Zip Line BrakePosted: 22/02/10 Author: Admin User
What is a zip line Boa Bungee Brake and how does it work?
The zip line bungee brake consists of a high density plastic block that is assembled on the zip line 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 zip line Boa Bungee Brake kit contains:
- 1 padded plastic block
- 1 length of heavy duty bungee
- All the necessary hardware for assembling and anchoring the brake
Boa Bungee Brake Installation instructions:
- Assemble the two plastic blocks onto the cable using three standard bolts and an eyebolt.
- Attach the rubber bumper to the block, making sure the pad faces the top of the ride (so the pulley will hit the pad).
- Using a quick link, attach the bungee cord to the eyebolt in the block.
- 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 zip line Boa Bungee 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.
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.
View the complete Boa Bungee Brake kit manual.
To purchase this braking system please visit our store: Boa Bungee Brake Kit.