Alien vs. Predator. a.k.a. a review of the new BD X4 Cams

The new Black Diamond X4 Cam.

The new Black Diamond X4 Cam.


Black Diamond has just released its new range of small cams.  They are officially known as the X4 Camalots. Rumor has it that internally, they were known as Predators, a tongue-in-cheek code word to take on Aliens, the one-time market leader for small cams.  While we were in Yosemite Valley in California, Trish and I decided to buy a set of these new X4s and try them out.

A bit of background to small cams.

The market for small cams is rather crowded, with many good products out there. That’s a far cry from a few years ago when small cams were rather scarce.

From left to right: BD X4, Metolius Master Cam, Fixe Alien, BD C3, Metolius TCU, Wild Country Zero.

From left to right: BD X4, Metolius Master Cam, Fixe Alien, BD C3, Metolius TCU, Wild Country Zero.


Let’s take a look at the cams currently available in SA:

CCH Aliens:

Aliens had been the defacto standard for small cams for a long time. Many people swear by them, with an almost cult-like following. The company or the product has had lots of issues though.  There was an infamous recall some years’ ago, after some shoddy workmanship was discovered. Then the owner Dave Waggener died, and so did the product, at least for a while. Then in September 2011 TechRock purchased the Alien name, design, patent and manufacturing tools. TechRock is a Spanish company that own a few brands, such as Roca, Faders and Fixe, and so the CCH Aliens were reborn as Fixe Aliens.  We sell them at R835.

Black Diamond’s own C3s:

There is Black Diamond’s own C3 Camalot, now a few years old. This is a 3-lobe cam design, hence the name C3, designed to fit narrower pockets. The head width is significantly smaller than other 4-lobe cams. I personally never liked them due to their unusual trigger mechanism, a flat and rigid plastic enclosure that is not very inflexible, especially in vertical cracks. According to Black Diamond the X4 will not replace the C3. The C3s sell for R785.

Metolius Master Cams:

Metolius cams have never been a big deal in South Africa. In the USA the company’s cams were at one time outselling BD, but over the years the company’s TCUs, PowerCams and SuperCams were all eclipsed by products from BD and other companies.

Then, a few years ago, Metolius came out with the new MasterCam design. The MasterCam was similar to the Alien design, with some improvements.  Its one drawback is that the trigger sleeve is a bit inflexible. The cam works great in vertical cracks (like Yosemite), but not so well in horizontal cracks (like we have in Cape Town). Nonetheless MasterCams were a major step forward and the well-respected Chris McNamara gave it the SuperTopo Editors choice as the best small cam on the market. The MasterCam is priced very well at R585, this makes it the small cam market leader in SA at this point in time.

Many people never liked the larger Aliens or Master Cams. For both of those cams, the trigger wire action is too stiff. Also, the narrow cam head width, a major advantage for small placements – becomes almost a liability with larger sizes. The units don’t sit very nicely any more – they tend to get quite square and almost feel like they could topple over. As a result, in the past I have only used the smaller size Aliens or Master Cams, opting for the BD C4s or DMM Dragon cams for larger sizes.  Fixe agreed with me – when they started making Aliens again, they only started making them up to the red size (which is a .4 C4 equivalent).

The new Black Diamond X4s:

There are 6 cams in the range. Purple .5 and Green .75 not pictured.

There are 6 cams in the range. .1/Red; .2/Yellow, .3/Blue; .4’Grey. .5/Purple and .75/Green not pictured.


The first impression is that they are really well made, like all BD products. The cams have a very solid feel to them. The trigger mechanism is smooth, not too light and not heavy.  That goes for the entire range, from smallest to biggest.  The steel is polished, the units are really shiny, beautiful-looking in fact. I would call them cool-looking.  Call me a gear junkie.

A Black Diamond X4 cam in pieces.

A Black Diamond X4 cam in pieces. Cool photo from SuperTopo.


