Wednesday, June 22, 2022

Self-Belay System for Home Climbing Wall

Most home walls are low enough that they can be use for bouldering with or without pads. My son is finishing up his house in the Bitterroot Valley and has dedicated a whole room for training during the cold months and when he can't make it out to the nearby crags and walls. His bouldering room is 20' x 30' with a 40 deg Moon Board at the "low" end of the room and an almost 20' tall 20 deg. wall at the tall end. For now he just has home made 2x4 holds so he can test the wall and the setup discussed below. The two end walls are connected by a 30' long vertical traverse wall. I'm jealous! 😊

 


The tall wall is high enough that you really don't want to fall off so is really a TR wall. However that requires a belayer and with a small child, it means that he or his wife often has to babysit so only one can climb at a time. Sooo...what to do? With a bit of adaptation, we figured out a good system for self-belaying by adapting a top rope solo system I've been using off and on for several years (https://sicgrips.blogspot.com/2020/08/vergo-for-top-rope-soloing.html). It allows the climber to fall/hang at any point, then continue climbing or lower down. Who needs a $2.5K+ TruBlue iQ system! (They are great systems though.) This accomplishes the same thing at a fraction of the price.

The main challenge we faced when adapting the system from outdoor climbing to indoor is the angle of the wall. Top rope soloing is a wonderful way to gain endurance by doing laps or for working on cruxes for a project. However it does have its limitations. TRSing feeds best when vertical. When it gets too overhung, or wanders/traverses too much, then it becomes less than ideal. Re-belays are the solution when climbing outdoors to help the rope run free and to protect it against edges.

  

My son's indoor wall is 20 degrees overhung which causes the rope to seek a plumb line to the ground because of gravity. This has two negative effects. It means the rope tends to hang up on your body which creates friction and doesn't allow it to feed freely. Secondly, it creates a downward and outward pull on you because of the weight at the bottom of the rope.  This is annoying and a PITA to say the least and can feel like someone is trying to pull you off the wall.

So we've adapted the re-belay idea from outdoors to the indoor wall by placing an eye bolt near the bottom of the route and running the rope through it. This keeps it close to the wall, away from your body and allows the Vergo to flow easily up the rope.

The keys to optimizing the system for him in this contect are:

  1. tow loop on the Vergo and chest sling to hold it vertically (very difficult feed otherwise)
  2. a ~9.5mm very flexible and pliable rope
  3. eyebolt to hold rope close to the angle of the wall
  4. adding the minimal amount of weight on the bottom of the rope so Vergo feeds well but does not impede climbing
Things to improve in the future:

Replace eyebolt with a pulley at the bottom to increase the smoothness and efficiency of the weight on the rope and pulling and slackening of the rope as one climbs and assumes various body position in relation to line of the route. 

Because this method uses a fixed top anchor, it doesn't allow you to wander too far from the route line. Therefore we're thinking of attaching the rope to a pulley at the top which would run on a horizontal static line across the wall. This would allow it to track/follow the climber's horizontal movement if the they "wander" around the wall. This would be paired with a horizontal line (non-weight bearing) at the bottom of the wall at the same height of the eyebolt which would include two pulleys connected by a swivel. One pulley for the climbing rope to to pass through to replace the eye bolt. And the other so it can easily slide horizontally to hold rope close to the wall but follow climber's horizontal movement like the top anchor rope set up. (Difficult to describe in words without taking the time to draw it out).

The main challenge in this scheme is that the top horizontal static anchor rope would be stretched between two points (like a slack line) and any "fall"/weighting of the climbing rope/pulley would multiply the weight of the "fall" by an X factor due to the physics of the shallow angle created by climber's weight sagging on the horizontal rope (like a slack liner fall). 

The proof of the pudding however, will be in the final product. I'll add a future post when/if we perfect that. However as it stands it's a good and reliable setup for a single route that doesn't wander.
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NOTE: The photos/video above show a Climbtech RollnLock at the back-up. I've also used a Microtraxion which works similarly, thought if the two devices contact each other, because of the MT's teeth, it is hard to release and descend without first unweighting it. Some say that the Rollnlock will not lock up if it contacts the primary device above it. That's not been my experience.

This article shows non-standard and non-approved use of these devices. Be warned and use at your own risk. Climbing is dangerous!


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