Tricams....A thing of the past?

I've been meaning to ask:

Do tricams have a constant cam angle?

There seem to be opinions on both sides in this thread:

rockclimbing.com/forum/Clim…

If the angle is increasing, would that mean that a less-cammed placement is less secure than an otherwise equivalent more-cammed placement?

This is somewhat counter-intuitive to me, because if anything it seems to me that they set more securely (in terms of "bite") when then are not completely cammed.

mbk wrote:I've been meaning to ask: Do tricams have a constant cam angle? There seem to be opinions on both sides in this thread: rockclimbing.com/forum/Clim… If the angle is increasing, would that mean that a less-cammed placement is less secure than an otherwise equivalent more-cammed placement? This is somewhat counter-intuitive to me, because if anything it seems to me that they set more securely (in terms of "bite") when then are not completely cammed.

This is something I have never given much thought but would like to know as well.

from good ole Mal of trango fame ...

Each tricam has a varying angle and it rotates through its range. Greg designed them this way for the soft sandstone flakes in Zion. The theory goes that as the cam rotates, the angle steepens, reducing the outward force so destructive to the soft sandstone flakes and, at the same time, increasing the rate of expansion. It's this increasing angle that makes tricams feel so secure in the small end of the range and tippy at large end.

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The engineers are going to crucify me for this but here it is in plain language.

All cams and sliding nuts, and, in fact, anything that will hold in a parallel sided crack, somehow convert downward force into outward force. Outward force is what will dislodge blocks and pry off flakes.

A passive nut in a constriction in a crack also generates outward force but because of the huge amount of friction between the nut and the rock, that outward force is less that what a cam would produce.

Since one side of the Tricam must slide along the rock to generate the outward force, some of that energy is lost (I can feel the engineers wince at that one!), therefore a Tricam will generate less outward force than an active cam.

Flame on engineers!
Mal


rockclimbing.com/forum/Clim…

;)

I don't believe tricams have the same outward force as SLCDs. But not being an engineer I can't do the math so I don't KNOW that, and can't accurately explain why. It's just something I'm visualizing. The closest I can come to explaining is by using a system where the forces are reversed, and even that probably won't be clear. But I'll try.

If you have a rope running a straight line between two points, and you put a give weight in it's center, it exerts far more force to both ends of the rope than if you side that weight all the way to one side of the rope (adjacent to the anchor point). The weight represents the axle of either type of camming device.

Poor explanation, I know.

Great discussion, all!

We're a bit biased, but indeed, we love our Tricams. The new configuration (tapered in their "wide" orientation) gives the Trimcam EVOs three potential placements, rather than the two most of us learned on. We also added the .25---black---to offer another size just below the ever-popular pink (.5). Note, too, that the black .25 offers a strength rating of 5kN--pretty great for a smaller nut. It's as strong in its cammed position, too--5kN. (Check out our smallest size, too--the white .125. Rated at 2kN when camming, it's more of an aid piece, but at 9g, it's a great option for tiny, funky placements.)

We tend to see more of the pinks and reds stuck than any other size. The guides we work with report that unless their guests have been thoroughly schooled on cleaning them, the smaller sizes can get stuck--especially when the follower begins pushing the Tricam deeper into its placement in an effort to remove it. With less experienced folks, it's nice to have both hands available for cleaning them.

Eldo, Gunks, Dolomites, alpine, we end up finding tons of places for Tricams. They replace medium-large nuts on your rack, while offering another camming option for parallel-sided cracks at the same time. They're also great in icy, muddy, dirty cracks--and if you gotta bail, you'd rather leave a couple of these, rather than a couple cams.

So--here's a quick incentive to get somebody new to Tricams into a set. Post your best "wish I had a Tricam" pic in the next few days and we'll send you a set--black to brown--for your rack. Your pic could be of a rattly nut or a perfect horizontal--any time you wished you had a Tricam, but didn't. We'll give it a week to pick a winner.

Go!

nbrown wrote:I rarely use them but when I do its because nothong else will work.

Here's mine. A roughly 100 foot section of steepish 5.6, the first pro is a slung horn 10 feet up coming out of a mini cave/alcove off the deck, the second is bomber solution pocket like your pic where, without a red tricam there would be no more protection until that tree. The pink and red tricams are essential gear.



They work great passively BTW.

Only option on a run out slab... wish I had a tricam...

I bought a set (evos) last year and used them very rarely. I was just out today and placed 3 of them, I think, and they felt pretty good. My concern is with them walking, though. I've never seen it happen, but I've 1) never cleaned my own tricam placement after completing a route and, 2) never fallen on a tricam.

I'm in Southern Ontario, one of those areas where the tricam is something many climbers swear by very vocally. If I can learn to trust that they won't walk, some of the horizontal limestone weaknesses with extremely irregular walls are very, very obviously better protected by a tricam than a cram.

