SAKA FLAKA (Fixed Leg Advancing Knee Ascender) Mod

Phil

Carpal tunnel level member
Location
Oak Lawn, IL
Hello and good afternoon. Phil here. I'm creating this thread as promised in this other thread: https://www.treebuzz.com/forum/threads/homemade-knee-ascender-new.48660/

The discussion revolved around the concept of a fixed knee ascender. Read the other thread for the details that have lead to me making this post and the linked video. I filmed it on my phone so apologies for the portrait view. I think it is still clear what is going on. I will eventually get a video of me actually using it but this was all I had time for. As with most of our ascending gear, technique plays a roll in tool efficacy. This device works very smooth for me. My only gripe is that over time my pant leg rides up and over the knee strap and I start looking like half a Canadian Mounty. But I have cool socks so whatever.

FLAKA Mod walkthrough:

List of parts:
Climbing Innovations for stand alone bungee and/or SAKA device: https://climbing-innovations.myshopify.com/collections/all
Chicago bolts: https://a.co/d/6LabplS
High Density Plastic: https://a.co/d/cSDbQYL
Blue knee strap: https://a.co/d/eoImQeq
5/8" webbing: https://a.co/d/gD6zPuH
Whipping Twine: https://a.co/d/57dOWkx
Glue: https://a.co/d/dibWU6F

FLAKA Camp Turbo Variant: Mini carabiner was switched to a locking one later. Note that due to the lack of a factory rear bolt and option for a second mounting bolt on the ascender body, securing the ascender to the tube sleeve required getting creative with how I stitched the 5/8 webbing. The SAKA bolts are hands down a better option for security and stability when mounted to the tube sleeve. The camp version works but I'd pick the SAKA if given a choice.

FLAKA Camp Turbo.jpg


I didn't say it at the end of the video I made, but if you watched the whole thing, thanks for fartin' around with me :)
 
Thank you! And thank you for the parts list. My October project is now planned out and most of the R&D has been done by you already. FLAKA
I hope it works as well for you as it does for me. If you have questions along the way feel free to reach out. It's worth noting that because of the webbing pocket made for the mini locking carabiner, the strength of the load bearing part of the foot strap will be how you glue/stitch it to the center of the tube sleeve. The area under and near that red hockey tape. If you're planning on making your own tube sleeve, I can share info for the tubing I used and how I glued them each inside the sleeve.
 
I hope it works as well for you as it does for me. If you have questions along the way feel free to reach out. It's worth noting that because of the webbing pocket made for the mini locking carabiner, the strength of the load bearing part of the foot strap will be how you glue/stitch it to the center of the tube sleeve. The area under and near that red hockey tape. If you're planning on making your own tube sleeve, I can share info for the tubing I used and how I glued them each inside the sleeve.
Thanks Phil. I have a SAKA same as the one you used that I will be modifying. If I run into an issue I will reach out. I will share my contraption when I finish it for your FLAKA approval.
 
Would, at a minimum, a stirrup on your pants cuff help?

I envision a cuff in the form of a 'spat' too. This idea comes from gaitors used with old-school 3 pin cross country ski gaitors.
Hell yes it would. My vision for the pants stirrup would be that the stirrup is attached inside the pant leg at a height just above the top of your boot. That a different dimension for different boots I know. The stirrup engages on your sock, then you put your foot in your boot so the stirrup is inside. Kind of hidden in its existence. Not sure if feeling the stirrup between your sock and boot insole would be bothersome or not, but that's the vision that popped in my head. I did buy lace hooks to make a pant hook like what's on Clogger zeros and some other climbing pants. Didn't work very well but I think that's because I had garbage materials.
 

This has been around for a little while.

Fk5 l'arboriste grimpeur on Instagram might have developed it? Not sure. Looks cool though
I've seen and held one of those up close. Spoke with the dude who used it and its not very durable. the rope around the boot gets abused and ruined pretty quick if you actually production climb. The length of the rigid piece is one size. I mentioned in my video, the length of the tube sleeve, or in this case the rigid rope column, is critical to fluid movement. One size only really works well for certain folks. Everyone else gets the "it kinda works" experience.
 
