When to use what cam?

Daniel T wrote:

I am not in the market for buying cams at the moment.  I am still trying to wrap my head around all the different styles of cams and their uses.

Why is there 4 different styles of cams from BD on the market? Even the aliens have several different types. At least Totem has 2 types of cams available. It makes it a little easier to get started in the mix.

1. Ultralights are a LOT lighter. But pricier.

2. Basic Camalot is a wide and stable design, if heavy. The wide stance resists walking and the force is spread better when you get an ideal placement.

3. X4's have the advantage of 4 cams (more reliable holding than 3) but with very narrow heads to fit in narrow spots.

4. C3s when the crack only opens up barely to take a cam. That tiny bit more narrow makes a real difference in shallow spots.

FrankPS wrote:

I think having more cam lobes in contact with the rock is better. If a four-lobe unit fits well, that would be my first choice.

C3's have the same surface area as most four cam units.  So this statement is inaccurate.  Ignore it.

 And having three lobes allows it to pivot in the direction of pull much more easily than the four lobe unit. BD did extensive testing on this. They created the X4 to compete with alens. 

Greg D wrote:

C3's have the same surface area as most four cam units.  So this statement is inaccurate.  Ignore it.

That may be true of total surface area, but not in holding better given small variations in the crack that prevent that surface area from being used.

Its a question of how effective the surface area is used, no?

King Tut wrote:

That may be true of total surface area, but not in holding better given small variations in the crack that prevent that surface area from being used.

Its a question of how effective the surface area is used, no?

True regardless of number of lobes.    

Greg D wrote:And having three lobes allows it to pivot in the direction of pull much more easily than the four lobe unit.

This may be accurate. But, Ignore it!

I prefer my placements [in the direction of fall] to stay put and NOT rotate. That’s why they have flexible stems and slings (extendables or not) to prevent rotation and ultimately walking. Walking micro cams... bad!  Since when did X4s have a problem not adjusting well (shoulder shrug). 

Ps. Are you guessing they have equal surface area or is this data available to us.  I know the middle lobe is wider but if TCUs were so equal wouldn't they be vastly more popular.  

FrankPS wrote:

I think having more cam lobes in contact with the rock is better. If a four-lobe unit fits well, that would be my first choice.

Edit to add:  On uneven surfaces which all but a few placements have more lobes equals more surface contact... Frank I think you were onto something here. Even if you didn’t realize it. More lobes are better as they divide the surface area into more adjustable surfaces over the same width. Imagine sipes on a snow tire vs a road tire or slick. More edges between the side walls of the tire allow for greater number of individual connections to the road surface.  Four lobes are more adjustable than three. Splitter cams only have two lobes further decreasing the conforming/adjustability. Imagine if both of those lobes sat on big crystals. Yikes. 

It’s really just preference, or even a matter of what you have available. People did it with pitons, nuts, rigid stem cams, etc, etc.. 

Climb with other peoples’ gear if you want to try different cams out. Then, climb on and learn your sizes for your gear. Mostly, gear fits or it doesn’t. A lot of what makes the cam your go to piece is a mystery. Or maybe it’s familiarity? Not sure. It’s not that complex once you’ve gotten some mileage under your belt. Choices of when and where to place spice it up. Nutcraft. Blah, blah, blah.

And we haven’t even touched the contact area you allow in your amygdala for the purely psychological pro. Clip the birdshit and go!

Jake Jones wrote:

You'll figure it out.  It ain't rocket surgery.

is it considered brain science?

Thanks for the info guys and gals.  Ill keep climbing on my Helium friends and use other peoples cams to see what I like.

There are not to many concrete examples here, so I'll try one. Imagine there is a shallow crack in a vertical corner. Let's say a rightfacing corner where the rock sticks out (towards the climber) left of the crack. When placing a TCU, make sure the side with two lobes are on the left and the center lobe is on the right. For confidence-lacking shallowness, the outside lobe on the left can actually be outside the crack, but it is still touching the protruding rock left of the crack. When placing a 4-cam unit, the outer lobes go on the left side and the two center lobes on the right. If the crack is just a little bit too shallow, the outermost center lobe of the 4-cam unit (on the right) might actually hang outside the crack. 

Granted an extreme case. I've seen it once in 20 years. A blue alien was quite unstable, but a purple Metolius TCU had full contact on all lobes. Not particularly aweinspiring (as the crack was slightly flaring as well!), but this was one piece as part of a three-piece nest (purple TCU, black alien, half-blind #3 BD nut). A fall would have been really short (gear at waist, low force), but with a bad landing, so all-in-all not too shabby.

Scottmx426 wrote:

I prefer my placements [in the direction of fall] to stay put and NOT rotate. That’s why they have flexible stems and slings (extendables or not) to prevent rotation and ultimately walking. Walking micro cams... bad!  

Sure, it is best if the cam stays exactly as you placed it.  But, when you fall (or take which has become popular with the new gen), the rope tension will likely pull on some of your placement at a angle perpendicular to your rope causing them to rotate out.  The stiff drive springs in the C3's reduce the likelihood of movement in the first place.  But, it they do rotate out of position, the stiff stem in one plane (flexible in the other), allows it to more easily rotate back into the direction of pull when fallen on.  Years ago, BD did lots of research on this and proved that this is superior to the very flexible stems of Aliens and such.  

Since when did X4s have a problem not adjusting well (shoulder shrug). 

Well, look at the several threads where people have decked after the X4 sheared out when loaded with the stem NOT in the direction of pull.  In some cases, 3 in a row ripped out.  

Ps. Are you guessing they have equal surface area or is this data available to us.  I know the middle lobe is wider but if TCUs were so equal wouldn't they be vastly more popular.  

