Is carbon fiber really the best material?
With more and more manufactures switching to carbon fiber as the material of choice for high end mountain bike frames, especially for the xc side of things, I am beginning to think that by the time I come to replace my current bike (thankfully awhile away) I will have to make my choice based on frame material more than anything else. I was intending when it came to it to replace my frame with the new version of what I currently have but as it’s now made out of carbon fiber I will be looking for something else.
To me Carbon fiber for a frame material for a bike that’s going to go off road seems stupid. Despite being much more towards the xc side of things, i like my bike to be tight and fast handling, more like a race bike but I still want a bike that I can ride down rocky track without the fear that either a rock is going to fly up and hit the down tube or I’ll crash and damage the frame. I realise that a rock hitting the down tube can damage any material but carbon fiber is well know not to ‘like’ sharp impacts.
I understand the properties and the advantages of Carbon but for a mountain bike frame that it seems daft. Paths like the Corrieyairack Pass in the highlands is a pretty good ride but littered with rocks that would have me constantly worrying the whole time about my frame, thus I would probably never ride it if I had a carbon bike.

I would be interested if anyone else feels the same and is it manufactures just plowing blindly on with something that isn’t suitable outside the race circuit, (how many people really have the need and cash for a specific race only bike?) or is it just me being paranoid and there’s nothing wrong with carbon fiber?

was saying the same thing yesterday to a mate who is thinking of buying something lightweight for a tour. 2nd hand too….

infact i wouldn’t buy a 2nd hand alu frame either.

i’ll stick with steel thanks.

Well, just take a look at other applications of carbon fibre; motor racing, in particular. F1 cars have to deal with far greater forces than a mountain bike, and they seem to work ok; I’ve never seen an F1 car crash due to sudden inexplicable CF failure. And that MotoGP Ducatti has a CF mainframe; that’s capable of what, 180mph?

Easton’s bars are tested to cope with forces greater than alu bars can take. I trust them.

Bikes like the Ibis Mojo are CF. The Ibis is protected with a tough rubbery finish, that loks like it would be good at repelling stones and that. I’m sure CF manufacturers consider points of weakness and vulnerability, when designing frames.

Your bones are made from Carbon Fibre. They are very light, and have incredible strength, considering their weight.

Don’t be so paranoid.

Carbon just seems wrong on a mountain bike. F1,Moto GP and road(race)bikes are where it’s best suited.

Carbon just seems wrong on a mountain bike.

Explain.

CF is used in road bikes and crashes there can often be far worse than anything a mountain bike will see – much higher speeds onto what is always a very hard surface.
Depends what you’re riding as well (what discipline, price etc), there’s still plenty of high end alu/steel/Ti bikes to choose from and always will be.

“”I’ve never seen an F1 car crash due to sudden inexplicable CF failure””

Indeed, but then you won’t see an F1 care drive off carefree after a brush with a tyre wall either – carbon fibre is deisned to work within its given parameters of stress – a MTB crash for example can’t be realistically judged or accounted for in terms of imposed stress on the carbon, so damage to the integratory of the frame can be caused – maybe without visible signs.

A plastic bike – ridden in rocks?!?! bad idea. (in my opinion)

I reckon that modern trail ones must be tough as old boots. I am happy to buy carbon bars from easton etc. I still have a bit of silly paranoia about them because the damage can remain hidden.

I dont like them though. I had a carbon full susser which I sold (mainly because I decided i did not like the ride) I dont like the way they look and I hate the noise they make whenstones etc hit the bike.It is all hollow and dull sounding. I prefer riding my five which sounds like a bag of spanners.

Plus it looks really tatty quickly, thats why I bought a metal road bike (i do ride it a lot too, not just look at it)

I agree that Carbon is great for some applications and I don’t expect it to shatter unexpectly but F1 cars run on groomed tramac tracks, mountain bikes not so much! Carbon fiber is really strong, stronger than pretty much anything if done right but cut and scrapes in it’s surface can be fatal and you only have to look at a used frame to see that cuts and scrapes from rock e.c.t are common.

