Check for the carbon fiber

jawscp · June 2007

Does anyone have ever heard about a company that checks with x-ray whether or not the carbon fiber is going to break it?
I mean, when falling occurs (and unfortunately it happens), or when you hit the fork, I think that the cost of the one or two radiographies shouldn't be expensive (at least not like buying a new fork/frame) and it would take off all the doubts regarding safety.
Sorry of being so paranoic, when I used to ride my Olmo (with steel frame) I wasn't so obsessed.
Carbon fiber is starting to gets on my nerves!

Gin a body meet a body coming trought the rye.
Gin a body kiss a body needs the body cry?

giant_man · June 2007

I think you're worrying waaaay too much here jaws. When you buy a new carbon frame it will be perfect, and depending on how you use it, it will always be perfect.

Carbon isn't that delicate. [:)]

SIZE IS EVERYTHING! or at least that's what my LBS tells me.

monty_dogcp · June 2007

Look up non-destructive testing in your yellow pages or sell your carbon bike. Unless you've suffered a serious crash or perceive a change in how your bike feels / hears then I wouldn't worry about it - otherwise you're beginning to sound like Chicken Licken!

jawscp · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Monty Dog

Look up non-destructive testing in your yellow pages or sell your carbon bike. Unless you've suffered a serious crash or perceive a change in how your bike feels / hears then I wouldn't worry about it - otherwise you're beginning to sound like Chicken Licken!
<hr height="1" noshade id="quote"></blockquote id="quote">

I am sorry for being a pain in the neck, but during my last ride I went into a manhole at 30mph/h and I heard a cracking and creaking noise coming from the fork.
When I reached home (safe'n'sound), I've checked the fork accurately and apparently there wasn't nothing wrong (except one little hole on the right dropout and a little white bubble inside the right blade.
Now, I've already placed an order for the new one... just in case...

Gin a body meet a body coming trought the rye.
Gin a body kiss a body needs the body cry?

monty_dogcp · June 2007

A few years ago I was descending a hill on a single-track road at about 40mph and a car came around the corner and stopped in the middle of the road - to avoid hitting the car I hit a bank of sand full-on, stopped dead and executed a full roll, still attached to the bike. Since then, I've used the same forks countless times including Paris-Roubaix and Tour of Flanders sportives twice without a squeak or groan from the forks - if you've ridden pave full-on at 50 kph and realise how hard it is on your bike, then your incident with the manhole was pretty minor.

pjm-84 · June 2007

Wish I could say the same. I've broken 4 carbon frames and one pair of forks in 3years. I currently have a shiny new replacement frame in my garage to swap across tonight.

The current score is that I do a carbon frame before I have to replace the BB or chain.

Paul

spasypaddy · June 2007

i dont have a carbon bike but i did hit a car at around 30mph and the only damage i can see is that my handlebar is snapped in two. The front wheel doesnt even appear to be damaged... getting it properly checked out next week and then im around 1/2 weeks from being able to get back out on my bike

http://img501.imageshack.us/my.php?image=bikeim9.jpg

2old2dieyoung · June 2007

I've done the same as Spasypaddy with a Scirocco which looks perfect to my untrained eye (apart from the tyre). My Squadra is now 2/3rds of its length with the bottom of the front forks back near the bottom bracket. Is it possible for a good LBS to truely say whether it is damaged or not?

Unknown · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by pjm-84

Wish I could say the same. I've broken 4 carbon frames and one pair of forks in 3years. I currently have a shiny new replacement frame in my garage to swap across tonight.

The current score is that I do a carbon frame before I have to replace the BB or chain.

Paul
<hr height="1" noshade id="quote"></blockquote id="quote">
If that really is the case, why the hell do you keep buying carbon frames?

Or do you crash a lot?

Nobody ever got laid because they were using Shimano

pjm-84 · June 2007

No I don't crash and believe it or not the frame manufacturer provides a warranty.

Currently looking into a Lynskey custom because even though I don't pay for the replacement carbon frame they are starting to p*ss me off.

