Mountain Project Logo

Small cams - how low do you go?

bearbreeder · · Unknown Hometown · Joined Mar 2009 · Points: 3,065

Last year petzl did a series of test and wrote up about it to show the forces involved in leader falls

They used real folks (not dummies or steel weights) with real belayers using grigris and reversos

Here you can see how rope drag can add significantly to the impact at the anchor pushing the forces to 5KN or more on a low fall factor

I believe this test was on a NEW 9.2mm rope and grigri

Older ropes may have higher impact forces, reversos may have lower impact, etc ...

But this test with real folks show that one can easily approach 5 KN with even low impact falls

petzl test

no one is saying dont use microcams .... But if you do use em back em up if possible

Your margin of error is exceptionally small, especially for beginners

;)

Da wong inspecting a blown out red x4, i caught him with his feet just missing the ledge The grey x4 that caught him took enough force that it wouldnt retract anymore Perspective 11a, nightmare rock, squamish

Rob WardenSpaceLizard · · las Vegans, the cosmic void · Joined Dec 2011 · Points: 130

i was obviously joking about the knots... maybe it was less than obvious. I like know my knots

patto · · Unknown Hometown · Joined Jul 2012 · Points: 25
bearbreeder wrote:Never trust a single micro cam if you can help it Sure they may hold ... But even if we ignore the "ratings", the simple fact is that your placement margin of errors is MUCH less than a larger cam should give one pause
How are you calculating this "margin of error". If the placement and rock is good then it is good. I don't see margin of error, I just see 5kN of protection.

bearbreeder wrote:Personally id take a well placed micronut over a microcam anyday
Well placed is the key to both. Badly placed is the failure of both.

Kevin Mokracek wrote:Do people really think about kN when they climb?? Learning to place solid gear is more important than learning what kN your last piece can hold.
Word.

rgold wrote:Obviously, the falls you can expect to hold have to be short low fall-factor affairs. Forgetting about the fall-factor part, once a micro-piece is at knee level, you should probably be thinking 50% or more chance of failure.

I normally agree with you but I find you comments overly conservative. If the placement is good I would have faith in a decent whipper. Like I said earlier fell 20-25feet onto a 00 Mastercam which held nicely. The catch was not at all dynamic as it was on a Mega Jul.
TSluiter · · Holland, VT · Joined May 2013 · Points: 314
patto wrote: How are you calculating this "margin of error". If the placement and rock is good then it is good. I don't see margin of error, I just see 5kN of protection. .
I'd recommend taking a look into this, it is very important.

Think of it this way: placing the center of a 00 TCU 1mm off-center has much more impact on the strength of the placement than placing a Valley Giant 1mm off-center.
Ted Pinson · · Chicago, IL · Joined Jul 2014 · Points: 252

Yeah, that Carbondale Short Bus video does a good job of illustrating how to use microcams like you guys are describing...notice he protects that ridiculous dyno with X4s (I think?), but uses a pair of them because falling off a dyno onto a single microcam would be terrifying, to say the least...

Jeff G · · Colorado · Joined Feb 2006 · Points: 1,098

I place small cams all the time. Usually they are for body wieght or very small falls. You can often times place a small cam above your head and protect the moves right at the level of the cam. Once your feet are above the cam, then all bets are off.
It's a fallacy to think every piece you place needs to hold a "whipper".

Anonymous · · Unknown Hometown · Joined unknown · Points: 0
Jeff G. wrote:I place small cams all the time. Usually they are for body wieght or very small falls. You can often times place a small cam above your head and protect the moves right at the level of the cam. Once your feet are above the cam, then all bets are off. It's a fallacy to think every piece you place needs to hold a "whipper".
Done that in more than one case. Placed a piece of gear to pull a small crux roof move knowing that once I get past the piece it likely would not hold a fall.
Pete Spri · · Unknown Hometown · Joined Jun 2009 · Points: 347
TSluiter wrote: I'd recommend taking a look into this, it is very important. Think of it this way: placing the center of a 00 TCU 1mm off-center has much more impact on the strength of the placement than placing a Valley Giant 1mm off-center.
Agree with Patto here.