Upon closer examination, I found that the smaller three X4 sizes (.1; .2 and the .3) are single axle designs like Aliens and Master Cams. The three larger ones (.4, .5 and .75) however utilize a double-axle design, identical to the existing BD C4 cams. So when looking at the X4 you actually need to compare them to Aliens and MasterCams for the smaller sizes, and to BDs own C4s or the DMM Dragon Cam for the larger sizes.

Armored Trigger Sleeve:

The BD engineers seem to have taken a careful look at both the Alien and Master Cam design and chosen the best of both worlds. Some of the X4 trigger designs use Kevlar wires that attach to the individual cam lobes, a design feature shared with the Master Cams. BD fixed the somewhat lacking Master Cam trigger sleeve design by taking the Alien black sheath concept and covering it with a series of steel beads. BD calls it an armored trigger wire.  This design is clearly more flexible than the Master Cam and will be more robust against wear and tear, especially over sharp edges, than either the Alien or Master Cam design. It works great. Well done BD.

The "armored" X4 trigger sleeve. The flexible plastic sleeve is protected by some aluminium beads.

The “armored” X4 trigger sleeve. The flexible plastic sleeve is the same as on Aliens, but is protected by some aluminium beads.


Internal Springs:

BD makes a big deal (haha excuse the pun) of the fact that the (smaller) X4s have internal cam springs. What that means at least on paper is that the cam lobes have been machined so that there is a slot in the middle of each cam lobe to accommodate the springs. That theoretically allows the cam head to be narrower. With the larger C4/X4 comparison that’s certainly the case, the X4 is 20% narrower than the C4. But with smaller Master Cams or Aliens, I found that the X4 design isn’t noticeably narrower.  In some sizes Aliens are actually narrower.

Here the "internal" springs are clearly visible. Photo by Matt Gooch.

Here the “internal” springs are clearly visible. Photo by Matt Gooch.



The other “selling point” of the smaller X4s is the range. Double axle cams have always had a bigger range. But small cams can’t accommodate two axles next to each other as the cam lobes are still too small, so BD came up with a new idea – a different oval axle design where the cam lobes move further out on the axle itself.  BD calls this concept the stacked axle design. Sounds all technical and complicated. In reality the BD marketing department seems to have gotten a bit ahead of themselves – on paper and in real life the head width and expansion range is very similar for the X4, MasterCam and the Alien.

The X4 stacked axle design up close (and slightly exaggerated).

The X4 stacked axle design up close (and slightly exaggerated).



Here the BD design doesn’t have a clear advantage either, but because all small cams are so light to begin with, a saving of a few grams isn’t going to make an impact on the overall weight of your rack.

The tables below compares some of the most popular X4, Alien and Master Cam sizes.


Cam Yellow BD X4 Blue Alien Purple Master Cam
Head width 29.9 mm 35.6 mm 32.8 mm
Range 9.9 – 16.5 mm 10.1 –17.0 mm 9.9 – 15.0 mm
Weight 54 g 71 g 65 g


Cam Blue BD X4 Green Alien Yellow Master Cam
Head width 33.6 mm 33.0 mm 32.8 mm
Range 12.4 – 21.2 mm 13.5 – 21.8 mm 15.7 – 22.6 mm
Weight 75 g 74 g 70 g


Cam Purple BD X4 Red Alien Red Master Cam
Head width 33.6 mm 33.0 mm 40 mm
Range 19.8 – 33.7 mm 19.8 – 33.8 mm 26.7 – 33.5 mm
Weight 91 g 88 g 91 g



None of the cam manufacturers use the same color/size coding for small cams.  Frikken A. Someone ought to pass a law that makes them coordinate cam color sizes. DMM chose the BD color scheme when they came out with their Dragon cams, why couldn’t BD follow suit and choose the Alien or Master Cam color coding? The European Union passed a law that as of 2014 all cell phone chargers need to be interoperable, someone ought to write to President Obama and do the same thing for cams.   The good news is that the larger X4s use the same color scheme as the C4s.

Field Testing.