The only frame that has far exceeded expectation is my trusty 7005. 4years and still going strong

Paul

jawscp · June 2007

In my opinion the right answer about the question: "Is the carbon fiber durable?" is: it depends. It depends because the weight of the cyclist is different. It depends because the average during the ride is different? It depends because the amount of miles a year is different. Therefore when somebody talks about personal experiences with carbon fiber, it would be better to know all this informations. But this is only my personal point of view.

i.e.
triathlete
158 pounds
3000 miles a year
19 mph/h (hilly course)

Gin a body meet a body coming trought the rye.
Gin a body kiss a body needs the body cry?

paulbricey · June 2007

There is something unreal about this thread - seems to have captured paranoid elements (hope that's not me as well....hello, help, who said that????) Why would you want to have your bike scanned everytime you hit a bump on a ride ?.... aren't corners dangerous?...what's that guy in the van doing ?...is everyone looking at me ...? What if the scan (X ray...?!?) itself affects the carbon structure eh - bet you never worried about that yet..or have you ?!. maybe we should only ride carbon bikes in the dark in case sunlight attacks the physical structure...!

If you ever had a scan on broken bits of your body & saw the bill you will know an X-ray starts at œ100+ and NMR scan take it up to œ500+ (per limb); so hows that gonna work ?....throw your bike away after each ride ?

Briceyinstockport

pjm-84 · June 2007

Hey I ended doing 130km on mine this morning.

Lean and mean 220lbs.

Paul

PhilofCas · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by jaws

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Monty Dog

Look up non-destructive testing in your yellow pages or sell your carbon bike. Unless you've suffered a serious crash or perceive a change in how your bike feels / hears then I wouldn't worry about it - otherwise you're beginning to sound like Chicken Licken!
<hr height="1" noshade id="quote"></blockquote id="quote">

I am sorry for being a pain in the neck, but during my last ride I went into a manhole at 30mph/h and I heard a cracking and creaking noise coming from the fork.
When I reached home (safe'n'sound), I've checked the fork accurately and apparently there wasn't nothing wrong (except one little hole on the right dropout and a little white bubble inside the right blade.
Now, I've already placed an order for the new one... just in case...

Gin a body meet a body coming trought the rye.
Gin a body kiss a body needs the body cry?
<hr height="1" noshade id="quote"></blockquote id="quote">

Jaws, similar happened to me recently, hit pot hole and heard a loud crack, wondered what the hell it was, it sounded serious. After riding for a mile or two (generally tugging and pulling at things along the way, no, I didn't stop, the bike felt the same) it dawned on me what the cracking noise was, the handle bar (road) had slipped forward in the stem a fraction, which made sense of the noise, could this have happened to you ??

rgisme · June 2007

It probably depends as well on which direction a shock acts on the fork/frame. If it's transmitted up through the legs I would expect them to be stronger in that direction than sideways. Having said that, a Harley (with rider and passenger attached) fell over on top of my road bike once, leaving both wheels pringle-shaped but the carbon forks are still going strong...

I'd be surprised if those forks were unsafe to use from going over a manhole. Do you want to give them away [:)] ?

beckc · June 2007

In my experience the weakest point on an admittedly elderly carbon bike, has been the bonding with the alloy rear hanger (any ideas about effective repair anybody?).

I would be surprised if your front end took any harm and if you did and the manhole cover was sunk or proud in the road you have an actionable case against the Local Authority or their contractors.

jawscp · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by paulbricey

There is something unreal about this thread - seems to have captured paranoid elements (hope that's not me as well....hello, help, who said that????) Why would you want to have your bike scanned everytime you hit a bump on a ride ?.... aren't corners dangerous?...what's that guy in the van doing ?...is everyone looking at me ...? What if the scan (X ray...?!?) itself affects the carbon structure eh - bet you never worried about that yet..or have you ?!. maybe we should only ride carbon bikes in the dark in case sunlight attacks the physical structure...!

If you ever had a scan on broken bits of your body & saw the bill you will know an X-ray starts at œ100+ and NMR scan take it up to œ500+ (per limb); so hows that gonna work ?....throw your bike away after each ride ?

Briceyinstockport
<hr height="1" noshade id="quote"></blockquote id="quote">

In my opinion is unreal buying an expensive carbon frame and (whilst in the Formula 1 and in the aeronautics field this material is constantly monitored), don't have any device that can check properly the status of frame.
It would been better if the cycle manufacturing industries, after they've made carbon frame, they would also invented a machine for testing our expensive bike.

