Treeflex chest ascender

[Tom Dunlap]

There is a long list of things to rave about the Treeflex. One of them is the front loops to attach a chest ascender for SRT.

Ever since I got my TF I've been fiddling with some sort of rig to keep the top of the chest ascender fair. My first solution was a setup patterned after the Petzl Torse. This worked but the webbing chafed my scrawny neck. There were a couple of variations on this configuration but they didn't quite work. During the ascent the top would droop a little and allow just a bit of a slack or candy cane above the ascender.

What I need is something with an elastic cord built in. Being able to adjust the tension would be a bonus.

Take a look at the latest solution.

The blue webbing is one inch tubular to eliminate neck chafing.
The elastic cord is 3/16" diameter I think. When I cut the cord I made sure that it was plenty long. After a couple of climbs I chopped off the end to the current length. When I ascend I pull the elastic through the cordlock to put some tension on the upper eye of the ascender. When I change over to climbing I just slack off the cordlock and leave the rig on. While I'm climbing I don't even notice it being on my chest. It would be simple to remove the rig too.
The split ring and mini figure eight are used to keep the ends of the elastic cord up and away from the ascender. Using two pieces keeps them fair to the whole setup.

When I'm done climbing and take my Treeflex off the neck tender and chest ascender stay attached.

 

[Chris_Cowell]

Re: Chest ascender on pretty much any harness

Tom

My version of the neck bungee is attached. Works well for me across a range of harnesses e.g. the Petzl Navaho selection, Petzl Sequoia SRT, plus the obvious.

Using either a half round Maillon Rapide or a karabiner in the lower hole allows a Croll (chest ascender) to adapt to pretty much any harness.

Chris

 

[Tom Dunlap]

Re: Chest ascender on pretty much any harness

Chris,

Thanks for sharing the picture. that is very clever!

Having the adjuster up and over to the side is a nice detail. Version II will look more like yours.

Mine only has two climbs on it and I always consider these setups works in progress.

 

[treetraipser]

Re: Chest ascender on pretty much any harness

are you using this system as a back up?

 

[Mahk_Adams]

Re: Chest ascender on pretty much any harness

Nice Chris, very simple solution.

 

[Kevin]

There's something about having a cord around my neck that triggers a concern.
I would opt for a loop runner across the back that the arms can slip through.

 

[Tom Dunlap]

Traipser,

A chest ascender is a component in some SRT configurations. It could be looked at as a backup I guess. The way I look at it is a second attachment point. When the chest ascender is setup right it allows the climber to hang very comfortably at anytime during the ascent. If it were considered just a back up it would be more integral with another tool instead of working on its own.

Kevin,

What is your concern? Choking? I guess it could happen. the elastic isn't that strong and if it did snag I bet that it would slip out of the cord lock. speaking of the cordlock, to address this issue I'm going to remove the stopper knot in mine so that the cord could slip out. thanks for helping me make it just a bit better. A work in progress!

 

[Kevin]

That would be a concern Tom, either choking or getting your neck snapped in a fall.

 

[Tom Dunlap]

I doubt that either would ever happen Kevin. The elastic has so much stretch that it would probably slip over my head before it gekked me.

How could my neck be snapped in a fall from the tether?

 

[The_REVerend]

Just a Croll in wolves clothing!

 

[Kevin]

In a short fall if a stub or branch got caught in the loop and that key ring broke the cord now becomes a noose.
The cord might break or pull through before that happens but if it gets bunched up at the adjuster and can't get through the hole something else might give.
It's a long shot but the potential is there.

 

[Tom Dunlap]

Agreed...long shot.

This is going to go into my 'windshield engineering' file to ponder while I'm driving. Right now I'm convinced that some part of the system would break a long time before there would be a risk of getting choked.

 

[Chris_Cowell]

Re: Chest Ascender for pretty much any harness

Kevin

That's not the first time I've heard concern over choking risk when talking about neck bungees.

You are correct, the risk is there. But overall, I'm not sure that the more commonly used alternatives are better....

Chris

 

[TLHamel]

Re: Chest Ascender for pretty much any harness

I could choke on my T-shirt if I tried hard enough. How about the climber that got hung up in his footlock strop and the top-rope during a competition?

