[Closed] Carbon fibre its rubbish

It was more a question would you pay 3 times the price for a frame

IMO the CEN testing is a moot point when it comes to carbon frames

CNT is supposed to negate the weave issue"/lay/pattern weakness in cf?

On One 456 carbon, smashed it down rock gardens at Laggan Wolftracks even done the world cup downhill course at at Fort William in 8 mins on it had loads of crashes on it done large drop offs and jumps and its still in one peice, probably done more than most people would do on a bike like this and its perfect, got my 36 RC2 Fit forks on it big 2.5 tyres and it suits me great
The frame passes all the toughest CEN tests so im more than happy with carbon, i know they are hand rolled so one may pass the CEN tests but obviously they are all slightly diffrent in tests.

by a 1860's beam engine(ellsworth).Thats my rant over for today,feel better now

I remember Truth frames saying you had to use an inline post, the seat tube wasn't strong enough for a layback one. Great.

Carbon all the way. If you don't want to buy one, don't, no one's forcing you!

Done a lot of stuff with carbon fibre on rallycars etc. It is incredibly strong for its weight and torsionally stiff. Its the intended application that always seems to be the problem. Unless the frame or component has a lot of protection say from a outer coating of resin etc they do seem to be compromised by a point loading causing a chip or crack. A friend of mine bought a Trek EX9 carbon hardtail and they left off the plate that protects the BB area from chain rub. When he commented that the BB area had a few scratches on the fibre off the chain they said it would be a good idea if he saved up and bought a new frame just in case. This was a 2.5K bike FFS! The bike had only just had its first service. I know, you would have thought that they would have set up the derailler so the chain stayed on the granny gear. As for getting a CF bike I could only justify one if I lost a shed load of weight. Steel is real for me at the moment.

With carbon, pick your manufacturer carefully. There are only a handful of carbon bike brands worth riding, were they are made properly, Time, Parlee and Calfee. There are a couple of others but cannot remember their names.

TheDoctor, anecdotal or hard facts?

I have long thought about just doing carbon frame repairs rather than design

can we have an original thread please?

I've broken lots and lots of bike bits. Frames, cranks, wheels, bars. All aluminium and steel. Never broken anything made out of carbon.

I had an accident on my road bike around christmas time. Not trusting the carbon forks afterwards despite them looking fine, I replaced them. Once I had the old pair in my hands I remembered watching a video of some chap hitting a carbon frame and a steel frame with a hammer. The steel one came out a lot worse. So I decided to try for myself.

After some proper hard wellying with a lump hammer, all I'd managed to do was knock some of the laquer off the forks. The carbon wasn't even dented.

A place where I used to work were making there own CF road bike with a well known bike manufacturer, in the process we cut up several brand new CF road frames they supplied and they all had cracks/de-laminations. I would never ride CF after I saw that.

I have a mojo frame waiting to be built up.. but now i'm not so sure... yes, seriously...

I know a man who smashed the buggery out his mojo in a very low speed stack on northshore, got a replacement from IBIS (for a knockdown price)and sold it as fast as possible, then went back to alloy.

Hope that helps 😆

So the way really is CNT

Thanks Tazzy, ebay advert appearing next week.

So the way forward really is[s] CNT[/s] carbon, no thanks...

FIFY

Rickmeister - Please tell me your decision to abandon a carbon frame is based on reliable evidence and not the random ramblings and opinions found on this forum!

CNT is good if you want something which may be as harmful to health as asbestos when it comes to the manufacture of it and any cutting of bars etc.. there is a lot of research being undertaken by various occupational health and safety groups and research bodies around the world.

at least cutting some alloy bars to length isn't going to give you pleural plaques in your lungs in the future 😀

Well its either that or smoke weed (your local lbs) or fire ak47's at someone

aluminum production isn't all smiles...

brain clouds anyone?

Ali swing arm failed on my Heckler (Pinch bolt type) which was coming up to 3 years old and more recently the rear end on Yeti ASR 5 which was 3 months old failed big time. Not to bothered though as both were replaced under warranty from Santa Cruz and Yeti. The way in which the carbon rear end went though was a bit worrying and it pains me to say it that others did tell me so prior to shelling out arond £1700 for the frame.
Oh well, i'm on to a 2011 575 now so watch this space 😆

You can make stuff badly out of any material.

As for longevity - does carbon not have good fatigue properties?

Hey laney 😉
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carbon has excellent fatigue properties.

It also allows you yo tune the flexibility with the material as well as shape so you can prevent overly stiff areas which can lead yo failures.

