Are Carbon Fibre Bicycle Components Prone to Catastrophic Failure?

[phb]

@Sator

No the only “relation” to Leuscher Teknik…

Thank you for clarifying.

The link in my post above could be considered more independent

CyclingTips began life in September 2008 as a simple daily blog written by Wade Wallace. The aim of the blog was to collect and publish all of the little cycling tips Wade accumulated over years of riding and racing around the world with the aim of reducing the barrier to entry of the sport. Over the years the site has grown in size and scope and Wade has been joined by several staff members.

and states:

FAITH IN CARBON FIBRE

Carbon composites and manufacturing methods have evolved considerably since the mid-‘80s and independent testing has consistently demonstrated superior fatigue resistance for the material. “The fatigue tests that we run here are almost a matter of going through the motions,” said Chuck Texiera, a senior engineer at Specialized. “We just about never see a failure or fatigue. Once you hit expected ultimate strength, the fatigue is like a gimme. If you subjected any type of metal frame — including titanium — to the same total cycles, typically they would not withstand it. It’s quite amazing.”

This seems to be very different to that indicated above and from a source which has a vested interest in promoting failure risks.

As outlined above…

@phb

I can see the merits of testing a used bike to see if it has been subject to a event which may have caused damage which isn’t visible to the naked eye…especially if one is spending a considerable amount on a (second hand) bike an wishes to ensure its integrity before committing to purchase (like taking a second hand car for a thorough inspection before purchase for peace of mind).

[omy005aw]

Hmm, OP headline mentions bicycle frames, but all the failures are associated with fork steerer tubes? Frame and fork are completely different parts.

Lots of steel, aluminium & titanium bikes (mentioned in the following post as being preferred) will have carbon forks with carbon steerer tubes. Some of the cheaper carbon framed bikes will have carbon forks with aluminium steerer tubes. Aluminium and steel steerer tubes are prone to corrosion. Aluminium especially, with galvanic corrosion due to the presence for moisture and the steel star washer inserted for stem fixation.

My bikes are either carbon or titanium framed with full carbon forks then carbon stem and carbon handlebars.

[Sator]

If you shop for “bike frames”, you will find that it always includes the fork to the point that they are almost considered a single unit. I don’t think I’ve ever seen a standalone bike frame advertised as “also includes a fork”. This is just assumed. I’m sure I’ve seen instances on Leuscher’s blog of failures in other areas apart from the fork.

[Sator]

“ We just about never see a failure or fatigue . Once you hit expected ultimate strength, the fatigue is like a gimme. If you subjected any type of metal frame — including titanium — to the same total cycles, typically they would not withstand it. It’s quite amazing.”

Leuscher has a cut-up of a Specialized S-Works frame and he praised it as being very well made:

Specialized S Works Tarmac SL5 Cut Up and Review

By the time I’d found his YouTube channel, I’d already put a deposit on a Specialized carbon-framed bike so imagine how relieved I was to see that. However, I’ve already quoted this next story once already but think it worth quoting again:

A good friend of mine had a very serious accident riding a new Specialized Roubaix S-Work, the front fork collapsed while he was on a fast descent due to a manufacturing flaw in the fork. He’s lucky to still be able to walk, but will live with back pain for the rest of his life.

Time (Sport) Marches On -- The Future Of Time Sport - Page 3 - Weight Weenies

In my industry, if a pharma or medical device company issued an unsupported blanket statement denying the credibility of case reports suggesting harm from their drug/device, such action would not only be condemned but we would refuse to take even the slightest of notice until it has been properly and independently investigated. In fact, Big Pharma knows not to behave like that, but take one step into other less regulated industries and one can be a bit shocked at how this sort of thing goes on unchecked.

The fact is that even if Specialized made good quality carbon frames, because there is no enforced standardisation for QC across the industry, there is no guarantee that the same can be said of frames from other makers. Some makers have different lines of frame manufactured in different factories eg high-end line in Taiwan, the budget line in China. The QC standards in both factories are going to be different.

