Grip-Brick Hold Positions

Photos show the versatility of the GripBrick and the various positions that can be achieved by positioning and adjusting the cord. 

As of May I have a number of grips left that I'm selling at $15/grip + shipping. If interested contact me at sic dot grips at gmail dot com.

GripBricks can be used singly or in pairs and can be used with free weights, weight machines, hanging, or clipped to a knotted sling shut in a doorway to provide a horizontal pull at waist height. I most frequently use them to warm up at the crag or to do strength training one arm at a time with isometric pulls of ~5 secs slowly increasing and decreasing the pull to max strength.

The following two photos show how a girth hitch around the cord knot can be used to adjust the elliptical small and large crimps for positivity and finger contact area.

  

El Tacaño

El Tacaño - GriGri Mods for
Lead Rope Solo

(The Cheapskate)
[updated 25 May, '23]

This is a summary of all my experiments and tinkering with modifying the GG for LRS. The naming is a nod to the El Mudo because it has the same basic functionality. If you aren’t a tinkerer and want the same functionality, then buy an El Mudo and support it's designer who is serving our community by constantly improving his design. It is a quality, bomber device made specifically for LRS and is probably the safest device available (with a back-up), and is reasonably priced compared to finding a used Soloist or Silent Partner at current eBay prices.

All my mods for LRS are way beyond the manufacture's designed purpose and will void any warranties; it may ruin your device; and are most likely dangerous for the inexperienced.

The goal of my tinkering is: better feed and immediate lock-up during weighting/falls. Said another way: I want it to be transparent in its feed and to be safe. I’m an old fart and risk adverse so I have no shame in setting a piece or clipping a bolt and hanging - I'm more into mileage and having fun than pushing myself then pushing my limits and getting something 'clean'. Given that, I do want to know that it's going to immediately lock-up. El Tacaño mods are good for minimizing fall distance on routes with objective hazards and /or cruxes low to ground. I'll leave the cutting edge stuff and big whippers to those like Brent Barghahn and Keita Kurkami who use similar systems but without some of the safety I've incorporated into my mods.

If none of my reasons apply to you...move along...just use a stock inverted GG 1, 2, or 3 which doesn't require any mods and 'should feed well'; 'should lock-up'. Note: none of these will lock up in a head-first fall so a backup is mandatory. 

The following are 5 major versions of the mods starting with the easiest and least "destructive" of the stock GG. The degree of difficulty of the mods is directly proportional to the functionality of the device (ease of feed and immediate lock up):

1) GG+* - 2-strand HUB cord, (set to TR mode) 

Feeds best with smaller diameter ropes, < 9.6 to mitigate friction. 2-Strand HUB cord - (Held Upside-down and Backwards) for connection to a chest harness. With this setup and the GG+ set to the top rope mode, it’s easier to lock up because it doesn’t have to flip up from hanging to vertical position. It's also easier for the climber to pull more rope for clipping because of higher position in relation to one’s body. This mod only requires one 1/8” hole to be drilled in pivoting side cover which doesn't weaken the GG; and doesn’t rely on holes in the plastic; no sharp edges; and keeps it away from handle. It can still be used for normal belaying. Allows centering of GG (side to side) and adjustment of the hang angle determined by where the overhand tow-loop is tied. 

Because the rope tab on the cam arm puts an "S" bend in the rope, the 2-strand HUB cord allows you to fine tune and adjust the angle for the least possible friction possible with a given rope. It's a simple matter of re-tying the knot for the chest harness hang loop and adjusting the length of the arms to change the GG+ angle of hang. If the GG+ is oriented close to vertical, the rope friction can be too great. Close to horizontal there is little rope friction - almost too good as the back-feed can become as issue. Also, in this position it can lock up if you're climbing too fast or pull rope up instead of down to clip. The middle photo where it hangs at 45-50 deg. and slightly rubs on the rope tab gives a good middle ground. It can be a bit finicky to set it initially set up and use but it's easy to make adjustments. 

Even though the spring in the GG+ is set to the TR mode it is quite weak but still requires a deliberate weighting on the rope to overcome the spring. I have heard of a some instances of it not locking up from a slow weighting from a high-clip position. Be sure to test on the ground and become familiar with the interplay of rope diameter and slow lock-up.  This is what lead to #2 below where I disable the spring (GG3) and eliminate that possibility.

2) GG3 - 2-strand HUB cord; deactivated spring.

