On Tue, 4 Dec 2018 09:58:32 -0800 (PST), Frank Krygowski
wrote:
On Tuesday, December 4, 2018 at 7:06:50 AM UTC-5, Sir Ridesalot wrote:
If you're like Tom and are thinking about buying a cheap Chinese knockoff of anything pertaining to bicycling then you might want to read this. When it comes to Chinese stuff it really is BUYER BEWARE!
This guy didn't even know he was getting a Chinese counterfeit item. (The price should have warned him)
https://www.bicycling.com/bikes-gear...ake-bike-gear/
Here's one of the best parts of that article:
"every carbon fiber product is a quality-control batch of one, and the finished outside shape tells you almost zero about what’s really inside.
I really like that phrase "... a quality-control batch of one..."
The further explanation was good, too:
"A frame can have hundreds of individual sheets of carbon fiber (called plies) of varying size and shape, which are placed in the mold in specific places in a rigidly defined order (called the layup). To make matters more complex, carbon fiber is unidirectional; its stiffness and strength characteristics apply only along one axis. To preserve those characteristics, a manufacturer must get the number, shape, and size of the plies, and their fiber orientation in the correct order, every time. That’s to say nothing of the actual grades of carbon fiber used, or the resin that holds the fibers in place and adds toughness and durability, or the sophistication and reliability of the manufacturer’s own production process."
- Frank Krygowski
But that is not only applicable to carbon fiber but to all cloth -
resin composite. The difference seems to be, primarily, that composite
bicycle frames are built to be light in weight rather then stiff or
rigid, or perhaps the term might be "strong".
Having built composite things - boat hulls and fittings - for ten or
so years I can assure you that a carbon fiber frame with, oh say,
quarter inch thick wall thickness would be "strong enough". But of
course it would also be "too heavy" :-)
cheers,
John B.