Metolius TCU climbing cams pulled until failure - Great Slow Motion! 

Better not climb then 💪🏼

Same 🍰

"Big" car lol. Pretty sure those cams could take care of most compacts. But yeah, if you are trying to dangle your 4x4 off a cliff, I reckon use three of them to be safe.

Or using slippery cracks!!

@@sammyd7857 You better remember to pack condoms on the next hike.

Ok, I disagree, if the pull force is 11.85 kN then the cam or more accurately the friction force between the cam and the rock that is acting in the opposite direction is also 11.85 kN. Since the friction surfaces are two then the friction force on one side is 0.5*11.85 kN = ~6kN

@@hsoley that's correct in the direction of the pull force (in line with the rigging) However to stay in place, cams push the rock perpendicular to the pull force. See at 7:20, "this way" pointing towards the rigging, and "this way" pointing to the sides =) Also have a look on how cams work and you'll see the relationship between the in-line force (these 6 kN you mention) and the cam reaction on the rock (these 25 kN), and you'll not surprisingly find the friction coefficient between the metal and rock: 6 / 25 = 0.24 =) So the total force is indeed the vectors 6kN in-line plus 25 kN perpendicular, which is 25.7 kN. So the in-line force only adds a small component to the total reaction force. The angle of the total reaction force is nearly aligned with the cam reaction force on the rock, just off by a small angle of atan(6/25), which is, surprise surprise, 13 deg, our camming angle =) All that means that cams are designed to meet the friction coefficient required to hold them to the rock. So it is not a "bad design" that cams put so much load onto the rock, they HAVE TO in order to take the climbers fall without sliding.

Since the other side of the rock is so big and not moving at all (can think of it as immovable), the force on the side that moved is actually double that: 4.24*P

what??

Turtle Stomper All I Gotta say is I enjoyed reading it twice. I’m taking a break. I’ll go back and read it a third time in a couple of days, still won’t understand! 😶

You need to trust your placement and the rock. Thin metal stuff, if you still can't bend it, will still hold multiple times your weight.

It Really helps to play with them over n over in safe situations to get to know em and how to place em! After a while of this you’ll know what works and what does not and then your trust will build even more! 🤘👽

Yes. This video and the math comment above enlightened and built some trust in me in cams and rock climbing equipment, especially certified ones.

Same, now I don’t trust that cloth sling part though

@@Thurston86 I completely agree. With your comment and the comments above yours. I already trust the cam to do what it supposed to do. For me the cam was never in question. Its the placement and the rock. And the only way to really know how to trust your placement is, like you said, to spend time playing around with it on the ground..or in a safe situation. After awhile u pretty much develop an instinct for it. Before u even place your cam u already know how good of a placement it is and how its going to sit in there just looking at it. Like every other skill you learn in life, it just takes practice.

You definitely start off with sport lead climbing first, trad climbing's definitely on the scarier side of things even for intermediate/advanced climbers

"As far as safety it was super good enough"

Always have been aid haha

@@danieljay8009 Sounds like've sent the pink one in the corner

@@danieljay8009 Yep, been used as clean aid for decades!

@@lonememe the only thing thats not aid is free solo trad climbing

@@danieljay8009 I mean if you don't fall and you're only pulling on rock then it isn't aid regardless of your equipment. But yes, falling on a cam has always been aid.

at 5:25 the engagement angel looks like ~45° I guess 13,5° is the max angel ?

I was scratching my head for ages before I posted. With you on tan angle, but I'm thinking real life and pull not perfectly central (worst case) you have a behaviour where the cam(s) on one side doesn't rotate on shaft but rather just pivots/rolls over the rock and the cam(s) on the other side does the camming. That case I think you have a mechanical advantage of 1/0.24 (roughly 4). Interested in why you say approx 2 not approx 4, because I've been thinking about this for a while and still head-scratching a bit :)

@@tomtom4405 Its because the load on the cam is distributed to both sides of the crack, with each side holding approximately half the load. The best way to see it is to draw a force diagram and you will see you need two frictional forces and two reaction forces (one for each side). In the case where the lobes are unevenly rotated so the axle is not central because of the constant camming angle the triangles used for the force calculation remain the same shape, even if they are different sizes. The cam may roll/pivot as the load is taken up, as the axles are slightly elastic and the rock may deform under the stress, but both sides are engaged and are applying an expansive force which relies upon the friction. Imagine if one side of a crack was perfectly smooth (mu = 0), the cam would not be able to engage and would just slide out. This (hopefully shows) both sides are needed in order get a camming action.

@@chrisp6582 thanks, I'd thought about this originally but I'd misunderstood the scenario of one cam not rotating on shaft. You're absolutely right. Even if one cam rocked but not rotated on shaft because of the log spiral it still expands by 13.5 (or 13.75 wild country) degrees. So it is always 2 cams/sides expanding. 1/(2*tan 13.5) is approx 2. Thank you for correcting me!

@@muchmore344 Hi Matthias, It looks like the cam is contacting the rock at roughly where the trigger wire is attached to the cam lobe. I'd guess the angle was approx 20 degrees but it is hard to tell. The 13.5 degrees is the camming angle in a parallel sided crack. Of course in nature cracks may not be perfectly parallel which would change the angle.

I wanted to say something about that too :)

Those things are used when rock climbing. Put those in a crack in a rock, clip your rope to it, and keep climbing. The person climbing behind you on the same rope pulls it out. If you fall, this thing is what keeps you from dying.

WOAH! Good eye! That's pretty crazy.

And they say that wiregates don't flutter...

@@10410003 That is my thought exactly!! Yikes! Looks like it was only wishful thinking.....

Perhaps that makes it less likely to walk it's way out?

Same, might start using a few of my old favorites because of this.

doing it next weekend!

Thanks! Will do! I also want a faster dyno and will drop test them too

Glad you like them!

me and many other rely on technology like this to keep us safe at work, so without these tests, we just rely on what we are told : "it should be safe". With what you are doing, we can actually see and know what are the limits, it truly helpful.

That, or even using two or three carabiners through the wire to increase the bend radius.

A bigger radius is not a realistic test. Climbers would only have a carabiner.

@@turning5462 You would never put the carabiner in the wire loop. You learn that day one for the exact reason showed here, it breaks easier.

That was wild 😳

i love it! haha

would be intresting!

@@Nasogaa yeah I use em a lot it would be really nice to test them

Bradford Burns. Common myth. Only applies if you are setting the cam on a table.

good onya! i use the same tricams so i'd be excited to see them get tested

hit me up on email skylining@live.com

Just to see if you are paying attention :)

“It’s hard to pull out” that’s what he said

That was our takeaway too.