Homemade knee ascenders

Bart_

Active Member
Location
GTA
I think you have too many brummels. Ironically my rope looks identical to yours, even faded the same. Mine has one bury coming back in to form the upper eye, stay buried past the Croll body and come back out to hit the lower hole, capture through it and dive back in for about a 6 or 8" long bury. Then the bottom just goes back in after sizing a foot loop, mine only stays in about 3" and comes back out as the foot loop tightening handle. My tubing anchors just above the adjuster exit and is cinched to the upper eye by one small zip tie. Tubing inside the rope of course. So its bury-out-bury at the top and in for 3"-out at the bottom. Then slip in the tubing,, then slip in the bungee. Mine may have been 9/16 or 5/8 line, bigger may ease the splicing considering fitting the tubing inside after. I'll measure my tubing and bungee later too. Might help.
 
Last edited:

Bart_

Active Member
Location
GTA
Some measurements (that won't unfortunately make splicing less - pick a word - when splicing fights back):

thickest od final bury under ascender 0.635"
bungee 0.175 od well used (years) 0.147 new od in my splicing box, still 0.150 od at bottom anchoring knot
hard tubing 0.275 od 0.187 id tubing end is right at the foot loop adjust splice exit
hard tubing 19" long, flush at top with top edge of croll
bungee just barely tensioned with small carabiner tied at top flush to roll
upper bury 7" long after bottom edge of croll
3" of bury pass through for foot adjuster
with foot loop set 5" id easy to slip over boot there's 4" of adjuster sticking out to grab
pretty sure I tried by guess by golly, re-did the foot loop and trimmed the pull tab after
also did the length bottom of tube to roll by placing my ankle to inside of my knee, did roll splice first, placed hard tube at ankle, did foot loop and threaded bungee last

main rope cover has twinned 0.076 dia fiber bundles, squishes down to 0.41 od still not sure what dia it started life as

same unit same bungee has been running trouble free since first Haas appeared. my guess is the clearance of 0.150 bungee inside 0.187 id tubing.

made a shorter one for my son, only ankle to knee different. And you can adjust that to some degree by fiddling the foot loop. Just leave some extra pull tab you can cut off later

take care
 
Last edited:

misfit

Active Member
Location
Baton Rouge
That is interesting. This is the first time I have seen that one. I am puzzled though. I don't see any advantage to having a stiff tether between the ascender and the foot loop if the ascender is strapped to the leg. The leg will advance the ascender no less and no more than the tether will. The tether just makes it more complicated and nonadjustable for leg length.
 

Tom Lynch

Active Member
Location
Brockville
That is interesting. This is the first time I have seen that one. I am puzzled though. I don't see any advantage to having a stiff tether between the ascender and the foot loop if the ascender is strapped to the leg. The leg will advance the ascender no less and no more than the tether will. The tether just makes it more complicated and nonadjustable for leg length.
You just leave it on all day, no annoying change over or extra cordage floating around.


 

misfit

Active Member
Location
Baton Rouge
I am in the minority, but I am a fan of bungee-less knee ascenders. I have been using my own homemade one for many years, and I enjoy having no bungee and being able to leave it on at all times. I just don't see the benefit of a nonadjustable stiff tether between the ascender and foot loop as opposed to an adjustable strap or cord, but I welcome any enlightenment.
 

misfit

Active Member
Location
Baton Rouge
Strapped to your calf? It doesn’t slide down?
Take a pic sometime, I’d like to see.
Mine is strapped just below my knee with a velcro strap, and, no, it does not slide down.
This subject has been discussed before. Here is a link to one of them: https://www.treebuzz.com/forum/threads/knee-ascender-without-a-bungee.40941/

And here is a link to my post on another thread on the topic where I describe my home made knee ascender: https://www.treebuzz.com/forum/threads/new-possibly-knee-ascender.37556/#post-555240
 

Bart_

Active Member
Location
GTA
The Knoot guy has the ascender 3 or 4" below his knee joint and takes really small steps. I set mine right at the pivot axis of my knee, big steps if you want or small steps as called for. I sometimes encounter brush and twigs on the ascender and simply clear it to let the bungee act. I could see the velcro strap version getting shuffled down your calf and needing readjustment mid climb. I can see if you set the strap right in the dent between your knee and bulging calf muscle it would tend to stay put if not obstacled, but the you're giving up step size again.
 

New threads New posts

Kask Stihl NORTHEASTERN Arborists Wesspur TreeStuff.com Kask Teufelberger Westminster X-Rigging Teufelberger Tracked Lifts Climbing Innovations
Top Bottom