Carbon?

[Rollon]

I see Carbon framed mountain bikes in the cycle shops and have tried one, obviously extremely light.
However I am unsure about their robustness as an off road bike frame material.
Following my roundabout collision with a car that failed to stop, the bike shop replaced the carbon forks (rest of frame being Alluminium). They explained that the manufacturers recommended this because the forks would have suffered shock. The car hit my rear wheel area, so there was no direct hit on the front, but the bike was flipped over, also there was no sign of any abrasion to the forks.
With there being more likelyhood of numerous shocks to a mountain bike and generaly dropping the thing when coming off etc, I hesitate to consider a full carbon.
Dave.

 

[mr Mag00]

i have had one for 3 years yet to drop it admittedly, but have given a good seeing to on some rough tracks. i dont see how it is more likely to fail than welds, but i am not qualified to back up that statement really, just my thoughts to match your thoughts

 

[lukesdad]

Had one for 10 years raced it fallen off it, no probs!

 

[Globalti]

I rode a carbon Spesh MTB around a car park and it felt like a magic carpet. A bit like my carbon Spesh road bike really. I wouldn't hesitate to get one.

 

[Rollon]

Thanks for replies.
One reason I asked was that a keen road cyclists, told me of what happened to his pals bike.
They were on a long road outing on their respective full carbon bikes, when his pals chain came off and jammed between the cassette and spokes. (he had removed the plastic disc). They managed to lever it our but several links were damaged, so they removed them. This left the chain rather short. They replaced it back onto the middle chain ring and middle gear, although it was tight.
He told his pal to leave it there and not to change onto the big chain wheel. He didnt take advice and proceeded to do so.
When they got home and stopped with the chain still on the large chain wheel, they could visibly seen that the chain stay was slightly bowed under the tension. When he removed the rear wheel, the chain stay was floppy and like paper where the carbon had broken down.
Dave.

 

[maurice]

I think it's fairly mature as a material now, I wouldn't hesitate in getting a carbon framed-bike - if you can afford it!

 

[mudplugger]

I think its just where the stress comes in a crash..my lad crashed several times in one race with no damage, yet one crash in another and a seat stay cracked.
Also, just because its carbon doesnt make it better than other materials..the quality of carbon frames varies.

 

[jamesxyz]

I too own a carbon (road) bike and am a little nervous about damaging it.

If you think about an F1 car - the carbon is immensely strong for its purpose (you can stand on the wings without them breaking) but very fragile in other ways

It is very susceptible to crushing forces (i.e. in a car rack or work stand) but then I've ridden the hell out of my aluminium bike with carbon forks and they're OK.

I'm happy with a road bike but i must say every time a had a knock on a MB i'd be worried about the frame failing later ...

I know that doesn't really help - talk to a dealer or even ring the manufacturer

 

[mudplugger]

If you are likely to do any dogging on it, carbon probably isnt strong enough Dave
http://tiny.cc/wn5uz

 

[jamesxyz]

If you are likely to do any dogging on it, carbon probably isnt strong enough Dave
http://tiny.cc/wn5uz

What differecne does the frame make if you want to go dogging? In fact do you need a bike at all for that you dirty old man to quote Steptoe

 

[mudplugger]

did you open the link James?

 

[Rollon]

If you are likely to do any dogging on it, carbon probably isnt strong enough Dave
http://tiny.cc/wn5uz

That front wheel seemed to collapse easily!?
Dave.

 

[mr Mag00]

the wheels are not built to take that level of stress through that angle.

 

[lukesdad]

just like other materials there are different grades of carbon fibre just dont buy a cheap one and remember tubing isnt as strong as box section.

 

[andyhunter]

i have a full carbon mtb bike a trek 9.8 with easton carbon bars, steam, seatpost, rock shock sid world cup forks, and it is extremly light and strong. any 1 that says carbon fiber aint strong needs to sit down and study, carbon fiber depending on the type used as the cheap stuff sh*t and the dear stuff class and way it is made threw the woving pattern techniques such as horizontal and vertical and diagonal in all different ways at the same time etc is far stronger than metal have never had a problem with anything carbon, not even bent a carbon hanger bracket but i have bent a magnesium hanger braket though and i treated my bike like it was a dh bike in certain technical areas of mtb racing. i have came off my bike few times threw mistakes, only thing i have broken on the bike is my saddle thus going over the handle bars which was a very light stelle italia saddle well the rails were in tack jus the seat came off but i still won the race many moons ago.