I am gonna see if I can make it work with my HAAS, because this solves some issues I have not otherwise resolved for myself.
 
Good job, @Phil, at designing and explaining your knee ascender so well. Looks good. The one I made is a bit simpler, but it probably does not have the range of movement away from the knee as yours does. Where you used that blue strap around your leg, I used the elastic hook-and-loop strap from the Notch Talon handsaw leg mount. It holds the ascender and allows me to stretch my knee away a few inches but probably not as far as your clever design. Good work.
 
When Richard made his original How To Make your own DIY Haas video (he edited the name to saka later) one observation was that putting two tubes instead of one into a flat band compromised the don't-bendiness of the semirigid link. The original Haas had the tube concentric with the hollow braid which resisted bending more.

I propose a FLAAS where an original gen Haas gets shrinktubed and use a saw scabbard elastic strap at the knee. Just ignore the ascent bungee. The A3 looks like its spliced Haas style in the pic. Maybe an A3 already is a FLAAS.

With the load inside your ankle instead of on top of your foot doesn't it torque your ankle?


Great to see you fabricating and experimenting:)
 
use a saw scabbard elastic strap at the knee
This had crossed my mind. I did not go this route because I had a self imposed restriction of keeping the saka as close to original function as possible. I also wanted to see how the bungee capture would work since it was material already in the system and I could fine tune its elasticity based on stopper knot location. Turns out it worked very well. The knee strap I use, I already had a few of because I bought some for use in my handsaw leg scabbards and didn't want to buy an elastic one just because. Not sure how the elastic knee strap would work after repeated weighting and unweighting during ascent either. Would it rotate on the leg, move up or down, be too floppy and walk the pant leg up even more than mine already does? Maybe none of those and it would be even better than my config. In the video I showed the rear of the ascender and how I had initially put a regular cinch strap through the gap between the two upper bolts. If there was an elastic strap that fit in that space, I would give it a try.

There was a bit of a technique curve to learn as well. Since I would allow my foot and knee to drift out of line with the rope when weighted, once I go to raise raise my foot, I find a reverse "J" or "L" motion works very well. On leg raise, I first move my foot back to center of body, in line with a straight rope, while at the same time moving my foot up. My knee naturally follows this same movement because bones and science. This greatly reduced the tendency of the tube sleeve wanting to taco or bow out and reduce the drag from the cam and ascender body. I find myself visualizing this motion during ascent and it has put me "in tune" with the device.
 
I've seen and held one of those up close. Spoke with the dude who used it and its not very durable. the rope around the boot gets abused and ruined pretty quick if you actually production climb. The length of the rigid piece is one size. I mentioned in my video, the length of the tube sleeve, or in this case the rigid rope column, is critical to fluid movement. One size only really works well for certain folks. Everyone else gets the "it kinda works" experience.
I have one and it's not too good and way too expensive. HAAS and SAKA are both way better.
 
I tried to pull a Kevin Bingham RW demo climb move ascending through a crotch the other day and having the Haas free from my knee wasn't enough. It articulated at first but eventually was just an impediment and had to be popped off the rope. Pantin and knee in the crotch for the final heave ho. And lots of biceps. My body votes that I'm no Kevin Bingham!

Kind of a climbing gear acid test.

I've never damaged the rope loop under my boot, but it is inside a sleeve. My only gripe is it's a bit bulky if you stand with your arch on a branch.
 
Thank you! And thank you for the parts list. My October project is now planned out and most of the R&D has been done by you already. FLAKA
For what its worth, since I made the video I decided to swap out the dmm xsre for a simple screw link. Mostly out of a desire to use the xsre elsewhere. I also went back to wrapping the ankle strap once around the tube sleeve before I put it in the cam to cinch it down which helps prevent the tube sleeve and stirrup under my boot from pushing straight down when I raised my leg.
 
Interesting mod; thanks for sharing.

I see the Illinois Trees poster on your workshop wall. And then I see you're in IL, so that makes sense. But my totally off-topic question is -- why do you have the poster upside down? :)
 

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