[Closed] Epic carbon fork fail.!

send the pictures [url= http://www.bustedcarbon.com/ ]here[/url]

Nasty

could i have the broken bits,i'm making a wheel jig

could i have the broken bits,i'm making a wheel jig

Not mine I'm afraid but I can ask.

could i have the broken bits,i'm making a wheel jig

I'd imagine Scott and/or the shop that he bought the bike from might want to see them...

So what did he do / hit? How did it happen?

Nasty. Really just went for no reason? But yes get them back, surely if one sets gone for no reason then others could.

Looks like one of Cynical Al's jobs 🙂

Pothole seems the most likely candidate, not a big one mind probably 8-9 inches in diameter and 4-5 inches deep. There was a half a dozen spokes broken as well but we couldn't decide on the order of events.

All frame materials fail but only carbon fails like this. Buying from a reputable brand does not protect you either as in this case. Glad the rider was mostly ok.

wow, ouch, wow

Aluminium forks fail similarly .......

Steel fotks mostly bent .

Fwiw ive seen seven carbon forks driven into a low bridge on a car roof turn the ti frame into scrap without failing !

Was he riding with eyes closed or was there no group etiquette towards potholes if in a group - 8-9 inches and 5 inches deep is a cavern ......

Wish him a speedy recovery though !

In my experience of a similar accident, steel forks bend and destroy the steel frame too.

I hit a similar pothole yesterday. Cornering and being overtaken by a car, I had little chance to avoid it. There was a loud crack and Immediately shat myself but all that seems to have happened is that my bars have rotated in the stem by15 degrees or so (Easton EC70 forks).

The only pics I've ever seen on failed steel or alloy frames are either bends or stress fractures. we've all seen endless examples of this catastrophic carbon failure. Who cares about warranties, this stuff permanently disables people.

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not a big one mind probably 8-9 inches in diameter and 4-5 inches deep.

What exactly would you define as big? Because If I hit that at speed I'd expect me or the bike or both to be broken.

Ive noticed that you get a lot of mileage out of that pic. I guess it saves from trying to think and intelligently contribute to discussions. I guess we all have our limits and you keep well within yours.

I agree, he should have just called you an asshat.

we need more helpful dissing of entire threads like that from hugor..it is especially good when they hint at superior knowledge but dont share this.
I have never seen aluminium or steel forks fold like that on a pothole

Wasn't dissing anything.
My issue here is the mode of failure.
Bends and stress fractures give you some chance of saving the situation.
Catastrophic failure gives you no chance.

Hmmm my thoughts....

Aluminium or Steel will usually signal the failure long before it actually fails in a catastrophic manner. There will be cracks, bending, creaking etc... and it will be visible as metals are homogenous structures and a crack will penetrate fully or simply will not exist.

Carbon fibre structures, being layers of carbon fibres in a resin, can hide minor cracks, delamination etc... within the layers. Until it's too weak to sustain an impact such as this. Then "bang" and a catastrophic failure.

IF you own this stuff you have to be a bit more observant than usual and the original design has to be even more tolerant of abuse.

I hope your mate gets better soon and that this was a design related failure rather than just wear/tear/fatigue.

Agree entirely with above.
But let's not let a little knowledge get in the way of an argument.

Another thought, after looking at the pictures again....

It seems unlikely that both fork legs would be hiding cracks/delamination in similar places and fail simultaneously.

My suggestion is that the wheel failed first (you mentioned spokes??) and the subsequent loading on the fork caused it to fail.

Let's hope he heals quickly 🙁

Most pics of failed carbon frames I've seen including those in the link above show it failing in 2 places at once.
In this case we have a ring of a fork which is completed by the axle. A rigid ring cannot fail in one place. It has to fail in 2.

My issue here is the mode of failure.

Having seen quite a lot of failed components, ime it makes sod all difference what the material is. a bar bends then snaps. a fork bends then either folds or locks the wheel.

I choose carbon because I feel safer on it.

surprised no one has mention carbon fibres heading for the heart.

