Restore my faith in carbon fibre...what would you do?

[rafletcher]

You could try the "not fit for purpose" route I guess.  Carbon, well, I had a conversation yesterday with a guy who races an ex-Italian olympic team carbon bike he's had 12 years. It's heavy by todays standards though....

[Steve Kish]

I did hear from a reputable source that carbon frames have an element of glass fibre in there and I did also hear that this is acceptable in the industry standards.

[vorsprung]

Carbon fibre = glued cloth.
Titanium = hi-tech space age metal.

Metal can crack too

[Rhys W]

I did hear from a reputable source that carbon frames have an element of glass fibre in there and I did also hear that this is acceptable in the industry standards.

Interesting... I heard a mechanic/bikeshop owner/ex-international racer friend dismiss a certain well-known, reasonably priced brand. He was sceptical of them and said "I don't know how much carbon is actually in them". At the time I thought they're either carbon fibre or they're not, what else could they be? Hmmm...

[border-rider]

At the Cycle Show 4 years ago there were "white carbon" frames and components on show. i.e fibreglass - but I think this was just a wrap to get a novel surface finish on standard carbon fibre

The big structural difference won't be the amount of carbon in the weave, but the number of layers of ply used and the way they've been laid up.  With some thinking you should be able to make a very robust frame indeed.  With little thought, the product may be crap.

[greenmeansgo]

So far as a replacement is concerned, their responsibility is to sell you a bike that's fit for purpose. That one clearly isn't.

It clearly wasn't, but I think I'd have a hard time arguing that a new one isn't fit for purpose (unless it broke again).

Having dug out a photo of when it was brand new, it does look like the break is at the bottom of the seat post (but of course now I have no way of checking this given the frame is at Bianchi):


I guess my preferred option would be get the value of a replacement identical frame in cash and then chose a new frame. Maybe a Mercian of some kind. I'll give trading standards a call and see what my rights are.

[mrcharly-YHT]

I'm not sure there would be much difference in strength between well-laid up cf and cf with some fibreglass in it. The build will determine the strength.

Looking at that fracture, I'd suspect pre-preg tubes where the cloth has ended and a new bit started. There doesn't seem to be any of the fibrous splintering I'd expect to see from a tube made of a continuous run of cloth.

[frankly frankie]

I think your just unlucky and have purchased a flawed frame.
things break.

This ^^

As for carbon fibre in general I think the material is extreamly overated. People think 'cos it's carbon it's best'. This is so untrue.

I don't think there are so many people on this forum who think that!!
Thing is, it used to be exotic and the most expensive way of building a frame there was.
Now, it is (or should be) dirt cheap, the easiest way to mass-produce frames.
Neither of those things affects how good or bad the material itself is.  Modern cheap carbon frames are probably much stronger than older exotic ones, but also a bit heavier.

What has happened is, as carbon fibre has come in for criticism, manufacturers have responded by increasing the tube wall thickness, at least on their 'consumer' bikes.  My first carbon frame, a TVT ('as ridden by' Greg Lemond) bought in the late '80s, had tube walls less than 1mm thick.  It survived 7 years heavy audax use plus some loaded touring.  Buy something like a Trek now ('as ridden by' Lance Armstrong), and the tube walls are about 3mm thick.

[greenmeansgo]

Trading standards suggest that a direct replacement on warranty is about all I can expect. Having lost faith in the material and being concerned it might break again doesn't mean a brand new replacement frame is not fit for purpose.

Were it to happen again (let's hope not!) then I could argue it's not fit for purpose. Sale of goods act would cover me outside of a guarantee period for reasonable use. e.g. broken frame after a few years of road riding is not acceptable, whereas you might come to expect things to break after a few years of dirt jumping...

I shall now tell myself that this was a one-off dud and the replacement will be just fine 

[The Mechanic]

I have been drooling over a Spesh Roubaix SL but am now thinking I should go for a top end Ti frame instead.  Either way I will probably get buyers remorse afterwards.

Good luck with the Bianchi.  I am sure it will be a one off and you will enjoy the new frame when you get it.

[mrcharly-YHT]

A straw poll on this forum suggested that Ti is just as susceptible to breaking as CF.

Top end lightweight frame = fragile (regardless of material)

Medium weight top end frame <should> = robust.


Most of the frames in the 2nd category atm will be steel. When CF frames of that type become available I expect CF will be regarded as more reliable and longer-lasting than steel.

[clarion]

A straw poll on this forum suggested that Ti is just as susceptible to breaking as CF.

The straw poll didn't correct for breadth of ownership or age of bike.

Just sayin'

[greenmeansgo]

A straw poll on this forum suggested that Ti is just as susceptible to breaking as CF.

