Why professionals dislike RADS?

Was watching a video review of the CT Quick Roll the other day where you can practically see Nice Guy Dave hold his nose when he brings up RADS - ahh! epiphany!

I've been yo-yo'ing on a Gri gri for most of my climbing, and it's by far my favorite system to climb on. @FluffyFish has said about the same, some other rec climbers too. (I'll save why I think RADS is a really good beginner SRT system for another post.)

Even after getting fairly comfortable on a Rope Wrench, I still climb RADS quite a bit of the time. Rope walking is good, but it has never struck me as being that much amazingly better. Or, RADS has never sucked for me as much as professional arborists make it sound like it should suck.

That disconnect had bothered me until I got I real saddle, and left the rock harness at home.

RADS on a rope bridge sucks. On a long rope bridge, it really really sucks. Kept slamming the ascender into the Gri gri. When I was paying more attention I could keep em apart, but progress was slow and awkward. No wonder professionals don't like it. On a rock harness belay loop close to your navel - what a beginner is likely starting with - the whole system works so much better.

That's where the epiphany came in. In his review of the CT Quick Roll, Dave mentions the advantages of having a pulley on the ascender, and how RADS people will probably like it because you really do want to save those precious inches of travel space.

Sounds great on paper, but even as an avid RADS climber, I couldn't care less. Ahhhh-ha!

It may be my size (I'm 6'1"), or the specifics of the harness w/ small locking 'biner on the Gri gri or well-tuned footloop length - but when climbing RADS, I can't touch the ascender to the Gri gri at all! I have as much room as I want, even with the pulley hanging off the ascender on a biner.

So, I've got this suspicion that the geometry of RADS works way better for some people than others, and that at the very least the harness has a lot to do with it.



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I think efficiency is the issue for work climbers. During ascent on any of the multicender devices or Rope Wrench for that matter the rope is dropping straight through, the climber shouldn't sit back on their system unless they need to rest. With a RADS you have a fairly convoluted rope path so it can never match the ascent effiency of the current SRT multicenders. RADS is very popular with rec climbers, if there's no rush, no worries.


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The reason it's actually an optimal starter SRT system for rec climbers is speed/efficiency up the rope doesn't matter. The good news is if a climber is on the heavier side for example, they can just work on pulling on the tail which is 3:1 and they stay sitting back on their harness through the climb "cycle". It makes climbing possible for many climbers who would have a lot of trouble otherwise and they can build their strength doing it so they have the option to try more efficient systems later on.

As Hachetation mentioned, a RADS can be optimized within its limitations. It can also be optimized with climbing technique, the left side of the body (one leg or the other in a foot loop) and left hand on the redirect ascender is moving 1:1 on the rope, the right arm is pulling the tail 3:1 so if you get your motion well tuned you can move reasonably fast, but not as fast and as efficient as more current SRT setups.

It is confusing to differentiate rec climbing from work climbing technique. They are the same and then they are not. A work climber can feel completely confident dismissing a rec climber's gear configuration or technique but they can be totally wrong, a pure rec climber (as opposed to a work climber on a rec climb) may develop or utilize techniques that work very well for them, completely valid.

I work climb now for a living, when I was a straight up rec climber with a white collar day job I got plenty of arbitrary and unrequested criticism from work climbers who did not understand the gear or technique I was using. Especially when I was ahead of the curve on SRT (pre-rope wrench). So it's productive to observe and ask questions before shooting from the hip. It's understandable to jump all over something that seems odd, non-standard or inefficient but there can be wisdom in unconventional ways.
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Climbing well on a Rope wrench, Runner, BDB, Akimbo etc. requires quite a bit of muscle/movement integration, people who've been doing it for awhile can forget that you don't arrive at efficient in minutes no matter how good the system. If you're in extremely good physical condition (most work climbers) and are open to feeling awkward for a half-hour you can get efficient pretty quickly on modern SRT systems. What we do so well (climb efficiently) can quickly become routine and taken for granted. In the meantime a dedicated rec climber can like a RADS much better than a Rope Wrench, it can take much longer or never to get smooth on a wrench if your overall conditioning and/or body/mass index is not favorable for fast vertical ascent .