I would be less worried if the carbon frame came with a fleshy covering like are bones…disgusted but less worried! 😉

CF is used in road bikes and crashes there can often be far worse than anything a mountain bike will see

indeed again! and replace in a pro race immediatly or straight after the finish and scrapped – not used again and again and then put on ebay or traded in at the local bike shop.

I would not use my road bike again after a heavy crash – and that’s a 2.2K frame. I could earn that in a month, but not from a wheel chair.

Carbon fibre in top end motorsport is not really the same thing as mountain bike parts.

F1 carbon structures are hand made in small specialist manufacturing facilities under incredibly tight controls.

Bike parts are mass produced in Korea.

something as small as a tiny amount of aftershave on the hands of someone laying up carbon weave can have a disastrous effect on it’s integrity.

Can’t say i’d be too keen on a carbon framed mtb as i know i’m not careful enough.

well, i fully trust the strenght of carbon – it is stronger in impact tests that aluminium or steel. What i dont like is the idea of falling of onto rocks etc… I’m sure some of the slight scratches on my trex fuel, if they were on the carbon models would have resulted in the carbon weave being damaged… So for a bike that i would be riding anywhere rocky or hard, i would just be scared of damging it to much in a crash. I do have a carbon scott scale though.And i love it.

I’ll wait a while till i get a ‘bigger’ bike made of carbon…

There are less and less high end xc full sus bikes that aren’t carbon. Plus have you seen what some of the carbon road bikes look like after a crash?! Or the British teams bikes after a crash on the track? Not that mach of them left, certainly not enought to ride home on! George Hincapie’s carbon steerer didn’t do so well at the paris roubaix a few years ago either!

I know that the track bikes e.c.t are built on the limit but still 😕

Hincapie’s steerer was an alloy one from a commuter bike! still on the whole i agree with you.

George Hincapie’s carbon steerer didn’t do so well at the paris roubaix a few years ago either!

It was an alloy steerer.

http://www.kgsbikes.com/go/news/technical-qanda-with-lennard-zinn-landis-s-drivetrain-hincapie-s-steerer-thomson-stem-and-chain-pin-replacement

http://www.bustedcarbon.com/

Sorry stand corrected!

Post attempt failure.

Not CF. Cheap cardboard…

Yes, but seeing as how aluminium, steel and even titanium can all fail, CF is no less appropriate a material.

This is Robert Kubica crashing an F1 car. All the energy absorbing bits have done their job, and broken away, as they are designed to. The bit holding him in remained intact. And saved his life.

F1 carbon structures are hand made in small specialist manufacturing facilities under incredibly tight controls.

Bike parts are mass produced in Korea.

something as small as a tiny amount of aftershave on the hands of someone laying up carbon weave can have a disastrous effect on it’s integrity.

Wel, that’s bollocks, from the start. Most bike bits are made in Taiwan, not Korea. And it does not in any way really matter where the thing is made; preference for Yerpan or US built stuff is just snobbishness. CF production, by firms like Spesh, Trek, Giant etc is as sophisticated as anything you’ll find. They’ve been doing it for a while, and have loads of data and sperience. I dare say they’ve considered things like stones chipping the downtube.

And contamination in a weld can lead to failure, too.

CF does require more careful manufacture, and this is reflected in the cost. something like an On-One will probbly cost £20 or less, to actually make, whereas a CF frame will cost hundreds of pounds.

There’s tons of CF parts and frames out there. I doubt the failure rate is significantly, if at all, higher than any other material. I’d trust a decent CF frame, over a cheap alu frame, any day.

The problem with CF failing is that it does so without any warning (no visible cracks etc) and does so in an instant – i admit CF bars are highly unlikely to break (unlike very light alloy ones) however a CF frame, although unlikely to break will have re-sale issues due to the nature of the how logevity is asessed.