[gordon]

@Sator

If you shop for “bike frames”, you will find that it always includes the fork to the point that they are almost considered a single unit.

Having built a few bikes myself over the past couple of decades, the fork was always an extra, (and from a different manufacturer) and often purchased from a different source.

[mark_m]

@Sator

I’ve already quoted this next story once already but think it worth quoting again:

Hi Satoshi. Bringing your observations and concerns to the community has certainly opened up an important discussion. There is a lot for all of us to process.

Firstly you have advised on two serious incidents, one tragic and another with a personal connection. That adds relevance to your observations and questions.

Secondly there is a large amount of information concerning carbon bike components, quality, failures and testing.

In the opening post

@Sator

Victorian Coroner to investigate cases of carbon frame failure such as reported here:

It would prove useful to know the future progress and outcomes from this inquiry.

The consumer component of the discussion introduces other aspects to consider including:

• Retailer and importer obligations for safe products,
• Current Australian and ISO standards
• Extent and nature of faults failures in use
• Manufacturing Quality concerns
• Differing needs and intended use
• User/rider knowledge, awareness and behaviours
• Marketing practices and strategies
• Amateur and professional riders associations and clubs
• Experience from overseas noting the long European tradition with professional riding as well as daily use.

There will be others who can add to this list.

It’s not yet evident from this discussion how the recent Australian incidents and experiences relate to those in Europe.

I’m not sure how best to add any new content.
My ex Engineers Hat has a slight advantage in understanding the mechanical failure and fatigue. Expertise in NDT methods and materials science overlap. There are many technical aspects of the failures noted that go well beyond just those narrow fields. These include design, application, field testing, manufacturing and …

Ensuring a product is fit for purpose may include standards for inspection and testing. The observations that there are services for NDT of bike components are note worthy. The cost of a third party testing program to demonstrate a need for changes would be considerable.

@Sator

Would it be possible for Choice to investigate using ultrasound scans to see if common bike brands sell frames with serious structural defects? Or at least if a journalist could interview Raoul Leuscher and others who do frame integrity scans in Australia for their perspective.

Hopefully the Victorian Coroner’s findings will assist and clarify what is needed.

In the interim I’ll be following up this discussion and concerns with the 3 of our 4 immediate family members who train and ride with clubs or as amateurs. Although several can only dream of fibre, unless it’s with breakfast.

P.S. added note - reference to Coroner’s findings.

DavidKeithMolloy_153917.pdf

The Coroner includes observations from an inspection of the failed front carbon forks of the bicycle involved in the fatal accident.

And on materials choices for frames etc

The Difference Between Your Bike Frame Materials Depends on Your Budget and...

There are some useful tips on the pros and cons of each option.

[mark_m]

Sometimes extra content comes to hand rather conveniently. The topic raised appears to have had considerable interest in the bicycling community, and the attention of the wider industry.

Just a few interesting items from the web that may put all the questions raised into context. The complexity of the consumer issues are compounded by the significant differences between users of uses of bicycles. At one end the casual user or local rider who does low kms and low speeds. At the other well financed amateurs or would be professionals able to clock up hundreds of kms in a week or even a day. Also comfortable pushing speed on the bitumen, and more on the downhills.

I’ve no guidance as to the numbers or percentage of bicycles in Australia are at risk of carbon fibre failures, to put the needs into wider community context.

After the death of a Canberra cyclist, should you be concerned about...

Your Carbon Fiber Bike May Be a Ticking Time Bomb

[phb]

@mark_m

After the death of a Canberra cyclist, should you be concerned about…

This is interesting as the forks in question were aluminium alloy. The article also states:

Any material is subject to the wearing forces associated with cycling, and as such, every cyclist must consider that each part of the bike has a finite service life.

I wonder how many cyclists spend a lot on their bikes to get the lightest possible and then chose not to replace some parts over time when the finite service life has been reached. I also wonder how many cyclists are willing to fork (no pun intended) out a significant amount of money to replace these potentially consumable products after a few years…and whether this is part of the reason why their replacement may not be occurring (another possible reason below).