Feeds best with smaller diameter ropes, < 9.6 to mitigate friction. This uses the same 2-strand HUB setup as above but uses a GG# in which the spring is Deactivated which allows the cam arm to pivot and lock on rope with the least downward movement of the climber. High clipping and/or “sitting” on the rope will always immediately lock-up. With the HUB cord there is no problem with the GG locking up. Because it’s held up vertically the rope feed is down away from locked position. However one needs to remember to pull slack down before clipping.However this is usually a natural action when leading - ‘pull down - clip up’. Should you pull directly up to do a high clip, it will immediately lock on you because of the deactivated spring.

3) GG3 - 2-strand HUB cord; deactivated spring; and ground down modified rope tab:

The modified rope tab decreases the “S” bend in the rope which causes friction. This mod still protects against the rope getting caught underneath the cam arm because the tab is still functional though reduced in size. It is helpful to use in conjunction with 2-strand HUB cord to fine tune hang angle for most efficient feed.

4) GG+ - single HUB cord; ground-off rope tab; CAS (Cam Arm Shield), set to TR mode. 

Here I switched to a 1-strand HUB cord. Simpler to set up and  holds GG closer to vertical. Because there is no rope tab it's not as critical to keep it at an optimal angle. With the 1-strand HUB cord it leans slightly because the one strand is a bit offset from the center of gravity of the GG. This might increase the drag slightly but is helpful in keeping the cord and chest harness connection away from GG handle - and it's also simpler to put on and take off. Because it’s using a GG+ the lock-up isn't as immediate as #2 and #3 above because it still has to overcome the spring in the TR mode. 

A CAS (Cam Arm Shield) was also created because the standard GG rope tab is ground completely off to give a straighter rope path and decrease rope feed friction. Because of the tab is hollow, it leaves several small holes through to the guts of the handle. The CAS seals this off so nothing can get in to jam up the handle.

Without a CAS there is a risk of the rope getting caught underneath the cam arm and slicing the rope during a fall as shown to the right. The CAS is designed to make that an impossibility. It is fashioned out of a small piece of 25 gauge (0.5 mm) 304 stainless steel and JB Weld steel epoxy is used to glue it to the cam arm. This version is the smoothest feeding systems possible with a GG and is better than any other LRS system that I’ve tried which includes all the major LRS devices…it’s just unfortunate that it has the anti-panic handle - but I suppose if one wanted the best feeding GG for LRS, they could learn to live with and become efficient at using the anti-panic handle.

The following photo shows the cam arm shield before being attached with steel epoxy. It was a bit too wide so I eventually cut the width down after I'd already bent it and held it in place to see how it fit. A bit of trial and error.

Chamfered hole for the HUB cord. Since the photo was taken I have changed to drilling the hole on the sloping face just below where it is shown. This causes the cord to better exit at an angle between the cover and body into the existing gap between cover and body of the GG. This saves having to file the plastic spacer to create better clearance for the cord.

5) GG3 - single HUB cord, deactivated spring; ground-off rope tab; CAS (cam arm shield)

 

This version uses a GG3 and has the spring deactivated like in #s 2 and 3 above. However it has the rope tab on the cam arm completely ground off like #4 above. It also has a CAS with a new rope guide tab. This is necessary because with no spring resistance, when the rope feeds through around the cam, it tends to rotate it and which starts the locking-up process on the rope causing friction. This ultimately defeats the purpose of grinding off the tab in the first place. By incorporating a new rope tab into the CAS, the rope path can be straightened out, allowing for a straighter rope path than in #3. However, in the long run I think it’s not worth the extra work because the gains in friction reduction are minimal over #3 above.  If one wanted the best feed possible in a GG for LRS, then #4 above is the choice. I haven't actually used this one yet but preliminary tests at home have convinced me that it it not worth the extra work even though it would seem the ultimate in rope feed and instant lock up. 

Additional mods:

The pivoting side plate was trimmed slightly and the edges were chamfered to increase opening clearance to decrease rope drag. This mod only applies to 3), 4) and 5) above. This is a minor mod but depending upon rope used, it can help with reducing the rope drag as well as provide a smoother and much more rounded opening where the rope will be rubbing when changing directions from feeding down while climbing, to pulling up during a fall. 

On several of the GGs, I shortened the length of GG handle by 3/8” - 1/2”. This provides more clearance of handle when cam arm pivots so it is less likely to catch on anything. It's interesting to note that the latest version of the Petzl Grillion (a version of the Grigri without a spring for use in an adjustable lanyard for rope work), also has a shorter handle than the GGs do. When the handle is shortened, it leaves a raw I-beam edge on the end that I filled with epoxy and then rounded and smoothed. For my small-medium fingers, it still leaves enough space to get 3 fingers on the handle to easily control the rap. I've never had an issue with handle interference so this is more of a preventative measure.

There you have it. Five major GG mods done over several years. It's kind of anal in scope and detail but then that's what I do. My favorites are #3 and #4 above though they all work.

