Alpine Climbing / Ice Climbing / Snow sports / Landscape / Patagonia / Everest / Pakistan / Alaska

Black Diamond C3 gear review

Reviewed by Jon Griffith

I really do think that cams are the pinnacle in climbing engineering technology- especially some of the new designs that are coming out. When it comes to micro-cams it is no exception. For years the Wild Country Zeros and the Aliens dominated the micro-cam market, until in 2005 Black Diamond released their version in the form of the C3. I have to admit that when I first saw a C3 it just seemed so ridiculously high-tech that I knew I had to have one. However beauty aint cheap nowadays and the C3s were relegated to my ‘If I get a bonus this year I’d like…’ list (we all have one don’t we?).
The main problem wasn’t really that is was an expensive bit of kit but because I couldn’t see myself using them all that much to warrant spending my next month’s electricity bill on one. I mean honestly how many people can put their hands up and say that they climb consistently hard enough stuff that they will use micro-cams all the time? Well if you’d asked me that question I would have pointed out that firstly I loathe crack climbing and that secondly the very thought of finding myself in a position whereby I’d have to use one is enough to make my stomach turn. That was of course until I started using them…

I think it’s a natural reaction to associate any piece of gear that has a micro connotation to it to the more hard-core climbers out there. To me there were two reasons for this. Firstly when we start trad climbing we tend to migrate towards easier routes with big holds and broken up rock allowing us for many larger placements (ie you don’t head for the closest blank wall in sight) and secondly, smaller gear has a lower fall rating. Whilst I think that the first point remains true, my second myth is starting to dispel somewhat.
Over the last 2 years I’ve become addicted to small gear. The reason is not because Ive become a better climber (I still shit myself when am run-out on rock) but because I have started to see these micro placements in the rock when am climbing allowing me to climb in the knowledge that I can exploit not only normal pro but also micro pro. Ok this might not seem like a big deal but this winter I didn’t find myself moving from one placement to another but instead climbing and when I felt that it was getting run-out or dodgy I knew that armed with a selection of pro from micro to large I could always find something to alleviate my panicking mind. Another great reason to embrace the micro side of protection is the weight saving associated with it. At your local crag this is not going to be a problem but up in the alps your rack is the heaviest thing that you carry and this winter I’ve been upgraded with WC Superlight rocks, C3 cams, and Black Diamond micro-stoppers…and the weight saving is really really noticeable.

So what is so special about micro-cams?

We’ve all used some kind of cam at one point in our out-door climbing lives. Some rock types are more suited to them than others but in general few people leave the ground without at least one or two cams on their rack. Cams are great because they take seconds to place and seconds to extract. I used to be a bit dubious of cams as at the end of the day a bomber nut placement really is…well bomber. The fact that the cam has to actively expand in the crack as you fall on it didn’t exactly inspire too much confidence. Of course there is nothing like taking a whipper on a piece of pro to convince you otherwise. Cams work, and damn well.
So what about the micro cams. Obviously the same engineering principles apply but what really sets them apart is that they have to have the same moving parts but on a much smaller scale. Compared to the likes of passive pro, its obviously a much harder engineering challenge to get the cams fully functional at a smaller size. The quality construction is paramount when it comes to cams as the failure risk is much higher when you are using pro that has moving parts- things break, freeze up, and lock up. You can imagine that when you are trying to squeeze the same moving parts into the smallest possible area things can get very tricky and complicated. I have been in contact with one of the designers of the C3 back in the US and I have been incredibly impressed with the massive amount of testing and complex computer programs that they utilise to get these micro-cams to be at their optimum. When you consider all of this, the price starts to become more understandable!

The C3

Entering into competition with the Zeroes and Aliens, which have been firmly established for years, the C3 was going to really have to hold its head above water to take off. Thankfully Black Dimaond have a very good history in the cam design market and millions (a bit excessive?!) of crack climbers around the world cant be wrong- from Utah sandstone to Chamonix granite the benchmark C4 camalot is king. However the C3 not only matched its competitors but actually upped the ante quite a bit.

Head Width

Its main difference that set it apart from its competitors is that the head width is, on average, 30% narrower than other cams of its size. Big deal? Well yes actually it is. When you are placing large cams issues such as head width aren’t a major problem as the crack tends to be quite ‘forgiving’ in its size. However when you are starting to use very thin cracks chances are that there is only going to be a very small section in the crack that can accommodate your cam safely. By minimising the head width you effectively allow yourself a lot more placements than with something that is a little wider and can not fit in the crack. This is of course especially ture for pin scars which although aren’t that comomon in the UK, they are in Europe and the US (see image below).
By removing the terminals at the side of the head as well as removing the springs the C3 therefore becomes a very compact little unit- effectively there is no wasted width as the whole head width is pretty much comprised of cam lobes…pretty clever stuff.

