Gear Review - Black Diamond C3 Camalots


Black Diamond C3 SetExperience - I have gotten a fair amount of mileage with the C3s. I have climbed with Matt's (Notch) three times and have got a lot of mileage on the #2 C3 I picked up in July. I have not fallen on one yet. I have owned the green and yellow Aliens for 3 years and have climbed with a variety of other sizes from friend's racks. Due to the well documented issues with CCH I am no longer comfortable climbing above the Aliens and have retired them to the aid rack.

Engineering - Kudos to BD for a beautiful, innovative piece of engineering. The engineering has resulted in integrated cam stops; and narrower heads and greater cam surface areas in critical range than comparably sized Aliens while still featuring stem flexibility in both horizontal and perpendicular, vertical placements. Of course the creative engineering is most likely a result of a "work-around" the Colorado Custom Hardware flexible stem patent.

Materials - The cams in the 3 smaller sizes appear to be constructed from 6061 aluminum and from 7075 aluminum in the #1 and #2 sizes. I assume, since the manufacturer does state it specifically, that the use of the softer 6061 aluminum alloy in the smaller sizes is to provide the appropriate amount of friction for the small surface areas or the cams in these sizes.

The term softer is a relative one since both these alloys are aircraft grade and possess more than adequate tensile strength for the cams. The issue actually be more related to the greater "compressibility" of the 6061 rather than a higher coefficient of friction. The greater compressibility of the 6071 would mean the cam lobes would deform more than the 7075 aluminum alloy resulting in greater surface area with the rock and thus great holding power. The metallurgists amongst us might be able to add further insight here. Aliens are made from the 6061 aluminum alloy. CCH does state this is "grippy" aluminum.

Cam Lobe Design - Related to the materials employed and the surface area of the cam lobes, is the presence or absence of serrations on the cam lobes. The 3 smaller C3s have smooth finishes on the lobes. The two larger sizes have serrations. Clearly the smooth surfaces of the cam lobes in the smaller sizes, or perhaps better put, the lack of serrations is to give the lobes the necessary surface areas to provide enough friction for the cams to perform adequately when tested with forces likely to be experienced during climbing activities.

I haven't quite figured out the role of serrations. As you can see from the photos below the serrations on the surface of my Aliens have been pretty well wore off, or compressed. Not sure how the lack of the serrations would effect the holding power of the cam. Here again the engineers, materails and otherwise, amongst us may be able to shed more light on this.

This brings up the entire issue of the performance and testing of cams. My view is that simply put; the smaller the cam the less force it will hold, and the less margin for error in placing them you have. The testing procedure sets up an ideal placement. It does not take into account variables associated with actual use such as the texture, stability, dryness or cleaness of the rock nor the configuration of the placement feature. Even the most modest falls most of us experience will generate forces on the top piece of 4 kN or more. This clearly is in the pull force rating of the smaller C3's.  Why the Aliens UIAA pull force ratings are significantly higher than the C3s strikes me as odd. In the fine print on the CCH website I did find this statement - "The minimum holding force for Alien cams is 5 kN."

The following are some informative links I came across in putting this review together.

Theoretical modeling of cam design and materials. For those of us with a mathematical bent.
Pictorial representation of cam testing by UIAA. Actual procedure is copyrighted and not freely available on the web.
Simple and clear explanation of interaction between cam angle, cam width, effective camming range, friction and holding power from Metiolius' website.
What Heavy Climbers Need To Know. Interesting information on rope testing, fall factors, pulley effect, impact forces and weight of climber presented in a clear concise manner. Pretty impressive increases in impact forces with increasing weight. Don't forget to add in the weight of all the clothing and gear we wear while climbing! My climbing weight is usually about 172 lbs. But clothing, harness, helmet, chalk bag, headlamp and rack can easily weigh 20 lbs or more.

Specifications

 C3 Backside Of Cam Head
Black Diamond C3 CCH Alien
Size Color Range (in) Weight (g) Strength (kN)
000 Gray .3-.5
 55 4
00 Purple .35-.54 57 6
0 Green .42-.62 59 7
1 Red .47-.74 62 10
2 Yellow .56-.89 66 10
Size
Range (in) 
Weight (g)
Width (in) 
Strength (kN)
color
.33
.33-.54
66
1.40
8
black
3/8
.39-.67
71
1.40
9
blue
1/2
.50-.86
74
1.30
9
green
3/4
.61-1.07
74
1.30
9
yellow


Fit & Finish - As one would expect from BD the fit and finish is outstanding.