LINKS

HUB cord details

De-activating GG spring

Grinding down GG rope tab

_________________
GG+* - while many people (including me) don't care for the anti-panic handle, and while it is a scourge for an experienced user, for those who want to make the most minimal modification to a GG and want to try a "safe" way to LRS (2-strand HUB cord), the GG+'s dual spring mode provides an acceptable way to try it out IMO. It should be set to the weak-spring (Top Rope) mode.

Note: While some of the photos often show an aluminum 'biner (which was handy to grab when shooting these photos), when actually using the El Tacaño I use a locking steel 'biner or a rated SS quick link.

Note 2: At some point I would love to take a couple of these and a weighted duffle/haul bag so it was rigged like a climber then push it over backwards off the top of a local cliff. This would simulate what a typical head-first fall might be like. It is typically said that a HUB rigged GGs won't catch a head first fall without a back-up. It could be tested both with and without a backup. Anyway, maybe in the future.

Decreasing Friction with a GG HUB Setup for Lead Rope Soloing

Decreasing Friction with a GG3 HUB Setup  (updated 02/16/23)

This is the third in a "holy trinity" of GG mods I've done over the years on a GG. To recap - there are two main ways a GG can be used for LRS: hanging and backwards (known as "inverted" by many) and the HUB (held upside-down and backwards). The inverted method, if paired with the right rope, is great for upside down falls and steep terrain with no objective hazards and it doesn’t require any modification for using it this way. However it needs falls with a significant “jerk” to overcome the GG spring tension in order to lock-up. This can lead to not locking up when high-clipping and sagging on the rope.  In contrast, the HUB method is good for high-clips and having the security of being being able to hang on a piece and lock-up at any point in time; ease of lock-up results in shorter falls; and for climbs with objective hazards and low angle slabs, FOR ME, the HUB method is preferable. The downside of the HUB method is it won't hold an upside down fall so a backup is mandatory (which it should be with any device and method). To achieve this functionality requires significant modification fo the GG which is a significant drawback for most climbers. The three mods are: 1) drilling a small hole in cover so that it can be held upright with a cord; 2) disabling the spring so that it will lock-up immediately in the event of a fall or a high-clip (if a GG+ is used this is unnecessary because of the dual spring mode - however it will never be as safe and and lock as easy as a GG3 with the disabled spring); and finally, 3) the mod described in this article will be modifying the rope guide tab on the cam arm to decrease friction in the feed. 

This last mod has the least affect of the three mods but if wanting to get the last once of performance out of the GG with the HUB setup, then it is worth considering. It should only be done after the first two mods and using with the rope and setup that you’ll use. It may be that it is unnecessary or undesirable…read on.

Before describing the mod and how to do it, I'd like to take a bit of a detour and talk about rope feed and friction in general. While ease of rope feed is usually thought of as one of the most sought after characteristics of a lead rope solo device, it needs to be understood in context. The device with the least amount of friction is NOT NECESSARILY the best LRS device. That is because feed and backfeed are in an inverse relationship with each other: the easier a device feeds, the more likely back-feed will be an issue. As with many things ultimately it will depend upon an individuals preferences given their setup and types of routes they climb.

A device like the Revo is generally considered the device with the least resistance and best feed. However that also means that it will be the first device (everything else being equal) to back-feed during a lead. Other factors that will affect back-feed is the angle of the rock face and if the rope drags across it; the size and type of rope being used; the length of the pitch, how many pieces of gear the rope travels through before getting to the LRS device. A lower angle climb with many objects or a horizontally wandering route will take weight off the live end of the rope and reduce the amount of back-feed. Finally the size/weight of the cache loop acting as a counterbalance will affect the degree of back-feed. So pursuing the best feeding LRS device needs to be done in relation to all these other factors.

The Silent Partner and Revo both have excellent feed (Revo more so than the SP because of the clove hitch used in the SP). Both are essentially giant pulleys that the rope travels around and the wheel/pulley is free to rotate. The GG’s rope path on the other hand, goes around a non-rotating cam and then changes direction where it exits the device. The friction comes from the the non-rotating nature of the cam and the change of direction/bend in the rope when it exits the device. Any time the rope makes an “S” bend, depending upon the diameter of the bends, it can significantly increase friction. See the first photo above that illustrates this.

So, if you look at a stock GG3 HUB rope path, it is easy to see how the cam rope tab causes this “S” bend. Depending upon the size and stiffness of the rope this may or may not cause more friction than is desired. If it’s not prohibitive, then this last mod maybe moot. If there is significant friction when climbing and pulling slack, then it may be worth considering this third mod. 

