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Kong Back-Up for use in top rope soloing

Original Post
tooTALLtim · · Boulder, CO · Joined Apr 2007 · Points: 1,280

I was interested in getting into top rope soloing, and so I read about it online, and talked with friends that TR solo. From what I’ve gathered, the Petzl Mini Traxion and now the Micro Traxion are far and away the most common TR soloing devices.

The Traxion family are designed as progress capture pulleys.Traxions function by allowing the rope to pass over the pulley in one direction, while a cam arm brakes the rope when the rope is loaded in the opposite direction; this camming action is accomplished with a toothed cam.Traxions are intended for hauling applications, though Petzl recognizes their use as top rope soloing devices, and has written much about top rope soloing. While effective, these devices are not engineered for top rope soloing. 

I could not find a device (on the market) explicitly designed for top rope soloing. With the lack of devices specifically engineered for top rope soloing, I looked to the fall-protection world. I was tipped off to this path after reading rockhard’s MountainProject post that the Kong Back-Up is used by many in Australia for top rope soloing. I was interested in using a device for top rope soloing that was intended to catch falls, and not for hauling loads, so I obtained a Kong Back-up, and started messing around with it!

The Kong Back-Up is a guided type fall arrester, being CE EN353-2 certified, and used primarily in the rope access world. When a rope access technician is utilizing their main line for ascent and descent, they are connected to their secondary line via the Back-up, or similar back up device (e.g. C.A.M.P. Goblin, Heightec Quantum and Vector, Petzl ASAP, DMM Buddy; all are CE EN353-2 certified). Should the technician become disconnected from their main line, or the main line fail, they would fall onto their secondary line, and their fall would be arrested by their guided type fall arrester. These devices are intended to catch a fall onto a static rope. There are a few configurations that these guided type fall arrester devices can be attached to the technician; some configurations require a shock-absorbing lanyard (known in climbing circles asa Screamer). Not all situations require a shock-absorbing lanyard, specifically those that keep the device close to technician, i.e. minimal slack between the technician and the device.

My testing utilized a Sterling HTP 3/8” diameter static rope. This rope is 0.475 mm thinner than the 10 mm minimum rope diameter as per Kong’s requirements. I didn’t have access to a static rope that met Kong’s requirements (10-12 mm), but decided that the Sterling rope would suffice since it is only between 16 and 5 human hairs too skinny.

tooTALLtim · · Boulder, CO · Joined Apr 2007 · Points: 1,280

I initially hung a length of rope and slid the Back-Up up and down the rope in its up-down mode (they call it “Free Mode”).  This up-down mode is designed to allow the Back-Up to slide up and down the rope as the technician is working. It slide easily on the rope, though would not slide down the rope in all orientations; the Back-Up had to held upright, otherwise it would brake. This orientation was facilitated by the steel carabiner that came with the Back-up: the steel carabiner’s weight kept the Back-Up low in relation to the attachment point.

I then looked at several carabiners for clipping the Back-Up to my harness. I wanted to keep the Back-Up from cross-loading on the carabiner, so after looking at a few orientation-restricting carabiners (Black Diamond Gridlock, Grivel Clepsydra, Sterling Falcon Talon, many more), I decided on the DMM Belay Master 2. The Belay Master was my choice for two reasons: it keeps the Back-Up oriented forward, and the plastic flap (they call it a “special clip”) can be used to attach the carabiner to a chest harness! I drilled out two holes in the flap, and tied a small string through the holes. When clipping in, I made sure that the carabiner was oriented as you see in the photo, so I couldn’t pull the flap open.

After playing with the Back-Up for a bit, I was interested in how the braking was actuated. I flipped open the plate, and clipped it back on the rope. I found that what I’ll call the Clip-In Cam pressed against the rope, pressed it against what I’ll call the Main Arm, and the Main Arm rotates and pinches the rope against what I’ll call the Stationary Foot. Functionally, this looks a lot like the C.A.M.P. Goblin.