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In his review of the CT Quick Roll, Dave mentions the advantages of having a pulley on the ascender, and how RADS people will probably like it because you really do want to save those precious inches of travel space.
Watching the video, it's obvious that Dave has no real experience with RADS ... his set-up was sub-par (bridge was too long) and his technique was less than stellar (place your foot below your arse before stepping up). I also think the Petzl Rollclip saves more "precious inches" than the CT Quick Roll in a RADS set-up. Dave did hit on the Quick Roll's main advantage in that it reduces the amount of gear needed when returning from a limb walk using SRT.

I have tried the Rope Runner, Rope Wrench, Hitch Hiker II, and a rope walker system with a chest ascender. Of those, I prefer rope walking, but dislike the switch-over needed to descend (then switch-over again when I need to ascend further) . The RR, RW & HH2 made me realize I very much dislike having to tend a climbing system. Being a part time hack, I'm under no pressure to climb fast ... and besides, I have a Wraptor to use when the climb is long.

My rope climbing preference is RADS using a Petzl ID on 1/2" rope. No tending rig around my neck, and I don't have to unload the system (remove my weight from it) when switching between ascend to descend. I sometimes add a foot ascender to the set-up to allow both legs to provide lift.

Is RADS an efficient climbing system? That answer depends on what's important to you. RADS is an SRT system, so one does gain a foot of progress for each foot of rope passed. RADS is not as fast as other SRT systems, so it may be considered inefficient to those who think of time as money. The best climbing system is the one YOU feel the most comfortable with. To me, the RADS system feels very safe and secure when climbing. I prefer RADS, and it really doesn't matter what anyone else thinks.

Bob Bob

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RADS / Yo-Yo is a great beginner system. I've found it's much easier to set up a novice on a short climb with a RADS system then a traditional Blakes system. It's perfect for people that want to go climbing once.

RADS / Yo-Yo is slow, very slow compared to different systems. It is also equipment heavy, both in actual weight and cost.

Great system to know and have in the toolbox. I've used it before and surely will use it again while recreational climbing. I don't think it would be my first choice for a working climb mostly due to the slowness.
Hoowasat, but isn't RADS actually a 3:1 not a 1:1? I climb on it frequently and use it for my captain hook setup as well, and I do believe that I pull 3 feet of rope through for every foot I rise up the line. That's what makes it less efficient than a true 1:1 anyway right? That and the friction through 3 different points.


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Hoowasat, but isn't RADS actually a 3:1 not a 1:1? I climb on it frequently and use it for my captain hook setup as well, and I do believe that I pull 3 feet of rope through for every foot I rise up the line. That's what makes it less efficient than a true 1:1 anyway right? That and the friction through 3 different points.
You are correct. It is a 3:1.