The main purpose of that tab on the Grigri cam arm is to keep the rope wrapped around the cam so that it can’t get caught behind the cam arm which could act as a knife in the event of a fall. I modified a GG+ in the past and totally ground off the tab. The result was one of the best/easiest feeding LRS devices outside the Revo. 

However, as shown in the photo to the right, in a weird fall, it could get caught behind the cam arm. While I’m personally reticent to use it for LRSing, it didn’t stop Keita Kurakami who used a similarly modified GG+ with an 8.1 mm rope when he rope soloed the Nose! (https://www.facebook.com/keita.kurakami/posts/pfbid02sUykWXzczJF3bJrUx3jKRGUY1sEQ8ApCHkciN7DDYNFiN83QH5mt4tuqDeZhKRqWl) http://www.alpinist.com/doc/web18f/newswire-kurakami-herson-free-the-nose?fbclid=IwAR13Alcfn2izJ6aMrhAKJ3Oy-jVQVc__rPXu9eamcJTZ4UMpmXn5oacN-08. 

I’m sure the feed with the small diameter rope was slick as owl shit, but I’d be nervous regarding the possibility of it getting caught behind the cam arm and getting sliced. In his defense, he did take 50+ falls in practice and training for the Nose and on the climb itself took 10 falls on the Changing Corners and the Great roof. Also, in light of the discussion above, it would seem the backfeed could be an issue because of how freely it flows through the device.

Now back to the GG3 HUB device. One way to help get rid of the “S” kink in the rope path to improve ease of feed but still keep its function of preventing the rope from going behind the cam arm, is to grind away a good part of the rope guide tab to straighten out the rope path. The resulting path can be seen in the righthand photo at the beginning of the article. 

By trimming the tab as shown below, enough of the tab can be cut off to straighten the rope path but still leaves enough so the rope can't get trapped behind the cam during a fall. I did it with a Dremmel tool and carbide grinding disk, it’s fairly easy to cut through the stainless steel material with a bit of patience and a steady hand. I held the Grigri in a vise while doing this. I then finished with a hand file and various grades of emery paper. I started off by first drilling a small hole to locate where the horizontal and vertical cuts would meet which also provided a nice radius for the transition between the two cuts. The end result may look sharp from the photos but all edges where the rope touches are well rounded. It also may look flimsy, but there’s still a significant amount of stainless steel and it barely makes contact with the rope as it slides past it while climbing. Also, during a fall, the force vector is away from the tab since the rope wraps around the cam away from the rope guide tab.

   

On a previous GG, I trimmed the tab down similarly but then fitted a stainless steel tube over it and filled the void with steel epoxy. While it looks a lot slicker and more professional, functionally it is not quite as good because the diameter of the tube impinges a bit more into the rope path and puts slightly more friction on the rope. On the same GG, in an earlier version of this mod, I fitted a small diameter roller bearing thinking that it would help reduce friction. However again, because of the diameter of the bearing, it impinged slightly more into the rope path and ended up with a bit more friction than this current mod.

Sooo, that's it.  The last of my holy trinity of GG mods.

As always, these are things I’ve done to modify my GG (and for a few friends). Do not try any of these mods without full knowledge and much experience, both lead rope soloing and with modifying equipment. You will void the warranty of the device; you could screw it up permanently so that it doesn’t function properly; and it could result in death. 

Having said that, for me, it’s one of the best devices out there. For those of you wanting this functionality but don't want the risk of modifying a GG, once the rope creep bugs are worked out of the El Mudo (v3?), it will definitely be a simpler and safer way to obtain most of the same functionality that I've sought after with these GG mods. If you're a tinker, then the hopefully the info in the three blogposts will be informative.

Postscript: Since publishing this I’ve come up with another couple ways to totally eliminate the standard rope tab on the GG3 and GG+ but still be able to keep the rope from getting caught behind the cam arm. 

 Mudo 2.0 - Initial thoughts and evaluation

El Mudo ("the mute") out of Mexico by Manuel Larios, is the newest soloing device since the Silent Partner, Soloist, and Solo Aid to be designed specifically for rope soloing. Many devices are currently being used but they are all repurposed as soloing devices and used outside the parameters of their design and are usually expressively forbidden to be used for soloing by their manufactures. However many of us still use and modify them for that purpose. Now the soloing world has a new purposely designed and built device for rope soloing - El Mudo 2.0. It is interesting to note the similarity in form to the old Rock Exotica Solo Aid, though it did not self-feed and there other differences. I'm just noting the form factor similarity.

