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Chockstone Forum - Gear Lust / Lost & Found

Rave About Your Rack Please do not post retail SPAM.

 Page 7 of 8. Messages 1 to 20 | 21 to 40 | 41 to 60 | 61 to 80 | 81 to 100 | 101 to 120 | 121 to 140 | 141 to 154
Author
Ukrainian cams?

Hawkman
12/11/2008
10:10:08 AM
>I guess it'd spread the load on the gear over a longer time as you move
>or weight the gear. Kind like suspension or dynamic rope but on a smaller
>scale, right?

I suppose so but ultimately an aid piece, that is more or less statically loaded (?), will have to hold your weight at some point.

IdratherbeclimbingM9
12/11/2008
10:14:26 AM
Hawkman wrote;
>How would the O ring help in an aid situation?
& ajfclark wrote;
>I guess it'd spread the load on the gear over a longer time as you move or weight the gear. Kind like suspension or dynamic rope but on a smaller scale, right?

Not quite (aj), but I agree that principle would also apply.

(H) Thin aid can be OK for bodyweight and hence upward progress, but rubbish for catching any subsequent fall that may happen. Anything that helps the thin aid to catch a fall is good and that is where screamers of any description help.

(aj) On second reflection thin aid either holds bodyweight or it doesn't. When pieces are so marginal that one dare not test them but ease onto them, ... and they still rip; ... then a screamer won't help in that situation.
The real world can be harsh on theory!

Post edit:
H
>hold your weight at some point
Yes. Your second post is on the money.

evanbb
12/11/2008
10:19:07 AM
On 12/11/2008 shamus wrote:
>(several years since i've
>done physics, feel free to correct) is that as they stretch, each amount
>of stretch increases the force that is exerted at each end / to stretch
>further they need more tension which puts more force on the gear.

2 of my favourite things in one post; pedantry and physics.

The goal of these Screamer type draws is to limit the shock load, which will be short duration but high magnitude. Compare the feeling of lead falling onto a dynamic versus a static rope. The fall energy will be constant (E=mgh), but the impact duration will be MUCH shorter for the static. So comparing a screamer with ripping threads and a stretchy ring, both will extend this impact duration and lower the maximum force. More than anything it helps your gear stay in. In both cases the climber's weight will be the same, so they will ultimately end up absorbing the same energy, just in dofferent ways.

Back on topic, and I notice that they've gone all the way and ripped off the BD dual axle design:
Dodgy Ukranian Rip Offs

They actually look pretty good. Are these the ones you bought Wombat?

IdratherbeclimbingM9
12/11/2008
10:21:51 AM
On 12/11/2008 shamus wrote:
>Only problem with this i can think is that while screamers act by limiting
>the force to a set amount (2kN until its torn all the way?) rubber rings
>etc all act as springs, and from what i remember (several years since i've
>done physics, feel free to correct) is that as they stretch, each amount
>of stretch increases the force that is exerted at each end / to stretch
>further they need more tension which puts more force on the gear.

Am not into physics, but thought the benefit was introduction of a greater time factor to allow dynamic components of the system to better absorb/dissipate the forces they were subject to.
... I can see a spring effect on marginal gear as being a dicey proposition, where it may survive the 1st hit but not the second.
Interesting game we play is it not?
Heh, heh, ehh?

ajfclark
12/11/2008
10:28:44 AM
On 12/11/2008 IdratherbeclimbingM9 wrote:
>... I can see a spring effect on marginal gear as being a dicey proposition, where it may survive the 1st hit but not the second.

Would several thinner rings of different lengths be better than one big one? Such that the smaller ones break absorbing some of the force but limiting the spring back to the largest unbroken ring. If the sizes were right each ring would stretch to at least the size of the next so it wouldn't shock load on a ring snapping. Would this start getting to bulky/easily tangled to be of use?

IdratherbeclimbingM9
12/11/2008
10:38:30 AM
You are probably right, but imo it would not be practical.

The beauty of the single O ring trial I did was that it was one bit of gear, (simple and uncluttered); probably would not break (ie therefore reusable on multipitch); and the situation does not arise that often anyway, so one item is not too heavy and can be used with judgement/discretion on only the piece requiring it most on any given pitch.

shamus
12/11/2008
10:38:38 AM
Complex systems in a tricky game, yes...
Both systems will result in increased time for the energy to be dissipated, but rather than treating the components individually, it is another dynamic element in a dynamic system. More saying that while during the tearing phase of a screamer, it will be limited to exerting 2kN on the gear. The stretchy ring will not be so restricted, may put far more tension on the gear or less, depending on the construction - compare the catch that would result from a few loops of bike inner tube to a 2cm-thick o-ring, and as the object stretches, the forces increase until either the fall is caught or the sling is reached and force is put directly onto the gear. But any soft-catch item is good, if i climbed hard, i'd have some :)

IdratherbeclimbingM9
12/11/2008
10:46:26 AM
>as the object stretches, the forces increase until either the fall is caught or the sling is reached and force is put directly onto the gear.

Exactly.
That is why I had a backup runner attached as well.