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Hoowasat, but isn't RADS actually a 3:1 not a 1:1? I climb on it frequently and use it for my captain hook setup as well, and I do believe that I pull 3 feet of rope through for every foot I rise up the line. That's what makes it less efficient than a true 1:1 anyway right? That and the friction through 3 different points.
No, it is 1:1. The amount of rope dropping below you as you ascend moves at the same rate as the section of rope above you. Just because it makes two 180° turns does not increase or reduce that rate. Try this: ascend a few feet up, secure an item to the rope below you but above the ground, then continue to ascend. You will find that item remains at the same distance above the ground regardless how high you ascend.
Nice vid!
i view this as a 'closed system' with only 1 path to ground (in electrical model view) to conserve all forces, so can foldthem against target. If Zer0 frictions effort in SRT or DdRT would be same, technique choice would be totally to whichever system worked best in your own power band. Also speed vs. effort, in DdRT effort is longer but less moment to moment effort to the same sum. As add friction to pulley/or bare support makes SRT more totally efficient, unless puts work outside your powerband. Even tho something is mechanically more efficient, it must be within your ergonomics to deploy at such efficiency. DdRT is also a retrievable rig. SRT will get more bounce/elasticity. Would take 200# to get same elastic response from dual support legs as 100# on single. Elasticity is a function of how much tensile strength is 'invaded'.
i would say that you can't lift yourself on the load side without switching some weight to the control side with hand pull. This hand pull weight would then be on control side to lift load side. Lift becomes 2:1 : use 50# on control side as lift of 50# on load side, 50# effort holding/moving 100# bod.
1 proof to 2:1 is there are 2 legs of line supporting carcass, 1 leg of 'waste' rope ejected from system(Zer0 tension past hand hold/friction hitch).
(If someone else is pulling you up thru control leg, then single support pulls you up, and 1 leg of line ejects from system)
Another: Must shorten both legs of support 1 foot to lift self 1 foot .
So must pull 10ft. to move up 5ft. etc.
It will take as much to keep moving as sit still holding with hand, + frictions.
Frictions would tax against lift, but then help on static hold.
To initiate / break thru inertia will take some more effort, then carry on/keep inertia moving.
To me a round log on the ground is sitting on it's own pivot. Half wants to move forward, half wants to fall backwards. (kinda also a positive mental attitude thing rather than pessimistic as approach work)
>>must break inertia of stillness (big effort pulse)
>>then continue roll of inertia is lots less work
>>only fighting imperfections and inefficiencies at this point, cuz half of round wants to fall back, half wants to fall forward, and inertia is broken thru the stillness.
So expect everything to need that high volume pulse thru system to init; then carry on.
Kinda like 2 cars next to each other at same speed/direction are moving,but not passing each other. Zer0 is just a speed, relative to surroundings. In own perspective to each other, cars aren't moving!
The best way i found to init a tough roll, weather tire or log etc.
(shows principle, but not exactly work-safest)
Stand on the pull/ go to side/towards target textures of tire or log etc.
reach over to the push/opposite side and grab upwards
Kinda jump up half a foot,the slam down with bodyweight and leg force pulses impacting thru system, on target side. Allowing hand grab to at same time pull up with leg force as leg force is pushing down.
This is 'my' bodyweight + 2xEffort (here effort input is leg impact) that have tried to present/champion for sometime.
The round load is a 1st class lever, the input of leg force down, is matched by legforce lift up by hand as equal opposites, passed the 1st class lever that is only lever that reverses direction. So that the usually 'wasted' equal and opposite force running away from work, is re-directed to apply on workload again. But to also include bodyweight.
Usually bodyweight and equal and opposite of work effort are 'expressed' /wasted into the ground as i push log etc. But here i try to show to put those 'wastes' to work on load,rather than as a separate 'ground connection'. Want only 1 'electrical path to ground' in closed system, then a 1st class lever to reverse the 'waste' back to work on the load!
DdRT is SAME! Only, efforts against own weight, but on log roll applying even bodyweight!
This is how i figured out the log roll, and getting over 8x return from a 5x jig etc., rescued someone much heavier etc. ( lifted 360# scared, epilectic tree climber with foot stuck in tree crotch upwards with 1 pulley and my 130#; initially went to stuck boot but saw that screaming scared hairy bear paw grabbing at me like a drowning man would , and went overhead and lifted rather than become 2nd victim)
sitting in DdRT. Feeling the forces, examining,then projecting that same strategy onto work.
Kinda a gymnastics thingy, to observe and digest forces thru own frame, and conspire on how to re-align and leverage those forces to success by conducting forces differently thru own self.

Of course leg effort input to be multiplied is greater than arm input.
Impacting into system with effort and bodyweight gives more power as a pulse thru system.
Truly, truly with this 2 people can seem to be doing the same thing with drastically different results; for the 2nd hand reach can be very deftly applied without notice,might just seem to watchers like are stabilizing self....
i use legs of support to show each leg counts
>>but also that these rope tension legs could be jsut as well table leg compression supports that would share weight equally /if equally applied,then be subject to geometries of deflections.
load/control legs then to differentiate functions and directions intuitively, this then follows into multiple pulley examinations.
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Well-Known Member
If you're talking about the amount of rope to pull to move one foot, it's a 3:1.

If you're talking about mechanical advantage, it's a 2:1. Pull 100 lbs to raise your 200 lbs body.
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