Tuesday, August 16, 2022

Grigri 3 HUB System for Lead Rope Soloing

 GG3 Cord Mod for Holding Upright and Backwards (HUB System) updated 5/25/23


This post will detail the HUB method for LRS. The acronym comes from the Grigri being Held Upside-down and Backwards from how it is normally attached to the belay loop for belaying a lead climber. This has been done for years using various different methods and modifications. I think I remember seeing the Euros doing it decades ago before I saw it here in the US. The HUB Cord method I detail here however is, as far as I know, unique. Over the years I’ve modded GGs different ways to be held up, but so far this seems like the best yet.  I
had four design criteria for attaching it to a chest harness:
  1. Mod needs to be easy to do
  2. Attachment point to the GG needs to be strong - not supported by plastic
  3. The angle that it hangs from the chest harness needs to be adjustable
  4. Cord needs to be kept away from the rope path and the GG handle which could interfere with lock-up
Although I use it with GG3 with a deactivated spring or a GG+ (TRS mode), it's possible to use with other GGs with the spring intact. However this is untested by me and I would wonder about its ability to lock-up in a high-clip situation. Others like Brent Barghahn use a GG3 in the HUB position without modifying the spring (As of My '23 I believe Brent now uses a GG+ in TR mode). Also of note: testing by Yan Camus and others indicate that a GG+ in TR mode and HUB position may not always lock up when weighting it slowly in a high clip situation. Using a GG3 with deactivated spring and the HUB System is the equivalent to a Rock Exotica Soloist or El Mudo but has the added ability to easily lower/rappel without adding or swapping anything out. 
First a discussion of the HUB System vs the Inverted hanging position. I feel the Inverted (hanging facing backwards) GG along with the running cache loop popularized in the last few years, are two of the best innovations for using a GG for LRS. Having said that, there may still be good reasons for some to prefer the HUB system I detail here. 
Ultimately it will depend on what you value most and the type of LRS you do as to which system might be best for you. The purpose of this post is not to convince you of either, but to inform of options…more specifically the HUB option since the Inverted method has been detailed many other places.
Comparing and contrasting the two systems:

HUB System (assumes use with a springless GG or GG+ in TR mode)

Advantages

  • Less possibility of high clip failure - quick and more positive lock up.
  • GG is held higher and in a better position to pull slack for clipping. Especially handy for those with short ape index like me. 
  • Less tendency to flip over backwards because of chest harness however it’s still possible.
  • Less flip-flopping around during a fall, thus reducing the length of fall - up to a foot less. This can be important if you are climbing on vertical or less terrain and there’s objective fall hazards.
  • Can adjust the feed resistance (and thus back-feed) by adjusting angle of the GG with the HUB cord.

Disadvantages

  • It most likely won’t hold a head first fall (unless backed-up - which I consider mandatory). Needs more testing though. Volunteers?! 😊
  • May not feed as well traversing - needs more real world testing.
  • Requires a chest/shoulder sling/harness which is a hassle and may take a bit of effort to get everything fine tuned.
  • Can’t pull rope directly up for a high clip - it will lock instantly and short rope you (springless GG, and GG+). However, if you pull slack down, then clip-up, it works like a charm. Once learned this becomes natural. (It’s the same movement as pulling more slack for the cache loop if you are using that method). Many people who use the Inverted GG method also pull a slack loop down before clipping up and is the norm for a Soloist and an El Mudo

Discussion

Better for vertical to less than vertical routes that don’t wander much and might have objective hazards. It is good for those who want peace of mind that high clips will always lock-up instantly if weighted. It’s a better set up for hang dogging, aid climbing, and routes where the crux is closer to the ground. 

Inverted  GG (Hanging Backwards) 

Advantages

  • Potentially holds inverted falls
  • Feeds fairly well in all orientations because it it free hanging and can orient itself to the direction of rope pull
  • Can pull directly up to clip (depends upon rope pairing)
  • Simpler setup - no necessary mods or chest harness
  • Could be a slightly softer lock-up because of the strong spring

Disadvantages

  • Takes longer to lock up because of it’s hanging orientation: needs to flip 180 degs and travel from the hanging to upright position
  • Not as convenient to pull slack for those with short ape indexes. Have to reach down further to pull slack.
  • Has proven not to lock-up on high clips or when sagging on rope without a significant jerk (as Yann Camus has demonstrated and others have experienced). It needs a significant fall/jerk on rope to lock-up because of the strong spring
  • Depending upon rope pairing, it can lock-up unexpectedly while clipping.