Gin a body meet a body coming trought the rye.
Gin a body kiss a body needs the body cry?

CPcp · June 2007

I got paranoid about my carbon fibre frame and forks cracking or breaking after hitting potholes etc Then I read they build Airbuses out of the stuff. Looking at the tensile stress and all the other engineering attributes of carbon fibre it outperforms steel. I've given up worrying now.

giant_man · June 2007

It would be interesting to hear which models have failed on you Paul. Please let us know which ones you have broken won't you?

SIZE IS EVERYTHING! or at least that's what my LBS tells me.

Grifcp · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by jaws

In my opinion is unreal buying an expensive carbon frame and (whilst in the Formula 1 and in the aeronautics field this material is costantly monitored), don't have any device that can check properly the status of frame.
It would been better if the cycle manufacturing industries, after they've made carbon frame, they would also invented a machine for testing our expensive bike. <hr height="1" noshade id="quote"></blockquote id="quote">

Whilst these failures are probably quite few and far between, I personally think jaws has a point here. There was a post on here a few months ago about a guy riding along on a fairly new Cr1, which just failed at the top and down tubes. He was very lucky, he was OK. I can't find the thread now so it must be out of archive.

There is also a thread on an American site about a guy that was not so lucky, riding a 6 month old Orbea...

http://bikeforums.net/showthread.php?t=294488

I do not post this to be anti carbon fibre, I ride CF forks, and I've got my name down for the Pedal Force group buy on their ZX3 CF frame. I post for the general information of forum users, so people can make their own minds up. Obviously, any frame material can fail, but I think its the way in which CF can fail that is the worry. I would be interested to hear what happened with pjm-84's 4 frames also.

pliptrot · June 2007

The carbon fibre bits of Airbuses are taken off and given a thorough ultrasound on a regular basis; this is the only way to check for damage in a material which usually fails catastrophically without warning. It's also unusual for Airbuses to hit potholes - or suffer any sudden impact shocks in the way bike frames do - so caution is required. The thing that always intrigues me is the durability of carbon fibre tennis, badminton and squash rackets, which are subject to frightening strains and impacts.

Frankly, the most likely problems with carbon frames are from where they are glued together, particularly where dissimilar materials are involved. I would normally have thought that -in this litigious society of ours - that manufacturers would have been savvy enough to prove their designs, materials and manufacturing, but many many carbon frames are from China, where poisonous toothpaste, deadly cat food and other hazardous products are produced. You pays your money.......

pjm-84 · June 2007

I afraid it makes horrible reading:

1) Isaac Force - drive side chain stay
2) Isaac Force - rear stays + fork legs
3) Isaac Impulse - Centre tube crack (yikes)
4) Trek 5.5 - BB shell cracked / cracking the carbon (still very stiff though)

Coppi 7005 = Still going strong

Paul

Noddycp · June 2007

Jaws

I think PhilofCas may have a point about your bars slipping in the stem. I've done it too - made the most awful bloody noise and only after a while did I spot that my bars were a tiny bit more down than previously. With some effort (quite a lot!!)I was able to reproduce it. Also - When a tube bends the greatest movement / stretching or compression is on the surface and that is where damage tends to occur. So - If some of the carbon fibre in your forks snapped enough to make such a noise surely there would be some visible sign of it.

Re the ultrasound - x-ray thing I think you wouldn't just need extremely high quality images but some real specialist expert opinion in interpreting them.

There is a fair amount out there about frame tests and you can probably take some of the points and apply them to forks.

Try
http://hea-www.harvard.edu/~fine/opinio ... -test.html

And as usual Shelson Brown has the answer - well at least some sense to contribute - http://www.sheldonbrown.com/

I do remember reading an article from a german firm (could be the ones refered to in the first link) linked fron pezcycling news (can't find the link now). Basically Carbon is stronger and more durable than you think and steel less. However as you can see if you read a bit about it there is some controversy about methods etc.

Hope all this helps

Cheers

Noddy

Physicists are atoms way of thinking about atoms

giant_man · June 2007

I have to say I'm shocked regarding the Isaac failures. Not really about the Trek though as have heard of failures in the past.

