Weak carbon Why?

fletch8928

A few of us were talking this weekend as a mate has just got a carbon Cube. He is around the 11 stone mark. We/the other lads are all pushing 16-17 stones and are all against carbon frames.
None of us said we would feel happy blasting around on one. Yet 1 has a carbon road bike too. All of us agreed that he won't have any issues but where has this mindset of ours come from? I have seen videos of damage, steel, aluminium and carbon. Bars and stems can fail no matter what.
I have not seen anything about the issues. I have also not asked about if there is a rider wieght limit on carbon frames. Are we being daft or is there something why we wouldn't feel happy that we have subconciously picked up on?

supersonic

It is a subconcious thing, just like it was with alu in the early 90s. Carbon started pretty badly. But as with alu, as new techniques were learned, it has come of age.

Most people associate it with racy XC stuff. But that is not always the case, depends what it is built for. You can get flimsy parts still of course, you can with anything if done wrong or used wrongly.

fletch8928

Kind of thought that may be the case. Not looking for a new bike, but will be, and after the weekend it got me thinking.

I got back into mtbing feb 08 and got a Scott Scale 50. Not the standard fat clumsy riders machine, and until it get smashed against some metal bars I never felt it wasn't strong enough.

fuelex

We come into contact day to day far more often with steel/aluminium than we do carbon.
I think the brain kind of knows what these materials can take and as such we just trust them more.
I've seen a carbon mtb bar snapped almost in two and looking like it was held together with a few threads of carbon but it was still unbelievably strong and hard to bend.

jairaj

I think its comes from the early carbon frames which were a bit flimsy. But manufacturing processes have come a long way and people understand the material and how to use it much better now a days. Just look at the top end Cannondale frames, they can build in flex for comfort in one direction and make it stiff for good steering in another direction.

I also think the way carbon fails compared to metals ie carbon tends to snap while metal bends. Makes people feel that carbon is weak but they don't take into consideration that the metal part is also ready for the bin. Just because its still in one piece, albeit a bent piece doesn't mean its still good?

Im no whippet but wouldn't hesitate to use a carbon frame and components if they were built for purpose.

jayson

I wouldnt have a problem riding a carbon frame (if i could afford to...) however i do have reservations over things like carbon bars and seatposts.

Theres always that little voice in the back of my mind reminding me that if they snap its gonna hurt in a big way which i just cant around.

Frodo1095

I am looking at a new bike atm, and trying to mull over between the Santa Cruz Nickel, Blur Lt and Blur LTc.

Every forum/article I read says the LTc is stiffer, lighter more nimble, tracks better and is bomb proof on drops, and a leap forward from the Blut LT, so as a long term investment it would be a good buy as it will always be a good frame to ride and I could happily upgrade onto.

But then you see pictures of frames with rock strike damage around the lower pivots after just a few weeks, the frame isnt cracked but, looks like small chips.
They says the frame isnt weakened in anyway but would the alu version have faired better, maybe or maybe not, but you dont see pictures of this damage on alu frames, is that because when we see it on an alu frame, we just assume the frame is ok but fear a carbon and generally more expensive one wont be ?

There is also the replacement cost in the back of my mind should it break (outside warranty period), could I afford to replace it ?

scotto

Not all carbon frames have weight restrictions, cannndale do not put a restriction on theirs.

It's more carbon components I worry about not the frame, would love to get carbon bars but keep having bad thoughts about them !

fletch8928

I am glad its not just me that has those thoughts.

The seat post isn't too much of an issue. you might tumble off but no more so than worrying about a chain snapping when out of the saddle trying to power up a technical bit. Bars would be a worry, even normal ones as that has potential to be nasty.

I watched a vid with a bloke twatting the hell out of a carbon frame with a hammer, it fell to bits. That isn't a true reflection of trail abuse and i did chuckle at what what he was trying to prove! look if you smash this lump hammer onto a bike frame its gonna get damaged beyond repair. Never!

Money to buy one isn't a problem. I have none and am not buying at the moment, hence its not a problem. When i do think about a new bike I can at least look and consider carbon? Although I wouldn't buy a bike just because its made of a certain material.

Kiblams

I read ina magazine recently that there is a German (can't remember the name) carbon MTB manufacturer that gived 99 year warranties on all of their carbon frames :shock:

So unless they are dirt cheap to produce; they must be pretty resilient.

Mancunianfightingcat

I don't think F1 drivers are too concerned that their 200mph cars are made of carbon!

Aluminium and steel bikes can also break!

njee20

Theres always that little voice in the back of my mind reminding me that if they snap its gonna hurt in a big way which i just cant around.

Whilst your aluminium bars snapping suddenly will have you laughing and joking!