Discussion

Better for steep/overhung routes where there’s no objective fall hazards. Those who want security re the possibility of upside down falls without taking extra measures to protect. It is generally easier system to set up though rope pairing is critical for good feed and lock up
There’s nuances to everything stated here - it’s not cut and dried or black/white. Test, practice and be safe. And as with most all soloing devices, the device/rope pairing is critical and can have a big impact on performance
The GG3 used here is an unsprung version that I’ve modded - but that’s a different story (see my previous blog post). Attaching a cord to the GG upside down and backwards has been done many different ways through the years and range from OK, to klutzy, to dangerous. I’m giving details on how I do it, which works good for me:
  • only requires one hole to be drilled that doesn’t harm the function or integrity of GG 
  • holds the GG at a stable angle that is easily adjustable 
  • is always held by one or more connection points when swapping devices
  • uses the cord connection to the ‘biner to help keep GG from cross-loading on the ‘biner
  • GG is still functional for all normal uses

How to Make the GG HUB Mod (now called the HUBBY system ðŸ˜Š  - Held Upside-Down and Backwards Bridle Yoke)

  1. Drill a small 1/8” hole in cover at location shown This does not affect the GG in any way (strength or function). 
  2. Chamfer the edge of the hole on both side so there are no sharp edges to wear on the cord. I used a larger drill bit tip to accomplish this along with a little piece of rolled up 220 emory paper.
  3. Insert one end of a 2.5 mm accessory cord through hole. (I have now transitioned to using 1.8mm polyester covered dyneema. It is more abrasion resistant and just as strong or stronger - see photos for GG+ near the end of the post)
  4. Put an overhand knot in it then burn the end so that there is a melted blob on the end that acts as a stopper. 
  5. The cover of the GG fits loosely so there’s already clearance for the cord. However I sanded the plastic spacer to introduce a bit more clearance so it didn’t bind or rub on a sharp edge and allows the cover to easily open and close. 
  6. On the other end (on ‘biner), I tied a Poacher's knot (half a double fisherman’s knot - see first comment below). This allows it to be loosened to put on the 'biner and then cinched down to help keep the GG centered and prevent cross-loading. The chest harness should also keep the GG upright mitigating cross-loading. (I have stopped using this in favor of a overhand loop on a bight. See description at end fo post)
  7. In the middle of the cord, I tied an overhand on a bight for connection point to the harness to hold it upright. The position of this will determine at what angle the GG hangs at. This will determine how well it feeds. There’s many variables depending upon whether it is an unsprung GG, a GG+ in TR mode or a GG with a normal strong spring. This will be unique for each rope/harness/GG setup and needs experimenting to find the angle for best performance.
See updated info at end of blog post

For the unsprung GG I’ve found that ~30-40 degs from vertical is best for my rope combo for good feed and lockup. For a GG+ I've found 40-50 degs works well. With other GG-rope-harness combo's it takes experimentation to find the best hang/suspend angle of the GG for optimal feed and lock-up.

The photos above show it paired with my new Maxim 9.5 Pinnacle which is sleek, supple, and pretty bitch’n.
For any setup, if the GG feeds too easily it will contribute to back-feed of the live rope. This can be dangerous and pull out dangerous slack from the cache loop. The ease of feed can somewhat be adjusted by changing the location of the overhand knotted hang loop. Increasing the angle toward vertical will increase friction and closer to horizontal will decrease the friction. There are also other ways to manage back-feed on the live rope strand. I won’t go into them here but one of the best and most user friendly is Arctic Bastard’s Gromm Hitches

Five ways to handle cache loop/back-up for HUB system

Having some type of cache loop and back-up are mandatory for good performance and safety. Here’s four possible ways. Each has its own advantages and disadvantages. Choose wisely.
  1. Cache loops pre-tied cloves on ‘biners clipped to gear loops ala Brent Barghahn https://www.brentbarghahn.com/climbing-blog/redpoint-rope-soloing-2021. Use keyless ‘biners and drop loops as needed. Use with a Metolius Super Safe harness or backup gear loops as shown in Brent’s blog.
  2. Cache loop with Microtrax on ‘biner clipped around waist belt. Separate webbing loop with ‘biner near belay loop. Only tie back-up knot on it between MT and GG as needed for cruxes then drop the knot when passed the crux.
  3. ‘Biner around waist belt with a Klemheist tied around rope to manage cache loop and act as backup. If using this method you have to hold knot with teeth while pulling slack ala El Mudo.
  4. Back-up slip knots pre-tied before cache loop. Pull to undo as needed as it nears the Microtrax. Microtrax should be on full strength gear loop or backed up.
  5. Backpack method - backup slip-knots pre-tied at intervals then stuffed in a backpack. Cache loop is pulled/feeds from backpack and backup knots untie as they “appear” by grabbing with mouth and pulling with free hand.
  6. The 

Current thoughts and experiments on using an unsprung Grigri using the HUB System

Current experimentation: Different ‘biners to connect the GG to harness and precautions to prevent cross-loading. How tight or loose the connection should be between chest harness and climbing harness via the GG and HUB cord. Currently, I try to adjust so that the weight is on chest/shoulder harness so it’s hanging as free as possible from the HUB cord. I use a large oval ‘biner to connect to the belay loop. This allows the ‘biner to slide up and down within the belay loop a bit which helps maintain the correct angle while moving around. If the unsprung GG gets into a horizontal position it will lock-up and prevent any upward motion, so beware!

