Carbon Fibre - perceived issues
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northerndave
Retrobike Rider
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A lot of those on the blog were extraordinary situations.. (although seatposts snapping could be due to repositioning.. on here the other day someone pointed out a manufacturer's components were designed to last a season.. is the same not true of CF? stress it in position once then expend it after a short period?)
Where steel wouldve bent, and maybe aluminium wouldve bent before cracking, carbon just gave up the ghost and snapped.
Maybe in the search for lightweight components they should give thought to dual materiels.. a thin steel tube would die a death under pressure, but if supported by a layer of CF, you'd maybe get a happy medium between the two.. lightness but with a resistance to snapping provided by the steel. Agreed it would still fail, but maybe with a saving few seconds to bail rather than be bailed... maybe.. admittedly it wont help too much with ultra weight saving, but when the perceived customer/consumer is not team based, not loaded with the money to replace components mid season prior to failure.. maybe it should be an option. Our Composite plates in our body armour get tested under xray for stress raisers and cracking.. I doubt the same is said for bike parts, although the practise maybe should be applied
I'll happily stick with Steel and Titanium..
Where steel wouldve bent, and maybe aluminium wouldve bent before cracking, carbon just gave up the ghost and snapped.
Maybe in the search for lightweight components they should give thought to dual materiels.. a thin steel tube would die a death under pressure, but if supported by a layer of CF, you'd maybe get a happy medium between the two.. lightness but with a resistance to snapping provided by the steel. Agreed it would still fail, but maybe with a saving few seconds to bail rather than be bailed... maybe.. admittedly it wont help too much with ultra weight saving, but when the perceived customer/consumer is not team based, not loaded with the money to replace components mid season prior to failure.. maybe it should be an option. Our Composite plates in our body armour get tested under xray for stress raisers and cracking.. I doubt the same is said for bike parts, although the practise maybe should be applied
I'll happily stick with Steel and Titanium..
These issues can apply to steel, alloy ti. I've seen many cracked steel bikes. A few cracked Kleins and many Cannondales.
I've lost count of the number ti parts i've broken. But does this stop me using them no.
Every thing can break and many things last a life time. Just a fact of life.
I've lost count of the number ti parts i've broken. But does this stop me using them no.
Every thing can break and many things last a life time. Just a fact of life.
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I'm building a 93 Trek 9800 OCLV.
Has it lead a hard life? Yes.
Will I thrash it? No.
Will it get ridden? Absolutely.
Will it get checked for damage regularly? Of course.
Would I be any different with a 93 steel or Alloy frame? Nope.
I think half the problems with older carbon was people expecting too much from light race parts. Carbon is strong for it's weight. Simple.
Has it lead a hard life? Yes.
Will I thrash it? No.
Will it get ridden? Absolutely.
Will it get checked for damage regularly? Of course.
Would I be any different with a 93 steel or Alloy frame? Nope.
I think half the problems with older carbon was people expecting too much from light race parts. Carbon is strong for it's weight. Simple.
The only other thing is that typically it's not designed for crush loads on the tube. You can engineer tubes like that - they just weigh more.
So pay your money and take your pick - as said superlight and fragile or heavier and durable.
Plenty of people folded up 753 steel frames and never said that steel was rubbish.
So pay your money and take your pick - as said superlight and fragile or heavier and durable.
Plenty of people folded up 753 steel frames and never said that steel was rubbish.
I don't think anyone said steel / alu / Ti don't break, but in situations other than a full on crash, they do deform or crack before catastrophic failure, giving you a chance to think about a repair. CF 'generally' doesn't, it just fails catastrophically.
Periodic checking is a good idea with any material, but visual checks are of limited value with composites. It could be delaminating, de-bonding or micro-cracking, and without Xray or ultrasound equipment, you won't know until it fails. This is why aircraft are X-rayed or ultrasound checked every so often.
Having said that, I'm absolutely sure that CF has been a learning process for cycle manufacturers, and modern, properly designed CF components are strong. I just don't think I would have the confidence, given that cycle companies don't have R&D ot testing budgets that multi-billion dollar aircraft companies do. However, I am 46 years old, so don't recover from face plants as fast as I used to!
Periodic checking is a good idea with any material, but visual checks are of limited value with composites. It could be delaminating, de-bonding or micro-cracking, and without Xray or ultrasound equipment, you won't know until it fails. This is why aircraft are X-rayed or ultrasound checked every so often.
Having said that, I'm absolutely sure that CF has been a learning process for cycle manufacturers, and modern, properly designed CF components are strong. I just don't think I would have the confidence, given that cycle companies don't have R&D ot testing budgets that multi-billion dollar aircraft companies do. However, I am 46 years old, so don't recover from face plants as fast as I used to!
I remember one of the biggest issues was that many peoples first introduction to CF back in the early nineties was through aftermarket products like seatposts and handlebars - probably the two least favourite components to fail for good reasons. There was one (in)famous company that made canoe paddles out of CF and just converted the production line to handlebars with hilarious consequences, then there was the carbon fibre 'flex-bar' that claimed the 2 inches of flex was controlled suspension. There really wasn't the R&D or H&S back then with those garden shed companies which is not something you want with a rapid fail material like carbon.
It took a lot to get me to trust carbon again after a seatpost failure[/quote]
It took a lot to get me to trust carbon again after a seatpost failure[/quote]
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