As for CNTs - there is hundreds of research programs all over the world (I am doing one right now) around CNTs in epoxy resin. The benefits of CNTs in carbon fibre laminates is still not fully understood or optimised or used to it's fullest. You can apply the CNTs to the fibres to make them hairy or in the resin to change it's properties and you can do lots of stuff like functionalisation to change the bonds.

I worry about consumer products with CNTs in - especially ones that people cut. They should be fully enclosed in resin so not really a problem but there is a risk. We have to incinerate all waste with CNT contamination.

Easton used to slap Zyvex CNT logos all over their stuff (zyvex has been in the industry for years doing CNT dispersions and resin). Recently they seem to have dropped the logos from their 2011 monkeylite and Haven ranges and I would like to know why. I suspect they are using a new resin system that is better than the old one with the added CNTs. As a nano technology specialist I shouldnt be downplaying them but sometimes other things are better - it is my job to make the nano stuff even better again.

After much resurch(down the pub) i've com to the conclusion that its mainly the junctions between two materials ie carbon and ali that are the main points of failure and after talking to a guy who repairs wheelchairs, which often use the same materials,he has often found that there's oxidisation on the ail surface that causes the bond to break.So my conclusion is stick to one material and all will be well in your world.

🙄

This thread is like a Jeremy Vine show!

Having abused my Kinesis XCPro3 for a year now with alu and carbon and EVEN interefaced 😉 I love it..... I have had 2 road frames, one with cracks but thought to be lacquer and one fork which cracked on first ride but all replaced, no injuries and still ride carbon as well as Alu bikes.....

I've got some 1996 PACE RC36 forks which are carbon and still going strong.

My ally 2005 Gary Fisher FS bike has Carbon seat stays and still hasnt snapped either.

Perhaps I am doing some thing wrong?

A material that you can slice with a Stanley knife, in mind isn't tough enough for throwing down rocks.

Tell that to Continental, Kenda, Maxxis etc...

I've got a carbon Spesh Roubaix roadie that's got a witness crack in the thick brittle paint on one chainstay where the carbon tube joins the alloy dropout. I ride it with the tyres at 110 lbs, the wheels are pretty stiff Ksyriums. Local roads are shite, with loads of worn out top dressing and the odd cattle grid thrown in. The witness crack hasn't grown at all in 2 years (I have close up photos) and the frame still rides like a dream, smooth, light, fast and flattering. I don't worry about it breaking because I reckon it's waaaay stronger than I think. If I ever hear creaking I will inspect it again (often do) and make a decision. Until then I will carry on thrashing it as I struggle to keep up with my riding buddy.

daznal - Member
After much resurch(down the pub) i've com to the conclusion that its mainly the junctions between two materials ie carbon and ali that are the main points of failure and after talking to a guy who repairs wheelchairs, which often use the same materials,he has often found that there's oxidisation on the ail surface that causes the bond to break.So my conclusion is stick to one material and all will be well in your world.

good pub research - stick with one material for parts like that. Using 2 materials is sometimes needed though:

Any good engineer knows that using carbon and aluminium in contact is a no-no. They are too far apart in the galvanic series.

a lot of carbon bikes have aluminium BB and headset fittings in the frame - done properly they will be wrapped in glass and epoxy before bonding the carbon fibre around. This saves the nasty corrosion. This approach is hard to do on slender seat stays and the like.

Glass wrapping is the old way of doing it now things are so much better...
I just started repairing bust bikes as opposed to busted other carbon things.it seems people don't want to bin their investment.not surprisingly the poor understanding and old wives tales are still pretty much the standard by which carbon is judged

Poor design is nearly always evident in busted things....however sometimes it's human error when processing the stuff

All depends on the manufacturer and method of manufacture.

All frame materials can break if abused or crashed.

My old Giant XTC Composite felt bullet proof - beautifully made, light and tough as old boots.

To be fair if I were to buy a carbon MTB it would be from one of the big three, they've been knocking out carbon frames for years and have impeccable warranties/customer service.

Although I would rather like a Maxlight XC Pro3 frame.

I broke my Whyte 19c. Well, I say I say I broke it, one of the cable guides de-bonded. Two things impressed me. The first was the painless replacement process (ignoring the time it took for the frame to arrive), the other was that the guides are no longer bonded.
Hats off to ATB sales for their customer service.

I also managed to destroy an Easton EC90 SL riser. Well I say I destroyed it, the bike it was fitted to fell off the roof rack at 50 mph. Again what impressed me was the bar took a direct blow, but all the damage was caused by the levers rotating and digging in to the carbon. They were otherwise intact.

Andyl, thanks. I wondered why the CNT logos had gone of the 2011 SL bars

So carbon is great - when applied / designed / manufactured correctly - just like any other material.