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OP Purple Link Cam Failure


ajfclark

14-Oct-2009
3:13:27 PM

Since we're talking about cams and stuff, anyone else read about this purple link cam failure?

"...when I fell the cam was at or less than a foot below my feet. The placement was in a pocket where the crack above and below the placement tapered out. It was cammed to the middle lobe ... The stem was angled down about 45 to 60 degrees"

More pics: http://picasaweb.google.com/bpfarra/Purple# [Edit: Link now dead]

Michael Lane from Omega Pacific responded: "Link Cams are specialty pieces ... [and are] vulnerable to damage and failure if subjected to torsional loading that requires the relationship of the head/axle and the rock to change much during a fall, especially if the placement is bottoming or loads the lower-end linkages to be stressed over any kind of edge or intrusion ... the fact that their lobes consist of hinged components when other cams are made of a single piece of material made this [torsional/bending loading issue is] an obvious characteristic from the start."

Furthermore he reports that Omega Pacific are taking action in response:

"1) We're looking at new link designs that strengthen the hinges to make them stronger.
2) We'll be rewriting our literature to emphasize proper placement of Link Cams with a clear warning about the potential consequences of placing them in ways they could be subject to damage."

More here: http://www.rockclimbing.com/cgi-bin/forum/gforum.cgi?post=2183828;sb=post_latest_reply;so=ASC;forum_view=forum_view_collapsed;


ambyeok

14-Oct-2009
4:10:55 PM

"Link Cams are specialty pieces"...

Doesnt their advertising say you can get rid of your other gear cause you only need link cams? Now they say they are specialty pieces? From what I can see their specialty is that they are especially uselss.


IdratherbeclimbingM9

14-Oct-2009
4:15:52 PM

On 14/10/2009 ambyeok wrote:
>"Link Cams are specialty pieces"...
>
>Doesnt there advertising say you can get rid of your other gear cause
>you only need link cams? Now they say they are specialty pieces? From what
>I can see their specialty is that they are especially uselss.

How so?

They may have changed their market spiel, but I like their units. If they make stronger ones in the future, then all the better!


ambyeok

14-Oct-2009
4:28:36 PM

On 14/10/2009 IdratherbeclimbingM9 wrote:
>On 14/10/2009 ambyeok wrote:
>>From what I can see their specialty is that they are especially uselss.
>
>How so?

Well, im pretty full of it cause ive never used one. So all ive seen is the ads and this picture of one broken. My gut instinct says too many moving parts (Im still scared of normal cams). So... please consider my defamation against the good people of Link Cams cheerfully withdrawn. Looking foward to hearing some opinions from people who have actually used them.


IdratherbeclimbingM9

14-Oct-2009
4:46:55 PM

I have the two original sized ones, and use them.
I like to try to keep them for use at belays due the greater variety of cracks that two items will fit; ... especially if that is all I had to work with at the end of a lead.
I like them enough to covet the newer smaller sized ones they have bought out.

The breakage of the above item sounds like similar would happen to some other slcds in torqued-head load situations. I expect the vast majority of loading situations for them would be well within specification of what they can handle.


ajfclark

14-Oct-2009
4:57:30 PM

Except that when retracted the heads of these cams are substantially longer. They might catch on something that a regular cam wouldn't in the same placement. If they do catch/bottom out/whatever they can apply more leverage due to that length. Given the thickness of the material around the joints in the lobes, it's not surprising that's where the breakage occurred.

That said I still think they are a very useful piece of gear, it's just something else to be more aware of when using them maybe?

patto

14-Oct-2009
5:01:04 PM

This is old news. Link cams are great but it should be bloody obvious that they are fragile if loaded incorrectly. Use them appropriately and they are fine.

On 14/10/2009 IdratherbeclimbingM9 wrote:
>The breakage of the above item sounds like similar would happen to some
>other slcds in torqued-head load situations. I expect the vast majority
>of loading situations for them would be well within specification of what
>they can handle.

Most cams I have dealt with can handle torqued head load situations. They are not ideal but in general they do not break. Link cams are particularly vunerable because they have long dangly hinged bits that get caught when the cam is torqued.


nmonteith

14-Oct-2009
5:04:20 PM

I love them. I've used all the 4 sizes and consider them my #1 bit of trad gear. They are especially good for those panic situations (usually involving laybacks) where you need to place gear blindly. They tend to morph into non-perfect placements.

mikepatt

14-Oct-2009
5:10:07 PM

On 14/10/2009 patto wrote:
they have long dangly hinged bits that get caught when
>the cam is torqued.

Has anyone actually caught their long dangly (hinged) bits in a torqued cam?
and BTW, patto, are you still trying to steal my identity? :-)


IdratherbeclimbingM9

14-Oct-2009
5:12:26 PM

On 14/10/2009 patto wrote:
>Link cams are particularly vunerable because they have long dangly hinged bits that get caught when the cam is torqued.