Most thin aid one expects to rip, but hopes it doesn't when it counts.
Thin is the fundamental concept of thin aid, and goes with the territory.

gordoste
12/02/2010
8:43:51 AM
interesting...

BD lab tests Ukrainian cams
Duncan
12/02/2010
11:25:16 AM
On 12/02/2010 gordoste wrote:
>interesting...
>
>BD lab tests Ukrainian cams

So he concludes that none of the cams meet their ratings, but three out of the four exceed the rating of a similar BD cam. The one that didn't exceed the rating of a BD cam failed at the sling, which was of unknown age.
Paul
12/02/2010
11:38:53 AM
On 12/02/2010 Duncan wrote:
>On 12/02/2010 gordoste wrote:
>>interesting...
>>
>>BD lab tests Ukrainian cams
>
>So he concludes that none of the cams meet their ratings, but three out
>of the four exceed the rating of a similar BD cam. The one that didn't
>exceed the rating of a BD cam failed at the sling, which was of unknown
>age.

Lets not forget that black diamond uses the 3 sigma rating system, with the rated breaking strength being 3 standard deviations from the mean, so their rated strength should be significantly lower than their breaking strength in most cases.

Also it was a pretty small sample size for the ukrainan cams.

aarond
12/02/2010
11:42:04 AM
Interesting...
Even if it exceeds the camalots doesnt mean they are still a good quality safe cam.
the fact that there deosnt seem to be any QC certification means one could fail at 18kn but the next could fail at 8.

i could manufacture cams in my garage at home test one and just cos it fails at 12kn doesnt mean anyone of you guys would use one.

if people are worried about expensive cams, wait til anaconda has their 30% off sales and get Kong cams then for $55... if you clip biners on them too they may even forget to scan then :-P
Duncan
12/02/2010
11:54:07 AM
On 12/02/2010 aarond wrote:
>Even if it exceeds the camalots doesnt mean they are still a good quality
>safe cam.

Well yeah, but it doesn't mean they aren't either.
cadmus
27/03/2010
3:35:44 PM
I bookmarked this thread some time ago and have been following it on and off.
I think the anecdotal BD testing article is silly for some of the reasons already mentioned. The gear could have been made an by east european company, there are others. It was old gear some guy retired long ago. There was no replication, no way to calculate variance… It was silly and clearly just for fun unless BD was trying to decrease competition, I highly doubt that.

Since 2008 I have been sending emails to the gear4rocks staff every 6 months or so asking about CE/UIAA endorsement. Several months ago they got CE certification on their first product line (without any redesigns needed). They claim on the website that they will be working on other product lines, I am guessing this is not a cheap process for them and that is the likely limiting factor. I can not fault them for that.

The website is here:
http://gear4rocks.com/
The “Links” cams are the ones that are CE certified.
The Set of 5 is here:
http://shop.gear4rocks.com/sets-of-cams/rock-climbing-links-cams-set-of-five-/prod_27.html
And the individual ones are here:
http://shop.gear4rocks.com/links-cams/cat_7.html

They are also on ebay.
http://stores.ebay.com/gear4rocks

I too was weary, but having spoke(email) with them often since this thread started, having translated a lot of the CE and Ukrainian testing certs/standards/forms... I ordered a set. I will post here after they arrive to give my impression.
best of luck,

IdratherbeclimbingM9
30/03/2010
1:40:45 PM
On 27/03/2010 cadmus wrote:
>unless BD was trying to decrease competition, I highly doubt that.

Nah, they'd never do that surely?
... What they published had the same effect though?
;-)

wallwombat
30/03/2010
2:16:57 PM
You could put a Black Diamond logo on a turd and people would buy it.

IdratherbeclimbingM9
30/03/2010
3:04:17 PM
On 30/03/2010 wallwombat wrote:
>You could put a Black Diamond logo on a turd and people would buy it.

... but only after fullfilling their belief of being able to pick it up by the clean end?
;-)
patto
30/03/2010
3:09:22 PM
On 30/03/2010 wallwombat wrote:
>You could put a Black Diamond logo on a turd and people would buy it.

As long as its a 3 sigma rated turd then I'll buy it.

That said DMM turds would be far nicer but even more expensive again.
Wendy
30/03/2010
6:10:14 PM
On 30/03/2010 wallwombat wrote:
>You could put a Black Diamond logo on a turd and people would buy it.

I suspect this about 5.10 as well.

But would they pay $449 for it?

IdratherbeclimbingM9
31/03/2010
12:59:46 PM
On 30/03/2010 Wendy wrote:
>On 30/03/2010 wallwombat wrote:
>>You could put a Black Diamond logo on a turd and people would buy it.
>
>I suspect this about 5.10 as well.
>
>But would they pay $449 for it?

Climb, clip, belay (shades of hip hop hooray); this is Wendy's 1,000th post to Chockstone.
Congratulations on achieving the milestone, ... and commiserations if simeyomeone gives you a hard time over it!
:)

 Page 7 of 8. Messages 1 to 20 | 21 to 40 | 41 to 60 | 61 to 80 | 81 to 100 | 101 to 120 | 121 to 140 | 141 to 154
There are 154 messages in this topic.

 

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