Min. diameter rope for Micro Traxion TR Solo?

What is the minimum rope diameter you confidently use with your Micro Traxion?

Looking to get into Top Rope soloing. Purchased a Micro Traxion on the basis that it's advertised as compatible with 8-11mm rope. After reading the technical information on Petzl's website for TR Soloing with the Micro Traxion, it recommends "one EN 892 dynamic single rope or EN 1891 semi-static rope of 10 mm minimum diameter."

I only have a 9.8mm rope and certainly do not want to buy a new one if I can confidently avoid it. Would appreciate hearing your advice/experience with ropes of a similar diameter using the Micro Traxion!

9.8 is basically a 10.  I micro on a 9.0 all the time with zero issue.

Thanks, Kevin! Do you use a back up ascender, and if so, which one and would you recommend it?

Most times I don't use a backup, shame on me I know.  When I do I use a Roll N Rock or Roll N Lock whatever its called, I forget.  Sometimes, like this week I just used a Grigri by itself.  

Ropes in the 9.5-10.0 range are totally normal and standard for microtrax TR solo.  Once you get to skinnier ropes (especially dynamic ropes) you have to worry more about sharp edge abrasion (and this is a risk to be aware of) and durability. 

Still - use of a backup device is strongly recommended. While many people do get away with TR soloing sans backup for years, there are also plenty of accident reports out there associated with people not using a backup and their single device failing to engage (and they take a ride). But I've never heard a report of 2 TR solo devices failing. Adding a second device is pretty minimal extra effort and adds a lot of safety margin.

I recommend the Roll N Lock for backing up the microtrax. It is similar to a microtrax but operates in a slightly different way. Also a lot less expensive.

My microtrax works just fine on a fuzzy 9.8 dynamic rope (with most of the dynamism beat out of it). Don't see much reason to use a skinnier rope unless it's a really long approach, but I'd trust the device down to 9.0 for sure...I'd just be really concerned about abrasion. Word to the wise: your redpoint rope probably isn't the best choice for TR solo, even if you just won the lottery. 200 feet of new cord will stretch a lot.

I'm using a Ropeman1 as and a stopper knot as backups. Probably overkill, I know, but I haven't died yet.

JCM wrote:

Still - use of a backup device is strongly recommended. While many people do get away with TR soloing sans backup for years, there are also plenty of accident reports out there associated with people not using a backup and their single device failing to engage (and they take a ride). But I've never heard a report of 2 TR solo devices failing. Adding a second device is pretty minimal extra effort and adds a lot of safety margin.

Funny, I've never heard of a single instance of a solo TR accident due to the device failing.

Gunkiemike wrote:

Funny, I've never heard of a single instance of a solo TR accident due to the device failing.

Well, let me tell you about a time where I had one of my devices fail (not technically an accident, but hear me out).  I use a pair of microtraxions, one held up around belly-button height with use of a chest harness, the other one ends up riding at mid-thigh height.

I wear Prana Stretch Zion pants when I climb, and they have this little webbing cinch strap on the waist.  Once, while climbing, I looked down and saw that that little piece of webbing had slipped perfectly between the teeth and the rope in such a way that it wouldn't have caught a fall. My system has a backup device, so I would have been fine if I had fallen.

I think of myself as a pretty analytical guy and I spent a lot of time thinking up possible failure modes for my system, but hadn't foreseen this possibility.  Moral of the story:  weird things happen, things you can't always predict.  Don't trust your life to a single device.

Also, to keep this relevant to the OP's question, I toprope solo on a 9.6mm dynamic rope frequently when rope soloing multipitch while seconding the pitches, and it's totally fine.  When doing toprope-only rope soloing, I prefer to use a 10mm static rope, because they are cheaper and more durable, so that way I'm not wearing out my nice dynamic rope over edges end stuff.  It's just more cost effective in the long run.

Gunkiemike wrote:

Funny, I've never heard of a single instance of a solo TR accident due to the device failing.

One of the wideboyz main device failed while lead soloing. There, now you know of a single instance.

There's also been plenty of stories of people grigris failing to engage 

Gunkiemike wrote:

Funny, I've never heard of a single instance of a solo TR accident due to the device failing.

You must not be paying attention. Microcender/Rescuecender devices are the most common culprit here (such as the example Artem cites above).  There was also an accident a while back in Squamish where someone's single device (Ushba) failed to engage and they slid to the ground. The GriGri is another common offender for randomly not catching. All devices have failure modes... strange things happen.

Also, for every accident there seem to be 10 "close-call" near-accidents, where someone's device failed to catch but they got saved by a backup device or backup knot. Had they not had those... 

Erik Strand wrote:

One of the wideboyz main device failed while lead soloing. There, now you know of a single instance.

There's also been plenty of stories of people grigris failing to engage 

That was actually a broken carabiner - the carabiner used to attach the GriGri to Tom Randall's harness failed in a high-fall factor lead fall while aid soloing. Carabiner broke. Saved by backup knot clipped to harness. Not really relevant to TR solo, since you should not be able to generate those sorts of forces.

