Carbon

RealMan

Is it really suitable for mountain biking?

There's no doubt its great for road, but then road bikes don't take many knocks. Nor do they have to deal with stones and such flying up and hitting the frame.

Its not just falling off and crashing and stones flying up and striking parts, but also things like over tightening bolts - how many people really have and use a torque wrench for their carbon bits? And just a bit of chain suck or cable rub can destroy a carbon frame.

Is this attitude just old fashioned? What's your opinion? Is it really the material of the future?

johnsav

never had a problem myself

i use a lizard skin to prevent chain damage
Couple of well placed stickers on the frame to prevent cable rub
and some helicopter tape on the main tubing to protect it from stones etc.

I think youl find on most carbon frames, the places such as the dropouts and other structural point are actually ally bonded into the carbon frame. So that reduces the risk from over torquing bolts and that.

and i do use a torque wrench!

supersonic

Carbon frames are advancing, and in many cases are now advanced, just like steel did, then aluminium

It can be manipulated in many ways which gives it a versatilty no other materials can match. Do it right and it has many advantages. Get it wrong, and it goes wrong spectacularly.

Plastics and carbon will be the future, I have no doubt about that.

Alloy too is very susceptible to chain rub.

carbonfiend

I have doubts about its impact resistance compared to metals, I spoke to somebody who works with CF and they echo'd this but they did add that very soon the epoxy resin used in CF is going to be so strong the impact resistance will match and better metals. My main gripe with CF in MTB is if you do prang it the cost of replacement is so high and for most companies is getting higher though On One might be about the change all this and really challenge the big guns with CF frames - hope so as I do love a bit of carbon
Not sure about carbon etc being the future I'm sure i have been reading that Giant are expanding the ali side of frames as they are finding further advances in hydroforming etc and its cheap

RealMan

I dunno, my chameleon suffered from chain suck and has some gouges in it (thank you, middleburn..) but its fine. I think it would've killed a carbon frame though.

ride_whenever

I've ordered my carbon 456....


I think it will be fine, you've just got to be a bit more careful with it tbh.

supersonic

Prices will come down, strength will get even higher.

And potentially cheap to repair too.

RealMan

ride_whenever wrote:

I think it will be fine, you've just got to be a bit more careful with it tbh.

But I must not be the only one who doesn't want to be "careful" with my bike. I want to go around corners a little too fast. I want to go off drops a little higher then I've done before. I want to be able to lean it against something without thinking "if that falls over its going to cost me". I want to crash and just worry about me (its never going to happen, no matter how much of a tank of a bike I have, but still..)

I have heard that the resins are meant to be improving, and if carbon does become as tough as aluminium or steel, then maybe I will one day.

supersonic

In many ways it is tougher than steel or aluminum, when applied correctly for the application. In fact tougher.

RealMan

Ok A level physics, here we go.

Tough is about withstanding dynamic impacts?

Or is that strong? Hard is resistance to dents and scratches right?

supersonic

Have a look at this:

http://www.youtube.com/watch?v=-lsDXEEU ... re=related

When he hits the alu fame, about as hard as he hit the Taurine to start, it is finished. TheTaurine took substantially more before it split.

http://www.youtube.com/watch?v=SDVpRSNtcPQ

Though it can be easier to see this damage in metal.

RealMan

I have to admit, the punishment it took in the vice was very impressive.

But what about in the real world? Do those experiments mean anything?

supersonic

What would you rather hit a rock on? The alu frame was dead lol.

Though the alu could be toughened. But would porobably weigh far more.

It is all about application of the material for the job.

Of course you can crash in different ways. Sharp objects, blunt objects, but I think the vids show that some carbon is certainly resiliant.

lugsey2k5

carbon is most susceptible to impact due to de lamination of the material and as you could see and hear from the tap test in that video it didn't sound to de laminate for a while when hit by a hammer and seemed fine after the vice.
carbon frames and also be repair relatively cheaply compared to the replacement of a alu or steel frame

Anonymous

RealMan wrote:

Is it really suitable for mountain biking?

Yes. Yes it is.

GHill

Early carbon frames/parts were pretty bad. Looking at the number of tough trail/AM bikes available in carbon suggests things are much better now.

Obviously means nothing (number of units, anecdotal etc), but I've heard about a lot more broken alloy Zestys/Metas than I have heard about broken Mojos/carbon Remedys/carbon Enduros/carbon Blur LTs.

Carbon rims are a different matter though. Even the best/strongest rims get flat spots, I'm not paying £2000 to replace my rims!

paulrockliffe

I'm not sure I agree with all of what you've put. I had a Diamond Back WCF bike from 1996 that snapped. Interestingly, it snapped in a way that I didn't even realise it was actually broken for over a year. I've also got a 1998 Trek OCLV 9900 Pro frame that is still going strong, despite my best efforts. So I don't think the early quality issues are necessarily as bad as people make out.

It's difficult to really get an objective understanding of the failure rate because you need to take into account numbers sold, miles ridden etc, I don't think the information exists. There have certainly been more reports of broken aluminium frames in recent years than usual I think, yet you rarely hear of carbon failure, but then what percentage of bike frames sold are carbon?

Anyway, my main point of disagreement is rims; watch the cannondale vice video linked to above. I think that's exactly the sort of property you want form a rim material. Unlike your aluminium rims, they're either going to snap or stay exactly as they were made. They won't bend or go out of true I don't think. Perhaps making them perfectly is the issue?

