Well this is controversial

[wafter]

Not so much controversial than simply a piece written by someone who is ignorant.

CF comes in many grades, same as other materials. Different grades will yield different features depending upon design goals.

I’ve owned great steel, alu and CF bikes. My favourite to ride is without doubt CF. My current CF bikes are more comfortable than the 531p steel I’ve had. They are undeniably stronger.

I’ve cracked steel. Alu is too flexible. I’ve had 3 racing crashes on my 6kg CF road bike, one at over 50km/h. Not a scratch. Saddle scuffed, brake lever scuffed, pedal scuffed…frame and fork perfectly fine.
I race my CF MTB. Come off that on rocky terrain loads of times at speed. It’s seen 4 years of abuse most bikes never see. Perfectly fine.

Carbon wheels are stronger than steel. GCN did a test with CF road wheels, no tyres, on off-road over rocks and rough terrain. Didn’t even go out of true.

My CF gravel bike will match or beat any steel bike as a Touring option where comfort and low vibration is key and be lighter and stronger too.

I have been riding bikes since the early 1970’s. All types. All materials. Socially, Commuting, Touring, Racing. The Article is nonsense.

Ignorant of what?

Simply stating that carbon fibre is "stronger" that steel is an incorrect over-simplification at best. Composites behave differently depending on the direction, speed and magnitude of loading; potentially giving them wildly variable properties and causing their performance to be anything between significantly superior and grossly inferior to metals depending on the situation.

Perhaps the biggest safety issue with compostes is difficulty in inspection. While your frames might appear "perfectly fine" to a cursory glance, that really doesn't tell you much and it's possible that previous impacts have left them internally damaged and weakened. Composites also typically have very low strain-to-failure characteristics so often give little warning prior to catastrophic failure.

While composities can give excellent performance when selected and treated appropriately, they're not the universally-superior wonder material that the marketeers would have you believe. Personally I think they have no place in safety-critical consumer goods and wouldn't entertain the idea of riding an old, crash-damaged CF frame without a proper inspection by someone who knows what they're doing..

 

[Illaveago]

Exactly, this rider wished he hadn't too.

View attachment 720324

That will be alright! Just epoxy some steel tubes in there .

 

[DogmaStu]

Ignorant of what?

Simply stating that carbon fibre is "stronger" that steel is an incorrect over-simplification at best. Composites behave differently depending on the direction, speed and magnitude of loading; potentially giving them wildly variable properties and causing their performance to be anything between significantly superior and grossly inferior to metals depending on the situation.

Perhaps the biggest safety issue with compostes is difficulty in inspection. While your frames might appear "perfectly fine" to a cursory glance, that really doesn't tell you much and it's possible that previous impacts have left them internally damaged and weakened. Composites also typically have very low strain-to-failure characteristics so often give little warning prior to catastrophic failure.

While composities can give excellent performance when selected and treated appropriately, they're not the universally-superior wonder material that the marketeers would have you believe. Personally I think they have no place in safety-critical consumer goods and wouldn't entertain the idea of riding an old, crash-damaged CF frame without a proper inspection by someone who knows what they're doing..

You can apply your criticisms to any material, including steel. All are subject to proper design, fit for purpose and quality control. All can be let down in those processes by incorrect methods, cheap materials (composites, like steel have vastly varying quality) and manufacturing errors.

I've broken steel frames but never CF. No warning. No visible stress fracture. Just a shear. So that's my personal experience.

Quality literally applies to anything. Buy cheap, get cheap. You can get dodgy steel bikes that haven't seen due diligence inspection regimes, same with CF or any material.

I wouldn't ride an old crash-damaged steel bike just as I wouldn't ride one from any other material. Guess what? I have a 6.1kg CF bike that has had 3 race accidents - one at over 50km/h, sent it and me flying in a sprint when I was knocked sideways. It bounced down the road. Not a scratch on the frame or fork. Zero damage. Still going strong after 40 000km. Like anything, it depends where the stress occurs.

I love steel, raced steel in the 1980's at National level, my favourite bike in the World is a steel Battaglin. One of my favourite bikes from my racing past was an alu Cannondale. But I've had decades of experience with CF too and it is the superior bike material for racing performance and...anything else in my opinion.

Stuff marketing, I'm talking from 100''s of thousands of km of personal experience in commuting, touring and racing over the last 40 years!

 

[matticus]

If all materials were equally good - provided you have good design and QC - then surely we/d have some concrete bikes?

 

[AndyRM]

If all materials were equally good - provided you have good design and QC - then surely we/d have some concrete bikes?

We yaba-daba-dooooo!

https://www.designboom.com/technolo...ike-old-bicycle-parts-play-to-diy-09-20-2022/

 

[matticus]

We yaba-daba-dooooo!

https://www.designboom.com/technolo...ike-old-bicycle-parts-play-to-diy-09-20-2022/

I'm sure that could be JUST as light as DogmaStu's race bikes ... if only the design was right!