These consumables could be like tyres, hoses etc on vehicles which have a finite life and will fail over time due to their age (and in some cases long term forces on the items causing fatigue). Likewise with aircraft, processing plant and equipment, and heavy and commercial equipment.

Maybe on purchase more information should be given on the design life of each of the bikes components and such information should also be communicated if one also services ones bike (like in the case of the cyclist’s death on the CyclingTips blog. This is done for other consumer products…and should possibly also be done for bikes.

The second article is also about the finite life of carbon materials used in the manufacture of bikes…leading to catastrophic failures. Again, I wonder how many cyclists with high tech (material) bikes fully understand the risks of riding a bike after its finite service life has been reached (either through time or through say a collision)…or are willing to take the risk of continuing to ride due to the high initial outlay of the bike.

[mark_m]

Good questions, and some of the articles go part way to answering them. Ensuring increased rider/owner awareness of the risks were also points raised in both recent Australian Coroners findings/recommendations.

Consumers make many choices, and AFAIK given the knowledge to make the right decision or a bad one will always act accordingly.

@phb

Again, I wonder how many cyclists with high tech (material) bikes fully understand the risks of riding a bike after its finite service life has been reached

@phb

I wonder how many cyclists spend a lot on their bikes to get the lightest possible and then chose not to replace some parts over time when the finite service life has been reached.

The issue of uncertainty in knowing the actual service life has been recognised as a risk and also a reason for avoiding regulation. I’ve an opinion on this but it is not as well informed as any expert might offer.

For carbon fibre components the uncertainty includes modes of failure which are difficult to predict, and in some instances may not be manageable through NDT strategies on their own. It is best for those interested to read the linked content and seek other information before making any decisions.

[phb]

@mark_m

The issue of uncertainty in knowing the actual service life

This is challenging as each bike will experience different range of riding conditions, affecting the actual service life. E.g. a mountain bike regularly ridden on rough tracks to a racing bike only ridden at velodromes…likewise a 120kg burly rider compared to a 40kg 12 year old…the use impacts resulting in lifespan would be different.

It is however possible, say like the aircraft industry, that conservative service lives are given and one can then chose to say have their components tested (like that offered by Leuscher Teknik or others) or have them replaced (if the testing costs are greater than the replacement costs). The aircraft industry does this and replaces when there is a risk that testing indicates risk of a fatigue.

[gordon]

Just a note of some relevance to expected lifetimes, some, generally higher end, components, frames, forks, wheels etc have weight limits specified by the manufacturers. Obviously the closer you operate to the limits, the shorter the expected lifetime. However in many cases the purchasers of bikes, especially when 2nd hand, will not be aware of the safe working loads.

[gordon]

@omy005aw

Aluminium especially, with galvanic corrosion due to the presence for moisture and the steel star washer inserted for stem fixation.

True for many bikes (and most have either Al or carbon fibre steerers these days), but it doesn’t have to be, as there are Al expanders / alternative star nuts, such as this one on my bike. Traditional star nuts can’t be used on carbon fibre steerers, as they would cut into the steerer and cause failure quite quickly.

This is my carbon fibre fork, now with about 29000km on it since May last year. It has a QC sticker, although I don’t know what that might specify exactly, and an individual serial number, and visually looks ok to me after wiping down and inspecting it. I had it out this arvo to replace the lower headset bearing, which has been a bit noisy for the past week.

[omy005aw]

I’m still seeing that all the linked articles are for “fork failures” not frame, as mentioned by the OP. The two are not interchangeable. Also one of the articles refers to a failed alloy steerer. As with most things like this, when it comes to a blame game with lawyers and inquires its the very fine details that matter.

[mark_m]

@omy005aw

I’m still seeing that all the linked articles are for “fork failures” not frame, as mentioned by the OP.

The OP specifically referred to two serious accidents, one a tragic fatality. Both related to fork failures. The wording for the topic was theirs.