The smaller X4 cams worked just as well or better than my Aliens or Master Cams.  They are smoother and the trigger armor makes them better than the Metolius Master Cams. I found them easy to place, and easy to remove, across all sizes. I didn’t take any falls on them though. Maybe next time.

The yellow Alien and Blue X4 are actually similar size.

Yellow Alien and Blue X4 in the same crack.  They are the same size.


The larger X4 cams compete with BDs own 4 or DMM Dragon cam. The only real benefit is a narrower head width.  This is only of benefit in places that have narrower pockets, and not longer cracks like we have in Cape Town. We did find that in Yosemite the pockets, pin scars, etc. are actually smaller, never quite .5 or .75 size, so the standard C4 fitted perfectly.  The armored trigger sleeve does make the larger X4 more rugged than the C4. From our shop experience we know that the C4 trigger wires do bend, buckle, get snagged, fray and eventually break, so a X4 should last longer.


The X4 head (left) is a lot narrower than the equivalent C4 design (right).

The X4 head (left) is a lot narrower than the equivalent C4 design (right).



Cam Purple BD X4 Purple BD C4
Head width 33.7  mm 45 mm
Range 19.8 – 33.7 mm 19.6-33.5 mm
Weight 91 g 97 g






Last but not least in any review must be price.  The X4s are expensive. R160 more than BDs own C4. And R345 or 60% more than the Master Cams. EINA.


Summary and Buying recommendations:

Overall, I think the X4 is a great design. BD does make a rather sweeping statement with their claims of larger range, smaller head width, and less weight. This may be true vs. it’s own C3 or C4 cams, but isn’t true across the board when compared to Aliens or Master Cams. Nonetheless the X4 is an excellent product. If money were no object, I would recommend them unconditionally.  But money is always an object. And the BD X4 is R930, vs. R775 for BDs own C4, or R585 for the Metolius Master Cam. That’s a huge difference, almost 60%.  So if you were on a budget and are buying your first trad rack I would still consider the Master Cams for smaller sizes, and the BD C4 for larger ones.

If you are buying your 2nd set and want maybe a bit more versatility (for smaller pockets) then by all means spend a bit more and get an extra X4 or two.

And if you already own a set of Aliens, and want a 2nd set or a replacement unit I would probably stick with them. The Alien design is now almost 20 years old but still works great. The X4 is clearly a better and more modern design, but in Yosemite, the Aliens still worked fine for me. In fact at the end of our trip I found myself racking up with Aliens if I knew the climb was going to test me – in tense situations where you have to be quick at placing gear I just couldn’t see myself figuring out what the new X4 color was for a particular crack size.

Alex and I discussing the pros and cons of free soloing with X4s. Alex: "I am psyched about these new BD babies".

Alex Honnold and I discussing the pros and cons of free soloing with X4s. Alex: “I am super-psyched about these new BD babies”.


And yes we got all of the above cams in stock.

Robert Breyer and Trish Gaertner

Mountain Mail Order web site.

An afterthought:

I thought I would add a close-up shot of the cam lobes of the BD X4 (top), Master Cam (left) and Alien (right).

You can clearly see the different textures of the metal, and the tread pattern, or lack of. The X4 has no tread at all, whereas the Master Cam has serious grooves cut in it.

Alien uses very soft dull alloy, while the BD and Metolius cams use a much harder polished shiny aluminium alloy.


cam close-up

19 Responses to Alien vs. Predator. a.k.a. a review of the new BD X4 Cams

  1. Mokganjetsi (Willem B) May 21, 2013 at 9:24 am #

    Cool review thanks Robert
    How does the metal-wear rank relative to Master Cams & Aliens? The Master Cams uses a slightly harder aluminium on the lobes than Aliens, making them more durable but sacrificing some “bite” (which I don’t think is an issue given our high friction sandstone in the WC).
    The price is a significant competitive disadvantage. Maybe prices will converge a bit to reflect US differentials ($59 vs $69) – I hope.