I've got got/had carbon frames, forks, bars, seatposts, stems, brake levers, saddles, cranks, wheels etc, none of it's ever broken! I had a 1994 Trek OCLV road bike, it was seriously harsh to ride, but hadn't fallen apart, sold it a few years ago, it's still around. I had another carbon road bike I rode into a car at speed, the (carbon) fork snapped, and the front wheel and bars (both alu) were trashed, but the frame was fine, I raced it for another year before selling it.

carbon MTB manufacturer that gived 99 year warranties on all of their carbon frames

Trek and Specialized (among others) give a lifetime warranty on the frame. Seeing as it's likely only valid with the original owner, 99 years is a bit of a 'gimmick', a bit like Cane Creek offering a 110 year warranty on their headsets.

Like all materials there are cheap, badly done examples, and well made examples. These days the vast majority of parts fall into the latter category. I'm don't think there's any areas where I wouldn't have carbon for fear of it breaking. There are places it makes no sense, chainrings, stems etc, but that's another thread altogether!

fletch8928

F1 drivers also don't reuse the car after a crash. Its not taken to bits and the shell they sit in put in a new body.
When we bail out/have an off and the bike goes bouncing off over rocks, roots or just down a bank, we pick it up and check for damage. Usually only paying attention to levers, mechs and wheels. Whilst giving the frame a quick glance. Granted there are less forces involved.

Thats why I was asking if its a subconscious thing I/we have. Nothing to really prove our thoughts.

The F1 car is a good example to throw in the mix, the rest of the comments have shown a positive towards carbon too. Some are saying post and bars would be given a wide berth but frames ok.

jayson

njee20 wrote:

Whilst your aluminium bars snapping suddenly will have you laughing and joking!

Thats the whole point, alloy bars will bend WAY before they will ever snap, carbon bars will just go crunch and then u hit the ground hard.

Dick Scruttock

I watched a video of someone smacking a carbon frame, the frame was fine and the hammer bounced off it, he did the same on a alloy frame and it soon god dented and became distorted.

I would have no hesitation in riding a carbon mtb, if done properly then you will have no problems at all with it.

njee20

Thats the whole point, alloy bars will bend WAY before they will ever snap, carbon bars will just go crunch and then u hit the ground hard.

That's a massive generalisation. Carbon bars may visibly crack, and alu bars may suddenly snap, it just isn't that clear cut.

milfredo

Frodo1095 wrote:

I am looking at a new bike atm, and trying to mull over between the Santa Cruz Nickel, Blur Lt and Blur LTc.

Every forum/article I read says the LTc is stiffer, lighter more nimble, tracks better and is bomb proof on drops, and a leap forward from the Blut LT, so as a long term investment it would be a good buy as it will always be a good frame to ride and I could happily upgrade onto.

But then you see pictures of frames with rock strike damage around the lower pivots after just a few weeks, the frame isnt cracked but, looks like small chips.
They says the frame isnt weakened in anyway but would the alu version have faired better, maybe or maybe not, but you dont see pictures of this damage on alu frames, is that because when we see it on an alu frame, we just assume the frame is ok but fear a carbon and generally more expensive one wont be ?

There is also the replacement cost in the back of my mind should it break (outside warranty period), could I afford to replace it ?

I have an LTC and it by far the stiffest bike I have ever ridden, it's leaps and bounds over my old Colier Primo and that was setup fairly hefty(ish). The chips on the lower links are from chain slap on the paint and lacquer not the carbon itself. You would get exactly the same on any painted bike unless it's anodized to a lesser degree.
I also use Easton Monkey Light bars that I have had for a fair few years now and also have a few nicks and scuffs as all MTB kit gets. These have done two years in the alps downhilling, drops jumps and crashes galore and I've never been worried about them breaking. Carbon is tough as nuts if made properly but as with any componets, there are always failures you just need to hope that it's not YOUR bars ;-)

MrChuck

njee20 wrote:

Thats the whole point, alloy bars will bend WAY before they will ever snap, carbon bars will just go crunch and then u hit the ground hard.

That's a massive generalisation. Carbon bars may visibly crack, and alu bars may suddenly snap, it just isn't that clear cut.

+1

A few years ago a housemate knocked over my bike. When I picked it up the bars had snapped clean off at the stem on one side, and they hadn't given me any reason to doubt them up to that point.

It was all cheapy stuff but still.

stumpyjon

I think there's little voice in all of us that looks for the negative in anything that we don't want, can't afford, don't understand. I think it's just human nature. Point is these products need to be fit for purpose or they wouldn't sell. They do sell (I've got a carbon road bike and carbon bars on one of my MTBs as well as carbon seatstays). It's all in the mind.

jmillen

I will admit to being extremely paranoid before and for a while after buying my carbon framed bike.

