If the design is that touchy, so be it, but I think the degree to which is it sensitive to placement is not as readiliy obvious as the fact that it is sensitive to placement. Make sense?

Given the fall, I would have also expected this cam to hold, or at least to pull under torque, but not to break. Rightly or wrongly, I guess.

It would be interesting to see if another link cam would hold this fall.

It does. I would say the inability [for anyone] to really make that judgment call of degrees should be a caveat to all to avoid such enclosed placements, particularly where the stem can not be statically aligned with the fall force vector at the time of placement. I strongly disagree with OP if they are saying it would be alright if only the stem had been free to rotate - you might get away with it, but it's a inherently a bad idea to allow the stem to rotate the head under any circumstance as far as I'm concerned.

We part company here, in my view it performed as well as could be expected it would under such circumstances. And I don't mean to be derogatory at all, but I technically] still consider this a classic case of pilot error.


I think the analysis Michael is presenting says the cam was fine...

healyje: I strongly disagree with OP if they are saying it would be alright if only the stem had been free to rotate - you might get away with it, but it's a inherently a bad idea to allow the stem to rotate the head under any circumstance as far as I'm concerned.

1) Always place cams so that the head of the cam is perpendicular to the stem during a fall. It’s not always enough to know that you’ve got a flexible stem that will orient in the direction of a fall. That stem is placing a lot of force on the head of the unit and that force can compromise your placement or damage the equipment. That’s good advice no matter what kind of cam you’re using.
2) Be sure to place cams so that, if they do shift during loading, they will not come into contact with edges, nubbins or other features that can put side-loads on the cam lobes. This is a good idea for all cams, too, but perhaps most relevant when placing Link Cams due to the fact that so much more leverage can be applied to the lobe assemblies when they’re unfolded than with other cam designs.

So,how many failed Aliens vs. # in use? How many failed Link Cams vs.# in use?

Link Cams don't appear to place anywhere C4's or other leading cams do.In theory they are more versatile,but that theory comes apart pretty quickly if they fail in the type of application cited here.WTF good are they if they have to be pointed down to work?

I'll venture there are ten times as many Aliens in use over a twenty year period as there are Link Cams in two.And there have been more than just this one that blew up.So if three or four Link Cam failures in two years vs what 10 or 12 Alien heads in twenty,which one has the better track record?

pwscottiv Do you really have the exact knowledge of the cams construction to comment on it's metalurgy just by looking at it?
How about you list the various components and their makeup as you see it and then let OP reply and see how close you are.
While you are there you may as well comment on any heat treatment or other processing that has taken place as well as the testing process and computer analysys.
May as well go so far as to suggest further testing that may reveal their fatal floors for all to see.

Failure rate of Link Cams far exceeds that of Aliens.

pwscottiv, I think we agree on a lot of points in this discussion, but here I think we part company. If safety were the ultimate goal, no one would be in the business at all. Willing 'guinea pigs' is what we've essentially been all along, most of you are just too young to realize it. Some incredibly bad gear has gone by over the decades - ironically, most of it well-made and robust, just poorly suited for the purpose of protection. There would never be innovation in climbing if designs had to be vetted as fool-proof for today's 'average' climber as described by some in this thread.

Manufacturers have a responsibility to produce the best possible products they can, but history is replete with dead-ends and products which need significant expertise to wield appropriately. And no, I'm not implying the Link Cams are a dead-end product, but rather one that requires some expertise to wield effectively and safely. In general, I think OP is doing a good job relative to the introduction and service of Link Cams. If the limitations have not been well-stated by them, I'm more than willing to chalk it up to a bunch of highly experienced folks who on one hand were excited about the pure potential of the design on one hand, and intuitively avoided such placements when field-testing them on the other.

It may turn out the liability costs of the general population of climbers using these is just too high in the long run for them to stay on the market, but I'll consider that a loss to a few due to the folly or inexperience of the many. Again, it must be a generational phenomena that simply because gear is sold commercially it somehow means climbers are in some way mysteriously absolved of their own responsibility and imperative in judging the fitness of the gear they use.

No, I don't. You're making a huge assumption that is completely inaccurate.

Regardless of your experience in other industries, at this company, we believe in doing everything possible to a) build great products and b) make sure people use them safely.

That includes being honest with our customers.

Every design in the world is a compromise: you give something up to get some other benefit. Link Cams are no exception.

The range is a huge benefit in many situations. But the cams are heavier than most and the links can present challenges that must be considered when placing them or they could become damaged. Every dealer and climber we've ever talked to can tell you that we've been clear about that since we introduced Link Cams.

As Roy Hinkley pointed out, the sales and marketing departments are my departments so whatever influence and direction that comes from this side of the building comes directly from me and I'm telling you straight: what you suggest happened ... didn't happen.

--ML

____________________
Michael Lane
Omega Pacific

Bottom line? I ain't gonna buy linked cams no more.

Are you telling be that you never loaded these laterally to see what sort of loading they could withstand before yielding or breaking? If you did, then why didn't you state the limitations in the instruction manual?

pwscottiv:

Are you telling be that you never loaded these laterally to see what sort of loading they could withstand before yielding or breaking? If you did, then why didn't you state the limitations in the instruction manual?

Likely because it's a limitation that could potentially be applied to most cams regardless of brand.

I think most experienced climbers/engineers would argue that claim... It's obvious that these cams are MUCH more fragile, than say a new Camalot, when loaded laterally.

You're changing the subject a little. But no problem.

I've already said we did perform that test.

Our instruction manual says: "... be sure not to load the links themselves over an edge as this could damage them. Such damage requires that your Link Cam SLCD be retired and destroyed."

As I mentioned in an earlier post, we will be a little more specific to reinforce this statement in future editions of our instruction manual.

As to why we didn't provide specific ratings or strength measurements in the manual ... Whenever we provide hard, subjective numbers, they're based on industry-accepted tests and standards. Breaking cam lobes in half is not a standardized test. That we found our linked assemblies to be stronger than other major brands was a good thing, but we still recognize that the length of unfolded linkages could become more easily damaged than other designs and made note of it in the instruction manual.

--ML

Quite a silly thing to say don't you think?

As stated in Michael’s summary of the report; The nature of the placement and the mode of failure are completely intertwined.

As placement adjustment/failure was occurring the orientation changed, this is what lead to the failure. And as it appears the only the lobes on one side endued up holding the force of the fall, but they ended up in a less than ideal orientation. Ie. They were not symmetrical. This could cause any cam to fail.

It's quite apparent that there was NO issue with how this cam was manufactured or designed with regard to this failure. It was a less than ideal placement that unfortunately failed. That is an unfortunate aspect of trad climbing; we work with what we have. Many people used to use aliens in such placements rather than BD, WC, Metolius Cams... Why, because they seemed to handle the less ideal placements better. Bottom line is there were limitations within the placement that were not seen or considered.




Not meaning to single you out there, it's just that these kinds of off the wall opinions seem to be everywhere these days on this site.

As I mentioned in an earlier post, we will be a little more specific to reinforce this statement in future editions of our instruction manual.

Well, hate to sound like a broken record, but how about just looking at them - solid stems, fragile segmented cams? Do you really need to be told or otherwise have it spelled out? Pretty obvious that stout stem can apply significant leverage on those fragile links if allowed to rotate after placing the unit or if it rests on an edge. To be honest, I would think it completely obvious to anyone who considered themselves passed the level of an intermediate trad climber.

The literature is pretty irrelavant in my view as it would be virtually impossible to list or characterize all the potential kinds of placements where you could run into problems with these units.