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by sn41 1099 days ago
Interesting... This is similar to the concerns that Vince Weldon, the Boeing engineer had over the 787 Dreamliner hull made of composites: that flaws could not be found by a visual scan.

https://en.wikipedia.org/wiki/Vince_Weldon

2 comments

I have a carbon fibre fork on my bike. I had a low-speed accident a few years ago, and took the bike to a mechanic to get it checked out afterwards. He said he'd checked everything, and it was fine - except the fork, which he had no way of telling if was undamaged or about to fail. I think i'll get steel next time.
this isn't true anymore. you can get carbon bikes scanned after and accident to find any internal damage. Ruckus in Portland, OR is where i've shipped to before with luck, but there's a lot more local options now depending on the scene
TIL! Apparently they do it with an ultrasound instrument:

https://www.olympus-ims.com/en/insight/ruckus-composites-ins...

Out of curiosity, does that actually work out financially, or is it really cheap or are carbon forks really expensive?
You probably wouldn’t do this for a fork. You’d just replace it. The carbon frame though can be expensive
Ouch! Folks across the street own a bike shop and sponsor an annual criteruim. Last year there was a crash right in front of our house - touch of wheels I suppose. There's a slight hill at the end of the street and I guess the riders could have been going in excess of 30 mph or more. No one badly hurt AFAIK but one bike had a broken frame. In this case no fancy equipment was required to detect the flaw. :-/
You may be interested in having a look at this relevant and interesting article "Nanoscopic origin of cracks in carbon fibre-reinforced plastic composites":

https://www.nature.com/articles/s41598-019-55904-2