The springs are now moved down the cam unit into the stem of the cam. Sounds odd but it actually works very well. Basically the lobes are attached to stiff trigger wires that are then fed through a very tough plastic casing down to the compression springs under the trigger bar….confused? Well see below…

The beauty of this system is two fold. Firstly you eliminate the space taken up by the compression springs in the head, and secondly it allows a very effective method of jamming the cam in place by allowing the trigger wires to individually expand each lobe as much as it can. All in all it gives for a more secure placement and should help the cam for walking as it should be already biting into the rock. This active gripping of the rock helps compensate for one of the drawbacks of a 3 lobe design cam unit (vs a 4 lobe).

The lobes

The cam also boasts an interlocking lobe design meaning that not only do you have an integrated camstop design but also that the cam maximizes the amount of surface area in contact with the rock when placed. This can be quite a sensitive topic so I wont delve deeply into it but at the end of the day when it comes to micro cams one of the critical factors for it holding a fall is that it has the maximum amount of surface contact with the rock. Why? Well put quite simply a cam produces a huge amount of outward force on the rock it is in contact with when a climber falls. For the larger cam sizes this is not a problem as there is alot of surface contact with the rock as well as it being rather more spread out over a larger area. For smaller cams you can imagine that not only is there less surface contact but that it is rather more concentrated on a smaller area. Cam holding power is very dependent on the rock strength around it as if the rock pulverizes under the force your cam isnt going to hold a thing. A 3 lobe design is, in theory, going to have a smaller surface area than a 4 lobe design as it is minus one lobe. However the interlocking design of the C3 allows it a much wider surface area in contact with the rock at the ‘critical angle’. Whether this is enough to make up for the lacking lobe comparing it to a 4 lobe unit is speculative and not something I can get any concrete quotable answer on.

The stem

This is a major discussion point when it comes to the C3s. There are many strong advocates of flexible, almost floppy, stems as they see them as safer due to the fact that they should help prevent walking as well as levering out of the crack in a vertical placement. Both the Aliens and the Zeros have pretty flexible stems and this is what many people dont like about the C3- it has a pretty stiff stem, especially in the vertical orientation due to the plastic sheath. Now whilst on paper it seems the logical thing to have a floppy stem for these delicate placements after having used the C3 I am not so convinced. The stem, whilst sememingly very stiff, actually happily folds back on itself in vertical placements (see image) and I’ve never had a cam walk on me due to the powerful compression springs holding the lobes in place.

Further more one of the designers at Black Diamond had something quite interesting to say that hadnt actually occured to me that might help dispel some of the flexible vs stiff rumors out there:

Not only do we have tests to show that it (the ‘stiffness’ of the stem) is not a problem, but we have tests that show too much flexibility is a problem in certain placements. Think about how cams work in a perfect placement: you pull straight down on the cams, that force is converted to a rotational force on the cams, and the surface of the cams push against the rock surface. Now place a highly flexible cabled cam in a vertical bottoming crack (the stem is sticking out horizontally). Should be good right? Think again about how the cams need to work. Pull straight down on this placement and you’ll notice a large component of the downward force is acting parallel to the cam surfaces. This is not how the cam is designed to work. The cams will not push against the rock surface without a force perpendicular to the cams plane of movement. In short, it stops camming and acts like a nut placement. You need some torque on the placement to convert the parallel load to more of an outward one that can act on the cams. This torque is provided by the stiffness of the cable, or the length of the shank of head terminal, or some combination of both. In testing, the high flexible cables did not generate the torque necessary to hold the falls and the units slid sideways out of the placement at very low loads. We even made C3s proto types out of softer cable, only to watch them fail our bottoming crack test because of this issue.

Interesting? I certainly thought so and I think this goes to show really how much thought and design has been put into these cams. They may look a bit gimmiky but they actually work incredibly well and its a testament to the years of product design and testing that they put into this unit.

Camming range

The C4s really took the cam market by storm with their larger camming range. In a nutshell, a large camming range means that a cam will be able to fit into more placements by being able to cover a greater ‘range’- Ie instead of just being able to cover say a crack of 22-30mm they can safely cover a crack of 19-33mm. This design feature was possible due to a dual axle system in the head. However the C3s do not incorporate this as it would seriously enlarge is head size. So how do the C3s compare? Well below are the stats tables compared to the Aliens and Zeroes

As you can see the Zeros and the C3s are roughly equal with the C3s maybe marginally better. On the other hand the Aliens certainly take the prize when it comes to greater camming range compared ot the Xeros and the C3s. The reason for this is that the Aliens have a larger cam angle. As usual there is a flip side to every coin when it comes to climbing gear. A larger cam angle allows you a larger range but it affects the holding power of the cam. All cam manufacturers draw the line somewhere in this trade off and this is why there are different ranges. Therefore in theory the Aliens have less holding power than the C3s and Zeros. (Note that I am not claiming this as I have no supportive evidence but this is the theroy behind it)