Regarding the Tom Randall accident - this is a good argument for using a steel quicklink to attach your lead solo device (much harder to break in crossload). But, again, not a primary TR solo concern.  

GriGri not engaging (which you do mention), is a concern also for any system (lead or TR) using a GriGri to solo with.

Erik Strand wrote:

One of the wideboyz main device failed while lead soloing. There, now you know of a single instance.

There's also been plenty of stories of people grigris failing to engage 

We're not talking about LEAD SOLO.

And Grigri's not catching? Geez, I wonder if that has anything to do with Petzl's advice to keep a hand on the brake strand?

I'm not proposing that accidents can't/don't happen in solo TR. As JCM says, weird things happen. I just don't consider solo TR accidents to be commonplace, or widely reported.

Artem Vasilyev wrote:

I just looked down at the pants I'm wearing (and also TR solo in) and sure enough - they're Prana Stretch Zions with the waist tab. I certainly believe you and see what you mean. This tab could get grabbed by the rope and wedged in between the teeth and carabiner - especially since it's right there next to the device on your harness. I'd hope that the camming action would still hold - but there is no way to know if it would until it happens... and over enough repititions we all know that weird things happen. They also only need to happen only once for our well-being/life to change in some manner. This makes me wary of trusting my life to one device since you're assuming that'll you'll get 100% perfect function from one device, all the time - good reason to tie or clip backups. Picture below:

To prevent this failure mode, I now tie the little cinch strap to a belt loop to keep it tidy.

I use a 7.5mm and Wild Country Ropeman 2.  i double the rope (its a 70m) and use a ropeman 2 on each strand.  I also tie back up knots.  I havent had any trouble with the teeth cutting up the sheath . 

Gunkiemike wrote:

I'm not proposing that accidents can't/don't happen in solo TR. As JCM says, weird things happen. I just don't consider solo TR accidents to be commonplace, or widely reported.

In your original post you said "I've never heard of a single instance of a solo TR accident due to the device failing.". There have been numerous instances, some of which are widely reported (if an article in Climbing Mag counts as widely reported).

More broadly speaking, I agree that TR solo is generally pretty safe, and I think the same is true of something like sport climbing. Both have accidents though, and one should be aware of what the common accident modes are and how to prevent them. In many cases some very simple changes in practices can more-or-less eliminate some of the largest risk-driving accident causes. In sport climbing, a frequent issue is being lowered off the end of the rope. If you keep the end of the rope knotted in the bottom of the rope bag at all times as a habit, no matter what, you can essentially eliminate this risk with a minimal amount of effort.

An equivalent accident cause to consider for TR solo is the failure of a single device. It doesn't happen that often, but it definitely happens. This risk is quite easy to deal with by simply using a second device. It is minimal effort and can be a very simple and tidy system - you don't need some elaborate science project system to be safe. But adding a second device goes a long way to increasing safety margins.

To me, arguing against a second device is like arguing against knotting the end of the rope. Sure, many people get away without doing it for a long time. But it is a low-effort intervention that if practiced consistently over time will significantly reduce your chance of ending up in the ER or morgue.

---------

Anyway, back on topic: I have on numerous occasions TR soloed on a single strand of a 8.5 mm Mammut Genesis half rope, using a microtrax primary and RollnLock backup. Both devices perform very well even on this diameter. This rope setup is mainly for seconding fairly easy alpine pitches (generally after solo leading them), and I bring this up as an example of device performance on skinny ropes. However, I would not recommend this setup as a "go-to" system for normal TR soloing at the crags, due to rope stretch, sharp edge resistance, and durability concerns. A thicker rope (9.5-10.2 ish) is suggested for most normal uses - so this is due to rope performance concerns rather than device performance.

Ive used a pair of microtrax and two 8mm mammut phoenix half ropes side by side for years with great results. Lots of falls with that setup and never had an issue.

BUT.... I have had a micro trax fail while assending a series of fixed ropes near sedona. I am not sure of the exact diameter of the fixed lines but I am guessing they were right around 11mm, right at the max for the device. Once the toothed camming thing is pushed out to that limmit, there is very little contact to engage it. I was using it as a backup to a single jumar, while jugging up some lower angle terain with good feet after doing insomnia canyon. I didnt weight the rope with the trax for severel hundred feet but when I did, it slipped right through.

So be carful of using to large of a rope.

edit: and my buddy was using my other trax and jumar the same way, about 15 minutes ahead of me, same result, and definitely got his attention that day as well!

Artem Vasilyev wrote:

Quick google

Does anyone know what device failed in this incident? I didn't see it identified in the article. Thanks

Chris Jones wrote:

I use a 7.5mm and Wild Country Ropeman 2.  i double the rope (its a 70m) and use a ropeman 2 on each strand.  I also tie back up knots.  I havent had any trouble with the teeth cutting up the sheath . 

That is gnarly. What made you choose this system? How many pitches have you done with this setup? 

Those ropes are SO stretchy, I use an old single rope or a static rope because it makes life so much easier when TR soloing.