Carbon fibre

[Cooper]

Good day Fellow Hubbers

 

Can any one advise me on the life span of Carbon Fibre , if it is the frame, shock , cranck etc

A bike shop advised me that Carbon Fibre has a life span of 5 years, ie if I buy a Carbin Fibre frame it will last only 5years or a World cup Sid shock will only last 5 years???

 

any comments / feedback please...

[kosmonooit]

I don't think thats true at all. Carbon does not fatigue like metal and things like aircraft have lots of carbon bits (like tail planes). Yes and my Scalpel chainstays (which are designed to flex) have lasted more than 5 years.

 

But thats just coming from my peripheral knowledge, perhaps we have a metallurgist in da house?

 

Probably just a sales pitch, thing is with sales guys they have the knack of talking like they know whats cutting, generally not the case, they just versed with the lingo and jargon, and know how to bull$hit with a str8 face

[Bike Mob]

5 year itch is a load of crap

[vanniri]

Load of crap!

 

On the other hand your preferences will last only 5 years and clever marketing will remind you EVERY year what you miss!

[Wayne Potgieter]

I think they consider 5 years to be "the products lifespan" This might affect the "Lifetime" warranty on a frame etc.

 

I know there are more hubbers out there that are more knowledgeable on this subject.

[gummibear]

Under average use it should last 5 years,the same as aluminium but it will last longer if looked after.Although i am not so sure that some of these 800 gram frames will last very long.

[nuge]

doesn't sound like a very smart bike shop assistant! considering carbon bits sell at a serious premium, i woulda thunk they'd be pushing the stuff in lieu of whatever else is lying around their shop.

 

or maybe they're just hippies trying to keep your carbon footprint on the DL! were they pushing you towards bamboo perhaps?

[Starvin' Marvin]

Under average use it should last 5 years,the same as aluminium but it will last longer if looked after.Although i am not so sure that some of these 800 gram frames will last very long.

 

Had read on the web about 85kg guys cracking their addict frames. So a 96kg guy like me has to steer away from those frames.

[Reg Lizard]

Had read on the web about 85kg guys cracking their addict frames. So a 96kg guy like me has to steer away from those frames.

I've been riding a carbon Spez frame for the past 3 and a half years and weigh 94kg's when I'm good and about 100kg's when I am bad - no problems. Doubt it if its true, but I don't think anyone keeps their bikes for 5 years anymore, I am already itching for a new one

[Eldron]

Lifespan in bicycles is like asking how long a piece of string is.

 

Humans are pretty puny creatures and stress alu and carbon below their elastic deformation points meaning the lifespan in infinite.

 

However...

 

The same puny humans also make the alu and carbon frame meaning that they contain errors. Framce break at these errors. For instance - every broken alu frame I've ever seen has broken at a stress raiser (a weld, a waterbottle insert, internal cable routing slot etc). Carbon is a bit more random because the carbon is layed up by hand.

 

The lifespan is governed by the "errors" in the frame rather than the physical properties of the materials.

 

I would only buy a carbon road or TT bike - my scandium mtb has taken many a knock that would have destroyed carbon. For me it's carbon for road and alu for mtb. Unless of course you have money flowing out of your ears in which case it's carbon for everything!!!

[Starvin' Marvin]

I've been riding a carbon Spez frame for the past 3 and a half years and weigh 94kg's when I'm good and about 100kg's when I am bad - no problems. Doubt it if its true, but I don't think anyone keeps their bikes for 5 years anymore, I am already itching for a new one

 

I'm not saying bigger guys shoukd stay from carbon, just the addict frame. I'm now on my 3rd carbon frame and the only reason I've changed is the itch for sonething new, next frame due 2012

[kennyg]

Carbon should theoretically last forever, as a correctly laid up piece that is not being stressed to a plastic zone (point of lasting deformation) should last forever. Hence, the use in the aircraft industry...

 

The areas designed to flex are a grey area as too how long they last. But the CF lay ups are generally relatively immune to fatigue, but there is always possible manufacturing floors to deal with there too.

 

The problem with carbon components lies in the stress mechanisms, the plastic zone is so small the the item shatters before any real noticable deformation is present.Things like deep scratches will affect the performance of the frame in some areas.

 

Many manufactures are pushing the carbon bikes to the limits, safety factors of 1 to 1.2, look at Scott for the qty broken frames, according to some of the FEA junkies doing proper composite design.This is probably the reason for an expect life of 5 years.

 

That means, get it wrong on an MTB or miss that pothole and your 5 kg bike is goop...

[Balsie]

Don't worry about 5 year rubbish!! Two years maximum and something new and better will catch your eye and you will convince yourself that you are 100% sure you need a new frame/bike/groupset etc etc I am lucky if I last 6 months

[kosmonooit]

And carbon materials technology is a rapidly evolving field, aerospace/defence leading the field, growing nanotubes of fibres etc this all trickles down to the bike industry when the products become commercially available. Cannondale had to sign limited release for 'ballistic' grade carbon material for their latest 'cross frame (well that's what the dood said on utoob)

 

Also check out Layered Metal Sintering if you are interested in 'state of the art' materials technology: they can basically 'print' a metal part now.

[grumpy]

Some famous cyclist, who's name escapes me now, said that weight, price and durability is the three factors in any bycicle purchase.

You can choose any two that is important to you, thus if weight and price is the important to then you must know that durability will go out of the window.

Similarly if you choose weight and durability then don't complain about the price...

 

Carbon is extremely strong, I hit a deep pot hole on my road bike doing in excess of 50km/h, both wheels and the frame was destroyed but the carbon steerer on the fork survived, one would have thought that the steerer would have snapped.

[Edition 507]

It has been scientifically proven that the lifespan of a carbon frame is inversely proportional to the size of your wallet.