GHill

paulrockliffe wrote:

Anyway, my main point of disagreement is rims; watch the cannondale vice video linked to above. I think that's exactly the sort of property you want form a rim material. Unlike your aluminium rims, they're either going to snap or stay exactly as they were made. They won't bend or go out of true I don't think. Perhaps making them perfectly is the issue?

Good points. But they are very expensive for someone to take a chance on.

That said, if the companies weren't confident in them, they'd probably not bring them to market.

paulrockliffe

Look:

http://www.bicycling.com/article/0,6610 ... -1,00.html

Someone else agrees!

GHill

Person trying to sell something says that it is good.

In other news, man takes dog for a walk.

toasty

Everyone is fairly paranoid about carbon frames, so the warranties generally seem to be very good. No company wants pictures of their carbon frame flashed around the internet, so they'll get it back asap and replaced. To be honest though, you don't seem to have as many failing anyway though, this isn't the 80's, there's tons of the things about, but how many do you see which have caved in after being hit by rocks?

Now, how many failed aluminium frames, from manufacturing faults have we seen recently? :P

Big trail bikes feel rock solid anyway, ever ridden a Mojo/Genius/Blur LTc? Far more solid feeling than a coke can thin butted aluminium frame. Never mind the cash saving cheap welding/hairline cracks issues.

Northwind

If it's made right, and appropriately for the job, then yeah- carbon's ace. You can do amazing things with it, put strength precisely where you want it... The big thing that most people miss is that even with scratches and knocks in it, the actual structure often isn't damaged at all, scraping the clear on carbon parts is exactly the same as scraping paint off a metal part but it freaks people out so much. With many (most? Probably not quite all), even the top layer of fibres aren't structural- often they're cosmetic, other times they're protective.

Chainsuck seems to be a major worry but it should be perfectly possible to build a carbon frame that's more durable in that respect than a steel or alloy equivalent, certainly there tends to be more material in a carbon frame because of the lower density. If you've ever armoured a frame against chainsuck with cable ties, you'll know it's not just about pure impact resistance. The question is always, is this frame made well, have they planned for these things.

Mark_K

I've had a carbon trek EX9.0 since jan 08 I've done loads of miles on it at welsh trail centers come a cropper on it more than once in rock gardens and on drops slammed into trees and just about every obstacle the trails can throw at me and the bike !!!! I've raced it done enduros on it commuted on it and ridden it back and forth to the pub (and yer its had some knocks doing the homeward journey ) In 20 years of on and off riding and having snapped aluminum frames in the past it is by FAR the best bike/frame i have owned. Yes its got a few scratches and a chip or 2 but i in no way have treated it more carefully "because its carbon" i just check over when i service and clean it for damage as i would any other bike frame ! For sure my next bike will be carbon tbh i wouldn't even look at buying a new trail bike/frame now unless it was carbon I'm that pleased with the plastic trek

t121anf

carbons used in formula one cars for suspension etc so it's got to be strong.

i'd have no problem owning a CF bike, but my bank manager might

El Capitano

I'm still very wary of Carbon Fibre. One of my riding buddies nearly had is calf muslce removed by a shattering Spinnergy wheel. That said, that was a fair number of years ago. I have carbon forks on my TT bike and CX bike. Both have, in their own ways, been given a fair bit of abuse of the past 12 months, without any issues.

However, I'm not about to get a carbon MTB frame. Although I know they've improved over the years and the strength is improving, I'd just have than niggling feeling in the back of my head that I really should be taking it carefully. In fact, the only carbon fibre on my NRS is the 10mm headset spacer...

Perhaps in a few years time, I'll consider getting an MTB arbon fibre frame/forks, when I'd be confident of their strength.

bomberesque

It's not a dissimilar argument to the "aluminium work hardens so frames only last 3 years" evidenced as nonsense by all the 20 year old frames still pounding the trails

I must admit to a bit of psychological horror when riding my carbon frame on rocky stuff, but that's mostly cost of replacement tbh and, as said, that's coming down. I've killed alu frames dropping them on rocks just the wrong way before but a quality alu frame is generally cheaper than the equivalent CF one today so I worry less about it.

the highly directional nature of carbon strength gives it a flexibility of application previously unseen in bikes, there are so many possibilities and some of them won't work ... but the ones that do

I just spotted the Ellsworth Enlightenment btw .... if I didn't already have the IBIS Tranny, I think I'd me making an expensive phone call about now

carbonfiend

i know i sound like I'm contradicting myself but I only ever rode carbon and ove it then i got a scandium frame and apart from the weight not sure the difference is worth the disparity in price.

supersonic

Aluminium frames can still be built very light, and scandium ones have come down in price a lot.

But so is carbon now, and may offer better vibration absorption characteristics.

RealMan

lugsey2k5 wrote:

carbon frames and also be repair relatively cheaply compared to the replacement of a alu or steel frame

What?

Can you repair cracks in carbon?

bomberesque

RealMan wrote:

lugsey2k5 wrote:

carbon frames and also be repair relatively cheaply compared to the replacement of a alu or steel frame

What?

Can you repair cracks in carbon?

yes, basically involves laying new weave over the damaged area to transfer load across the crack afaik. perhaps not as tidy as grind out and reweld that you can (dep on PWHT) do with alu and steel though. not sure how many folks offer such a service for high modulus etc hi-tech carbon frames yet though but glass fibre repairers (roughly the same thing) have been fixing canoes and boats etc for decades

RealMan

And how extensive does the damage have to be before it is unfixable?

For instance, I have a carbon frame in my garage that is cracked all the way around the seat tube, and has big damage on the head tube from cable rub.