  2. Robert Breyer May 21, 2013 at 9:34 am #

    BD has used a lot harder metal on the X4s vs. the Alien steel.. X4 is similar to Master Cam steel.
    That to me is a double-edged sword. Like you write, many people love the soft bite of the Aliens, how they almost deform and contour into rock for extra gripping power. The X4s have almost gone to the other extreme – they dont even have grooves machined on all the lobes for extra grip.
    After a week of climbing with my set they look as good as new.
    You want to volunteer for some friction coefficient testing? 🙂
    – Robert

  3. Mokganjetsi (Willem B) May 21, 2013 at 9:46 am #

    “You want to volunteer for some friction coefficient testing?”
    Sure!!! As long as I get to keep the equipment 🙂

  4. shorti May 21, 2013 at 9:54 am #

    Before you get too eager, you actually have to fall on it! Sorry buddy, seams like no free gear for you 😀

  5. Phlip May 21, 2013 at 10:02 am #

    Below extract from a mail I sent to my good friend Jaak and posting it here on subsequent request from Robert:

    Nou net Robert se Predator (X4) review gelees.
    Hint hint..
    As hy iemand soek om fall tests te doen op hulle.. ons sal gladly ‘n bietjie rond val op een of twee.
    Double Jeopardy het ‘n placement wat tot dusver net die geel Alien vat.. en ons val baie op hom. As die X4 equivalent daar pas sal ons goeie fall tests kan doen en die beaded sleaves se wear kan toets. Wonner ook of die equivalent Master Cam daar sal pas.

    Ek noem dit maar net vir jou (hint)

  6. jacques May 21, 2013 at 10:08 am #

    Janee, die X4 .4 is so te sê die selfde size as die geel Alien. Robert het ingestem om sy eie X4 stel vir julle te leen vir die DJ send – ek weet hoe jy klim en ek besef jy sal definitief alle hulp wat jy kan kry benodig… 😉

  7. Mokganjetsi (Willem B) May 21, 2013 at 10:35 am #

    Sure Phlip can fall on it…… but can it hold a 0,1 tonne whipper??

  8. Phlip May 21, 2013 at 10:55 am #

    @Jaak: Haha, jip.. elke bietjie help.
    Serious!?! Dit sal frieken ossem wees!

    @Mok: have you done Roulette? Welcome to come do some testing with us. Pretty sure the piece before the crux on the traverse (small blue C4) can be substituted for a X4.

  9. Mokganjetsi May 21, 2013 at 12:13 pm #

    Definitely keen for Roulette!! Not so keen on falling unless there is some bomber backup gear……

  10. Nic Le Maitre May 21, 2013 at 2:48 pm #

    The grooves on the cam lobes are a marketing gimmick invented to help sell the cams when they were first invented. No one would believe that they would work effectively without something to help grip the rock.

  11. Richard May 22, 2013 at 8:11 am #

    Nice one guys, I am certainly intrigued. I’ll have to add my name to the friction coefficient testing list 🙂 
    Some other bits and pieces:

    Sizes: the FIVE BD X4 (sizes .1 to .5) are covered by SIX Aliens (black to red). ..

    Internal springs: Once a spring on a small cam pops out, it is a real pest to get back in, and they never seem to return to their original shape and have a tendency to keep popping out. So for me, the internal spings could be a real plus IF that reduces the chance of the springs popping in the first place.

    Metal: If you end up taking reasonable falls on tiny cams, you really prefer it if they stay put. Here, the softer metal and bite of the Aliens has always been a huge advantage for me over the competition.

    Sleeves: older CCH Aliens had a trigger sleeve made of interwoven metal, which has covered by material. I guess you could consider this internally armored? Anyway, for some reason the later CCH aliens and the new Fixe Aliens just have a material (albeit strong) trigger sleeve. Seems to me like a step down in design. Go figure. BD clearly noticed this, which is good.

  12. Andrew Porter May 22, 2013 at 9:34 am #

    Robert, excellent article.

