Fatality due to carbon fork failure

Al Wright

I came across this news item on CTC(UK) website;-
http://forum.ctc.org.uk/viewtopic.php?f=5&t=62501

http://davesbikeblog.squarespace.com/

An American cyclist was killed in an accident caused by failure of the carbon fork on his Cervello Soloist bike. Cervello had recalled the batch of suspect units in August 2008. However, some are likely to slip through the net, especially with second hand sales.
I don't know if any went on sale here.

easygoing39

Thats something that always worrys me,whenever the speedo goes over 55kph I always worry about carbon failure,keep thinking my bars or forks could suddenly snap!!I never think about it on my all alloy bike.

DirkVoodoo

It's important to regularly inspect your bike, but at the same time freak accidents shouldn't put you off enjoying it.

Do you worry about your car suddenly bursting into flames every time you get into it?

I can't really talk though, I have a totally irrational fear of flying.

Tallon

What's carbon failure?

Lusk Doyle

DirkVoodoo wrote: »

Do you worry about your car suddenly bursting into flames every time you get into it?

Are you saying that The Simpsons is not an accurate portrayal of actual life situations? :rolleyes:

Chips Lovell

easygoing39 wrote: »

Thats something that always worrys me,whenever the speedo goes over 55kph I always worry about carbon failure,keep thinking my bars or forks could suddenly snap!!I never think about it on my all alloy bike.

I've seen more alloy bars snap than carbon ones.

cdaly_

AIUI, when alloy bars go they tend to breeaak relatively slowly while carbon bars will snap pretty much instantaneously.

Chips Lovell

I've seen two sets of alloy bars break instantaneously on people.

morana

cdaly_ wrote: »

AIUI, when alloy bars go they tend to breeaak relatively slowly while carbon bars will snap pretty much instantaneously.

mine went very quick!

I suppose you need to get into the habit of checking your frame and forks on a regular basis. Its easy to take off your fork in a minute give it a good inspection and reassemble with a torque wrench.

Raam

My alu bars broke on me a few months back. They kinda eased off, but it was quick.

el tel

Pedantic I know, but describing items such as forks and frames etc. as being 'carbon' is lazy. Unless of course they are soley made of carbon; in which case failure should be expected.

jameverywhere

el tel wrote: »

Pedantic I know, but describing items such as forks and frames etc. as being 'carbon' is lazy. Unless of course they are soley made of carbon; in which case failure should be expected.

in which case they'd be made of what, graphite? diamond?

Lumen

el tel wrote: »

Pedantic I know, but describing items such as forks and frames etc. as being 'carbon' is lazy.

The correct term is carbon fibre reinforced plastic. Or just "plastic".

dave2pvd

Lumen wrote: »

The correct term is carbon fibre reinforced plastic. Or just "plastic".

Plastic is an enormously broad family of materials. IMO, it's a bit like saying 'metal'.

Should we settle on carbon fiber fibre?

Raam

dave2pvd wrote: »

Plastic is an enormously broad family of materials. IMO, it's a bit like saying 'metal'.

Should we settle on carbon fiber fibre?

No, that's too obvious.

el tel

Just carbon composite

This covers carbon weave, fibres and filaments as well as plastic, resin or epoxy matrices.

Lumen

dave2pvd wrote: »

Plastic is an enormously broad family of materials. IMO, it's a bit like saying 'metal'.

I dunno, I have several metal bikes.

munsterleinster

DirkVoodoo wrote: »

It's important to regularly inspect your bike, .

And the tell tale signs are

cdaly_

Vladimir Kurtains wrote: »

I've seen two sets of alloy bars break instantaneously on people.

morana wrote: »

mine went very quick!

Raam wrote: »

My alu bars broke on me a few months back. They kinda eased off, but it was quick.

