View Full Version : Carbon fibre test for damage?

11-14-2016, 16:11
I am thinking of getting some of the Costco carbon fiber poles next time they are available. But I was wondering how do you know if the poles get damaged? For carbon arrows, there is a flex test where you flex the arrow. if fibers are broken you will hear it and pitch the arrow. Releasing a bad arrow can arrow can explode and send carbon everywhere including into your hand.

Carbon bikes are also sensitive. if your bike falls over on to a hard edge it could ruin the bike. Much harder to know if it is damaged and if it is damaged you could have a catastrophic failure at 40 mph on a down hill with serious injury.

What a about trekking poles. With so much bang around on rocks, dropping them etc. Do they become damaged? Do they explode just when you need them? Or is it lest traumatic?

11-14-2016, 16:25
Never heard of what you state, Good to know more of the limitations of CF.

I have had trekking poles fail, none meant more than a harmless fall, one, made of wood, fractured before impaling me in and around the family jewels during a fall.

I have no idea about any test, always assumed CF poles are a working or broken item, either one or the other with no inbetween. Interested to see other replies.

11-14-2016, 16:26
Some times tapping carbon fiber structures with a coin, like a quarter, can generate a dead tone when there is a crack associated with the location being tapped.

11-14-2016, 16:38
how sure are you the poles will come back to Costco? I saw them 2-3 years ago but haven't seen them since. you can get them on Amazon though -- https://www.amazon.com/gp/product/B00XM0YGW8/ref=zg_bs_3401281_3?ie=UTF8&refRID=J6FNNEK73VG1QHZWFJVJ&th=1

11-14-2016, 17:49
Thanks Secondmouse. Good to know. you might be right I asked at Costco and they did not remember them.

Another Kevin
11-14-2016, 19:05
Hmmm. You've got me thinking. Carbon fibre composites in industry are usually tested with ultrasound. I wonder if something like echOpen (http://echopen.org/) or Murgen (https://hackaday.io/project/9281-murgen-open-source-ultrasound-imaging) could be adapted to the task. And whether the adaptation might find a role in niche markets such as bicycle mechanics and outfitters, to inspect frames and hulls.

Just the usual musings of a weird engineer.

11-14-2016, 19:28
Hmmm. You've got me thinking. . .
Awesome thinking! I like it.

11-14-2016, 19:44
I bought a pair of carbon fiber poles for hiking day hikes around the mountains in Phoenix. They are decent poles, however, not as light as my REI carbon fiber poles. They are easily 1/4 the cost at Costco for the carbon fiber poles, however. I have used them for quite a few hikes with the heavy load of my daughter in my backpack. (45 pounds plus my fat arse). I am not sure how much weight you are attempting to put on the poles so I am not sure why you would need to test them. They have been at my Costco as recent as a couple months ago. I wouldn't worry about them exploding. I would just use them until they fail and hope you are not using them to cross a death defying gorge. They are good poles for the $$.

11-14-2016, 20:45
Carbon fiber is very strong in one direction, but if damaged it can be weak and fail when you don't want it to. For example in arrows, you often hit your own arrows. if you break some fibers they can be unsafe and explode when you release them. For arrows there is a flex test people do to make sure that has not happened. A crushing type blow can cause the damage leading to failure.

So that is why I was asking if there were any type of test for checking poles after dropping them against a rock or some other action that might damage fibers.

11-14-2016, 20:47
I broke one in PA . Lots of rock . Got cought in the rocks and I shattered the bottom section. Cascade Mtn tech brand . they sell repair sections on line. Ok poles for the price.