P.S. If a GG is used with a cache loop, it should be on the climbers left. This is on the side of the GG with the moveable plate and has the rounded lip for lowering. If the cache loop is on the climbers right, it can run across the handle and make it harder to access it for lowering.
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Hub Cord on a GG+

Plastic spacer ground/filed/sanded slightly to increase clearance for 2.5mm cord


Addendum
An alternative way to rig the either the GG3 or GG+ is to eliminate the second arm of the cord is shown below. It is a bit simpler but it will hold the GG at a slight angle sideways which will incrementally increase friction. This setup does not allow you to adjust the angle that the GG hangs at from the chest harness. However for some smaller rope pairings, the feed may be adequate smaller diameter ropes (i.e. <9.4). An advantage of this simplification is that it keeps the HUB cord and harness connection away from the handle.



Addendum #2
I have made several minor changes in the evolution of the HUB cord. First is a change in terminology to distinguish the single leg cord above from the dual leg versions. The single cord I'm calling the HUB Tow cord (shown above), while the second I'm calling the HUB Bridle.

Secondly, I've changed from using 2.5mm accessory cord to a 1.8 polyester/dyneema cord. It fits through the gap between the pivoting cover plate and the body easier than the larger diameter cord.



Thirdly I've changed from using a Scaffold knot that can be cinched down on the 'biner to an overhand on a bight which makes it is easier to put on and take off. I've sized the loop to allow the bulk of the knot to clear the body of the GG which allows the tow loop connection to be better centered (see last photo in the composite above).


Lastly, I failed to show the beveled/chamfered cord hole in the inside cover of the GG. This protects the cord against the sharp edge of the hole. It is done by using a drill bit several sizes larger than the diameter of the hole with a small amount of pressure to remove the sharp edge of the hole and put a light bevel on it.



Note: While some of the photos show an aluminum locking 'biner, I normally used a rated stainless steel quicklink or a auto-locking steel oval or symmetrical pear 'biner.




7 comments:

  1. The "sliding loop made with half a double fisherman’s knot" you discuss is called a Poacher's Knot (https://www.animatedknots.com/poachers-knot), aka Strangle Snare, Halyard Knot, Double Overhand Noose, or Double/Two-Turn Scaffold Knot.

    It is closely related to the Scaffold Knot, which (properly) has three turns and is also known as a triple overhand noose. The Scaffold Knot is often (improperly) used to the refer to the two-turn variation as well. The Scaffold Knot is commonly used in the arborist/caving/IRATA worlds for connecting a carabiner to the end of a rope. It holds the carabiner orientation nicely (minimizing chances of cross-loading), uses little rope, and comes untied easily (slide the biner out and the knot falls apart). It is also quite strong, but does have an incorrectly tied "death knot" version that is visually similar when dressed. See https://www.youtube.com/watch?v=e343To9hznU for pull-tests and death-knot variation discussion

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  2. This is very useful information. I also have an unsprung GriGri and lead solo (usually Lov2). I have tried your setup and feel it is safer. Safer than Lov2 and Revo. I think this information should be shared with a wider audience. The cord configuration is very well thought out. Well done you!

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    1. Thanks for the feedback. I shared this info on the FB rope solo group. I'm way behind but will post on SICgrips Instagram account also.

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  3. Hi. How much are the disadvantages if I do this with a spring-intact GG3? I'm looking to try this for aid LRS, so will be fairly slow, small movement climbing.

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    1. Sorry for the delayed response. I'm just learning how to approve and respond to comments. I'm not an aid climber so may not be the best one to address that. Having said that I would think the disadvantage is that it will not always lock-up if you high-clip and weight it - which seems to me to be what aid climbers do. If you weren't into disabling the spring, I would either get a GG+ and use the TR spring setting or buy a Petzl Grillon ($$) which is basically the same as a GG without a spring.

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  4. Hola ! Excelente blog .Quiero usar un grigri clásico para top Rope . ¿Como puedo usarlo sin modificar resorte y con garantías de seguridad ? También he visto por la web gente que lo usa sin arnés de pecho y de primero.Gracias .

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