It's very rare for forks to fail in the middle - same as spokes - they always go at either the crown or the dropouts.
The only other pair of carbon forks I've seen snapped like that took one hell of an impact in a side on crash which wrote off the front wheel.

Just wondering if he hit the pothole, damaged the wheel, crashed and *that* broke the forks or if the forks failed and caused the crash. My guess is the first scenario.

Whichever, it's time to ignore the general shite spouted about carbon vs steel vs aluminium, take the bike back to the shop and see what options there are for getting it sorted.

Could have been really nasty. :winces:
My so killed a pair of HSC3 forks when someone ran out into the road infront of her as she was riding at 25mph. Ripped one of the dropouts out and one fork leg broke at the crown - also ground down a pair of Chorus ergos to the brake pivots. she wasn't very impressed - although she had to wait in A&E for awhile as they were attempting to revive a car crash victim. As she said to the ambulance guy waiting at reception with her "puts things in perspective".
Hope your mate's ok.

and it will be visible as metals are homogenous structures and a crack will penetrate fully or simply will not exist.

That's excellent news, I'll be able to tell the NDE chaps at work that they don't need to bother to xray/UT stuff any more 😉

Something went through the wheel, jammed against the forks (stopping rotation) and the forks failed at the contact point?
I know someone who had a nasty accident after a rabbit jumped into their front wheel and brought things to a rapid halt.

i saw enough shattered carbon whilst working at a cannondale test centre to put me off using it.

at least once a week there would be another broken Super6 on the rack. a broken fork, snapped seat or chain stay, a light crack in the top tube where the user lent it against a wall or railing.....

had three guys end up in hospital due to carbon failures (had lots more end up in hospital as a result of rider idiocy).

i lost count of the number of FSA carbon bars that were replaced. when the bars were fitted to the stem using a torque wrench you'd still find that the carbon had de-formed after a month of use.

horrid stuff, IMO.

All frame materials fail but only carbon fails like this

I've got a pair of forks in the garage snapped.

They're steel though, sorry to disappoint your world view.

at least once a week there would be another broken Super6 on the rack. a broken fork, snapped seat or chain stay, a light crack in the top tube where the user lent it against a wall or railing.....

How many carbon frames do cannondale sell in each of those weeks though?

Bends and stress fractures give you some chance of saving the situation.

Depends, maybe if you spotted them, if not your still feked!

could i have the broken bits,i'm making a wheel jig

Got a couple of pairs of busted reynolds 531 forks from over the years, unfortunately there's not bustedsteel.org website so nowhere to host pics of them. Any use to you? One pairs bent, the other's got about 2" of steerer tube left after it snapped.

its all down to human error in the end

I see enough broken carbon working as a cycle mechanic to distrust it. I've still got carbon seatposts and suspension fork lowers though.

It's not all down to human error in the end. It's down to the fact carbon fails catastrophically and is more prone to hidden damage than other common materials in the first place.

Still the best material for light and strong - at least at the point of manufacture, if made properly.

My Verdict : avoid unless rich and must have the lightest, or sponsored. A manufacturers dream as if they play their cards right the warranty costs shall be offset by the large profits and shorter product lifespans, meaning returning customers.

I find it strange that if Carbon is such an inherently dodgy material that so many of the big manufacturers are pushing forward with it, surely it woudnt be worth their while if they were going to get warranty claims every 5 minutes...... I'm not sure that the shorter product lifespan argument makes much sense. Anyhow, carbon frame, seapost and bars and I'm not dead yet.

I know someone who had a nasty accident after a rabbit jumped into their front wheel and brought things to a rapid halt.

Would you care to elaborate on this?!

YAWN The record is as broken as those forks!

If you guys really want a bike that won't hurt you when something breaks then you are going to have to ask for one with some redundancy and be prepared to ride a bike that weighs 90% more as all the critical structure (which lets face it is pretty much everything on a bike) has to be doubled up. Regardless of the material every bike part is made for minimum weight for what it does and as such any failure will normally result in total failure of the part.

I find these scare scaremongering views on carbon but no actual real knowledge of it or seemingly metal failures quite ignorant tbh.