After playing with the Back-Up for a bit, I wanted to find some failure scenarios. I found that if the Clip-In Cam is disabled (held up, not allowed to cam on the rope), the Back-Up will slide up and down the rope without braking ONLY if the device is kept in a vertical orientation. While the Clip-In Cam is disabled, the Back-Up will catch the rope and brake if the device rotates in relation to the rope; the rope presses against the top of the Main Arm, and rotates the Main Arm so that it presses against the Stationary Foot. This was reassuring to me, as I thought that even if something jams the Clip-In Cam (shirt, sling, etc), the Back-Up will still catch and brake if my body rotates out of purely vertical. 

tooTALLtim · · Boulder, CO · Joined Apr 2007 · Points: 1,280

After messing around with disabling the Clip-In Cam, I realized that this is basically how the Heightec Quantum functions, since the Quantum does not have an equivalent Clip-In Cam. Also, I’m guessing that if I performed the same test on the C.A.M.P. Goblin, I’d arrive at the same result.

One way that the Back-Up differs from the Traxion family is that you will DISABLE the Back-Up if you grab it while falling, or something else pulls down on the Back-Up WITHOUT loading the carabiner clipped into the Back-Up. This is identified in the Back-Up’s Instructions of Use

“Warning: like other systems and self locking knots e.g. “Prussik” the “BACK-UP” blocks only if the load is applied to the connector only: never load the “BACK-UP” IN ANY OTHER WAY, as for example in figures 8 and 9: “BACK-UP” WILL SLIDE ALONG THE ROPE: DANGER OF DEATH!” 

Though I don’t think that grabbing the Back-Up while falling is going to be a concern, it is a failure mode that isn’t inherent in the Traxions. I don’t imagine anyone able to hold the Back-Up in away that the carabiner doesn’t catch some load and engage the Back-Up, and, if you remember, the Clip-In Cam can be disabled, and the Back-Up will still brake if the rope presses against the Main Arm and rotates into the Stationary Foot. I was also thinking a situation where someone might use a Traxion as their primary arrestor, and the Back-Up below it, but I think that it could generate Figure 9 and disable the Back-Up. Of note, the Petzl ASAP will lock up even if you grab it.

tooTALLtim · · Boulder, CO · Joined Apr 2007 · Points: 1,280

The Back-Up also has an up-only mode (they call it “Lock Mode”), where it will slide up the rope, but automatically brake when moved down; this mode is similar to the Traxion’s functionality. I was interested in this functionality, since of the other guided type fall arresters, only this and the C.A.M.P. Goblin have this option.

tooTALLtim · · Boulder, CO · Joined Apr 2007 · Points: 1,280

This is ability to change modes is achieved by a button and lever arm. Pressing the button lifts a head out of a hole, and allows you to slide it to the other hole. It feels like there is a spring within the Main Arm that is adjusted. 

Looking at the Main Arm in both modes, the up-down mode keeps the Main Arm parallel with the rope, while the up-only mode rotates the Main Arm so that it held in tension against the Stationary Foot (the "Up-only" labeled picture wouldn't load, but it is the second photo).

My first impression when testing the up-only mode is that it was much harder to slide up the rope. I wanted to quantify this resistance, so I tested both modes with a fishing scale. I held the carabiner as if it was clipped into my belay device, and the fishing scale attached to the string I’d tied in the flap.

 I tested up-down mode first, and found it averaged 0.13 kg of force to slide the Back-Up up the rope; this is after I tared the weight of the whole thing at rest.

 I then tested the up-only mode, and found it averaged 0.80 kg of force to slide the Back-Up up the rope. Dramatic!

I was interested where the Micro Traxion fared in this trial, so I tied a small bit of string through the clip in point, and attached the fishing scale. I found the Mini Traxion to average 0.25 kg of force to slide it up the rope. A bit more than the Back-Up in up-down mode, and a lot less than the Back-Up in up-only mode.

In the end, I didn’t feel like this fishing scale testing was quite apples to apples, as:

-I didn’t tare the weight of the Micro Traxion

-I was keeping the Back-Up oriented, and not the Micro Traxion

-The range of force for the Back-Up was pretty wide since the Back-Up was kept oriented

If I had to make a qualitative assessment, I’d say that the Back-Up (in up-down mode) and Micro Traxion were quite similar, while the Back-Up in up-only mode was a lot more work to pull up the rope.

I made a simple chest harness to keep the Back-Up high so I wouldn’t take a short fall when I wanted to hang. I dislike things around my neck, so I made two points that go around my shoulders and meet at my sternum. I tied the small string in the Belay Master to a short bungee cord, and tied that through the chest harness. I think I’ll clean this up a bit, but it worked for initial testing.

