Irrational fear of Carbon?

I had a 1994 OCLV road bike, it's still around. It was a harsh ride, but it hasn't killed anyone, to my knowledge.

That shot of the steerer snapping is awesome (in terms of timing), I doubt that ended well!

For me:
carbon seatpost broke (USE)
carbon forks broke (PACE)

Carbon bars have not broke (moketlite)

I'm happy with the strength of carbon – I ran a 2 year-old secondhand monkeylite bar for a while, and while I think it bent, it never broke. But with metal bits, they break, you get bruised, you recover, sorted. With carbon, the bits enter your bloodstream and you have to be amputated?!! wtf is wrong with bike makers?!! 😯

Carbon fibre dont scare me! Its Ti bolts I dont like

What about Carbon bolts?

€9-11 each

There's nowt wrong with ti bolts, nothing wrong with aluminium bolts as long as you're sensible about where you put them!

Hincapie also broke the steerer on his carbon Trek in P-R a couple of years ago.

Dodgy stuff that aluminium.

the carbon haters recently tried to blame jens voights trip along the ground on a fork failure…till they realised the fork was still in one piece…..ooops

Now I'm all for new materials that work, but 10-20 years of development of a frame material in the niche top end of a small sport like cycling is not a long time.

Carbon is stiff, it isn't strong and it is only stiff in a specific direction. It doesn't yield, it snaps and unless the lay up is well designed and the QA very thorough, well you're onto a loser.

Making a carbon handlebar that lasts is pretty easy, but making a frame that lasts – that's a different matter. I have no doubt that some manufacturers are getting it right, but I think a lot of the motivation behind using CF by the big brands is to save money during production.

CF has its place in bike frames without doubt, weight weenies and bike tarts always want something different and lighter. But my nice, light aluminium frames will do me just fine!

Jimmer – I am a carbon feartie but you are wrong – weight for weight carbon fibre is stronger than alloy – hence its use in racing cars.

Where was that Kona Kula frame? That's clear proof of how much tougher alu is than (lighter) carbon frames!

TJ: let's not forget planes too. They're prone to falling out of the sky because the carbon has suddenly failed. Oh wait…

jimmer the statement is nearly as wrong as the bloke who said that the japanese were the only people who make carbon fibre

njee – planes are a whole other issue. They are only held in the air by faith. I mean a jumbo is hundreds of tonnes – throw it down a strip of road at 100+ mph and expect it to fly? dinnae be so daft laddie.

Unexplained plane crashes occur because someone stands up and says " what is holding us in the air?" Everyone thinks about and thinks " I don't know" Cue loss of faith and a big plane shaped hole in the ground

yes indeed I was wrong – balls! What I meant to say was that CF is reknowned for its stiffness (hence its application in aircraft wings) but each layer is only strong in a specific direction.

My point being that if the lay up design is poor you could quite easily end up with a duff frame and I'd imagine the lay up for a bike frame is pretty complicated given all the different stresses it's subjected to at different points.

RE the use of CF in F1 cars – look at what happens to the suspension wishbones when they get loaded in a direction other than the ones they're designed to be loaded in…

As for njee20's comment, any material can fail if it's damaged, poorly designed, used beyond its intended limits etc etc.

I'm not for one second saying that aluminium, steel or ti is the best frame material in the world. I'm just trying to point out that CF isn't without risks or flaws too.

Personally I don't need a 4" full suss frame that's less than 5.5lbs or a road frame that's less than 2.75lbs though.

Its a nightmare subject for me, I understand carbon is ace, I ride carbon bars, used to run RC31's with a massive disc & do stoppies, jumps the lot, but am currently looking at racey hardtails and have dismissed carbon as a frame material and am looking at ultra light scandium(wasnt that Kona scandium?).. Wish I hadnt seen this thread and just blundered along without questioning myself

😳

have dismissed carbon as a frame material and am looking at ultra light scandium

That's a position which certainly isn't based on real world data. I'd trust a CF frame over an ultralight (scandium) aluminium one any day.

My point being that if the lay up design is poor you could quite easily end up with a duff frame and I'd imagine the lay up for a bike frame is pretty complicated given all the different stresses it's subjected to at different points.

But the point is that the layup design isn't poor in any modern carbon bicycle frame. They really do know what they're doing, and 20 years is actually quite a long time in the context (10 years is a silly number to throw up – I've had a carbon framed bike for 12 years which hasn't yet fallen apart – they were pretty well developed then).

Well first of all I would like to see CF used in a bike… 99.99% of the time it's not CF, but thermoplastics. CF by itself is just poo for bikes.

As for use of CF/thermoplastic for off road duties, can someone please explain to me why the MX manufacturers have not used it yet?

Using a technology for something doesn't make it the panacé.

99.99% of the time it's not CF, but thermoplastics

Well nobody uses CF on it's own (apart from for very, very expensive brake discs), it's always in a matrix. However that matrix isn't thermoplastic on bikes, but the conventional epoxy. Good job, as epoxy works a lot better than thermoplastic.

However I susect you don't actually have a clue what you're talking about (like many on this thread).

that matrix isn't thermoplastic on bikes, but the conventional epoxy

And kevlar and glass fiber… Spot the irony 😉

So what's the opinion on a bike frame that is predominantly aluminium but has carbon seat stays?

ARACER… Yes I get it, but it doesnt change the irrational fear that I have, thats why its irrational.

Jimmer dont get me started on ally/carbon frames, they are bonded, that cant be good, obviously exept in planes and the Aston Martin and Lotus Elise and VX 220 chassis… Would I have a plane or an Aston or a Lotus or a VX… yup sure would,,, would I have a carbon/ally frame nope…

Irrational knows no bounds..