In these initial observations and tests I’ll compare the El Mudo to a GG3*/GG+* HUB set-up since that is what it most closely resembles in setup and function. Some might say it would be relevant to compare it also to the Soloist, however because it's no longer available (and I dumped mine years ago), I'll only mention it in passing. However, from memory, I'd say it very similar to the Soloist - maybe a bit more finicky in setting up but with equivalent performance, maybe slightly smoother feed with the added ability to easily lower/rappel. Lock-ups are also probably more positive from what I can remember with the Soloist.

The Mudo works by having a brake pivot that is inserted into the body and is secured by the security pin/axle. The rope feeds up from the bottom around the top of the brake pivot much like a bearing surface or pulley, then back down and out to the bottom rope anchor. The pivot brake is held up by a 'biner connected to a chest harness. This pulls the pivot brake up away from the body and allows the rope to feed freely. The brake pivot is somewhat "floating" in that the pin/axle is in an elongated hole in the body and because of the slot in the pivot brake, it is free to slide up and down and move slightly back and forth. During a fall or a high-clip the brake pivot is pulled down into the body and pivots and pinches the rope on both the leading edge of the body going in and the trailing edge coming out. This assures a secure brake on the rope and provides more contact area than the Grigri design which only pinches the rope in one place by the cam arm.

Feed                                                                             Lock-up

Before I go any further I'll summarize some basic stats and a summary of my impressions that will be detailed further down in the article. 

	El Mudo V2	GG3* / GG+* (with HUB cord*)
size	9.8 x 6.5 x 4 cm	10 x 6 x 4.5 cm
device weight	356g	GG3* - 176g GG+ - 201 g
climbing weight (harness attachment and chest harness attachment)	472g including 8mm cord and pear 'biner	GG3* - 286g GG+ - 311g includes maillon, HUB cord, and stainless clip for chest harness
cost	$140 + shipping	GG3* - $75-$88 GG+ $77-$140
harness attachment	8mm accessory cord or webbing**	8mm rated maillon or steel 'biner
recommended rope size	9.8-10.5 (probably could go down to 9.5 - needs testing 10.5 seems too big to me. Realistically, probably 9.7 to 10.0 is the sweet spot depending on the specific rope	8.5-11 (realistically 9.0 - 9.7 for LRS)
rope characteristics	flexible/pliable/smooth	flexible/pliable/smooth
device construction	all stainless steel!!!	seel/aluminum/plastic
construction assessment	super bomber - high quality - heavy duty	adequate - based on long history of use for LRS
lowering	add 'biner to use as handle to unlock and lower	integral handle: GG3* - super smooth GG+ - is a scourge because of anti-panic handle
high clip lock-up	yes	GG3* - yes GG+ - yes, but spring slightly delays
needs chest harness	yes	yes
chest harness attachment	round stock symetrical pear 'biner	needs mod: drill for 2.5-3mm cord and then use small stainless non-climbing rated clip/'biner
purposely designed and made for LRS	yes	no - must be modified and is beyond it's designed purpose and specs
needs cache loop	yes, for best feed	yes, for best feed
* GG3 with deactivated spring	https://sicgrips.blogspot.com/2022/08/deactivating-spring-in-grigri-3-for.html
* GG+ in TR mode
* HUB cord	https://sicgrips.blogspot.com/2022/08/grigri-3-hub-system-for-lead-rope.html
** see below for a way to rig to make it easy to put on/off
	FUNCTIONALITY*
ease of set-up	6/10	7/10
rope pairing	5/10	7/10
overall degree of confidence in device	9/10 (once set up correctly)	GG3* - 8/10 GG+ - 7/10
functionality for LRS	8/10	GG3* - 8/10 GG+ - 7/10
overal usability and ease of use	7/10	GG3* - 9/10 GG+ - 7/10
versatility	6/10	GG3* - 7/10 GG+ - 8/10
suitable for multi-pitching?	Possible but a bit of hassle - have to un-rig to add a TRS device. Best for cragging	Yes - but have to swap out for TR Solo device or pull rope while ascending
can be used for belaying up second?	no - only if belaying off harness and redirecting through anchor	yes - super easy to belay off anchor
can be used to belay leader or top roping?	yes - similar to an ABD feeding rope to leader takes practice	yes - purposely designed for (GG3* needs a bit of a modified technique) GG+ - dual spring modes
true auto lock-up belaying with hands off	yes	GG3* - yes GG+ - yes, in TR mode but not as fast/positive as GG3*
putting on / off / loading rope	Flat Fig-8 or Double Fishermens tie-in with 8mm cord - alternate attachment - see text	steel 'biner or maillon
feed while climbing **	good - dependent on rigging and rope. Takes some finessing to optimize but ultimately a smooth balanced feed	good - depending upon rope and rigging. Takes a bit of finessing with setting up and adjusting the HUB cord.
creep after lock-up	yes, depending upon rope rope-pairing is critical	no
high clip lock-up	yes	GG3* - yes GG+* - yes-slight delay due to spring
lowering	add 'biner to use as handle to unlock pivot brake and lower	GG3* - integral super smooth GG+ - is a scourge because of anti-panic handle
holds inverted falls	no - only with suggested supplemental Prusik/Kleimheist cache loop/backup	no - only with some type of backup
* This is my subjective impression and evaluation based on my limited use, the equipment I have and the methods described here and via the links. Further insight will be discussed in the review below.
** See the "feed discussion below in the review.