1mm is irrelevant as camming angle is constant and has nothing to do with strength. If your placement is bad, the 1mm will tip you out on a micro cam and render the cam useless, but that is all placement, as Patto stated.
Shelton Hatfield · · Unknown Hometown · Joined Apr 2011 · Points: 650

Sometimes when I'm gripped and it's all I can get in, I'll place a marginal small piece above me, but clip it with a long sling so I'm not introducing a bunch of slack if the piece blows.

Kevin Mokracek · · Burbank · Joined Apr 2012 · Points: 342

All this talk is pretty pointless. You place what you can and place it as best you can and hope for the best. If you constantly think about factor this and factor that you will end up psyching yourself out and end up sticking to routes you know you will be able to do. And that's fine if your happy with that but if you want to push your limits or climb new routes you eventually will end up placing marginal gear and will have to be okay with it.

Bill Lawry · · Albuquerque, NM · Joined Apr 2006 · Points: 1,812

"... but if you want to push your limits or climb new routes you eventually will end up placing marginal gear and will have to be okay with it."

True ... if one's goal is to push climb skills and protection skills at the same time.

bearbreeder · · Unknown Hometown · Joined Mar 2009 · Points: 3,065
patto wrote: How are you calculating this "margin of error". If the placement and rock is good then it is good. I don't see margin of error, I just see 5kN of protection. Well placed is the key to both. Badly placed is the failure of both. Word. I normally agree with you but I find you comments overly conservative. If the placement is good I would have faith in a decent whipper. Like I said earlier fell 20-25feet onto a 00 Mastercam which held nicely. The catch was not at all dynamic as it was on a Mega Jul.
squamish granite is known for being some of the best in the world ... and cams still pull

a microcam that moves shift slightly can open right up, the rock can be pretty slick and not hold (see the vid), etc ... sure everyone on MP places gear "perfectly", in the real world your stuck with the placements and gear you DO have

just because you took a fall on a small mastercam and it held doesnt mean they will always hold ... the purple TCU is perhaps the most pulled size out here ...

heres a NON micro cam pulling on what many would consider a good enough placement

youtube.com/watch?v=-WPM1Hd…

and heres some advice on cams from someone who makes and tests em ...

ICam placement rules
As the founder and head designer of Metolius, Doug Philips has spent an immense amount of time testing and improving cams over the last twenty years. Here are some tips on cam safety based on his vast experience.

Doug Phillips
1. No matter how good a placement looks, you can never be sure it will hold.
During my tests, about one in twenty good-looking placements pulled out when loaded.
The challenge is to figure out why the cam pulled, and what could have been done to prevent this from happening.

To understand why cams fail, we classify pullouts into six basic categories:

Lubricants (water, dirt, dust, moss, ice)
Poor rock quality
Cam movement (walking, misaligned)
Poor placement
Cam design
Poor maintenance
Lubricants
Anything that gets between the aluminum cam lobe and the solid rock wall can act as a lubricant reducing the friction. Water is an obvious lubricant as is dirt or fine dust. A dirty seeping crack with a thin layer of moss can cause an otherwise good placement to consistently pull out.

Poor rock quality
There are three categories of rock to avoid: soft, smooth, and weak:

Soft rock tends to crush under the load of a fall. The crushed particles act as a lubricant causing the cam to slip. After this type of failure, the cam lobes will often be coated with a thin film of pulverized rock.
Smooth or polished rock will not allow the cams to grip. Smooth stone can be found in water polished cracks as well as glacier polished stone. It is very unnerving to watch a cam consistently pull out of a super smooth crack that would otherwise be a perfect placement.
Weak or fractured rock will break, causing the cam to loose traction. When a cam pulls out of seemingly solid stone, I often find a small piece of fractured rock near one of the cam lobes. Occasionally a larger chunk of stone gets blown out of the crack due to an existing fracture or weakness in the rock.
Cam movement
Cams will move from the motion of a passing climber, rope action and impact from a fall. This movement can lead to pullout failures, as the cam is no longer positioned to hold a fall. To prevent this, place the cam so it has room to move and still remain in a good camming position. A long sling will reduce unwanted movement and allow you to fall on the next piece without putting any outward tension on the lower cam. Cam pullout failures commonly occur with a sharp outward or sideways pull rather than the downward pull you had intended.