Don't confuse Metolius TCU's with C3's.  They are quite different.  Are you guessing the are not vastly more popular or is this data available to us. 

Greg D wrote:

C3's have the same surface area as most four cam units.  So this statement is inaccurate.  Ignore it.

It's not the surface area of the device that matters, it's the surface area that is in contact with the rock.

A small nut that is fully in contact with a constriction may be better than a large nut that is only partially in contact.

Of course it will depend upon the characteristics of the particular placement, but more lobes will generally allow for more contact as there are more ways the lobes can adjust to the shape of the rock.

Hobo Greg wrote:

Are c3's double axle? If not, I am not sure they are rated to hold as a nut.

I don't think he meant placed passively like a nut, just slotted more easily like a nut.  The stiff stem helps in this case.  

Nonetheless, a double axel is not the determining factor in all small cams whether a cam is rated as a passive placement.  I believe it is the strength of the cam stops.  

edit:  it depends on the brand.  BD's with double axel can be placed passively.  Some other brands that are single axel can be placed passively.  It depends.

Hobo Greg wrote:

Are c3's double axle? If not, I am not sure they are rated to hold as a nut.

C3s are single axel.  They are rated based on whe forces that can withstand, as are nuts, each size, manufacturer and configuration gets it's own rating.  In general, the smallest sizes hold 5kN or less, and then it ramps up to 7kN or more as they go from timy to merely small.  Now, this is breaking strength, and holding strength may be much, much less depending on the quality and type of rock, and the quality of the placement.  The wee cams have a very small adjustment range, and thus a very small margin for error in placement.

Matt Himmelstein wrote:

C3s are single axel.  They are rated based on whe forces that can withstand, as are nuts, each size, manufacturer and configuration gets it's own rating.  In general, the smallest sizes hold 5kN or less, and then it ramps up to 7kN or more as they go from timy to merely small.  Now, this is breaking strength, and holding strength may be much, much less depending on the quality and type of rock, and the quality of the placement.  The wee cams have a very small adjustment range, and thus a very small margin for error in placement.

That's not what Hobo Greg was asking.  He was talking about a cam placed passively. 

So, to answer the question:  Per BDs intructions, C3's should not be placed passively.  And, the smaller X4's should not either.  Only the larger X4's with the double axel can be placed passively.  .4, .5, .75.

Greg D wrote:

Sure, it is best if the cam stays exactly as you placed it.  But, when you fall (or take which has become popular with the new gen), the rope tension will likely pull on some of your placement at a angle perpendicular to your rope causing them to rotate out.  The stiff drive springs in the C3's reduce the likelihood of movement in the first place.  But, it they do rotate out of position, the stiff stem in one plane (flexible in the other), allows it to more easily rotate back into the direction of pull when fallen on.  Years ago, BD did lots of research on this and proved that this is superior to the very flexible stems of Aliens and such.  

Well, look at the several threads where people have decked after the X4 sheared out when loaded with the stem NOT in the direction of pull.  In some cases, 3 in a row ripped out.  

Don't confuse Metolius TCU's with C3's.  They are quite different.  Are you guessing the are not vastly more popular or is this data available to us. 

From outdoor gear lab:  regarding C3...

“The bad news is that these cams [C3s] tend to walk more than others due to the narrow head and stiff stem. The stiff stem also makes them awkward in weird aid placements where there is more "torquing out." In those applications a more flexible stem is better. It can be nice to have a set of these on El Cap, but we prefer the new Black Diamond Camalot X4 which is only a little wider and has much more holding power and versatility.

I really like this climbing cam in some applications but am not ready to commit my whole rack to them like I have with the Black Diamond Camalot for the bigger sizes. I prefer a four-cam design like the Metolius Master Cam or the X4 that feels more bomber, is less likely to walk, and works in pin scars better.” 

~Not confusing Metolius “TCU” with C3. Using the “TCU” vernacular to represent any cams with 3 lobes. Metolius TCUs are almost obsolete.  They still work and are light weight but other units do the job just fine and are narrower. I think C3s are awesome units!  They just aren’t as versatile as “4CUs.”  Data on the subject isn’t necessary.  They are supplemental pieces.  Only 2-3 companies still manufacture three lobe cams. They’re great however when nothing else works.  

Here's the way I look at it (this addresses comments upthread a ways): If C3's were more stable than four-lobe cams, why would they even make C4's? Why not just make all sizes of cams three-camming units? I believe the answer is because four-lobe cams are less likely to walk or rip out.  The C3's serve a purpose in those pin scars or pockets, but four-cam units are safer, with a good placement.  Flame on.

Scottmx426 wrote:

. Metolius TCUs are almost obsolete.  They still work and are light weight but other units do the job just fine and are narrower.....Only 2-3 companies still manufacture three lobe cams. They’re great however when nothing else works.  

This is not true in my experience. It may be less common than it used to be as 4 cam units have gotten narrower in the smallest sizes....but I know of more than a few routes with "pods" that 3/4-1" TCUs fit in far better than any 4 cam unit, imo.

King Tut wrote:

This is not true in my experience. It may be less common than it used to be as 4 cam units have gotten narrower in the smallest sizes....but I know of more than a few routes with "pods" that 3/4-1" TCUs fit in far better than any 4 cam unit, imo.

Hence the “ALMOST” part. I know they work.  I own some and still use them. But hardly ever. 

Scottmx426 wrote:

Hence the “ALMOST” part. I know they work.  I own some and still use them. But hardly ever. 

Yes, but they can be very useful in pin scarred areas (lotsa pods).

best