CONSTRUCTION

The construction is super bomber because of the stainless steel and the thickness of it. I don’t think there is any way that they device would ever break before the rope did. Some pull and drop tests could confirm that. In fact, I would think that future versions of it could be lightened by thinning the walls of the body by 25-30% and thinning and rounding off the excess material on the ends. Alternatively the body could be made out of aluminum. I personally would like to see the lightening holes in the sides of the body like v1 had. I see no reason how or why it would interfere with the function of it. Many ATC devices have lightening holes in the sides of the body (i.e. see the BD Guide)

SETUP 

The body is tied into the harness with 8mm accessory cord with a rethreaded flat figure-8 or double fishermen's bend. This is a bit of a hassle by contemporary standards but certainly effective and light weight and with no possibility of cross-loading. I suppose over time it will become easier to tie but certainly it is not user friendly for switching devices. An alternative setup that I came up with is to tie a loop with 5/8" tubular webbing with a maillon to secure the loop ends. This makes it easier to get on and off. The "price" you pay for this is the additional weight of the maillon.

I have also heard of another climber who used a large steel oval to tie is with and the 'biner went around both the waist belt and the leg loop strap. While NOT recommended by the designer, the user reported that it worked well, though one needed to make sure that it was free to rotate and slide on the 'biner. Also, when putting axle on/off, it is no longer held to the body (like with a cord tie-in). Therefore using a small dia. cord through the provided holes in the body and axle would probably be a good idea so that nothing is dropped when putting on/off. 

I had hoped that Petzl Omni might work because of the large diameter smooth curve which would be perfect. But alas, the cross-section diameter of the 'biner stock is too large to get through the Mudo hole tie in point. 

BRAKE PIVOT 'BINER

The 'biner used to hold the brake pivot up and connected to the chest harness in fairly finicky. I have found a lot of ‘biners that don’t work. Many ‘biners don’t work because: have too large a nose; I-beam construction that unpredictably hangs up on the "ears" of the brake pivot; cross-section of the ‘biner is too large (Dmm Oval) to fit the pivot; ‘biners with that are too slanting (too acute an angle); or having gate openings that are too small to fit the width of brake pivot, etc.

'biners that don't work                                                     'biners that work

In general pear 'biners work the best - especially those made from round stock. So far the one that works the best is a small old round stock Petzl Attache. Generally more symmetrical pear ‘biners work. Since it's only used to connect to chest harness and hold the weight of the rope for good feeding, even key-chain type aluminum 'biners can work. 

Best 'biner for Pivot Pinch Pin: Metolius Element or Attache; BD Pearlock; Rock Exotica Pirate; DMM Phantom; and Wild Country Xenon.

CHEST HARNESS

A chest harness is required for holding the Pivot Brake 'biner up. I did not test with a full chest harness but with both a Petzl Torse and an improvised chest sling made both with a length of 3/4" webbing or with two, 2' slings. I prefer those to a heavier dedicated chest harness since it's main function is to hold the pivot 'biner and rope up so that it feeds well, I found any of those to be adequate. Others may prefer a full chest harness. 

SETUP AND ADJUSTMENT

The adjustment and relationship between the chest harness, pivot 'biner, the Mudo body, and harness connection is critical for proper functioning and feed. It requires a bit of experimenting to get everything adjust so that it optimally feeds and locks up when weighted. The designer has stated that it is important to keep the body as close to the harness as possible. Using a cord to tie-in, this is somewhat difficult because of the tight access and space once the harness is and trying to tie and dress the knot. This may be one reason to use 3/4" tubular webbing and a maillon as shown above.

ROPES 

The suggested rope size ranges from 9.8 to 10.5. that are fairly new and pliable. From my limited experience of trying different ropes, I would think a new pliable rope of around 9.7 to 10.0 would be ideal. I didn't have access to one so I just had to try various ropes (10 of them) that I have from a new 9.4 Beal Stinger through to an old 10.2 Mammut Supersafe. Finding the right rope to maximize ease of feed and minimize creep is definitely a challenge - the device seems to be fairly finicky in my tests. Less forgiving so than my GG3* setup for sure. 