Now for some evidence:

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All look pretty catastrophic to me and all magical metal which couldn't possibly have hidden faults 😉 (look up United Airlines Flight 232 )

PS glad your mate is okay. Bike parts can be replaced.

how is it not down to human error Do you think its the carbons fault in fact its pretty useless just sat there on its own,Just like aluminium,Steel,Titanium ,Somewhere along the line someone made an error wether it be design manufacturing or end use ,end of lifecycle .it was a human that brought it into existence it all boils down to that at the end of the armchair engineering analysis things don 't just break.

Where the OP's forks failed0looks like a design flaw to me, unless there was an impact right there.

I can't imagine a pothole did it, he'd have flatted and trashed the rim.

An impact of this magnitude means you are over the bars no matter what material your forks are.

Thread resurrection.

Scientific detail - since I last visited this thread I have seen a BMC road carbon road bike with a fracture at the seattube/seat stay junction, and a Yeti ARS five with a broken swing arm.

Just keeping you up to date. I may be back. No failures noted in other materials.

Scientific detail - since I last visited this thread I have seen a BMC road carbon road bike with a fracture at the seattube/seat stay junction, and a Yeti ARS five with a broken swing arm.

Listen everybody knows that they build rocketships and jet aeroplanes out of carbon.
There's only 2 possibilities here - either you're lying or these riders were travelling faster than both of these.

I've seen a titanium frame cracked through on a ride in Swinley. Does that make all titanium suspect?

I reckon so. I've seen my mate's Ti frame snap clean in two on the seatstay & chainstay. Lethal material for a frame if you ask me. 🙄

That squirrel really had a death wish. The worrying thing is that squirrels at Swinley seem to line up to do exactly that!

My mate did similar with a pigeon in London. Nobody cared - pigeons are foul, fact!

Far out!!! Poor squirrel alright. Wicked pics!

Listen everybody knows that they build rocketships and jet aeroplanes out of carbon.
There's only 2 possibilities here - either you're lying or these riders were travelling faster than both of these.

Genius. I wish I worked in a bike shop again just so I could use this line to deny EVERY warranty that came along 😀

Bike number six to go in the last two months. This time a Cube near the seatpost. Cube are replacing without the slightest fuss.

Pinarello FP x 2
Time x 1
Planet X x 1
Boardman x 1
Cube x 1

The squirrel story
http://pardo.net/bike/pic/fail-016/

Bike number six to go in the last two months.

Ah they're not mine, but they belong to fellow club members.

Read this unbiased but very interesting [url= http://www.cyclingtipsblog.com/2011/08/are-all-carbon-bikes-created-equal/ ]article[/url] on this a few days ago.
Presents some good points.

Ah they're not mine, but they belong to fellow club members.

Unless youre behind them at the time.

I have ridden aluminium, steel & titanium hardtail frames. They have all cracked. I have no reason to believe that a carbon frame would behave any differently!

Don Ferris of Anvil said on:

http://www.frameforum.org/forum2/index.php?showtopic=2317
That: "Even the largest and most efficient cargo aircraft have a payload ratio of less than 4 to 1, with most being less than 3 to 1. In other words, for one pound of aircraft weight, they can carry 3 pounds of payload. A 20 pound road bike with only a 150 pound rider has a load carrying ratio of 8.5 to 1. Put a 200-pounder on that bike and it grows to 11 to 1. Put that 200 pounder on a 40-pound DH rig designed for 9-g loads, and you're still at 6 to 1. No the best way to compare stresses obviously, but it does put into perspective how bicycle frames are exceptionally stressed for their mass."

Similar story applies to CFRP, if used on aeroplanes; there is a system of classification of parts on planes eg critical parts, sensitive part. Sensitive parts, if they fail, will cause a drop in aircraft performance in flight eg speed, fuel consumption etc, Critical parts, if they fail, will lead to the plane falling out of the sky. CFRP is not first choice for critical parts.