Green alien, yellow C3 and yellow alien stackedHead width - The head width of the #2 C3 is 1-3/16” versus 1-3/8” for the yellow Alien. This is a very significant difference. This to me is a big positive factor for the C3. I can remember a number of times when I knew my Alien placement would be golden if it had been just a bit narrower in the head so I could get it in a narrow pocket.

Cam surface area - I compared my #2 C3 with a range of .56 to .89 inches with the 3/4" yellow Alien which has a range of .61 to 1.07 inches. The #2 C3 despite being a TCU, versus the FCU design of the yellow Alien FCU, has a greater cam surface area in the critical area. This is due to the interlocking, overlapping cam lobe design of the C3.

The photo of stacked head-on view cams has the green alien on top, the yellow C3 in the middle and the yellow alien on the bottom.

I defined the critical location by the wear on the cams that has occurred from placing them.  At the beginning of the critical area the two cams had equal width. At the end of the critical region (more cammed) the C3 was 1/8” wider than the Alien. In cams this size, for me this is a significant holding power factor.

Integrated cam stop - The interlocking cam lobes, as seen in the photo, provide an integrated cam stop. This is a nice safety feature to have but in cams this size and the placements for which they are designed not a major factor for me.

Weight & Strength - The C3 cams are lighter across the range. The C3 cams are comparable to the Aliens’ strength ratings in bigger sizes but less strong in small sizes.

Be aware directly clipping the loop rather than clipping the attached sling reduces the strength ratings by 2 kN. (I actually read the little manual that comes with the cam!) Pretty significant strength reduction. Couldn’t find comparable info on the Aliens but suspect it is the same deal. That is, of course, assuming you don't have an Alien whose loop was improperly crimped. Then it is body weight, maybe!!!

Cams LengthwiseTCU vs FCU – in the placements where these cams most often go I’m not sure pivoting versus walking is an issue for me. 

Feel – We all know the Alien feel is great. C3s have a good feel as well. C3s trigger and thumb loop feel just a bit more comfortable and solid with my fingers than the Aliens but not a big deal. Trigger pull strength with the C3s is just not an issue when climbing for me. Never notice it.

Durability – My Aliens are beat to hell and still functional. The yellow has taken one pretty severe fall and another reasonably good fall.

The green has absorbed one very mild falls. The C3s look as if they will be similarly durable. My one concern is the retractor wires. They seem as if they may be the most vulnerable part of the C3s. Due to the unique design of the cam significant bending or kinking of the retractor wires, unlike other cams, could affect function. 

Flexibility – Flexibility in an horizontal placement is fine. Not an issue. What does appear to be a potential issue, when you first inspect a C3, is a perpendicular placement in a shallow vertical crack. These placements, old piton scar type placements, are a big reasons why we carry these type of cams.

When weighted in this configuration the stem unit twists and folds over itself. This not only torques the head of the cam in an vertical manner, top set cam lobes getting force applied outward and bottom lobes being pushed inward, but also in a twisting manner as well. The top cam lobe will be pushed sideways in one direction and the bottom set sideways in the other direction.

Aliens with their flexible stem torque the head in the vertical direction when weighted in the perpendicular, vertical configuration; but do not apply the twisting torque seen with the C3s.

I have sling tested the hell out of my #2 C3 in perpendicular placements in vertical cracks. I have also sling tested, somewhat more gently, a few of Notch's. My cam stood up to the abuse as well as any Alien would have.

Cams Side-By-Side I have had a chance to briefly discuss the C3s with a New Paltz luminary, who I respect and trust, in the early Fall. He has been climbing with the C3s for over a year and an half beta testing them for BD. I posed the perpendicular placement in a vertical crack question to him. He replied quickly and confidently that it is just not a problem. We got interrupted at that point and I was not able to follow up with him in more detail. I will next time I see him.

I am confident climbing above my C3 when in such a placement.

Summary - I will likely get one or two more C3s to fill out the small end of my rack. The plusses are the narrow heads, robust critical cam area and integrated cam stops. The negatives are the premium price, the funky twisting of the shaft when loaded when placed vertically in a shallow crack and potential durability concerns noted above. My real preference would be that a reputable manufacturer would start producing Aliens!

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