SIZE IS EVERYTHING! or at least that's what my LBS tells me.

monty_dogcp · June 2007

The vast majority of testing of aircraft parts is through visual inspection - they are not removed and X-rayed on a regular basis excpet for major overhaul of structural parts - it's too expensive. Because of the cost of NDT, this is usually reserved for investigation of known faults or for the major overhaul of structural parts. Typically, the part is designed to last it's 'design-life' and development testing and analysis is used to predict the mode of failure and then the part is re-designed not to fail. Often, it's cheaper to replace and throw-away a 'lifed' part that to expensively re-qualify it. Excluding manufacturing faults and crash damage, I expect the unexplained catastrophic failure of carbon frames is extremely insignificant - particularly judging by the number of bikes out there. Just get out and ride!

fat man on a bicycle · June 2007

here you are jaws-this is what you need

http://www.medekit.com/controller/Catal ... yUnit.html

nil satis nisi optimum

jawscp · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by fat man on a bicycle

here you are jaws-this is what you need

http://www.medekit.com/controller/Catal ... yUnit.html

nil satis nisi optimum
<hr height="1" noshade id="quote"></blockquote id="quote">

WOW!
At this price it's a bargain.
I am going to buy two Dragon Mobile/Semi-Portable Digital X-Ray Unit[:D]

Gin a body meet a body coming trought the rye.
Gin a body kiss a body needs the body cry?

Philip Davis · June 2007

A carbon fibre part is highly unlikely to have any hidden damage from an accident. Because of its high modulus of elasticity it tends to fail catastrophically, or not at all. There is only a tiny 'half way' stage in which it will suffer from microcracking. Steel or aluminium are far more likely to suffer from this (i.e. metal fatigue). Most carbon frame failures seem to be at bonded joints - any weakness there caused by an impact should be visible on a close inspection.

So basically, if your carbon structure has survived a heavy impact without any visible damage, it is almost certainly fine. There is always a small chance of some form of invisible damage that could lead to failure, but it is less likely than with alu or steel or ti.

I hate to advocate drugs, violence or insanity to anyone, but they've always worked for me.' Hunter S. Thompson

jawscp · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Noddy

Jaws

I think PhilofCas may have a point about your bars slipping in the stem. I've done it too - made the most awful bloody noise and only after a while did I spot that my bars were a tiny bit more down than previously. With some effort (quite a lot!!)I was able to reproduce it. Also - When a tube bends the greatest movement / stretching or compression is on the surface and that is where damage tends to occur. So - If some of the carbon fibre in your forks snapped enough to make such a noise surely there would be some visible sign of it.

Re the ultrasound - x-ray thing I think you wouldn't just need extremely high quality images but some real specialist expert opinion in interpreting them.

There is a fair amount out there about frame tests and you can probably take some of the points and apply them to forks.

Try
http://hea-www.harvard.edu/~fine/opinio ... -test.html

And as usual Shelson Brown has the answer - well at least some sense to contribute - http://www.sheldonbrown.com/

I do remember reading an article from a german firm (could be the ones refered to in the first link) linked fron pezcycling news (can't find the link now). Basically Carbon is stronger and more durable than you think and steel less. However as you can see if you read a bit about it there is some controversy about methods etc.

Hope all this helps

Cheers

Noddy

Physicists are atoms way of thinking about atoms
<hr height="1" noshade id="quote"></blockquote id="quote">

Thank you for your tips.
Unfortunately I am pretty sure that my handlebar didn't change the position, plus the front wheel is perfectly straight.
Therefore when I went into the manhole, I presume that my fork has absorbed all the impact.
In short words I've already placed an order for a brand new Columbus Mega Carve.

Regarding the site I've tried the first one but It doesn't work.

Cheers

Gin a body meet a body coming trought the rye.
Gin a body kiss a body needs the body cry?

FFSake · July 2007

giant mancp wrote:

I think you're worrying waaaay too much here jaws. When you buy a new carbon frame it will be perfect, and depending on how you use it, it will always be perfect.

Oh dear.

olr1 · July 2007

If you are worrying so much about your carbon frame, maybe you should by a nice heavy 531 frame and ride that. It's a bike, it may break, it may not, but suggesting that bike companies should X-ray your frame every time you run over a bump in the road is just silly.

Check for the carbon fiber

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