FEED/CREEP/BACKFEED

I found feed with the 9.4 and 9.5 ropes that I have to be wonderful and slightly better than than either of my GG HUB setups. However both are below the recommended rope size (9.8-10.5). At the larger rope sizes 10.0-10.5 to be too large for good rope feed. However, this really is dependent upon the specific rope. It's hard to make any generalizations.  I also found that the lock-up and high-clip was just as good the GG set-ups. 

HOWEVER, I did run into a sliding creep down the rope once it locked up. Creep ranged from ~5"/sec with a slick/pliable 9.4 Beal Stinger .5" second with an older 9.9 used fuzzy rope that feeds decently but still had some creep, though not as much as the 9.4. The 9.4 is well outside the suggested rope size limit so that is somewhat understandable. However I have a 9.9 which to me would seem an ideal rope size for the Mudo but it still had some rope creep which was annoying. Only large diameter stiffer ropes (10.2-10.5) had no creep. However ropes of this size didn't feed well in my experience. 

The whole rope creep thing is interesting because among other users some have found no creep while others have found almost as much creep as my smaller 9.4 but with a 9.7. I find it a bit annoying to start slowly sliding down the rope. It is easy to remedy by flipping a bite of rope around the free end of the Mudo body as shown below but should not be required when hanging on a rope. It will be interesting to see as others gain more experience what they experience as far as creep. At this point I find it perplexing the wide discrepancy that others have reported from absolutely zero creep at lock-up to almost as much creep as I've experienced. I have not experienced this with my GG set-ups using the same ropes. At this point, it remains somewhat of a mystery what exactly is the culprit since the results with different people and different ropes are all over the place. It does NOT seem to be the set up as I changed all kinds of variables in the waist belt and chest harness attachments and it did not seem to affect the results for me. It would be nice if they could sort this out and make the necessary modification before a v3 is released.

At one point I thought maybe the climber's weight has something to do with rope creep. I'm a lightweight at 125-130 lb which it seems would be counterintuitive as a contributing rope creep factor. Some heavier climber have not experienced the rope creep while others in the 175 lb range have experienced almost as much as me. It seems like it is more a function of the size/sheath weave/dry treatment/newness of rope/ and the pliability of it. Maybe the bottom line at this point is to find a rope that works like others have done with the Eddie and GG1 and then stick with that rope. Unfortunately, at this point, I don't want to have to go out and buy a new rope in the 9.7.99 range.

LOCK-UP

As I mentioned the Mudo locks up well whether a high clip or an actual fall, though I'll leave it to the young bucks to actually take whippers on it. At 71, I'm old school where the mind-set is that you just don't fall. I've tested it enough though to know that I can trust it should I have an unexpected fall. If you want a system that you can trust will catch you, I feel the Mudo is about as safe as one can be. I climb conservatively and if I get in over my head on a climb or get pumped out, usually I just just put a piece in and hang on the device. Thus the high clip capability is important to me. My real back-up is me: my experience: knowing my capabilities and climbing within them. 

INVERTED FALLS

A head first fall is a "weakness" of the Mudo, but is no different than a Soloist, or a GG and a HUB system. The chest harness pinning the solo device down so that is can't pivot independent of the climbers body orientation is the "culprit". For those who use this type of device, it is just part of the "cost" of doing business and one needs to take back-up precautions with any device held vertical with a chest harness. It should never be used without some time of good and reliable backup system.

CACHE LOOP / BACKUP

The owner's manual suggests using a combo cache loop and back-up knot/third hand consisting of a kleimheist/prusik loop attached around the harness waist belt on the back/side. This serves a dual purpose of maintaining a cache loop while at the same time maintaining a back-up knot that will pull tight when the cache loop runs out and act as a third hand to trigger the lock-up of the device. Or, when it runs into the body of the Mudo and stops the fall that way. This is a low-tech and innovative way to handle both. The down-side is that unless you have two hands free, you have to hold the rope in your mouth while cradling the Kleimheist in your hand sliding it along the rope to increase slack in the cache loop. This low-tech method could work well on any LRS device to serve the dual function of cache loop manager and back-up/third hand.

I personally. prefer to have cache loops clove hitched to 'biners on a reinforced gear loop as shown by (https://www.brentbarghahn.com/climbing-blog/redpoint-rope-soloing-2021). As you progress and the cache loop runs out you simply reach down and drop off another loop. See linked article for a full description. The benefit is that you don't have to muck around with hold the rope in your mouth and pulling the slack out and it's very quick and easy to release a new loop. The downside is you're carrying more weight on the waste belt of the harness.