I was now ready to try the Back-Up outside! I didn’t want to jump on something difficult as I was still learning about the Back-Up, so I setup a TR on a 30 metre 5.5 climb in Eldorado Canyon. The route was less than vertical, and I tied the end of the rope so that it was suspended off the ground. I put the Back-Up in up-down mode, and climbed up and down the route a couple of times. The Back-Up slid easily up the rope, and I had to coerce it a little to slide back down the rope. I found that it caught the rope and braked me when I wanted, even when I was quite close to the rope and orienting it vertical to the rope.

I was happy with this initial outside test, and hopped back outside a few days later on a vertical climb (Metamorphosis). I rapped in with a Grigri and stopped about 20 m from the end of the rope. I pulled up the slack, butterfly coiled it, and tied it off to provide weight. I then put an ascender on the rope, and clipped it to my belay loop. I unweighted the Grigri, and attached the Back-Up to my belay loop above the Grigri. I removed the Grigri, and clipped a Yates Screamer to my belay loop, and the other end of the Screamer I attached to the rope with a Maillon Rapide brand quicklink; Scott Bennett posted a photo of this method in a Mountain Project post, though I disliked: girth-hitching to the belay loop, using a standard (not shock-absorbing) sling. I then weighted the Back-Up, removed the ascender, and tied some bungee cord through my chest harness to the string I’d tied in the flap of the Belay Master; I was then ready to climb!

After all this build-up, the climbing was quite fun! I started with the Back-Up in up-down mode, and it fed nicely and braked when I leaned back slightly. It still did not slide down the rope easily, and I needed one hand to help it down. After climbing up for a bit, I switched it to up-only mode. The up-only mode didn’t allow the rope to feed as easily through the Back-Up, as expected. But while climbing, I didn’t really notice it, as the force was on my chest harness, and I was focused on climbing! I enjoyed the mental reassurance of knowing the Back-Up couldn’t slide down the rope at all, though the Back-Up would rotate on the carabiner a bit as it had difficulty sliding up the rope due to the extra friction; I recreated the rotation in the photo. I didn’t like that the Back-Up rotated on the carabiner, so I’m thinking about putting some spacers or tape on the carabiner to keep it oriented.

A few thoughts after trying the Back-Up outside:

-The rope fed smoothly most of the time, but it was annoying having it rarely rotate and stop feeding rope. Keeping it from rotating it is high on the things-to-figure-out-next list.

-I could definitely see down-climbing a little with the Back-Up, especially in up-down mode. It takes a little finagling to get the angle right, but it’s possible.

-I liked that the Back-Up grabbed the rope quickly in up-down mode, and I felt confident trying hard moves knowing I could just sit back and it would stop me right away.

-I like that the Back-Up is designed to catch falls.


Thanks for reading this all! If you’d like to share some questions or constructive comments, please do so. Oh, and, yer’ gonna die.

Ģnöfudør Ðrænk · · In the vicinity of 43 deg l… · Joined Nov 2017 · Points: 2

Nice review.  I have been using the Camp Goblin which is very similar to the Kong Back-up, and I have not encountered any rotation problems similar to what you recorded.  After a year of use, the Goblin has been trouble free.   I cant guess why there is a difference.

tooTALLtim · · Boulder, CO · Joined Apr 2007 · Points: 1,280
Ģnöfudør Ðrænk wrote:

Nice review.  I have been using the Camp Goblin which is very similar to the Kong Back-up, and I have not encountered any rotation problems similar to what you recorded.  After a year of use, the Goblin has been trouble free.   I cant guess why there is a difference.

Thank you for the reply! I'll look into getting my hands on a Camp Goblin and trying it out. Could you perhaps post a picture of your TR setup?

Ģnöfudør Ðrænk · · In the vicinity of 43 deg l… · Joined Nov 2017 · Points: 2
tooTALLtim wrote:

Thank you for the reply! I'll look into getting my hands on a Camp Goblin and trying it out. Could you perhaps post a picture of your TR setup?

Gear is in storage until winter lets up, but my setup is simple:  quicklink goblin to belay loop and weight on the bottom. That's generally it.

On complicated routes, I add another ascender on a second line, quickdrawed to leg loop for back up.

Never bothered with chest harness.  I have had countless falls with no problems.

Nate Doyle · · Sierra Foothills · Joined Feb 2016 · Points: 39

...nevermind, I read about it...

