Components of a Self-Advancing Knee Ascender (SAKA)

[Dave Rohach]

Well, thanks for pointing out the wonderful health issues that I have to look forward to! Thanks, guys, for such a vivid futuristic life awaiting me! Just remember "Karma's a Bitch", I think most of us know 1 or 2, from our past. Wait, I may have just wet my pants. UUGGGHHH.


Dave6390 in WI

 

[NE Tree]

Ok, this just took me 15 minutes to do, while we were talking about it.View attachment 34728
Really a quick throw together.


Dave6390 in WI

That's really similar to mine Dave. Mine is made from 1/4 inch am steel rigging line. Has been working great for about a year now.

 

[Dave Rohach]

Amsteel is strong as hell, and practically indestructible. That's a perfect choice, I think Arlo, commented on the ascender being capable of life support, I would think the Amsteel would follow suit as well. So that's a Win/Win. The 3/8" Tenex can be considered the same. I do believe?


Dave6390 in WI

 

[Richard Mumford-yoyoman]

Just a couple things to add to the recent conversation.
Length of the device: Think of walking up a rope like walking up the stairs, MOST people have no problem taking the standard steps under most situations.
If you are using a bicycle or backward bicycle movement to walk up a rope it may not be as efficient as just lifting your feet straight up and down. If you are using the motion to keep the ascender engaged, pointing your toes or doing anything else special that you would not do walking up a ladder, there maybe something, NQR (not quite right), about the setup.
Just some food for thought.

 

[monkeylove]

Well, at my age I can finish a cup of coffee and go piss in 15 minutes... everything else takes longer...

And then go piss again in 15 minutes because the stream just ain't what it used to be.

 

[Dave Rohach]

It even smells like freshly brewed coffee! What a waste!


Dave6390 in WI

 

[JeffGu]

All true. Somebody famous once said that growing old wasn't for wussies.

 

[Dave Rohach]

We'll see in another 10-15 years. I'm still paying for the stupid shite I did when I was in my 20's-30's! Ouch!


Dave6390 in WI

 

[Climber429]

Ok, this just took me 15 minutes to do, while we were talking about it.View attachment 34728
Really a quick throw together.


Dave6390 in WI

NICE!!

 

[Climber429]

Just a couple things to add to the recent conversation.
Length of the device: Think of walking up a rope like walking up the stairs, MOST people have no problem taking the standard steps under most situations.
If you are using a bicycle or backward bicycle movement to walk up a rope it may not be as efficient as just lifting your feet straight up and down. If you are using the motion to keep the ascender engaged, pointing your toes or doing anything else special that you would not do walking up a ladder, there maybe something, NQR (not quite right), about the setup.
Just some food for thought.

I recall one of your vids with you explaining your "stride" or walking up one step or two. Makes sense and would require me to dial it in, the bungee(s), to a personal length/preference. As for length of SAKA, do you agree with the length or top of ascender being level with the bend of the knee if i may ask?

 

[Dave Rohach]

Ok, here's a pic with a tape to see the position.


It appears to sit @ 22" from bottom of boot to top of ascender. This puts the bottom of the ascender just above my knee @ a 90* bend. Hopefully, this and any info that YoYoMan gives you will be sufficient for your build. Best of Luck.


Dave6390 in WI

 

[Climber429]

Ok, here's a pic with a tape to see the position.View attachment 34741
View attachment 34742

It appears to sit @ 22" from bottom of boot to top of ascender. This puts the bottom of the ascender just above my knee @ a 90* bend. Hopefully, this and any info that YoYoMan gives you will be sufficient for your build. Best of Luck.


Dave6390 in WI

Perfect! I get ya now, for some reason i figured the top of the ascender would be just below or at knee level.

Appreciate the pic! Explains it perfect!

 

[Dave Rohach]

You definitely Don't want the 2 devices running into one another. It'll take some practice to calculate your stride, I personally don't like taking long foot lifts, like it was said earlier in the thread, normal ladder or stair stepping range, this will keep your knees and thighs from tiring as quickly on long ascents. Glad I could help.


Dave6390 in WI

 

[Climber429]

You definitely Don't want the 2 devices running into one another. It'll take some practice to calculate your stride, I personally don't like taking long foot lifts, like it was said earlier in the thread, normal ladder or stair stepping range, this will keep your knees and thighs from tiring as quickly on long ascents. Glad I could help.


Dave6390 in WI

Not too many trees up here (that i know of just yet) taller than 100-120ft local to me so i got 200ft hank of 1/2" XTC Fire & NE Ultra-Vee.