As with all micro-pro it quite often boils down to the fall rating. Afterall a 2kn piece isnt going to hold a fall as a 70kg person will exert a force of 1.4kn just hanging from the rope off it. Its no use extolling about the greatness of micro-cams if they wont save your life. Once again I’ve compiled a table of strength ratings vs Zeros and Aliens:

NB:The smallest cams (4kn) are sold for aid use only

As you can see the Zeros and the C3s are very evenly matched on this front. Interestingly the Aliens start to show the compromise for having a larger cam angle (as discussed above) and have a lower strength rating. I am actually just assuming that this is why they have a lower strength rating but it could be something entirely different such as the actual construction of the cam unit itself breaking. When you see how tiny the size is of a No. 00 cam you will appreciate how impressive it is to get a 6KN strength rating. It is also worth taking into account that gear manufacturers give strength ratings of what they can guarantee that it will hold, not some kind of average as some people believe. In other words the likely hood is that the cam will be able to hold higher than that, in fact as Black Diamond say “We rate our stuff using a 3 sigma system and have broken 1000s of units to come up with ratings that are very conservative using this model….as a general rule we have the most conservative ratings in the business.
Nevertheless it is worth taking a little extra time to think about fall ratings when placing such micro-pro. Personally, and I stress personally, anything around the 10kn mark I dont think twice about but the 6kn mark does eer towards the ‘have a think about putting some pro in soon afterwards’. It’s always worth a brushing up on fall factor ratings and the like if you arent fully clued up on it. Knowing how to assess when to put maybe just a single micro-cam in and when equalizing two of them makes the difference between climbing safely in the knowledge that it will hold your fall and that panicky elvis-legged approach of ’oh crap, am I going to die if I pop off now?”.


Not exactly a major issue as far as I am concerned as these things are micro and therefore bloody light. When it comes to saving a mere 10 grams here or there I’d much rather it be 10 grams heavier and better built than the other way round. However for those of you who like to save yourself a few grams here are the comparisons. As you can see the C3s sit neatly between the Zeros (lightest) and the Aliens:

The Test

Well to be honest I wasnt too convinced that I would use them all that much when I first got them. Initially I had thought that I would take them out for a little play this winter, but that they would really get the most use in the summer climbing season. The first climb I took them to was the Goulotte Perroux/ Profit which is a IV, M5 multi-pitch off the NW face of the Midi. Not a particularly hard climb but it was a real eye opener as to the versatility of these cams.
The C3s have a good sized trigger bar and a firm tumbloop allowing easy use with winter gloves on which was something that was lacking on the Zeros and the Aliens making them almost impossible to handle with gloves on- ok its maybe not a major point if you use these for summer rock but I like to use my gear year-round. Both C3s that I had were placed on pretty much every single lead. I had jokingly told my parnter at the time to try and whack at least one in so we could see how there were but instead of trying to ‘force find’ placements for them we found that they were almost the first things off the rack. They’ve been used continuously ever since that climb and been really invaluable to my winter climbing rack. They have yet to freeze or lock up and they still work very smoothly. From hanging belays to desperate mixed, and even a bit of aiding these cams have really performed well. They’re very rugged little things and whilst the heads are definitely starting to show wear (a normal occurrence) the springs, trigger bar and plastic sheath as still good as new.
One issue that has been pointed out is that the plastic sheath in the smallest size (000) gets in the way when the cam is placed so that you cant see the actual cam lobes from below. Since this cam is for aiding its quite important to be able to see if you have placed it correctly before you weight it. As I didnt have this size its not something that I can comment about.


As you can probably tell I’m quite taken with these little micro wonders. You can really see that alot of time and effort has been put into these cams to make them live up to the Black Diamond ‘seal of approval’. I tend to abuse my gear alot and am impressed that they have yet to lock up at all. At an RRP £53-£55 they are the most expensive micro-cams but as with much in the climbing gear world you get what you pay for. The Zeros are only just cheaper at £52.50 and the Aliens come in quite a bit cheaper at £47-£50 (however it is getting increasingly hard to get hold of Aliens (especially in the UK)). After having played long and hard with the C3s I do think that they are my favorite micro-cams- the particular features that I like are the strong individual springs that hold the cam lobe actively in place and the usable trigger bar. On top of that, of course, you have the narrower head which gives it quite an edge over its competitors. Of course there will be many who are die-hard Alien or Zeros fans and there is no doubt that they are also great cams but the C3 really does offer a revolutionary design that I think is fantastic.

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