Top end lightweight frame = fragile (regardless of material)

Medium weight top end frame <should> = robust.


Most of the frames in the 2nd category atm will be steel. When CF frames of that type become available I expect CF will be regarded as more reliable and longer-lasting than steel.

Does the 928 fall into either of these categories? I got it as a free upgrade because the 1885 I was going to buy had a dent in one of the tubes, so I hadn't looked into it as I wasn't intending to buy carbon fibre.

I wouldn't think it's a top end frame, though it is pretty light. The advice I got at the time was that it wouldn't do very well if crashed or knocked about with e.g. D locks (neither of which has happened), but as a "best bike" it'd be fine.

As others have pointed out:
(a) things break
(b) perhaps you had an less than perfect frame
(c) an experience like this will affect your perception of the material

All the best with its replacement.

Thanks to all for the input and reassurance.

[mrcharly-YHT]

I'd count the 928 as lightweight.

I know Clarion didn't like the straw poll because, without correcting for numbers owned and age, steel looked bad.

What astounded me was the numbers of Ti breaks reported. It was a high proportion of the total Ti bikes owned on the forum. Certainly much higher that for steel, even without correcting for age of some of the steel bikes.

That's probably due to the level of quality control on medium to high-end steel bikes. Reynolds set the benchmark - you have to build to our standards or you don't use our high-end tubes.

I don't believe there is any such program in place for Ti or CF.

[clarion]

I would agree that the figures for Ti were surprising.  And, even here, I think that the number of CF frames owned is higher than Ti, and the ages will broadly correspond, so similar numbers fo the two materials raises questions about Ti frame design/building.

My dad, as a former head of materials and laboratories for RR, has a lot of experience of what you can & can't do with Ti, and he thinks that drawing bicycle tubes and welding them into a bike frame lighter and stiffer than steel but with the same strength is not a difficult proposition, so long as your methods are precise and your QC is high.

Not sure what the issues are.

[Tim]

I've just been told¹ we've cracked a chainstay So add another one to the steel frame failures.

I think that counts as my first killing² of a frame.

¹By Mercian where it is for repainting and such and now also to have a chainstay replaced.

²OK, not killing, as it will rise again.

[Zoidburg]

I don't think Ti shines when used as butt welded tubes.

I think early lugged/bonded Ti frames may have been that way for a good reason and not a cost related one either.

Ti has struck me as something that seems to shine when used in machined and extruded lumps that are mechanicaly bonded or glued - welding does not seem to be something it likes.

It may be a wonder material of aviation grade but modern jet planes are not built like spitfires as a rule.

[Hot Flatus]

Welded ti is fine.  It is just much more of a fussy process than steel or aluminium and needs to be welded in a controlled atmosphere.

I've got 2 ti, 3 cf, 3ally and 1 steel in my shed. The only ones I expect to fail are the ally and possibly one of the ti because it is of dubious origin.

My advice is take the replacement Bianchi and enjoy it. If in the unlikely event of another breakage get that one replaced too

[border-rider]

Welded ti is fine.  It is just much more of a fussy process than steel or aluminium and needs to be welded in a controlled atmosphere.

That's the point.  Ti should be a high-end frame material; when you get Far-Eastern factories turning out frames at £200 or so then it's not going to be.  The problem was that many of these were rebadged, marked up in price and sold on as high-end.

[Hot Flatus]

Hence why I wouldn't be surprised if my cheapie ti fails.

If you paid £800 for a Setavento, you could have had the same frame for £330.

[border-rider]

Hence why I wouldn't be surprised if my cheapie ti fails.

Indeed.  I'm half-expecting my Airborne to crack; I'm not expecting the MC to.

[hatler]

Back on the legal replacement point, surely if this product has failed like this then the customer is entitled to a refund from the retailer ?  Yes ?

[clarion]

Zoiders is right, though, it's true.  While welding Ti is not an issue for RR or BAe, it does become more problematic in a far east bike factory building cheap frames.

Most of the time, it will be OK, but it doesn't take much to move from OK to not OK.

I agree that lugged & bonded Ti frames would be better from a construction/use viewpoint, but welding means you aren't limited by the lugs you have available.

[Hot Flatus]

Oh come on, there are thousands and thousands of reliable welded Ti frames out there. It's a perfectly appropriate material, and Litespeed have been churning them out for years without recourse to welding them in a lab by White-suited scientists

If you buy anything that has been knocked up in a back alley workshop in China with no quality control you can not expect reliability

Let's not get all hysterical about it.

[mrcharly-YHT]

Nobody is getting hysterical.

We are just noting that there have been a high proportion of failures of cheap Ti frames.