Link Cams fail spectacularly where other commonly used gear works.There is no comparison.

Do you know that for sure? What is the material, form, alloy and heat treat? Maybe you want to amend that to "available at the same weight and cost". The failed links look like they could be castings. If that is true, one could get better material properties out of a forging or machined piece at a higher cost.

I'm of a similar opinion to Healyje... You've got to know your gear and its limitations. While the specific limitations due to powmet might not be obvious to everyone, the fact that the design is so different than everything out there should be enough to cause one to pause a moment and think about whether it should be used the same as everything else. From the looks of it that may not be the case. It's different and as such needs to be used differently. Personally, I rather like them.

-aric.

Sorry,but you're dead wrong there Patto.All ropes cut over roughly the same edges,and we learn to mitigate that issue or deal with it,ditto biners.Link Cams fail spectacularly where other commonly used gear works.There is no comparison.

They are metal injection moldings, aka powder met parts. And yes there would be better properties for this application from machinings and even better from forgings. Also switching from stainless steel to a high alloy could have benefits but there are down sides, cost, lack of corrosion resistance...

Edit:
Sorry adatesman, just saw your post. I have been ranting about these for a while and I just don't feel it is the right manufacturing process to not inform people highly that although there range allows for awkward placements they have more limitations than forged friends. People just need to know that all this is is a cam for perfect vertical cracks, nothing more they can't take as many placements as any other cam out there. Forged friends make provision for the gunks tie off and informed people of the limitation. You are going to see more failures trust me because people will always find a placement where it fits but it will stress a brittle linkage in the wrong way...

Normal cams also break when used inappropriately. The one that comes to mind first was the small trango cam that basically exploded when overcammed in an Indian Creek splitter. fully overcamming is a failure mode I wasn't aware of until that incident.

*SNIP*

I take a little issue with Joseph's apparent stance of the cam's design is at an optimum and the consumer should 'know' what all limitations of the design are without explicit instruction from the manufacturer. Should a 6th grader know that powder met parts are not very good in tensile applications and tend to fracture rather than yield?

OK. I understand your point and I agree. All parameters cannot be defined. However, known limitations can be defined. I would have to go back to product tags which are not available to me at the moment, but I am guessing that the literature attached to new 'biners says not to place them over an edge.

OK - so how many folks here looked at the cam lobe linkages on Link Cams and said:

A) "Sweet! Those little axle tabs look so frigging burly they'll never break!"

B) "Hmmm, a bit sketch on the little axle tabs, wonder how easily those might break?"

C) "Dude! They have linkages? No shit! Hell, it had a trigger I could pull (smooth as silk) so I never even noticed that - wtf!"

Hoo boy, here we go again.

. . .

Link Cams are built as well as any such a design can be and with the best materials available. The design delivers unique advantages, but along with those advantages comes limitations due to the current state of material science. The linkage tabs (that the axles go through) are thin and frail and there is just no way to change that without simply producing an even heavier product.

Bottom line is, at the moment you pull a Link Cam (or any other piece) off your rack, you are staring at the reality of the full potential and all the limitations of the piece - place it accordingly. With Link Cams that means that any placement that will exert [leveraging] sideways forces on the linkages, or one where the cam lobes of a rotating cam will encounter obstacles, should be avoided at all cost.

There's likely nothing wrong with this Link Cam or the rc.com LST one - they just ended up being used in placements that played to their limitations rather than their advantages. If you aren't prepared to deal with the limitations of any given design along with the advantages, then you probably shouldn't have it on your rack.

If every time I bought a biner it had to have a tag explaining the failure mode of a carabiner in ways everyone could understand... think about what that means. Your disclaimer would have to clearly describe (and for illiterates, you'd need lots of pictures with circles and arrows) the dangers of back-clippping, using a solid-gate biner on the rope end, using a wire-gate biner on a bolt, using a bent-gate biner on a bolt, not allowing a biner to be weighted over an edge, not allowing a biner's gate to get pushed open by a rugosity, etc, etc, etc...

No engineering degree, knowledge of metallurgy, or design experience required. An IQ capable of sixth grade education should amply suffice. I mean, what exactly does run through your mind when you look at those little axle tabs?

[image]http://www.cascadeclimbers.com/plab/data/500/omegasfront_1_.jpg[/image]

There are better materials available at a higher cost and perhaps better designs.

But it doesn't seem like too much to ask for the manufacturer to provide instruction for proper use of the cam.

...doesn't mean it is obvious to others. I would suspect there are many individuals out there who are smart, capable climbers who may not see the inherent weakness of this design and material choice.

Well, since you asked, when I saw those, I thought "wow, that is pretty clever." I never thought about engineering, metallurgy, or design.

Oh, I agree it's clever alright - but that was the end of it for you? Not a single thought that, "hey, those axle tabs look a little fragile"? Did you bother to consider how durable these cams might be? Or what the limitations they might have?

Look at the photo above - name a material of any kind or any manufacture that would provide more than a marginal increase in breaking strength.

Rock is infinite - there is no way to list or even characterize all the possible ways to use or misuse a Link Cam. It's completely on you when staring at the rock with Link Cam in hand to determine the suitability of any given placement.

Sorry, I disagree. Anyone looking at the picture of the axle tabs above and who doesn't react with studied concern and cautious use of them shouldn't be trad climbing.

Now, because of my background in science, I am a late adopter of new things. I want a pile of usage data that shows me the things I need to watch out for because I don't know how to predetermine those things myself (not an engineer, not going to try). I let the data start disproving things, as is happening right now.

Well, depending on what stainless steel they are using, the strength could nearly double by using a high strength carbon steel.

I wonder how those people are supposed to know they shouldn't be trad climbing. Or is that the only litmus test?

Oh, I see - bomb until proven otherwise - so that's your approach to climbing gear?

So, maybe think back, way back, to say age eight or nine - did you need 'data' to keep from sticking your hand in fire or running out in front of a car? Or did you weigh the data on whether a branch might hold you when climbing a tree? Or did you just say, "hey, it's a branch - what's the problem..."

Again, LOOK AT THE AXLE TABS, what 'data' is required that is not provided by a glance and a modicum of common sense? Your argument is so divorced from the basic observational skill and common sense necessary for trad climbing as to be mind boggling. Any kid who's snapped a few sticks, plastic silverware, pencils, and bent a few clothes hangers should be able to figure it out - if they're going to be a trad climber.

Yes, I'd very much consider the just such a litmus test. The lack of personal responsibility on display here is pretty astounding from my perspective. Probably a generational thing; old trad climbers rarely take anything for granted - especially gear.

We're doing a couple things to address this:

1) We're looking at new link designs that strengthen the hinges to make them stronger.

and

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.

Oh, I see - bomb until proven otherwise - so that's your approach to climbing gear?

So, maybe think back, way back, to say age eight or nine - did you need 'data' to keep from sticking your hand in fire or running out in front of a car? Or did you weigh the data on whether a branch might hold you when climbing a tree? Or did you just say, "hey, it's a branch - what's the problem..."

Again, LOOK AT THE AXLE TABS, what 'data' is required that is not provided by a glance and a modicum of common sense? Your argument is so divorced from the basic observational skill and common sense necessary for trad climbing as to be mind boggling. Any kid who's snapped a few sticks, plastic silverware, pencils, and bent a few clothes hangers should be able to figure it out - if they're going to be a trad climber.