 

[AndyRM]

I'm sure that could be JUST as light as DogmaStu's race bikes ... if only the design was right!

Just needs a bit of drillium and it'll be rocketing 'round velodromes in no time.

 

[Dogtrousers]

This is just the same old "You're not doing it like me so you're wrong. Stop being wrong right now."

I've never ridden anything but steel bikes. On the very rare occasions I've been looking for a new bike I've never taken a punt on a different kind of frame in case I don't like it. It's not like components that you can just swap out if you don't like them, with a frame you're stuck with it.

But CF is self evidently an extremely effective and successful frame material. To deny that is simply to ignore the obvious.

I'm planning to hire a bike on hol this summer. I intend to get a CF bike just so I can have a go on one to see what I've been missing. Who knows, I may have a damascene conversion.

 

[matticus]

But CF is self evidently an extremely effective and successful frame material. To deny that is simply to ignore the obvious.

My point is not that "CF is rubbish", but that it has different strengths/weaknesses to other materials (be they wood, concrete, or aluminium).

Denying that any one material has weaknesses is daft; of course design has to take materials into account and will mitigate weaknesses, but ultimately some materials are rubbish for bike frames, and several are good but have their own weaknesses.

 

[rydabent]

Just curious which three incidents you're referring to? Ones where the "tail has broken off".

I'm no expert so I'm interested to learn about these three specific incidents of structural failure of either the vertical or horizontal stabilisers.

One was out of NY, one over the south Atlantic, and I forget the other one.

 

[Dogtrousers]

One was out of NY, one over the south Atlantic, and I forget the other one.

The one over NY you're thinking of was probably AA 587 that came down just after 911. Cause was pilot error. You're right that the tail failed but the pilot was putting in such crazy inputs that it was stressed far in excess of the design limits. The material made no difference.

The one over the S Atlantic is probably Air France 447. No structural failure there, the plane was intact right until it hit the ocean. Pilot error again.

The one you can't remember might be Air Asia 8501. More pilot error. An A320 pilot tried the old "switch it off and on again" manoeuvre on the flight computer while in flight. Not a bright thing to do, resulting in complete loss of control. The first thing they found was the tail. Not sure if it was intact when it hit the sea or if it broke up in flight

Really not much to do with bike frames I know.

 

[rydabent]

The one over NY you're thinking of was probably AA 587 that came down just after 911. Cause was pilot error. You're right that the tail failed but the pilot was putting in such crazy inputs that it was stressed far in excess of the design limits. The material made no difference.

The one over the S Atlantic is probably Air France 447. No structural failure there, the plane was intact right until it hit the ocean. Pilot error again.

The one you can't remember might be Air Asia 8501. More pilot error. An A320 pilot tried the old "switch it off and on again" manoeuvre on the flight computer while in flight. Not a bright thing to do, resulting in complete loss of control. The first thing they found was the tail. Not sure if it was intact when it hit the sea or if it broke up in flight

Really not much to do with bike frames I know.

They blamed the pilot for using too much rudder too fast. That was a total cover up. The control surfaces like the rudder is run by the computer, so either the software in the computer was bad, or the CF vertical tail surface was weak. In either case it was faulty design by Air Bus.

When I used to fly Cessna 150s, several time I slammed the rudder clear to the stop in cross wind landings, and the tail didnt fall off.

 

[rydabent]

The one over NY you're thinking of was probably AA 587 that came down just after 911. Cause was pilot error. You're right that the tail failed but the pilot was putting in such crazy inputs that it was stressed far in excess of the design limits. The material made no difference.

The one over the S Atlantic is probably Air France 447. No structural failure there, the plane was intact right until it hit the ocean. Pilot error again.

The one you can't remember might be Air Asia 8501. More pilot error. An A320 pilot tried the old "switch it off and on again" manoeuvre on the flight computer while in flight. Not a bright thing to do, resulting in complete loss of control. The first thing they found was the tail. Not sure if it was intact when it hit the sea or if it broke up in flight

Really not much to do with bike frames I know.

You cant control a plane if the rudder and the whole vertical tail surface is gone. Always blaming the pilot is a cop out.

 

[rydabent]

CF this and that is not really the wonder material that it is made out to be. It is just like fiber glass. It is mostly plastic resin reinforced with either glass fibers or carbon fibers. So basically bikes, carbon wheels, and airplanes are mainly plastic.

 

[wafter]

CF this and that is not really the wonder material that it is made out to be. It is just like fiber glass. It is mostly plastic resin reinforced with either glass fibers or carbon fibers. So basically bikes, carbon wheels, and airplanes are mainly plastic.

"Forged carbon" is the best one IMO - as I'm sure you're aware the equivalent of "chopped strand mat" fibreglass before the marketing knobbers got hold of it. Sweepings off the cutting room floor squashed into a placcy injection moulding, and up-sold as a great technological advancement..