Argh the armchair engineers are all here today.

Nothing wrong with carbon. Perfectly strong enough.

Advice would be to try before making judgements.

Wel, that’s bollocks, from the start. Most bike bits are made in Taiwan, not Korea.

And thats bollocks too, as most carbon bike bits are made in China.

something like an On-One will probbly cost £20 or less, to actually make, whereas a CF frame will cost hundreds of pounds.

And that’s bollocks too.

Ah, but more general bike bits/frames are made in Taiwan! 😀

I’ll happily use carbon, you all assume that the frames are built to the point at which any small scrape will damage them, ever heard of over engineering?

I’ve seen steel, aluminium and titanium fail

There are less and less high end xc full sus bikes that aren’t carbon. Plus have you seen what some of the carbon road bikes look like after a crash?! Or the British teams bikes after a crash on the track? Not that mach of them left, certainly not enought to ride home on! George Hincapie’s carbon steerer didn’t do so well at the paris roubaix a few years ago either!

I know that the track bikes e.c.t are built on the limit but still

A stack on the track will have a greater effect on the frame, much like hitting a tree. A lot of the crashes on the track are at 55-65kph, I’ve totaled alloy and steel frames on the track. If you think about the stress put through a frame doing a standing start, if it was weak it would snap. I used to put out 2218 watts during a standing start, I know Chris Hoy and Craig Mclean put out a bit more. They only bike I hated using was the Lotus, it was so flexy. All the BC frames are built to the highest standard with strength, weight and aerodynamics taken into account.

Oh aye. A “famous” bike designer once said that carbon bikes have no “soul”.

Argh the armchair engineers are all here today.

Nothing wrong with carbon. Perfectly strong enough.

Advice would be to try before making judgements.

No one’s really quoted anything engineery, just opinions and observations – and a bit of fact, which is what is also going to sway folks opinions when purchasing your frame should you wish to trade it in or flog it. People see titanium, steel and alloy as more durable and quite rightly so, as carbon isn’t as tried and tested – so it’s important when considering a purchase.

And that’s bollocks too.

No it’s not. And you know it. On-one’s are cheap to produce. As are lower-end Spesh’s and Giants etc. Don’t try fooling us.

I’ve never seen an F1 car crash due to sudden inexplicable CF failure.

the difference being that an F1 car only has to last one race, and isn’t expected to survive driving over rocks.

Your bones are made from Carbon Fibre

they ent. The only pure carbon in your body is barby charcoal

I agree with Rudeboy in regards to it not really mattering were the bikes made…apart from I think it’s sad that if you buy a Uk/USA ect brand it’s not made there but thats another story.

And I don’t think that CF frames are going to fail all over the place but you still can’t escape the fact that Carbon fiber isn’t good at with standing cuts, knocks and scrapes that mountain bikes are subjected too. Not to say that a ti/steel or alu frame will with stand all punishment, (I have seen loads break over the years) but just maybe more suitable at with standing a knock and there is something more comforting about them…but maybe it’s just me…

Not going to pretend I know anything about engineering, but I’ve been riding long enough (and am lucky enough) to have 5 bikes and it’s just occurred to me they are all different materials:
Carbon road bike
Ti ‘cross bike (very nice 2nd hand On-One – ta Brant)
853 steel hardtail
Scandium Full Susser
Alu tandem.

Would’t risk rock impact on carbon mtb, but otherwise I can see it’d be great.
Alu road bike cracked after 3/4 years of occasional riding.
Wouldn’t go without a steel hardtail.
Scandium seems lighter and tougher than other alu.

In resonce to the “arm chair engineers are all here today” ,perfectly willing to be corrected, hell I would love Carbon to be the wonder material, would make future bike purchase a lot easier. I am not anti carbon or anvances in technology at all…it’s just I also think I am correct in thinking that Carbon doesn’t like sharp impacts e.c.t which for a MTB frame seems unsutible, were as a alu/ti/steel frame can more easily shrug them off…but not to say that they won’t fail in another way but to me the impact from rocks seems quite a present one in MTBing and thus I would end up constantly worrying when ever I rode.

