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Small Cam Strength - 000 C3


Original Post
mattm · · TX · Joined Jun 2006 · Points: 1,390

I finally completed my C3 collection with the "aid only" 000. Rated at 4kN this thin is TINY. Ball nuts are stronger for the size but the cams sometimes work better. Totem made a video a while back showing how the rated strength is based on an "open" placement vs an ideal, closed one. The Green Totem basic rated at 7kN tested to over 11kN in a good placement. While I wouldn't expect the same sizable difference in the tiny 000, is it reasonable to assume at least a bit more than 4kN at 90% retracted? I have no illusions that the 000 is anything but marginal as tiny cams are iffy no matter what but, I am curious as to how tiny cams "rate" real world. I believe Metolius runs into similar territory with their tiny cams and CE requirements?

Ted Pinson · · Chicago, IL · Joined Jul 2014 · Points: 190

People have fallen on them and not died, if that's what you're asking. I wouldn't want to take a 40' whipper on one, but people have.

Kevin Mokracek · · Burbank · Joined Apr 2012 · Points: 200

Use that 000! Don't save it for aid only, if it's the only thing that will fit use it rather than using nothing. You also have to take into account rope stretch, harness stretch, give in the belay all reduce the impact force. If you got em, use em.

anotherclimber · · Unknown Hometown · Joined Apr 2016 · Points: 70

Thank you for asking this, I've been curious about this too for quite some time and look forward to reading answers. I don't own any C3's, but I do own Metolius Ultralight Master Cams. And in the micro 5kN sizes, that's sizes 00 and 0, I bought doubles. The thought process is that if I need to use them, if the rock feature allows, I place two fairly close to each other with separate slings. Kind of the same idea of "nesting" multiple micro nuts nearby each other.

Check out the following video at 2:50 for relevant part:

Carbondale Short Bus
youtube.com/watch?v=rkbD73o…

He places two 000 C3's near each other. So if one blows on a fall hopefully the other catches.

Ted Pinson · · Chicago, IL · Joined Jul 2014 · Points: 190

^^ Another idea is to clip both of them to a sling equalized with a sliding X. That way, you get a bit of load distribution between the 2 pieces rather than one taking 100% of the first and then shockloading the second. Pretty much the only time I would use a sliding X...

Anyways, the impact forces in a typical leader fall are actually pretty small, assuming a competent belay. It's not going to hold a ";;s@&$ hits the fan";; extreme type of scenario like a FF2 or ground-fall potential hard running catch, but as mentioned, it's always better than nothing.

kevin deweese · · Oakland, Ca · Joined Jan 2007 · Points: 350

One thing (as I'm sure your aware of with your larger C3s) is that they need to be placed in the direction of pull as they tend to rotate and pop out more than four-lobe cams and the smaller the size of the C3 the greater this issue becomes. For aid, it's not an issue but for freeclimbing, I will always extend any microcam placement if it's a C3 to prevent the rope from turning a marginal placement into a worthless placement.

anotherclimber · · Unknown Hometown · Joined Apr 2016 · Points: 70
Ted Pinson wrote:^^ Another idea is to clip both of them to a sling equalized with a sliding X. That way, you get a bit of load distribution between the 2 pieces rather than one taking 100% of the first and then shockloading the second. Pretty much the only time I would use a sliding X... Anyways, the impact forces in a typical leader fall are actually pretty small, assuming a competent belay. It's not going to hold a ";;s@&$ hits the fan";; extreme type of scenario like a FF2 or ground-fall potential hard running catch, but as mentioned, it's always better than nothing.
My understanding from the reading I've done here is that the sliding X for equalizing two pieces of rock pro has been looked down upon as not actually working well due to the system locking up under a fall scenario thus negating its supposed equalizing qualities. And then if one of the pieces does fail you have a shock loaded system much worse than if you have put them nearby with the same length sling, or further apart and adjusted the slings lengths to be as close to the same as possible. See the following links:

mountainproject.com/v/knot-…

mountainproject.com/v/kn-an…

Do you have different information or experience to lead you to this conclusion to use a sliding X in this scenario?
Ted Pinson · · Chicago, IL · Joined Jul 2014 · Points: 190