I'll read about it on my own of course when not on my cell but, I wonder what makes these devices different from the others in their design and this in regards to catching falls. For the most part it seems like a very similar device to Traxions, Roll N Lock et al. Minus the teeth (or clamp style flat teeth like on the Roll N Lock.) Seems like camming devices that use different hardware/tech to basically achieve exactly the same results. Or am I missing something?

Sunny-D · · SLC, Utah · Joined Aug 2006 · Points: 700

Great review! thanks for taking the time to post this up.  

Dallen 

Nathan Hui · · San Diego, CA · Joined Feb 2016 · Points: 0

Cams provide force multiplication.  One of the design parameters for cams is how much force multiplication you want.  A more aggressive cam will catch faster and more reliably, but will put greater forces on the rope (less deceleration distance).  A less aggressive cam will catch slower, and has a higher chance of not catching, but this will reduce peak forces on the rope.  This is a gross simplification of the actual parameters, but should be roughly correct.  Has something also to do with whether or not the cam is spring loaded, cam surface area and shape, etc.

Insert name · · Hell · Joined Dec 2011 · Points: 60

99.9% sure on this, but for what it is worth, but the Kong backup and ISC Red are only considered a reliable backup on ropes that are weighted beneath the device (tightlines, rope with weight off ground to allow system to feed, etc).

I can verify the Kong falls in this category for anyone. 

Brocky · · Unknown Hometown · Joined Jun 2016 · Points: 0

You might be able to reduce the Backup sideways movement by attaching the string to the carabiner, on each side, trapping the device, and connect the bungee cord to the string.  You could also eliminate the string by girth hitching the bungee directly on the carabiner, trapping the device in the middle of the hitch.

George Bracksieck · · Unknown Hometown · Joined Oct 2008 · Points: 1,590

I have a new, unused Kong Backup for $139. 

tooTALLtim · · Boulder, CO · Joined Apr 2007 · Points: 1,280
PosiDave wrote:

99.9% sure on this, but for what it is worth, but the Kong backup and ISC Red are only considered a reliable backup on ropes that are weighted beneath the device (tightlines, rope with weight off ground to allow system to feed, etc).

I can verify the Kong falls in this category for anyone. 

Hi PosiDave,

could you please cite/verify your source? I breezed through Kong's Instructions of Use for the Back-Up again and could find no mention of this requirement. English starts on page 26. 

Is it possible I need to read through EN 12841 type A or EN 353 standards?

tooTALLtim · · Boulder, CO · Joined Apr 2007 · Points: 1,280
Brocky wrote:

You could also eliminate the string by girth hitching the bungee directly on the carabiner, trapping the device in the middle of the hitch.

I'm going to try that out next time I go out, and will report back! It just dumped several inches in Boulder, so it'll be a little bit.

Insert name · · Hell · Joined Dec 2011 · Points: 60
tooTALLtim wrote:

Hi PosiDave,

could you please cite/verify your source? I breezed through Kong's Instructions of Use for the Back-Up again and could find no mention of this requirement. English starts on page 26. 

Is it possible I need to read through EN 12841 type A or EN 353 standards?

I am used to it in the Rope access world. Let me send a email and find out what they say.

HY Chung · · Taiwan · Joined Apr 2017 · Points: 0

hi tooTALLtim,

Great review!! I'm wondering have you tried an overhang route and how's Back-up doing? Currently I've a Petzl Microcender placed between my belay loop and chest harness to do the TR solo, however I found the rope would stop feeding when the route goes overhang. Does this happen to Back-up?

tooTALLtim · · Boulder, CO · Joined Apr 2007 · Points: 1,280
HY Chung wrote:

hi tooTALLtim,

Great review!! I'm wondering have you tried an overhang route and how's Back-up doing? Currently I've a Petzl Microcender placed between my belay loop and chest harness to do the TR solo, however I found the rope would stop feeding when the route goes overhang. Does this happen to Back-up

Thank you HY! I haven't tried the Back-Up on an overhanging route yet. It just snowed a bunch here, but I'll report back when I get a chance to try the Back-Up on something overhanging. Thank you for the suggestion!

Conor Mark · · Asheville, NC · Joined Jul 2014 · Points: 690




Nathan Hui · · San Diego, CA · Joined Feb 2016 · Points: 0
Conor Mark wrote:



I thought these devices had to be tended with one hand for going down?  At least that's what I've been seeing on the Petzl ZigZag product videos, but maybe it's just that one?

Guideline #1: Don't be a jerk.

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