If someone can correct me on the material properties of carbon fiber please do

I’ve seen two XTC carbon frames fail due to impact, once on a rock and the other was a small dog (both rock and dog were fine) It’s impact damage that is the concern and for me it’s the not being able to see the damage. If I stack on a metal frame I can see damage in the form of dents, not so on carbon.

Anyone remember the first Look TVT frames and the Spesh Epics from the 80’s if carbon had issues then we wouldn’t be using these days.

Formula one demonstrates the strengths and weakness of CF.

Very very strong and light when intended forces are applied. Brittle and weak when loaded in other ways

CF is the first mountain bike frame material that really has no ability to deform plasticaly. So we’ll never see a dent or bend.In many ways a plastic deformation is safer than a brittle failure

I think the question we need the answer to is what was the frame intended to be able to cope with. Was it designed for rock strikes and or being dropped onto rocks. I’m sure a CF bike could be over engineered for all eventualities, my question would be are they?

Quck edit having seen last to post

If we generalise from Cf to composites in general then its worth remembering that bullet proof vest are kevlar, they have good impact protection.

There is something simlar going on with the Yeti 575’s carbon rear end.
I was told by the guy running uplift at Cwm that hes seen ‘loads’ of 575 cracking. Then at Afan the shop keeper in Skyline said he had seen about 5 break.
I asked Yeti importers/warrenty (as i was worried) and they only have records of 5 cracking in the UK. And 7, Yes SEVEN examples of the alu version cracking!!
So did all (despite two of them being in Scotland!) of the carbon ones crack at cwm then drive to afan to re- bust them?
Or do people like to slam what they dont have???

On-one’s are cheap to produce.

I wouldn’t want to discuss another manufacturers frames.

Oh aye. A “famous” bike designer once said that carbon bikes have no “soul”.

Yeah. Envelope stuffing innit.

Or do people like to slam what they dont have

I’d love to have a host of carbon bikes but two things stop me, my riding style (or lack of) and money to replace them

The other aspect is what is the advantage of a CF frame? How much of the weight of a nice light bike is the frame? 4 lbs out of 25? so save 1/2 a pound on the frame – does it really matter?

Carbon fibre scares me on mtb components not because it is weak but because of its brittle nature. Overstress a metal component it will deform. Over stress a CF component it will break.

This carbon thing is a bit of a myth. Prolly founded in the old 90s days when people made insanely light xc parts out of it before they’d really got to grips with how the material works. Yes, there was a lot of breakages, and yes when it fails it does so more catastrophically than most materials. But aluminium can fail spectacularly too, and is nowhere near the strength of carbon. But people these days have no worries riding that. Things break, no matter what they’re made of. There’ve been loads of advancemets in carbon over the past few years and I think it’s basically a non-issue now. The idea that any stray stone is gonna chip the frame and cause it to capitulate is so alarmist that the Daily Mail might baulk at it and run with a ‘humanity under threat from virus that’s killed 17 people’ sensation instead.

There is something simlar going on with the Yeti 575’s carbon rear end.
I was told by the guy running uplift at Cwm that hes seen ‘loads’ of 575 cracking. Then at Afan the shop keeper in Skyline said he had seen about 5 break.
I asked Yeti importers/warrenty (as i was worried) and they only have records of 5 cracking in the UK. And 7, Yes SEVEN examples of the alu version cracking!!
So did all (despite two of them being in Scotland!) of the carbon ones crack at cwm then drive to afan to re- bust them?
Or do people like to slam what they dont have???

Well thats a could story and some one needs to follow it up

I’ve heard the 575 thing a few times. I have no idea what the truth is on this.

But will the importer know about all failures? Is the importer reporting failures they’ve accepted responsibility for or all failures? How many Yetis bikes are CF how many are AL