RRC Archives

caribe wrote:

geckodru wrote:Option 1. Lightly grip the Sum between the pinky and palm of your break hand.

Gripping the Sum and holding the Sum down appears to be the problem. Light grip might become death grip for the 0.75 sec that it takes to deck someone.
-If this grip also controls the directionality of the device and if the autoblock depends on device directionality, does not this grip also possibly lead to a crippled device?

The Sum is designed to be perpendicular the body/guide rope when feeding slack. Any variation that involves you feeding slack with the Sum not perpendicular to your body is misusing the device. Just don't do it!

As for the light grip, if a quick upward tug of the guide rope doesn't pull the device out of your hand, you need to adjust how you're feeding slack. For me, with a 9" hand span, only my pinky & palm touch the Sum when feeding slack. For my partner, with her 7" hand span, she has a slightly different technique that does involve her ring finger.

Your strongest fingers remain off the device; instead always wrapped in break position around the rope. If the device is perpendicular, it will be tugged upward and out of your grip. If you hold the device down, you are creating a straight !-pass for the rope to flow through.

Let me repeat myself:
Any variation that involves you feeding slack with the Sum not perpendicular to your body is misusing the device. Just don't do it!

http://www.youtube.com/watch?v=Gczsrz1wkmo
Did you see this? Can you see how option 1 is a death trap? They were feeding slack with the Sum orthogonal to the standing belayer. Reiteration of a moot point is a moot point.

caribe wrote:http://www.youtube.com/watch?v=Gczsrz1wkmo
Did you see this? Can you see how option 1 is a death trap? They were feeding slack with the Sum orthogonal to the standing belayer. Reiteration of a moot point is a moot point.

Yeah I saw that video. There's no rope in the device. Even if Todd put a rope in the Sum, he has a three finger, white knuckle grip on the device. The only finger he doesn't have on the Sum is his pinky. It is great demonstration of how not to hold the Sum.

Also, that video demonstrate that some Sums will not cam if you grip them tightly. Even if the cam fails, the device works like a standard ATC and will stop a climber if you have your break hand on.

In the video where Todd was pulling rope through, he did not have a break hand on the rope.

geckodru wrote:In the video where Todd was pulling rope through, he did not have a break hand on the rope.

And that is the issue. If you can (or you are encouraged to) hold the device instead of the rope you will, and if you do the task of your break hand has been divided. The division of labor could cost the belayer fractions of a second when she/ he needs them. This is the intellectual crux of this conversation and hence my Batman comment earlier. There is no way I am picking on Spidey.

geckodru wrote:

caribe wrote:http://www.youtube.com/watch?v=Gczsrz1wkmo
Did you see this? Can you see how option 1 is a death trap? They were feeding slack with the Sum orthogonal to the standing belayer. Reiteration of a moot point is a moot point.

Yeah I saw that video. There's no rope in the device. Even if Todd put a rope in the Sum, he has a three finger, white knuckle grip on the device. The only finger he doesn't have on the Sum is his pinky. It is great demonstration of how not to hold the Sum.

Also, that video demonstrate that some Sums will not cam if you grip them tightly. Even if the cam fails, the device works like a standard ATC and will stop a climber if you have your break hand on.

In the video where Todd was pulling rope through, he did not have a break hand on the rope.

The idea that some Sums will not cam if you grip them tightly, while some will, is what disturbs me. That seems like an inconsistency in manufacturing, and if there is one inconsistency, how do we know there aren't more?

ok goddammit, i've never seen or used or watched the linked videos, but what's the mystery about pinching this SOB? is this suppose to hold the release lever from actuating/cam engagement? one finger/pinky versus 3 fingers??? is that engineering???? WTF.

i hope i've just missed the point.-sorry

clif wrote:but what's the mystery about pinching this SOB? is this suppose [prevent] cam engagement?

yes

clif wrote:one finger/pinky versus 3 fingers??? is that engineering?

The point of the video is that it don't take much pinching.

thanks Art.

lost my last post but this seems key so i'll repost....

if there is some casual curve to the allowable pressure which disables the MOST CRITICAL aspect of the device that's seems retarded to me. HANDS OFF the side of the thing and just lock off the rope, end of story. yeah, making sure the 'z' axis rotation is free is really good and important, BUT, one should never get confused about grabbing the device to do so as this proper alignment should be (IF THE LOCKING BINER is the correct size) an automatic reflex of the rope loading.

I hope this thread has demonstrated that the device design has an unrecoverable flawed. It has for me. I think it has for some others too. Just ask yourself WWRND (What would Ralph Nader Do)? I actually owned a Corvair post-Nader. The year was 1982 and the car was a 1960 model--first year of production--unsafe at any speed. It just about killed me on more than one occasion. I traded it in for a 650 CC Honda CB straight four street machine (motorcycle) in 1985. But I was in denial for 3 years . . . I loved that car. http://en.wikipedia.org/wiki/Chevrolet_Corvair Thought I own the world getting laid in this machine. I remember struggling to forgive her whenever I was on my back under the car fucking with the clutch cable.
The question is why? Why get attached even after it threw the shadow of death over me and others? Why not get rid of it sooner? Why not use the head and not the heart?

geckodru wrote:I have a lot of experience with the Faders Sum. When Faders was testing the Sum, I was lucky enough to be invited into the preproduction test group.

Since the device is no longer on the market because of safety concerns, I'd say that group failed in their task.

There is a reason the Sum is no longer on the market... as these previous 9 pages have shown, it's a complex design loaded with potential pitfalls. Of course, an outright recall as this sketchball, hypersensitive device truly deserves would be an admission of liability by the manufacturer. Our new friend geckodru has driven this point home with his complex and arcane posts, all of which comfortably miss the point that the SUM is a complex and arcane device to use, dooming it to statistical inferiority on the bell curve of safety. Of course, as always it still takes a sketchy belayer to make decking a reality (all devices and techniques, including the hip belay and Munter hitch, are safe IF used correctly), but it is clear that the many quirks and nuances of the SUM makes that reality all the more likely to occur.