You must use shallower placements than I like, as in my experience, if the narrow end of the range is utilised, then alignment issues are not cross-tortional to the head, unless (as is the case for the broken item), it is placed in a pod.^{(Heh, heh, heh ~> I prefer to use tri-cams in pods!)}
If the placement takes the wider range end then I have found it is not an issue, unless one goes out of their way to find a rickety placement!


wallwombat

15-Oct-2009
11:31:36 AM

I just noticed Rock Hardware have one of these on sale at the moment.


IdratherbeclimbingM9

15-Oct-2009
12:04:35 PM

On 14/10/2009 nmonteith wrote:
>I love them. I've used all the 4 sizes and consider them my #1 bit of trad
>gear. They are especially good for those panic situations (usually involving
>laybacks) where you need to place gear blindly. They tend to morph into
>non-perfect placements.

Comparatively speaking, how do you find the smaller sizes (0.5 & 0.75) re frequency/usefulness of placements vs the larger sizes (1 & 2) ?

Have you found the smaller sizes to be more or less duplicating your pre-existing similar sized slcd's? ... ~> as I am debating if they are overkill, for my rack that has abundant cams in that range not to mention nuts!


nmonteith

15-Oct-2009
12:11:29 PM

I actually only own the red and gold versions, but have climbed on others racks which have the two
smaller ones. They are all just as useful as each other... they overlap each other so 4 cams is equiv to
carrying about 6 normal cams. What i like most about them is that they work so well in offset crack placements, but also in parallel cracks. Also having one emergency cam on my rack can give me a lot
more options when i've used everything else at the end of a long pitch. I just ordered the two smaller
ones.... :-)


IdratherbeclimbingM9

15-Oct-2009
12:24:34 PM

Thanks for the feedback.

On 15/10/2009 nmonteith wrote:
>I just ordered the two smaller ones.... :-)

Yes, the on-special prices at the moment are definitely tempting!

gfdonc

15-Oct-2009
12:30:18 PM

I bought two of these in February - the green (0.7) and red (size 1).

They're great. Climbing that long route in Austria, we only took those two cams. Yes they're heavier than any normal cam but you get such a great range of sizes covered - I'd have otherwise taken 4 cams to cover the range.

I thought the size 2 was a bit too heavy and the small sizes covered by the purple one (size 0.4? no wonder these Americans couldn't invent a simple grading system) a bit marginal. So the two middle sizes suited me very well, and overlap everything up to about a 2.5 Friend.

Talking with some overseas climbers in the Pines a few months back they said they'd stopped using them because of unreliability issues with the trigger wires, but I believe Omega Pacific have changed the design to resolve that issue.


nmonteith

15-Oct-2009
12:44:01 PM

p.s. I haven't done any serious aiding for a while - but i reckon these link cams would be awesome as
'crack jumars' for speed climbing on splitter crack pitches. Just attach one (or two if you can get them!)
to each etrier - then just plug and go all the way up the pitch, stopping occasionally to place some other
form of protection. I used this technique (with 3 sizes of normal cams on each etrier) many years ago
when i did an Ozy in a day ascent (inc driving to and from Melbourne!)


nmonteith

15-Oct-2009
12:46:34 PM

On 15/10/2009 gfdonc wrote:
>Talking with some overseas climbers in the Pines a few months back they
>said they'd stopped using them because of unreliability issues with the
>trigger wires, but I believe Omega Pacific have changed the design to resolve
>that issue.

The first generation had a bodgy plastic attachment point on the trigger wire that kept breaking. They
replaced that bit within 6 months of releasing the cams on the market. I've had both the old and new
generations and the new one has had zero problems with trigger wires.


nmonteith

1-Feb-2010
11:16:26 AM

I broke my purple Link Cam on the weekend. One of the cam lobes broke at the lower axle/rivet. The force placed on the cam was about 45 degrees sideways and I shock loaded it pretty hard. It obviously tried to twist - and the torsional forces broke the delicate mechanism being forced against the rock. It caused a total failure of the piece and I took the resulting plummet.


pmonks

1-Feb-2010
11:30:28 AM

On 1/02/2010 nmonteith wrote:
>I broke my purple Link Cam on the weekend. One of the cam lobes broke at
>the lower axle/rivet. The force placed on the cam was about 45 degrees
>sideways and I shock loaded it pretty hard. It obviously tried to twist
>- and the torsional forces broke the delicate mechanism being forced against
>the rock. It caused a total failure of the piece and I took the resulting
>plummet.

If you have a chance could you post some photos? Being a big fan of link cams (at least in the larger sizes) I'm keen to know more about their envelope.

egosan

1-Feb-2010
11:31:42 AM

Nice work, Neil. Happy to see you post this rather than the coroner. Will you be reporting
the incident to Omega Pacific?

On 1/02/2010 nmonteith wrote:
>I broke my purple Link Cam on the weekend. One of the cam lobes broke at
>the lower axle/rivet. The force placed on the cam was about 45 degrees
>sideways and I shock loaded it pretty hard. It obviously tried to twist
>- and the torsional forces broke the delicate mechanism being forced against
>the rock. It caused a total failure of the piece and I took the resulting
>plummet.

There are 41 messages in this topic.