I was being extremely careful over the easiest of terrain, but after a few months and realising that they wouldn't have built a 140mm trail bike which couldn't take some abuse, I've pretty much forgotten its a carbon frame whilst riding.

As of yet (touch wood) I've never had any issues or reasons to ride differently although once I stop riding, I do tend to be a bit more careful when leaning it up against things etc (amusing really given some of the stuff I ride over).

MacAndCheese

Psychologists would probably say it comes from early memories - when you were a little kid plastic toys from Fisher Price ect. snapped...Metal Toys like matchbox cars didn't, therefore we think all plastic is going to snap!

Strangely, like a lot of people on this thread, I would use a carbon frame but never use carbon bars!

Anonymous

fletch8928 wrote:

F1 drivers also don't reuse the car after a crash. Its not taken to bits and the shell they sit in put in a new body.

They wouldn't re-use an aluminium car either though, if they even survived the crash.

fletch8928

Cheers for the input guys.

I am not buying but its good to hear from carbon owners.

I guess they wouldn't throw a frame out there if its not fit for purpose. Every material can fail or last a long time.

jmiilen. Its not just you that leans the bike carefully and wonders why when you have been bouncing it all over the shop. Except when in a rage and i let it drop to the ground and then kick the imaginary object.

jairaj

fletch8928 wrote:

F1 drivers also don't reuse the car after a crash. Its not taken to bits and the shell they sit in put in a new body.

Errmm yeah they do. Due to cost reduction initiative many manufacturers don't have spare chassis and have to repair the old one. for example Mark Weber had to re-use and old repiared chassis that Vetle had discarded after he went for a flying lesson in the Velancia GP and totally trashed his chassis.

fletch8928

You do learn stuff everyday. I had no idea that if a F1 car gets trashed like that they rebuild it. Sort of like a cut 'n' shut job?

Anonymous

jairaj wrote:

fletch8928 wrote:

F1 drivers also don't reuse the car after a crash. Its not taken to bits and the shell they sit in put in a new body.

Errmm yeah they do. Due to cost reduction initiative many manufacturers don't have spare chassis and have to repair the old one. for example Mark Weber had to re-use and old repiared chassis that Vetle had discarded after he went for a flying lesson in the Velancia GP and totally trashed his chassis.

:shock:
seriously?

MrChuck

yeehaamcgee wrote:

jairaj wrote:

fletch8928 wrote:

F1 drivers also don't reuse the car after a crash. Its not taken to bits and the shell they sit in put in a new body.

Errmm yeah they do. Due to cost reduction initiative many manufacturers don't have spare chassis and have to repair the old one. for example Mark Weber had to re-use and old repiared chassis that Vetle had discarded after he went for a flying lesson in the Velancia GP and totally trashed his chassis.

:shock:
seriously?

I don't think Vettel's chassis had been though anything as dramatic as that though had it? I expect Webber's chassis from Valencia will have gone straight in the bin.

vengeance111

what do people think about the raleigh m-trax
thats got a alloy frame but with a carbon seat stay ?
id always be worrying about the bond and thinking it would snap

jayson

MrChuck wrote:

yeehaamcgee wrote:

jairaj wrote:

fletch8928 wrote:

F1 drivers also don't reuse the car after a crash. Its not taken to bits and the shell they sit in put in a new body.

Errmm yeah they do. Due to cost reduction initiative many manufacturers don't have spare chassis and have to repair the old one. for example Mark Weber had to re-use and old repiared chassis that Vetle had discarded after he went for a flying lesson in the Velancia GP and totally trashed his chassis.

:shock:
seriously?

I don't think Vettel's chassis had been though anything as dramatic as that though had it? I expect Webber's chassis from Valencia will have gone straight in the bin.

There was nothin wrong with the chassis Vettel just said he dint like the feel of it so dint use it.

Anonymous

vengeance111 wrote:

what do people think about the raleigh m-trax
thats got a alloy frame but with a carbon seat stay ?
id always be worrying about the bond and thinking it would snap

No comment on the M-trax, but bonding is fine. In fact, the Lotus elise is held together by a bonding agent, and is one of the best handling car chassis available.

The Rookie

An F1 car consists of a centre tub which takes the driver and fuel tank, then all the panels you can see (and the underfloor you can't) are attached to that, the front suspension and the engine (which in turn takes the gearbox and rear suspension) all the cooling etc is all outside the tub, in front impacts, even at 150mph all the energy is absorbed by the nosecone leaving the tub intact for use again. It takes a pretty huge 'regular' accident to damage the tub, damag is more usually done by someting 'spearing' it.

Simon