    You should seriouly consider opening a business one day with Snort – both of you have an ability to write lengthy articles that contain one or two very worthy points, but pad it with so much waffle that nobody actually cares about.

    I did though pick that magic point up, and for the first time this year I have a reason to be excited about going to work. In a day or 2’s time, a little package courtsey of the friendly and helpful staff at CityRock will arrive and make my day. I am jumping all over the walls in anticipation.

    I spend a lot of my time on Magaliesberg rock, which is ultra polished. Cam placements that would be bomber anywhere else can pop just too easily. Metolius master cams and the Wild Country Zeros work well in most cases. But, Aliens currently rock, and the set on its way to my office is about to get a thorough testing. (The little blue guy protects the crux of 3 of my projects)

    As for the X4 – physically they look awesome (I have seen them at Drifters). I like the flexible stem, and the range looks impressive to the eye at least. But, I have doubts about how well they will stick in the polished Magaliesberg rock, so for now I am going to wait until someone else throws their cash at them, and let them test them out.

    To the testing crowd: if you send anything up north, I will help fall on the various cams to test.

  13. Ebert May 22, 2013 at 1:41 pm #

    very well written and displayed, i want some:(


  14. Snort May 25, 2013 at 11:23 am #

    Andrew, on polished rock, like some of the Magalies and some of Karbonaatjies routes and elsewhere I would always bet on the softer metal of Aliens for grip. I have popped many Friends, Camelots (C3 and C4’s) in slippery quartzite. In fact a popped small C3 sliced Tony Dick’s head open when it pulled from what I thought was a bomber placement about 2 years ago. It was even placed above his head and there was a very low fall factor. Never pulled an Alien! and fallen on many.

    I had a look at the X4’s and on first impression I personally cannot see any particular advantage to having them on my rack. That is not to say that they are not beautifully engineered and I shall definitely try one or two. I would still replace my Aliens on my rack with Aliens of all sizes that are available right up to 2.5 inch if they were available.

    My rack for Yellowwood, Blouberg, Fitzroy and Magalies would always include a full set of Aliens with Offsets as extras mainly because I can shave off a kilo from my rack.

    On Rough rock like TM, and Tafelberg and Krakadouw I would use whatever. But then weight is still an issue

    Excellent review RB

  15. Justin Lawson May 31, 2013 at 8:50 am #

    How about this as a test?

  16. dee Jun 3, 2013 at 8:21 pm #

    Thanks so much for the article, I have been waiting ages to see a review of these. Could you please please upload a picture com pairing the head width of the x4 and the C3. I climb in a place with super shallow craics and before committing to a set I would love to know the head with difference. I am living in Turkey at the moment and I have to order online as there is no store where I can comp air the sizes. Thanks for the article.

  17. BAbycoat Jun 5, 2013 at 9:00 am #


    X4s, courtesy of
    Head Width: [0.1] 29.9 mm; [0.2] 29.9 mm; [0.3] 33.6 mm; [0.4] 32.8 mm; [0.5] 33.7 mm; [.75] 38.4 mm

    and C3s, courtesy of
    [000] 1.0in [00] 1.1in [0] 1.1in [1] 1.1in [2] 1.2in

  18. BAbycoat Jun 13, 2013 at 1:38 pm #

    PS – @Snort

    Aliens are manufactured with a 16 degree cam angle. Theoretically that gives a larger range, smaller holding power. But your (and others’) experience suggest that the softer lobes more than compensate for the angle..

    BDs are (apparently) manufactured with a 14.5 cam angle … so still on the slippy side of things (especially as they use a harder alloy for the lobes). Not surprised by Tony’s experience.

    Metolious goes for 13.25 degrees – lower range, more holding power (hence “Power Cams”). They’re a cheaper option for smooth Magalies Karbonaatjieskraal rock- not surewhether anyone stocks them in SA though.

  19. Paul de Villiers Apr 26, 2014 at 4:27 am #

    Thanks for the great article Robert. It’s definitely one of the more detailed articles on the topic out there.

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