Poor placement
Wide flares, bottoming cracks and irregular rock features make it difficult to get solid cam placements. Help optimize the security of a placement by maximizing cam-to-rock contact. Place good gear before and after difficult-to-protect sections. In my tests, I have occasionally been surprised by a bad looking placements that hold when drop tested. Most of the time however, if a cam looks bad, it will pull out.

Cam Design
The brand of cam makes a difference. Metolius cams are made with holding power as the primary design criteria. The main variables are cam angle, aluminum alloy, surface contact area, and cam alignment.

Cam angle
The cam angle we use is 13.25 degrees. This sacrifices range, but increases outward force, making the cams harder to pull out.
Aluminum alloy
Our aluminum alloy is 7075 for small and midrange cams and 6061 for larger sizes. The 7075 is stronger, maintaining cam shape under load in the small sizes. This is less of an issue in the large cams, so we switch to the lighter weight, less expensive, 6061.
Surface contact area
Surface contact area is important. More surface area will create more friction increasing the cam’s security. Also, more surface area spreads the load more, improving holding power in soft or weak stone. Our Fat Cams were designed with this in mind.
Cam alignment
Maximize holding power by lining up the cam lobes with the direction of pull. The original Friends did this by using a rigid stem. The Metolius cam’s relatively stiff “U” shaped body aligns the cam lobes with the direction of pull.
Poor maintenance
Like all technical equipment, cams require maintenance. This includes cleaning, lubrication, replacing old or worn slings and repairing frayed trigger wires. Be sure to retire worn out cams.

2. Place two good cams at critical spots
Because one in 20 cams pull, reduce cam pullout by putting in a second good piece. This gives you a 99.75% chance that one placements will hold. Equalize them if possible.

3. Place the cam in as fully retracted a position as possible without getting it stuck. This is the green zone on our Range Finder system.
Tight placements help to guard against the following types of pullout:

Pullout due to cam movement
Rope movement shifts cams. Long slings help, but you can increase security by placing the largest cam possible. If the cam moves to a wider crack section it will still have good contact with all four cams.

Pullout due to poor rock quality
If the rock on one side of the crack fails the cam lobes on that side will begin to slip. A cam with a tight placement (green zone) has a better chance of holding. If the rock on both sides of the crack fails, the lobes dig into the rock. The tighter the placement, the more the cam can expand before failure.

Pullout due to lubrication
When the cam pulls because of wet or dirty conditions it will move through several inches of crack before failure. If only one side of the crack is wet or dirty, the cam lobes on the wet side will tend to slip first. If the cam is in an open position the cams on the dry side will tip out and the placement will fail. In a tight placement the cams on the dry side will not tip out, greatly increasing the chance the placement will hold. I’ve observed a tight cam placement jamming just below the original placement.


sure no one calculates KN ... but every beginner (or even "experienced" MPer") should tell themselves

"oh SHIT ... thats one effing small cam, better get something else in too" if they can

;)
Bill Lawry · · Albuquerque, NM · Joined Apr 2006 · Points: 1,812

"heres a NON micro cam pulling on what many would consider a good enough placement "

Just so many more are not misled, that was undoubtedly bad placement geometry ... whether it had pulled or not.

bearbreeder · · Unknown Hometown · Joined Mar 2009 · Points: 3,065
Bill Lawry wrote:"heres a NON micro cam pulling on what many would consider a good enough placement " Just so many more are not misled, that was undoubtedly bad placement geometry ... whether it pulled or not.
hmmmmm

well here is the pic so we can have many pages of PHUN

there is a slight flare ... but most folks i know would consider this an acceptable, though not perfect, placement

theres many a climbs with worse placements

the intrawebz is funny ... many many many folks preach on "perfect placements", but in reality when climbing not too many placement are indeed perfect except on the ground

heres another one for MOAH PHUN

youtube.com/watch?v=faKH_cU…

;)
Bill Lawry · · Albuquerque, NM · Joined Apr 2006 · Points: 1,812

"there is a slight flare ... but most folks i know would consider this an acceptable, though not perfect, placement"

In my opinion, any flare in the wrong direction is bad. None of us have good enough eyes to say whether a discernible flare is enough to render the cam angle ineffective.