Similar story applies to CFRP, if used on aeroplanes; there is a system of classification of parts on planes eg critical parts, sensitive part. Sensitive parts, if they fail, will cause a drop in aircraft performance in flight eg speed, fuel consumption etc, Critical parts, if they fail, will lead to the plane falling out of the sky. CFRP is not first choice for critical parts

But isn't the rear stabiliser and rudder on the A380 all carbon? I'd say that was a critical part... Certainly wouldn't want to be in one if it broke off!

FWIW I have no issues with carbon bike bits. I've seen catastrphic failures in all materials and I've seen carbon bend without failure. After all the chainstays on a Cannondale Scalpal are carbon and designed to bend.

Was the hub still clamped in the dropouts after the crash and can we see a pic of the wheel?

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Didn't know Chuck Norris rode mountain bikes 😆

No the best way to compare stresses obviously,

The most important part of that paragraph.

The [s]most important[/s] only useful part of that paragraph.

Critical parts, if they fail, will lead to the plane falling out of the sky. CFRP is not first choice for critical parts

fearmongering at the very least

Do you think A380 etc. get leant against lammp posts and chucked in the back of transists?

[img] https://mail.google.com/mail/?ui=2&ik=b2e8d9b789&view=att&th=13223bf79a6d1d2b&attid=0.1&disp=thd&zw [/img]

Carbon Fork - Fine
Aluminium Frame - Goosed
Brick Wall - Scuffed

I think the issue (if I have one) is that all the carbon I see breaking is 'just' happening. They've not been in crashes, just riding and racing road. The latest, the Cube is only two months old.

Whilst I've broken three steel frames (a hat trick, MTB/crosser/road bike) they've all hit something.
I've yet to see a steel or aluminium frame just break up on it's own.

Once you've worked in a bike shop or really looked into warranty claims you realise that 99% of broken parts are broken from "just riding along and then....."

I was just riding along and my fork just snapped 🙄

Hitting a pot hole at speed is going to do some serious damage to any ROAD bike,

I've only ever broken one frame, a carbon Scott Genius which went right behind the bottom bracket where they'd stupidly designed it with two little carbon lugs connecting to the rear end. My Mk1 Ti456 is still going but I'm waiting for it to snap at the chain stay like all those other pre-brace models.

I dont really have a point, beyond if you weigh 85kg++ and ride a bike (badly) that isnt the last word in design perfection its gonna break some day.

I was just riding along when the Scott broke. Bike of the Year 2005 too.

oldgit - Member

Bike number six to go in the last two months. This time a Cube near the seatpost. Cube are replacing without the slightest fuss.

Pinarello FP x 2
Time x 1
Planet X x 1
Boardman x 1
Cube x 1

You don't know if your PX is broken though do you?

In fact, 100% of the evidence says it's not, and you still keep suggesting it is, or is this a different one? Send it to me, I will ride it. If it's broken in 6 months you can have it back, if not then it's mine to keep, seems fair!

Anything brakes, anything made cheaply is more likely to break than a well made product (that's not [i]necessarily[/i] directly proportional to cost), what it's made of is irrelevant. Carbon can crack and show signs of failure, alu can just fail. To say that you only get 'JRA' failures with carbon is ridiculous. The number of warranty carbon frames I dealt with at the LBS was in single figures, we had a Spark that cracked on the aluminium shock mount, and an OCLV frame where the bonded alu sleeve for the BB came out. A couple of S-Works frames with cracked alu swingarms too. Actual failures of carbon frames were incredibly rare.

Not for certain. Obviously I now have what appear to be cracks in both chainstays.
I have ridden it since, and seemed well until I went uphill. Then it started to flex so badly the rear tyre rubbed the stays each side as I put the pressure on.
I was out that day with someone who says he can sort it.

To add another slant to this, I've bent(!) a carbon seatpost and snapped spectacularly a set of Alu bars....

Not all CFRP (Carbon Fibre Reinforced Polymer) is the same.
Carbon fibre without the polymer (plastic) is just string.
There are different types of carbon fibre as well as different types of plastic.

[i]Didn't know Chuck Norris rode mountain bikes[/i]

he doesn't he sits on it and the trail moves under him.