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Good question and I can't pretend to have any insight into how many Gs we're likely to be pulling in normal riding or in a crash.
If you have a big crash it's not so bad for the bar to break of course. It's when you're landing a drop or pinning it down a rocky trail that it would be more dangerous.
If you read the article you'll see the 200kg load is repeated 100 times and a data logger looks for a change in response. Bars that show a consistent response are deemed ok. Seems like a fair non destructive test to me.
Your bike has 5 points of contact, your weight is distributed amongst them. 200kg is applied alternately to either end of the bar in an oscillatory fashion during testing. Unless you're a gymnast performing a single handstand on one side of the bar during a crash, I wouldn't worry.
monksie - Member
"tend to fail catastrophically"I keep reading this but I've yet to see an explanation of what it means or see evidence of it.
It means carbon doesn't really fatigue so you don't get a gradual degradation of strength. It's just there until you overload it to failure, then it's suddenly completely gone. As in fractured, zero strength.
FWIW I've discovered that you can scratch, scuff, chip and grind carbon bars across rocks and they won't fail. It's not as fragile as some people think.
chakaping - Member
FWIW I've discovered that you can scratch, scuff, chip and grind carbon bars across rocks and they won't fail. It's not as fragile as some people think.
You can chip and scrape the ends as much as you like and be fine, do it right at the root next to the clamp and let's see - maybe it'll be fine. Do you feel lucky?
The trouble with cheap carbon stuff is that its performance is entirely dependent on the manufacturing standards and consistency from one batch to the next. So your cheap bars might pass the 'bend over the knee' test, but how will it fare in a crash? On a rocky downhill? On a jump? Rigorous destructive testing will reveal the answers but having confidence that the next one off the production line will have the same properties requires stringent QA processes.
Is the material batch up to snuff? Has it been laid up by trained personnel? In the correct clean environment? Has it had sufficient consolidation? Have the ply orientations been designed carefully and realised accurately and consistently? Has it undergone the correct cure cycle? And so on. The reputable big brands will be able to say yes to all of those, and probably have a papertrail to prove it.
A cheap no name (or knockoff) Aliexpress item laid up in a backstreet shed by whoever they could drag off the street that day, not so much.