Are carbon fibre mountain bikes as durable as aluminium ones

Enwezor

I only know 2 people who have carbon fibre mountain bikes and they both have cracked their frames.
Now this could be just very unlucky or a dodgy batch but I'm very interested to understand if people with carbon fibre mountain bikes have had any frame-related problems with their bikes as I am about to buy a light full-suss and am in the budget range where I could get a carbon-fibre bike.
I'm just not convinced about their durability. Any views?

Cheers

jayson

Carbon fibre is on eof those materials that i really cant make up my mind about. On the one hand we have aircraft and F1 cars built from the stuff and they're supremely strong and light and should be enough to convince anyone of the benefits of the material, but on the other hand ive heard more than a few stories online of handlebars, seatposts, frames etc etc snapping which really does terrify me at the thought of it.

It may be strong and the incidents we hear about may just be an isolated few but for me it has to break the psychological barrier and that is far more difficult, atleast for me.

stevieboy

If an aluminium frame snaps the rider is generally classed as being awesome, hardcore etc

If a carbon frame snaps the whole world jumps up, arms aloft blaming the material

Bit's fail, bikes brake, joints crack, but when it's carbon everyone seems to remember.

Never had a problem with my scale (the frame was replaced, but that was down to a CNC'd part being out of tolerance), I happily throw it down loads of stuff that I 'shouldn't'

toasty

What were the bikes that broke just out of interest?

I think with carbon I'm much more trusting of big monocoque frames than those which are half alloy/half carbon. You end up with awkward joints, welds and bits glued in.

Part of the bonus of carbon for me is also being able to make a hardtail which flexes and absorbs some of the impacts. This doesn't really appeal quite so much with full sus obviously, you'll just be getting unwanted lateral movement.

Saying that, Yeti, Ibis, Santa Cruz, Spesh etc have done some awesome carbon bikes I'd happily throw off high things

Northwind

It's all about construction, you can make a bad carbon part or a weak carbon part just like you can aluminium... Especially since some are intentionally built so light. Also, of course, carbon when it does break, does so dramatically, chances are you'd destroy an alumiinium equivalent with the same impacts but it'd not be so impressive.

mookiebaylock

I have a carbon Scott spark and I love it... They have been making bikes out of the stuff for years so I don't have any concerns about build quality. Once you've crashed it and realised that it can take punishment it's not an issue. I'm happy throwing it down, over or through anything my nerve would allow me to on any bike.
Also doesn't show any scratches as much as a painted frame!

Stephen-Hawking

My Carbon Cannondale has had a years worth of hammer and been bounced around a fair bit with no issues at all. Love it, it's the muts nuts.

ESHER SHORE

I don't trust it myself....in a rough and tumble environment like mountain biking which has numerous crashes, rock strikes, scratches and whatnot...

the problem with carbon is that is extremely labour intensive, which means expensive unless doing in an offshore factory with cheap labour, which means issues of quality control relating to construction start to arise - this is becoming problematic as there is currently a real trend for carbon frames, seatpost, bars, etc.

if carbon is not right, it will quickly fail, and can fail horribly

you can also deep damage to the matrix in a crash, which may not be evident, leading to premature failure

comparing F1 and Aerospace to Mountain Bike parts is not useful, because F1 and aerospace components are built to extremely high tolerances in expensive labour intensive specialist facilities, often in the UK, Germany or the States


most of the manufacturers, even the big ones, use the cheapest contractors in China to do their CF bike frames and parts :shock:

I have seen several big names carbon frames catastrophically fail, including a 3 week old Scott Ransom in Whistler (guy staying in our chalet), have also seen several Easton CNT bars fail - one belonging to a young, 8 stone rider

aluminium alloy is much easier to manufacture with good quality control, it has proven manufacturing technology and damage is easily visible

it has good strength to weight ratio and durability over several seasons, is cheaper to buy which means more budget for parts to attach to the frame, and if you do damage your frame in a crash, its cheaper to replace

Uncle Peter

Stephen-Hawking wrote:

My Carbon Cannondale has had a years worth of hammer and been bounced around a fair bit with no issues at all. Love it, it's the muts nuts.

Does yours have the lifetime guarantee? I know some of the more recent Cannondale models have lifetime guarantees and unlimited rider weight specifications.

IMO go for a good Titanium frame, like this one...

http://www.bikeradar.com/gear/category/frames/mountain/product/lynskey-ti-456-08--31339

Or a Merlin, like mine.

supersonic

I have seen alu, ti and steel frames crack within a few rides. I have seen CF frames last tens of thousands of miles.

I have no problems trusting a modern CF frame, they are built to much better standards than say 10 years ago.

gcwebbyuk

What is the best exotic money no object frame material out there as a balance of strength / weight / comfort?

Carbon / Titanium / Magnesium(?)

I always thought that titanium would be more than carbon, but that On-One looks pretty damn good!

supersonic

Has to be CF. Titanium just to heavy to get to the really light weights, but possible more durable. Comfort is a matter of design really - but CF seems to have good high frequency absorption qualities.

barney9304

My SJ carbon seems to be very durable as it gets dropped all the time as I am such a shite rider :oops:
I had to get over the confidence problem when I first got the CF frame but after that I don't think about it much now its just a bike to have fun on.

gcwebbyuk

With regards to weight - if one Manufacturer - say Specialized - made the Stumpjumper in Aluminium, Carbon and Titanium (which they don't ) what sort of weight differences would there be?

supersonic

Again, depends how constructed! If you left all the frame tubing sizes exactly the same, the CF would be lightest, then the alu, then the titanium.

But they wouldn't do that, the material is taken into account ie stiffness.

gcwebbyuk

Ah i see what you mean now.

Do you know what the weight difference between my A5 alu stumpy and the carbon one would be?

Didn't feel much when i picked them up in the shop - a slight difference but not much.

I imagine the carbon would ride much better though.

supersonic

I dunno to be honest, not much! Ride would be different, better or not is what feeks best to you ;-)