Tricams don't walk. That's a SLCD specific problem caused by the nature of how the devices operate. There's a chance they could be rattled out if not placed on a long enough sling, but it's not very likely. Tricams are one of the only things that work well on limestone, although I still wouldn't whip on them out of fear of rock fracture.

Old lady H wrote:Are tricams better than cams for columnar basalt? I'm not remotely close yet, but sooner or later I will need to lead this climb (my avatar pic), as it was my first, almost successful one. Other than that, tricams seem like a great investment for the back country. Idaho has a bit of that, here and there. ;-)

I've never once felt like my tricam-less rack has been lacking at the Black Cliffs. Sure you might be able to find placements for them but they're not at all needed if you've got a good selection of nuts and cams. If anything the pieces that would be the hardest to live without on the columnar basalt at the cliffs would micro cams, since they give you solid pro in those little seams where nothing else will work. Btw, I'll get around to replying to your PM one of these days, I swear...

mbk wrote:I've been meaning to ask: Do tricams have a constant cam angle?

According to "Off Belay" #9 Feb 1978, Abalakov cams (very similar to Tricams) follow a logarithmic spiral described in polar coordinates.

They show design coordinates for both 70 and 75 degree cam angles.

"The cam angle determines the crack-fitting range and is an important factor affecting the ability of the cam to jam, or lock itself into parallel-sided cracks. As the cam angle gets closer to 90 degrees, the crack fitting range decreases, but the ability to lock increases. We chose a value of 70 degrees as a compromise between these two considerations"

They also state: "Based on our force analysis, Abalakov cams generate a lateral, crack spreading force of about 1.5 times the load on the nut"

Old lady H wrote:Are tricams better than cams for columnar basalt? I'm not remotely close yet, but sooner or later I will need to lead this climb (my avatar pic), as it was my first, almost successful one. Other than that, tricams seem like a great investment for the back country. Idaho has a bit of that, here and there. ;-)

I've only ever climbed faces on basalt but based on the general feel of the rock, my limited geology knowledge, and my somewhat limited understanding of tri-cams, I'd say probably not, unless you are worried the rock will be too smooth for cams to work. Tricams, due to the stinger, can be better than SLCDs in very slick rock, and the basalt I've climbed was quite slick in places.

I think that tri-cams are an amazing piece of gear, but not in all locations. They really shine all over the southeast because the rock tends to form features such as oddball pockets and horizontals and these are the placements where cams/nuts will be total shit and a tri-cam will be bomber.

That being said, in other locations, where cams/nuts work 99% of the time, they are less useful. I love my tri-cams but unfortunately SW Colorado rock doesn't really lend itself to tri-cams much and I don't really use them often. In these cases, the only thing tri-cams really have going for them is their extra versatility compared to large nuts; they work just as well as a large nuts but also give you the flexibility of having a camming action as well.

As with everything in climbing, "it depends". If you're in an area where tri-cams shine, most locals will rack 'em. If not, you probably won't need them.

All good posts and loving the pics--keep 'em coming!

Wish you had a tricam... But the nut tool was not long enough...

When I read the title of this thread, my first response was that they were never even part of the present. However, I think it's just a function of where you climb. In CA, where you're mostly climbing on granite, almost no one uses them. I came maybe think of a handful of times where I've seen them on anyone's rack, and they were probably visitors. There is the rare place, like Courtright, where the smaller sizes are supposed to be useful, but, climbing for 35 yrs. in CA, I've never placed one and can think of only a couple of times where one would have come in handy.

"How the *^%* are we getting down from here Mateo?!"

After realizing that the #4 the guide book "recommends" is a *really* important piece of gear for the crux we're trying to figure out the cheapest option to bail. Instead of leaving cams we decide on the biggest "most stuck" rocks we can find. Less then ideal indeed. If only we had brought a set of CAMP tricams ;)

Fat Dad wrote:When I read the title of this thread, my first response was that they were never even part of the present. However, I think it's just a function of where you climb. In CA, where you're mostly climbing on granite, almost no one uses them. I came maybe think of a handful of times where I've seen them on anyone's rack, and they were probably visitors. There is the rare place, like Courtright, where the smaller sizes are supposed to be useful, but, climbing for 35 yrs. in CA, I've never placed one and can think of only a couple of times where one would have come in handy.

A good majority of my climbing is done on the granite found in Little Cottonwood Canyon and I have found them to be invaluable there as well as on the granite found in Joshua Tree. But like you said, maybe it's an area thing. But again, no one I know uses them here in SLC.

I've also found the to be extremely useful in quartzite as well. But I guess it's like any gear...practice placing it enough and you can learn to find more and more placements and spotting them becomes easier.

I use tricams almost every time I go climbing. Our local basalt is often "wavy" rather than parallel sided cracks, and the tricams are often more secure than active cams. There are plenty of horizontal cracks, and gas pockets in the basalt as well.