Might buy another shorter 100-120' or so hank of something else when possible, maybe smaller diameter, different strand, static, not really sure yet. I wouldn't mind buying something i could use to anchor to the tree base to my TIP/branch, kinda like SRT up to a crotch with either a ring or pulley up top for DdRT attachment to save on abrasion and also give me options to switch systems with time if that makes sense..

Will both ascenders work on both my 1/2" ropes?

 

[Dave Rohach]

The only reason that I could think of is how you are stepping, toes up, toes down? If your rope has a habit of constantly coming out, you can clip a non-life support carabiner (really small one) or a quick link in the foot ascenders' stopper hole.
As usual, a picture says 1,000 words.


Dave6390 in WI

 

[Richard Mumford-yoyoman]

....this and any info that YoYoMan gives you will be sufficient for your build. Best of Luck.


Dave6390 in WI

Ok, do something for me, walk up to a set of stairs. Who do you know that can't walk up those comfortably? Most stairs are built to a 7-11 type code, 7" rise -+, 11" run. So put your first foot on the first stair....now the other on the next....step up, how far did you rise? About 14 inches right? Lets make it about 16 inches just 'cause tree climbers are cool. Now the optimum travel for MOST situations is to be able to lift the leg with the foot ascender about 16 inches before it contacts the ascender at about knee level. This in essence provides between able to walk the stairs one or two at time, that is what the SAKA should provide. Picture you are standing in front of those stars again but with your SAKA and foot ascender, you lift your foot ascender up and it should reach the height of that second stair before it contacts the ascender on the SAKA.
If that does not work, the SAKA could be adjusted in length. Children would do well with a shorter length as it is difficult to raise the rest of their gear high enough to be comfortable.
Now what we did was without the rest of our gear, so the next thing is to look at the other gear that may prevent our steps.
Adjustable bridge...adjustable tending tether...suitable attachment placement...extending the footloop above the laces...
............to be really dialed in, ALL of this stuff has to be considered, not just where an ascender is positioned at the knee. Maybe we shouldn't even call it a knee ascender but the "upper" ascender.

 

[Dave Rohach]

Extremely well said! Thanks Richard.
Yea, tree climbers are cool, just look at a spectators face when they watch us climb!


Dave6390 in WI

 

[ARLO]

Ok, do something for me, walk up to a set of stairs. Who do you know that can't walk up those comfortably? Most stairs are built to a 7-11 type code, 7" rise -+, 11" run. So put your first foot on the first stair....now the other on the next....step up, how far did you rise? About 14 inches right? Lets make it about 16 inches just 'cause tree climbers are cool. Now the optimum travel for MOST situations is to be able to lift the leg with the foot ascender about 16 inches before it contacts the ascender at about knee level. This in essence provides between able to walk the stairs one or two at time, that is what the SAKA should provide. Picture you are standing in front of those stars again but with your SAKA and foot ascender, you lift your foot ascender up and it should reach the height of that second stair before it contacts the ascender on the SAKA.
If that does not work, the SAKA could be adjusted in length. Children would do well with a shorter length as it is difficult to raise the rest of their gear high enough to be comfortable.
Now what we did was without the rest of our gear, so the next thing is to look at the other gear that may prevent our steps.
Adjustable bridge...adjustable tending tether...suitable attachment placement...extending the footloop above the laces...
............to be really dialed in, ALL of this stuff has to be considered, not just where an ascender is positioned at the knee. Maybe we shouldn't even call it a knee ascender but the "upper" ascender.

Hello Richard, after looking at the new commercial version of the SAKA I stand corrected regarding it functioning as life support. It appears that the commercial version has the bottom hole of the ascender bolted to the body of the SAKA so there is no way to attach a life-support tether to the bottom of the ascender. In my home-made versions this is not the case and I can easily insert a screw-lock into the bottom hole of the ascender and attach a tether to the screw lock. The lack of this capability on the commercial SAKA could be a problem for climbers who want at least 2 life-support connections to the rope while rope-walking. So now I am wondering if you might want to market a version of the SAKA that has an ascender with 2 holes in the bottom of the ascender, which would allow the connection of a life-support tether?

 

[Tom Dunlap]

How/why would you have a life support connection in your system below your waist?

In a fall support the climber would be upside down. If you want to have a second connection point it should be above the waist.

There are standards and regulations that deal with what is expected of fall arrest and life support.

 

[Richard Mumford-yoyoman]

What Tom said, it's not what the SAKA is for. Those that want a second, life support, rope friendly connection, perhaps just for ascent, probably find placing a prusik above above the multiscender most practical.