 

[Kevin]

Re: Chest Ascender for pretty much any harness

If one person uses it then the risk is lower but when a few hundred people start using the same method the risk escalates.
If it happens once in twenty years and it costs a life is it worth the risk?
I know you can get hit by a car crossing the street too.
Awareness is the key to safety.

 

[familytree]

Re: Chest Ascender for pretty much any harness

hey chris, i would have to disagree with you as far as the other harnesses being more of a chokeing hazard as others, simply because it attaches to the rear of the harness, not around the neck, although i do agree with both you and tom that it would be hard for your set up to pose a choking threat

i use the croll with my treemotion, not an easy task by any means, requires a lot more equipment and is difficult to unattach if desired, both you and tom have nice simple solutions, because i dont use srt during work, purely for canopy access, i do want to take the chest ascender off during my work climb, which makes your set up perfect

 

[Lazarus2]

Re: In-efficient Chest Ascender Straps

The bungee could easily be a choking threat, by a branch pulling up the cord from over the shoulder, because of the stretch. I doubt this would be a real danger though, as the cord should snap - depends how strong it is.

A non stretch chest harness is no real risk - other industry uses full body harnesses as standard; any real risk would've presented itself by now.

The way they DO become a very real choking threat, is if they are left in situ, with the Croll unclipped from the harness but left to hang. Don't do it.

The Croll on a bungee isn't very efficient - allows slack and doesn't offer support - Frog walking will make it work, but again its not optimal in terms of efficiency. The key to the practical perfection of a well set up Frog walker system, is the ability to instantaniously switch between Frogging or Frog walking or branch hopping in a safe and efficient manner. Frog walking works well in dense canopies, Frogging when stradling a trunk etc.

Caving harnesses are very low slung to maximise efficiency. This is the ethos of TFX design. You can get a Croll to work with many harnesses, but it isn't as efficient as a purpose designed frogging harness.

Being able to crank up and slack off a non stretch strap is key to frogging efficiency and safety; when set up properly, the Croll is the primary support, not the back up.

 

[fhfr436]

Re: In-efficient Chest Ascender Straps

[ QUOTE ]
The Croll on a bungee isn't very efficient - allows slack and doesn't offer support

[/ QUOTE ]

The bottom of the Croll is still rigidly (non-stretchily) attached to the harness. Only the top of the Croll has the elastic - to compensate for the changing length between the shoulders and waist (front). When I've used a homemade version of a Petzl Secur, the Croll is slacking up on every cycle when I draw my legs up (and my torso curls) and the harness "stretches" away from my pelvis. An elastic link in the system would be great! If I tighten up the Secur enough to eliminate the slack, I can't get my body upright!

FYI, the Secur is just a simple strap that wraps around the back of your belt, then splits to go around each side of the neck and come back together in the upper Croll loop.

http://en.petzl.com/petzl/Produit?Produit=174

 

[Tom Dunlap]

After trying several flat webbing configurations and finding them uncomfortable I decided to go with the elastic.

I've found that with my setup the ascender stays up and fair more of the time than with the flat webbing rigs. It's a simple tug on the toggle to tighten and squeeze to loosen so I can go from one to the other smoothly.

The way that Chris has his set up is clever. Yesterday I thought of a little mod to that. Now I have to find my smaller diameter shock cord.

 

[Lazarus2]

Re: In-efficient Chest Ascender Straps

I've spent alot of airmiles using a secur.

I see it all the time with climbers using the Frog - They stand on the ground and adjust the chest harness snug.

Then they get on the rope, and don't adjust it to the sitting position, and wonder why it doesn't tail smoothly

First you have to set the leg loops tight. Then set the buckle so that it sits just down from the collar bone. Then when you sit down, crank her up!!!

This way you will find it tails supurbly, you don't have to pull yourself back up to the rope. The Petzl buckles are a joy to use - easy to slack off or tension up as required.

Bungee loops and frog walking are OK, and preferable over some dense short distances, but they aren't as ergonomically efficient as true Frogging with a supporting chest strap; you have to hold yourself upright with bent arms, take (more) shorter steps with total body weight each step.

Not that I'm trying to convince anyone - tree climbers just want to do it their way for no other reason. FWIW, My reasons are long term productivity, safety and ergonomic efficiency.