Ah no, I didn't mean over a day or so. Mine went in a matter of a few seconds but didn't snap off instantaneously. Enough time to sit back onto the saddle and consider stopping.

kippy

munsterleinster wrote: »

And the tell tale signs are

I don't think there are many that can be spotted by the naked eye, so inspecting, while a good idea to watch out for hairline cracks etc, isn't gonna stop parts from breaking.

As someone mentioned above, these things happen on occasion and when a number of "ideal" conditions occur you will have serious injury or worse, however this is rare.
No more than planes crashing or fatalities in car accidents.

Raam

munsterleinster wrote: »

And the tell tale signs are

A missing chain stay is one sign.

manwithaplan

el tel wrote: »

carbon weave, fibres and filaments as well as plastic, resin or epoxy matrices.

I'm now curious about which of these mystery things my bike is made of. My friends and family are always asking me to get more technical when I talk about my bikes.

DirkVoodoo

munsterleinster wrote: »

And the tell tale signs are

Eh, VISIBLE cracks or defects. Yes, plenty of cracks will probably be hard to spot, but visual inspection is the first port of call for most material failures and regular inspection, as I thought I said, will help minimize the risk outside of any "freak accidents". Not many of us (I know of one person who is the exception) have access to any x-ray or thermal imaging technology, I'm trying to be realistic and practical.

Clearly, if you're bike looks like this, then is probably isn't safe to ride:



But you can still look for things like this, they are easy enough to spot and might indicate your frame is borked:

doozerie

manwithaplan wrote:

I'm now curious about which of these mystery things my bike is made of. My friends and family are always asking me to get more technical when I talk about my bikes.

Tell them the truth, your bike is made partly of plastic, partly of cuddles, but mostly of extreme unrelenting suffering.

smacl

DirkVoodoo wrote: »

Clearly, if you're bike looks like this, then is probably isn't safe to ride

Looks like the Pinarello Brompton still has some minor teething troubles

07Lapierre

smacl wrote: »

Looks like the Pinarello Brompton still has some minor teething troubles

Looks like the fork is about to give way any minute!

Mycroft H

http://www.bustedcarbon.com/


I like steel. Its not going to snap on me, rather just bend.

moggs1972

is that pinarello a "compact"? the toe overlap must be a bitch.:o

the_doctor

Al Wright wrote: »

I came across this news item on CTC(UK) website;-
http://forum.ctc.org.uk/viewtopic.php?f=5&t=62501

http://davesbikeblog.squarespace.com/

An American cyclist was killed in an accident caused by failure of the carbon fork on his Cervello Soloist bike. Cervello had recalled the batch of suspect units in August 2008. However, some are likely to slip through the net, especially with second hand sales.
I don't know if any went on sale here.

The guy lived several towns away from me! No one around here sells Cervelo since they sell direct. They cater to the Triathlete crowd. A lot of these guys buy the bikes through the mail or second hand.

I would not buy anything without going through the Local Bike Shop.

IMO People should be sticking with stable brands such as Fuji. They should be avoiding brands such as Specialized, who have a history of engineering problems such as bad seatposts or wobbly bottom brackets.

It is sad that the fellow died. He was a nice guy. He was on a quiet road. I'm waiting to hear more from somebody in the local clubs such as the NBW. I personally think that there is more to the accident. I suspect that the failure lead to a chain reaction of poor events. For safety it would be nice to know the whole story.

Bill

doozerie

BX 19 wrote: »

I like steel. Its not going to snap on me, rather just bend.

Tell that to the rear dropout on my steel-framed Kona MTB, which snapped at the chainstay join while I was riding it home from work one day. The join to the seat stay remained intact so I was able to ride it (carefully!) the rest of the way home. I'm not sure there is a bike frame/parts material that won't snap in some set of circumstances.

triggermortis

To test composite structures all you need is a coin to tap on the surface, and the noise should tell you if it is solid or damaged. A dull thud is not a good sound and means the laminations have separated, or delaminated, due to damage or defect. A ringing means the material is ok.
This is how composites are tested in situ on aircraft.