Manual Larios also is developing a custom ATC type device called the Yomi which will allow you to pull slack similar to a Micro Trax but also locks ups like a ATC in guide mode should the cache loop run out. I’m looking forward to seeing and hearing more about it in the future. It could streamline the cache loop/backup process for the Mudo and other LRS devices.

I would love to see someone do some inverted drop tests with a full body weight dummy, both with and without the Kleimheist/Prusik to confirm that it will only lock up when the cache loop runs out. Could it be possible that the Mudo will lock without the back-up in a head first fall? I doubt it, but it would be good information to have knowing that most likely even in an inverted fall that it would lock before the knot came tight or hit the body. All this is conjecture till someone performs some actual drop tests to simulate an inverted fall. 

LOWERING / RAPPELLING

One main advantage that the Mudo has over the Soloist is that you can lower at any point in the climb by inserting a 'biner in the unused hole and pulling on it like a handle to release the Mudo which works well and gives a smooth decent. This is not quite as simple as a GG3 where you can simply pull on the handle to lower. However on the positive side there is no handle to get caught on any thing during a fall and hinder a lock-up. Just make sure you have a spare 'biner that fit the hole of the Mudo well.

CONCLUSION

Is the Mudo v2 a valuable addition to the world of LRS? I'd say it definitely is. It's no small task to design and manufacture a LRS. Manuel Larios has also shown a willingness to embrace feedback to constantly increase the quality and functionality of his product. Is it the right device for you? That depends upon many factors and how you rate and value those factors. Only you will be able to determine that. If you want a bomber device specifically designed for LRS and don't mind the initial setup, rope pairing of finding the right rope in the 9.7-10.0 range, the extra work putting the device on/off and also don't mind running some type of back-up for inverted falls, then it may be ideal for you. If you're a tinker and don't mind modifying a device that's not intended for LRS, want instant lock up with smaller ropes (9.0-9.7), then a GG3* costs less, are easier to rig and lighter and more versatile, then maybe that's the device for you. Functionally with the mods I've done, the GG3* is very similar to the Mudo. Most however will not want the added burden of modifying the GG and many will value the fact that the Mudo was designed ground-up for soloing.

If you're more concerned about inverted falls and want the device itself to be able to stop them itself (without having to rely on a backup system which you should have anyway), then the SP (extinct), Revo, or inverted Grigri setup may be what is best for you but they are outside the current discussion and they each come with their challenges also. There are so many factors and only you can decide.  Another good reminder: LRS is dangerous on potentially deadly no matter what device - choose wisely and no the strengths, weaknesses and how the who LRS works together. Ultimately YOU are the backup.

Suggestions for a future version

I would love to see the issue of rope creep solved. As I mentioned above, I don't feel that it is a show stopper but it is annoying. It could be that is will be like some other rope soloing devices where rope pairing is critical and that once you find a rope that works well, you stick with brand/size and replace regularly when worn. I will continue to experiment with different ropes and setups in hopes of finding something that will have no/minimal creep. 

I can envision a future version of the Mudo that would attach with a maillon/steel 'biner, that has a horizontal 'biner hole (like most devices) and has a side cover that pivots that rotates centrally around the axle like the Silent Partner. This would allow the brake pivot and axle to be permanently attached to the device and easily opened for slipping a bite of rope around the pivot brake, then rotating back closed and held closed by inserting a ‘biner through the body that connects it to the belay loop. This would eliminate the whole process of threading and and tying a rethreaded figure-8 rope, which would make it make it easier for multi-pitching. It would also mean there are not multiple separate parts to drop or get lost. Finally it would aesthetically be a nicer/simpler solution and also potentially lighter. 

I also think the body could be made with thinner walls or aluminum body. Either of these would lighten the device which I feel is over-built. 

It would be nice to have the "HowNot2" guys do some pull and drop test on the Mudo. I don't think there will be an issue with the device breaking, however it would be interesting to gather info re rope slippage. Slippage per se, is not dangerous and can even provide a bit of a cushioned stop. However, slippage beyond a certain point could be disconcerting and dangerous if it is going to significantly increase the length of a fall. Some devices are designed so specifically so that beyond a certain factor, the rope will slip. 

A side note regarding feed and back-feed. Ease of feed and back-feed are indirectly proportional. That is, the easier a device feeds (the more transparent it is while climbing) the more prone to back-feed it will be. Therefore the goal is a happy balance between the two. I think the Mudo has found that balance. It can be adjusted slightly by varying the angle of the body to the brake pivot which is controlled by how tightly or loosely it is rigged to both harnesses.

As always, these are my observations to date and YMMV.

——————————————————————