Both of those threads emphasize issues with the sliding X for BELAY ANCHORS, which I never do for the reasons stated. However, as the second link points out, these issues are much less significant when rigging two pieces on lead, which is why I said that this is the only time I would ever consider using a sliding X. The second link actually discusses several situations, such as this, where a sliding X might be useful.

eli poss · · Durango, Co · Joined May 2014 · Points: 456
Ted Pinson wrote:Both of those threads emphasize issues with the sliding X for BELAY ANCHORS, which I never do for the reasons stated. However, as the second link points out, these issues are much less significant when rigging two pieces on lead, which is why I said that this is the only time I would ever consider using a sliding X. The second link actually discusses several situations, such as this, where a sliding X might be useful.
I would just extend them separately. You aren't getting a whole lot out of the sliding x and there is a possibility that 1 ripping could reduce the impact of the subsequent fall onto the 2nd microcam. In theory, there will be a split second after the first piece rips and before the 2nd piece catches the fall. In theory, this split second where the rope isn't loaded could potentially allow the rope to recover some of its elasticity, giving you more overall stretch in the rope and therefore more energy dissipated.
Matt Carroll · · Unknown Hometown · Joined Dec 2013 · Points: 35

I agree about not using the X. also, most times I'm placing the 000 I'm not at a place where I want to camp and dick about with a sling trying to make an X.

20 kN · · Unknown Hometown · Joined Feb 2009 · Points: 1,348

The cams probably fail in a steel jig at a load a bit higher than they are rated, as do most cams. However, achieving that load in the real world without the piece ripping or the rock failing is unlikely. I've never actually heard of a cam outright failing from excessive load unless it was defective (e.g. Aliens), tipped out or otherwise improperly loaded. In virtually all cases the cam pulls for one reason or another before the maincable outright fails. So yes, the 000 C3 probably holds more than 4kN, but you're unlikely to hit the failure load without the piece ripping.

Ted Pinson · · Chicago, IL · Joined Jul 2014 · Points: 190

^^ Good point. One thing I've always wondered: is there a correlation between rated strength and holding strength? In other words, if a cam has a lower rated breaking strength, will it also be more likely to pull in a given placement, all things being equal? This seems like a difficult question to test, as there are a lot of factors affecting holding strength, but also an important one, as people often use this to judge how "safe" they are (better to be 40' up from a #4 than a 0.1), but are we fooling ourselves?

20 kN · · Unknown Hometown · Joined Feb 2009 · Points: 1,348
Ted Pinson wrote:^^ Good point. One thing I've always wondered: is there a correlation between rated strength and holding strength? In other words, if a cam has a lower rated breaking strength, will it also be more likely to pull in a given placement, all things being equal? This seems like a difficult question to test, as there are a lot of factors affecting holding strength, but also an important one, as people often use this to judge how "safe" they are (better to be 40' up from a #4 than a 0.1), but are we fooling ourselves?
Hard to say, but I suspect there is not a major correlation. If all we did was test the placements 90% retracted in Yosemite splitter granite, maybe. But if we test every placement in every type of rock, I think the results would even out a bit. Among four-lobe units, I would say the most important factor in determining the likeness of a small cam holding in most placements is expansion range. Small cams have extremely little expansion range and as such they are very easy to tip out. Simply calling take and resting on a micro cam is sufficient to consume a sizeable portion of it's range let alone actually falling on it.

In short, I sort of view cam strength like UIAA fall ratings. Interesting info to know, but irrelevant to practical application in all but the most exceptional of scenarios.
Ted Pinson · · Chicago, IL · Joined Jul 2014 · Points: 190

Good point. I would say that expansion range probably coincidentally correlates with strength ratings, as larger cams tend to have larger ranges and are less ";finnecky,"; not to mention the increased surface area. Nevertheless, the quality of the placement is infinitely more important than the size of the piece.

Kyle Tarry · · Portland, OR · Joined Mar 2015 · Points: 162
eli poss wrote: In theory, there will be a split second after the first piece rips and before the 2nd piece catches the fall. In theory, this split second where the rope isn't loaded could potentially allow the rope to recover some of its elasticity, giving you more overall stretch in the rope and therefore more energy dissipated.
If the pieces are a couple inches apart, the rope isn't going to be able to "shrink" more than those couple inches before it gets loaded again. Given that in a typical 10 foot FF0.5, the rope might stretch 5-10 feet, a couple inches of recovery is hardly significant.
Guideline #1: Don't be a jerk.

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