I wouldn't not buy a carbon frame based on whats been said on this thread, I suspect a few of the -ve views are trolls, or at least armchair engineers who's mate once saw a carbon frame snaped on the internet.

So what's the opinion on a bike frame that is predominantly aluminium but has carbon seat stays?

Pointless. If you're going to do cf do it properly. In any case all examples I've seen are heavier than the complete alu frame they're based on.

And kevlar and glass fiber… Spot the irony

Is the irony that you still don't know what you're talking about? What has kevlar or gf got to do with the epoxy matrix used to hold the carbon fibres in place?

juan – Member

that matrix isn't thermoplastic on bikes, but the conventional epoxy

And kevlar and glass fiber… Spot the irony

What irony? The material is being manipulated to give the best resulst besides which your alloy frame isn't aluminium it is an alloy of it along with other metals.
I use CF bars on my MTB and CF forks and seat post on the road bike and don't have any worries on the strenght of them. The whole 'CF suddenly snapping' thing makes me laugh as alloys do that just as much.
I was riding my bike to work this winter when i hit a huge hole in the road that had appeared over night, I hit it with enough force to take out both of my tyres as well as cause the bars to rotate downwards but the forks are fine and hve covered over 100 miles since then icluding hitting other holes and such in the road.

Well I can't say I have read the whole thread, but after tonights episode where my carbon post snapped just above the frame I must say my next one will be ally or Ti.
I'll get around to posting the pics sometime, but in the meantime keep an eye out for a 'short' carbon post on the classifieds soon 😉

RE the use of CF in F1 cars – look at what happens to the suspension wishbones when they get loaded in a direction other than the ones they're designed to be loaded in…

That's what they're designed to do. Having them break off in a crash is a way of dissipating energy away from the centre of the car.

My post about Ti bolts was based on personal experience- the my head and the road kind!
Never had any problems with anything carbon.

I remember a while back when Scott brought out the Ransom freeride bike with the whizzy carbon frame, and there were all the doubters going on about the frame's integrity when being ridden hard. Sure enough, not long after there was a post on this 'site saying someone had heard a loud crack and a rider behind on a Ransom found his frame had broken just above the BB. Funnily enough, though, the broken frame was an aluminium version…

I remember that one Count. The was the normal carbon is bad post on here untill the guy came forward with the pics of the alloy frame.
All things can snap the only real difference is that you may find a crakc in a metal frame first.

the scary thing about carbon is the armchair engineers views of it
and that your mum heard about a failure…it does really shag it for the less technically adept…who have fearfull thoughts of a carbon shard heading for their mitral valves

the true thing is that yes carbon just does go bang the other true part is that theres a reason why and till lately part makers didnt understand it….

OCLV bullshit is just another marketing hype thing that trek thought up it was actually invented by a complete other company and even then there was a failure rate which was considered acceptable.
and in some cases was a case of overcompaction not optimum compaction via a bladder

remember the two guys in charge of treks composites design were messing about just like everyone else at the time.

i keep trying to get this idea across to people but composites in the early days was a suck it and see aproach even bert rutan messed about a fair bit

carbon used in brakes is a completely different carbon to the kind used in anything you will get your hands on in a bike shop and is much more expensive…the binder or matrix aint resin…wont go into it but try getting carbon to covalently bond

bonding stuff again is misunderstood and im sure everyone has seen a glued joint break but as with anything they are usually poorly designed glued joints with very poor overall procedures when it comes down to the nitty gritty

thermoplastics are pretty amazing for composites its been done..i have done it …its easier to use epoxies as thats technology people are used to working with on bike frames

but try getting carbon to covalently bond

I know. Tsk. spent 20 minutes doing it min my garage last night and it just wouldn't do it for love nor money 🙂

Clubber, that was very irresponsible. You might have bought yourself a one-way ticket to the amputee ward.

Been there done that. I now have a carbon fibre arm and leg which I fixed to the stumps with some carbon wrap and epoxy. Seems to be working ok so far…

Until your carbon fibre leg and arm shatter without warning, and you need more amputations… 😯

but try getting carbon to covalently bond

thats not hard, it does it all the time!

It could be worse, you could have an irrational fear of it but also appreciate its many advantages. Then you could do what I do and spend loads on Easton CNT stuff and ebay it for a mahooosive loss about a week later. Mainly cos you think that if you look hard enough and in the right light and squint a bit you might be able to see a tiny scratch which will undoubtedly lead to sudden catastrophic failure and death.

Then you can try and convince yourself that carbon forks are a good idea on the new ht build you're planning…

(If anyone wants to bagsy any future CF kit that I buy and then get "the fear" about then feel free to do so!)

(If anyone wants to bagsy any future CF kit that I buy and then get "the fear" about then feel free to do so!)

Do you take orders? 😀

Seems very odd to worry about carbon failure being rapid and catastrophic. In any even where I expect my alu bars to snap/bend, I cant see the bending period being any use to me whatsoever. During the slower bending time I cant see me being able to identify the bending failure and react in time to stop it half way.

I've owned a carbon-swingarmed FR bike for a long time, I've abused it, I've wondered if it would snap but never let it worry me. Yet somehow I still would be concerned about carbon bars.

Makes no sense.

A brief synopsis of what I always post on these threads:

I ran a carbon DH bike for a few years. It eventually cracked in a massive crash at fort bill, which put me in a neck brace in hospital.

Where did it crack in this massive impact?

The Alu headtube insert. The carbon was fine.

I just noticed by Carbon Rush is cracked, boo hoo, sniff.

From do anything pride and joy

to spares bin:

I have been racing since 1989 and have owned over 50 bikes and this is the first frame I have ever bust!