it one time, but once they found out that ZipLineGear offers an 85% refund for installation tools returned in good working condition, they figured it was well worth the $22.50.
Joe, having attached the cable grab to the main line, watches in admiration as Bob cranks it tight with the come-along.
Bob terminates the cable on the second anchor without breaking a sweat while Joe puts the pulley on the cable.
The pull kit has been put away and Joe volunteers to take the first trip down the zip line…
…and it looks like Bob and Joe Stick will be picking up a bungee brake when they return the pull kit.
Application of U-Bolt Type Cable Clamps
July 23rd, 2008
Have you ever tried tying a knot with steel cable? If you haven’t already- don’t bother. Tying off a steel cable requires the use of cable clamps, otherwise known as wire rope clips. The cable is folded around something called a thimble, or a tree in some cases, and is clamped back to itself with three of these nifty clamps. It goes something like this:
Step 1: Turn back the specified amount of cable from the thimble. Apply the first clip one base width from the cut end of the wire rope (U-bolt over cut end – live end rests in clip saddle). Tighten nuts evenly to recommended torque.
Step 2: Apply the next clamp as near the loop as possible (when using a thimble). Twist on nuts firmly but do not tighten.
Step 3: Place the third clamp equally between the first two, take up the slack, and tighten all nuts evenly on all clamps to recommended torque.
Step 4: Perform a weight test on the cable and retighten all clamps to the specified torque- cable will stretch and shrink slightly when tension is applied.
The following table provides the recommended torque for each size cable clamp; if you don’t have a torque wrench, just keep them tight and check periodically for slippage.
|
Clip
Size Inches |
Minimum
No. of Clips |
Amount of
Rope to Turn Back in Inches |
Torque in
Ft. Lbs.* |
|
3/16″
|
3
|
5-1/2″
|
4.5
|
|
1/4″
|
3
|
7″
|
15
|
|
5/16″
|
3
|
7-3/4″
|
15
|
|
3/8″
|
3
|
9-1/2″
|
30
|
Cable clamps can also be used to create a loop around the entire anchor, instead of just a small loop for hardware connections. It’s pretty straight forward- I think the only concern is to make sure the cable loop doesn’t come out from the first clamp at too large of an angle (keep the first clamp a reasonable distance from the tree/pole).