... whether it is a micro-cam or not.

Marc801 C · · Sandy, Utah · Joined Feb 2014 · Points: 65
Bill Lawry wrote:"... but if you want to push your limits or climb new routes you eventually will end up placing marginal gear and will have to be okay with it." True ... if one's goal is to push climb skills and protection skills at the same time.
Nope. Marginal gear is a fact of life on a lot of climbs - many of them most climbers would consider difficult.
bearbreeder · · Unknown Hometown · Joined Mar 2009 · Points: 3,065
Bill Lawry wrote:"there is a slight flare ... but most folks i know would consider this an acceptable, though not perfect, placement" In my opinion, any flare in the wrong direction is bad. None of us have good enough eyes to say whether a discernible flare is enough to render the cam angle ineffective. ... whether it is a micro-cam or not.
actually there IS an easy way ... the pull test, which this cam obviously "failed" ... visually if you were to spot that by eye in squamish granite, most would consider it a "decent" placement ... if you didnt then you wouldnt be climbing alot of stuff out here =P

craig luebben rock climbing

wild country cam book

wild country cam book

as a side note, when you place a microcam ... give it a good tug if you can ... it might surprise you especially in squamish where the cracks often have crystals in em and are uneven at the micro scale inside ...

not to mention that we have this thing called dirt, mud, rain, morning condensation, and vegetation ... if you arent a fair weather climber always climbing the most well polished climbs (which i undoubtably am)

;)
Bill Lawry · · Albuquerque, NM · Joined Apr 2006 · Points: 1,812
Marc801 wrote: Nope. Marginal gear is a fact of life on a lot of climbs - many of them most climbers would consider difficult.
Agreed. Sometimes that's all there is. And it's a personal choice whether to "be ok" with a steady diet of that under lead-limit climbing ... well my partner might have a say as well. :-)
Bill Lawry · · Albuquerque, NM · Joined Apr 2006 · Points: 1,812
bearbreeder wrote:actually there IS an easy way ... the pull test
Honestly, I have a hard time thinking of a "pull test" as overcoming doubts from a visual inspection. Edit to add: And I am advocating to be doubtful if there is a flare in the wrong direction.

By the way - although I don't recall the source - I do recall reading of some evidence that giving a cam a tug can improve the contact between the rock and the metal - enough to improve ability to hold a fall. But I'm still dubious that it is telling about a placement in a discernable flare.

Even 1 degree of flare significantly "eats away" at the designed ~13 degrees.
bearbreeder · · Unknown Hometown · Joined Mar 2009 · Points: 3,065
Bill Lawry wrote: Honestly, I have a hard time thinking of a "pull test" as overcoming doubts from a visual inspection. Edit to add: And I am advocating to be doubtful if there is a flare in the wrong direction. By the way - although I don't recall the source - I do recall reading of some evidence that giving a cam a tug can improve the contact between the rock and the metal - enough to improve ability to hold a fall. But I'm still dubious that it is telling about a placement in a discernable flare. Even 1 degree of flare significantly "eats away" at the designed ~13 degrees.
well with metolius you theoretically have "more" to work with ... since they are 13.25 deg, the"narrowest" of any common cam

i remember climbing this year on lake louise quartzite and having a cam i considered to be a very good placement (even, no flares, textbook range) rattle out ... fortunately i dont fall on easy ground

so i lowered back down to it, thinking i screwed up the placement some how ... nope it was as "textbook" as you could get with a draw on it ...

so i yanked on it and it came right out over and over again everytime i placed it

i wished i had taken a vid as MP would be freaking out claiming it would be impossible =P

it was a purple totem ... quartzite can be a bit slick

there was probably a reason i brought some tri-cams on that trip

;)
Guideline #1: Don't be a jerk.

Trad Climbing
Post a Reply to "Small cams - how low do you go?"

Log In to Reply

Join the Community

Create your FREE account today!
Already have an account? Login to close this notice.

Get Started.