Friday, November 20, 2009

Testing > C.H.R.D.T > Climbing Hold Review Drop Test

We've been working on this for a long long time... we wanted to look at peoples holds and then see if we could break them. Through trial and error we've got some numbers and a video for you all.

Now let US, and when I say US I mean the folks over at Climbing Hold Review put something straight before we start. We're not trying to damage anyone's business, we're just testing holds and seeing what we find out along the way, this is simple testing, simple everyday things that could happen to your holds.... that's it. Enjoy the read... but first let me tell you what we called this little shin dig :
Now first of all we made a test bench and we started torquing holds up on it, we also tested what someone with a normal T wrench can tighten a hold down to, taking the average, we found that if you're really hanging on the wrench you can get between 12 and 18 ft lbs of torque. Now not many people understand torque... so we went and tightened holds down to 20 ft lbs which is 240 inch pounds of force on the area of the hold.

Every hold was taken up to 20 ft lbs of torque and here's what we found:
  • At this force you're likely to pull your t nuts into the wall and into the back of the hold
  • We used a 5ft long torque wrench so to get the forces we applied with a T wrench you are essentially the Hulk!
  • One of two things will happen if you hit the magic number of 20 ft lbs:
  • 1) You've got a great chance of shearing your t nuts threads
  • 2) You might compress the material of the hold you're testing
Basically what happens is the inset washer is pushed towards the back of the hold... this means the hold doesn't sit flat on the wall anymore and has now become dangerous to use as the structure of the hold has been compromised.

With that test done, we went to 30 ft lbs and gave up! At that pressure you just pull your T nut through the wall. In a one off "let's see how tight we can tighten a hold til it snaps" moment we took one of the hollow backed Holdz Ripplez and went nuts on it (for regular readers this is the hold that Noodles threw out of the 2nd storey window onto concrete to have it bounce!)... the hold took 30 ft lbs and then we grabbed a scaffold bar and went up to 50 ft lbs (600 inch pounds) and then we got scared and stopped because if this hold broke into pieces then someone was going to get killed by shrapnel... it would have been like a bloody grenade going off!

In a separate test when we were researching what we wanted to do Noodles' dad drilled and tapped a 3/4 inch piece of steel plate (not a simple task) he grabbed one of Noodles holds (which in this case was a Holdz Mini Jugz from 7 years ago) and then tightened it down to the steel plate. The thinking behind this is that the thread won't rip like a T nut and therefore you can really tighten the hold down.... wrong! Holdz holds take martini headed bolts, and therefore the driver used to tighten them is small... what we found with this: is that even with really expensive allen drivers all you're going to do is snap them. (Three of them to be exact)

So we moved onto the fabled DROP TEST! Yeah, this is basically where you're going to break most of your holds anyway! Of course throwing holds into a box without a care will also crack and chip them, that's why we're careful with ours :)
The test is a simple one, no rocket science here.. knock a hold off of a ladder that is 57 inches high (just less than 1.5m), film it and see what the damage outcome is... and cue the video:


PROBLEMS WITH OUR METHOD:
Right, we know there are some flaws with the science in what we've done, here's what they are:
  • Compounds > Some holds are resin some are PU
  • Mass > We have a 700% varience in force because all of the holds were different weights
  • Shapes > Not everyone makes the same shape, so this will impact results
Now using some simple math and a quick calculation we can even things out a little work out the force that was exerted upon the hold at the moment of impact! Using:
F = ma
Where F is force in Newtons, M is mass in kg and A is acceleration (9.81 metres squared) we can work out and see some interesting figures!

RESULTS:Damaged means: that the hold took some scuff marks or chipped slightly, nothing that would stop you using the hold
Broke means: The hold broke either fatally or to a degree that rendered it unusable

CONCLUSIONS:
Now you can see that urethane holds in general took a larger force hit (across the weights) than the resin holds and still remained intact! The only resin holds that broke in test 2 (Dropped from the garage ceiling) was the Friction hold and the Nicros hold. The Friction hold snapped clean in half at the bolt hole and the Nicros snapped on one end (But the climbing area is still intact)

Not one urethane hold broke during the tests apart from the Element worm, and that is because of the shape of the hold, think of a big handle, really it's not all that surprising. Even when dropped from a greater height the urethane holds just bounced, some took some light scuffing but nothing that compromised the holds in anyway
What has surprising to see what the Holdz hold breaking, you can really tighten up these holds and they always remain intact... but drop one from a small height and they snap

WHAT WE'LL DO DIFFERENTLY NEXT TIME?:
  • Multiple drop tests of each hold
  • Take the time that it takes for the hold to hit the floor from a standstill (so we can get better figures for our calculations)
  • Have a smaller mass range
  • Try to use similar shapes
AWARDS:
Despite what we found, we do have some awards :)

Best Noise: Go's to the Globe for making the loudest noise when it hit the floor
Best Bounce: Element Climbings Aftershocks, from the ceiling of the garage, bounced and hit me in the knee when I was on top of the ladder.
Highest Torque: Holdz Ripplez took the highest load, we actually stopped as we were scared
Surprise Surprise: Megahold's Roof Jug, we've broken these because of their badly placed bolt holes when we've climbed on them but when dropped they were fine

We're going to make sure to test all new holds and mixes in the future with a drop test. Chances are we'll do mass drop tests like this one and then publish our findings.


5 comments:

nice said...

雖然不能常常來看,仍然祝你人氣百分百 ..................................................

Anonymous said...

That goes double for me!
-Dale

ntmb said...

lol

Anonymous said...

Nice tests.
About "Holdz holds breaking" - there is nothing surprise, they are hard but too brittle. It can be improved by increasing an elasticity of polyurethane polymer chains. So, they need a little bit of chemistry :)

Best Regards,

Greengrip

Anonymous said...

To be fair the Holdz hold was Polyester not PU