Comments on: Belay Device Friction Test

By: Top Posts on All Climbing from Jan 2009 — All Climbing

Top Posts on All Climbing from Jan 2009 — All Climbing — Sun, 01 Feb 2009 17:36:11 +0000

[...] Belay Device Friction Test Posted on Tuesday, January 13th, 2009 in Climbing Gear Following up on their climbing shoe rubber friction test, Spadout has recently released a belay device friction test. While highly unscientific not rigorous, this is at least a nice starting point for an objective debate over which tube-style belay device is best (they did not test auto-blocking devices). Their overriding view on the tests were:We believe two key factors that distinguish belay devices are the range of friction the device can provide as well as the maximum friction it can achieve. If you enjoy the content on this site, please make sure to subscribe to the RSS feed. [...]

By: Jim Titt

Jim Titt — Sun, 18 Jan 2009 10:41:35 +0000

Hi Tom
You may not be aware that this test was completely discredited on rockclimbing.com recently and for good reasons:-

The tester appeared to have no knowledge of the fundamental principles behind this type of device and failed to realise that a static test will give meaningless results.
The results are wildly innacurate, with some devices being given a braking power 50 times that of others which both theory and practice tell us is not the case.
The results contradict the findings of other highly regarded tests by qualified, independant testing authorities such as the German TÜV .

The test as it stands is completely wrong in almost every respect, gives a false picture of the relative effectiveness of an essential piece of safety equpment and has no place in climbing-related literature.

I am an English engineer, living in Germany and owner of Bolt Products manufacturing rock anchors (bolts) for climbers. I have no commercial interest in any of the manufacturers concerned, do not produce any similar article to those tested and have no connection with the author of the test.
I have however over the years done some work on the theory and testing of belay devices and in my profesional opinion the test is completely worthless.

(I have an unpublished paper on belay devices which includes all the required information and basic theory if you would like to confirm this for yourself or obtain a third party opinion)

Yours
Jim

By: Tom Markiewicz

Tom Markiewicz — Wed, 14 Jan 2009 01:16:46 +0000

Pete, you have a valid point. “Highly unscientific” are not the right words for what I was trying to imply.

Probably the better phrasing would have been “not rigorous” because by definition they did use the scientific method thus making it scientific.

Post has been edited and thanks for calling that to my attention!

By: Pete

Pete — Tue, 13 Jan 2009 23:49:07 +0000

I wouldn’t call it “highly” unscientific, that’s unnecessarily harsh. Their methodology is perhaps a little basic to fully explore the performance of the devices they tested, but it’s a reasonable start without making things too complicated. Furthermore it’s repeatable as they’ve fully disclosed their methodology and they’ve provided their results data for us to draw our own conclusions.

All things considered it’s a worthwhile start at objective performance testing and comparison for a complex category of devices and certainly not worthy of being derided as unscientific.

By: l0k1

l0k1 — Tue, 13 Jan 2009 23:44:01 +0000

for me it’s definitely the trango jaws. my climbing partner weighs more than twice what I weigh. I tried a number of different belay devices before settling on the jaws. I can easily and smoothly belay my partner with the jaws, far more so than with any other device I’ve tried.