The discussion is open for more specific examples and content related to carbon fibre frames. Doubtless frame failures and repairs occur on a regular basis. Perhaps they are not as likely to cause serious injury? The list of standard frame repairs and pricing from The Carbon Bike Doctor - Sydney suggests frames fail too!

[airedale]

Just to throw something else into the mix - counterfeit carbon frames - people could be fooled into thinking they’re getting a great deal on a pinarello on ali babba, but it turns out to be a chinarello instead, made with absolutely no quality control… https://www.bicycling.com/bikes-gear/a20045553/to-catch-a-counterfeiter-the-sketchy-world-of-fake-bike-gear/
And I’ve had my fair share of bike failures too - three cracked frames (aluminium), thee broken cranks, two broken pedals, a sheered rear suspension pivot, and two rims worn through to failure (the most recent after 35000km commuting on sydney’s roads). maybe it’s time I went on a diet…

[Sator]

There is a cut up and comparative review of a fake Pinarello (“Chinarello”) vs a real Pinarello on Leuscher’s YouTube channel:

It’s rather depressing because the real one isn’t a great deal better overall than the fake one and at certain points the fake one is actually a tad better.

I’ve also been thinking about the issue of “trustworthiness”. Who would you trust more? An owner-operator of a small business like Leuscher (who is putting himself at risk of litigation from manufacturers by applying his aerospace industry NDT methods to bikes)? Or would you trust the PR statements of a multinational corporation making cut-and-paste blanket corporate denials of any liability? If this were the 1960s we might be saying: “I was talking to my friend, a lung doctor, who said he suspected that the cigarettes we’re all smoking causes lung cancer. I was shocked but I feel relieved now after writing to my cigarette company who reassured me that smoking has no ill effects on my health and on the contrary is highly invigorating. I guess my lung doctor friend is stirring up hysteria to drum up business for himself”. This one isn’t as bad as that low hanging fruit, but systematic denials of any problem are a standard part of the corporate playbook and they often end up being dragged kicking and screaming through the courts before admitting an iota of liability.

Sadly, it in the nature of the beast as you might know if you’ve watched the documentary “The Corporation”.

[gordon]

@omy005aw

I’m still seeing that all the linked articles are for “fork failures” not frame, as mentioned by the OP

I’ve edited the title to better represent the initial discussion, although other materials are now included, as they can also fail unexpectedly.

[Sator]

I think that one is just semantics.

If you shop for “carbon bike frames” it will always include a fork without even so much as stating the fact. When people Google the issue “are carbon bike frames prone to failure?” they wouldn’t search for the term “components” but rather “frames”.

I’m a functional grammarian. In functional usage I would argue that “bike frame” commonly refers to the total unit of seatpost, frame, and fork. These are almost always sold as a single unit termed a “bike frame”.

At other times in functional usage the seatpost and fork can be considered seperate from the frame. However, in many, if not most cases, either the fork or seatpost, often both, are proprietary to the frame and designed to function with the frame as a single unit.

I’d argue that it’s a bit of a throwback to 1950s style prescriptive grammar that one would insist that a “frame” and “fork” must always be considered separate entities and refuse to allow other functional usages of the term “frame”.

[mark_m]

@Sator

If you shop for “carbon bike frames” it will always include a fork without even so much as stating the fact.

Just an observation, but one well known retailer in Melbourne refers to a frame + forks consistently as a “frame set”. IE a matched set.

It’s not unusual to find well loved bikes with front forks that are not original, which leaves it open to use either interpretation?

[JB456]

After reading of your various failures @gordon above, I wondered why. Perhaps now I know - many more KMs per year than I will ever do! I have yet to experience failures of components in 25 years of riding, apart from flat tyres and user error.
Canyon Spectral AL MTBs are notorious for weld failures and the FB page is full of people asking if they have the dreaded crack. So I would say it is not only carbon that is the problem.
We do put a lot of trust in our bikes from the tyre on the road to the integrity of the frame. A blowout on a fast descent can be as bad as a frame that cracks at the worst moment.