Busted Carbon

[Mr Pig]

...people don't buy the lightest stuff, they buy durable, reliable stuff. ...And the world is full of people who pay no attention to instructions and warnings

I agree with everything you said.

Yes, they use carbon and composites in aircraft construction but that's not a good argument for its use in everyday bikes. In aircraft design each component has a design lifespan and its wear characteristics calculated as carefully as possible. This is backed up by an incredibly tight program of scheduled examination including, in critical parts, removal from the aircraft for thorough testing.

Also, materials are employed in configurations that ensure that it will be almost impossible for their loading limits to be exceeded in normal use. If it is suspected that excess stresses have been encountered extra testing will be scheduled.

You can compare the use of carbon fiber in bikes to the use of carbon fiber in aircraft if you like but you need to be clear about it. You'd have to say that it would be a bit like giving an airliner to someone who knows nothing of aircraft construction and letting them fly it around deciding for themselves if and when it needed serviced!

It's not about whether a material is physically strong enough for the application. It's about the management if the material during its working life. I believe that increasingly bike manufacturers are remiss in entrusting component care to average users who are not qualified for the job and using materials that require too much specialist knowledge. They of course cover themselves, by stipulating care instructions for critical components, but turn a blind eye the fact that many users will either ignore them or be unable to interpret them correctly. So when failure occurs they can wash their hands of blame as their instructions were not followed. Not good enough.

Products should be designed to be strong enough for the life they are likely to lead, not the life they might lead in ideal circumstances. Bikes get knocked, dropped, bumped and bashed. Things get overtightened, forced, twisted and thumped and their should be a reasonable safety margin to allow for a bit of ham-fisted treatment. Use carbon in competition, fine, but I don't see it as being a wise material for the average cyclist.

 

[Bigtwin]

My forks are CF
I was in a shop notsolongago and the touchy female proprietor was looking at me funny as I was tapping the CF tubes

Take it from me, if you go into a shop and ask the female serving if you can give her tubes a good banging, you are going to run into trouble.

 

[dan_bo]

How did that happen?

It went 'phffffffffffft'! and then I was lay on my back with the handlebars in the air and the bike still clipped to my feet. I did swear.