Pros and cons of a carbon Frame

[Sapper]

Hi all,

I currently have a Trek 1400 2003 model and it has served me well for commuting and a 350 charity ride to Paris.

I guess I have a case of upgradealitus, though to be honest at the moment I am not commuting enough (20 miles round trip) to justify the cost. I am however trying to get into relaxation riding as well as the commute.

However my LBS will sell me a carbon frame on the Cycle to work scheme, though I might have to top it up.

Question though is what are the real advantages of a carbon frame over a standard alloy frame.

Additionally would I be better of buying an of the shelf carbon bike or having one custom built. I am not sure if they will do a bike in the cycle to work scheme but I am very close to Shorter Rochford in Finchley.

So comments, thoughts and suggestions please. Additionally worthwhile links on carbon frames would be appreciated.

Yours Aye


Adrian

 

[Globalti]

Alloy is stiff and can be uncomfortable especially in smaller sized frames.

Carbon is more flexible and can be built to give a smooth ride.

Alloy is more robust. Carbon can be damaged in an accident or a fall against a hard object.

You won't be able to get a bespoke carbon frame.

I dislike riding alloy and love riding carbon.

 

[HLaB]

A carbon frame is lighter and more absorbing of vibrations but there always the question mark over their survivability in terms of a crash (instant right off). There have been other questions about longevity but I think they've been around long enough to answer that. I ride a carbon bike, a alu bike and a scandium bike; for a long ride I'd much rather ride the carbon bike its lighter, easier and more comfortable but for everyday riding I prefer to use the other frames, I'm maybe being paranoid, mainly because of these doubts but also because I like to keep the carbon bike in pristine condition.

 

[Sapper]

Thanks..

so the shop keeper wasn't exaggerating about the smoother, less vibration ride...

When I meant bespoke, buying a carbon frame and having a choice of fittings, not that I would know what components to choose!

I would keep the Trek for real fowl weather or winter usage and keep the carbon for the warmer months...

Adrian

Alloy is stiff and can be uncomfortable especially in smaller sized frames.

Carbon is more flexible and can be built to give a smooth ride.

Alloy is more robust. Carbon can be damaged in an accident or a fall against a hard object.

You won't be able to get a bespoke carbon frame.

I dislike riding alloy and love riding carbon.

 

[PpPete]

Have you considered titanium?

Brings nearly all of the benefits of CF with, supposedly, better longevity (although cracked Ti frames are not unknown).

Someone in the trade who's opinion I respect (decades of experience both as a rider and in the business - and sometime contributor on here) told me that in his eyes, at anything around or below £2K price point (£1K frame and £1K componentry) titanium was better value. To be fair he has an interest - he sells Ti bikes, but he is so passionate about cycling in general that I'm sure it wasn't just sales puff.... and he owns two of them himself, one is his "commuter / tourer", the other his "sunday best"

 

[Globalti]

I ride a titanium mountain bike and from some of the massive clangs I've heard when rocks have hit the down tube, I'm pretty sure carbon is not a good choice for a mountain bike. When you're blasting down a bridleway at 25 mph and a big rock with sharp corners flies up you need a strong frame. Carbon is phenomenally strong when stressed in the right way but fragile the wrong way.

 

[dellzeqq]

there are good carbon frames and poor carbon frames. Good carbon frames are stiffer than any other type of frame, but don't resonate on the road, saving your body the trouble of dampening. Good carbon frames can be crashed time and time again and be unscathed.

So - when your LBS tells you that you can have a carbon frame the real question is 'which one?'

 

[snailracer]

I ride a titanium mountain bike and from some of the massive clangs I've heard when rocks have hit the down tube, I'm pretty sure carbon is not a good choice for a mountain bike. When you're blasting down a bridleway at 25 mph and a big rock with sharp corners flies up you need a strong frame. Carbon is phenomenally strong when stressed in the right way but fragile the wrong way.

Apparently, you can get mountain bikes where the carbon frame is "armoured" with a tougher material at the down tube and other susceptible areas. Which proves your point that carbon may be stiff and strong, but it's not "tough" in the way that metal is.

 

[Fast_Mark]

Why not an 853 steel frame. As light as ti, stiff (albeit not as stiff as carbon), cuts out the vibration but much tougher than aluminium or carbon.

Not ridden one myself, just throwing it in to confuse matters further

 

[Globalti]

Er, no, very thin-walled steel tubing is as susceptible to damage as anything else.

 

[ColinJ]

I have an old CAAD 5 aluminium Saeco Cannondale bike and it is a joy to ride. It isn't a modern design - I think Mario Cipollini was winning races on it about 10 or 11 years ago.

I'd be quite interested in riding a carbon fibre bike to compare with that. I'm sure that the CF would be better, but just how much better? There isn't going to be a huge weight saving or increase in stiffness. Some, yes, but enough for me to bother about? As for comfort - yes, I would like more of that, but 50% of the problem is taken care of by using lower tyre pressures.

As for carbon fibre mountain bikes ... ask bromptonfb! He spent time in hospital having his facial injuries tended to after the front of his CF MTB suddenly parted company with the rear! I'd be very wary of CF in that application because of the potential damage caused by rocks getting thrown up at the bike on fast, rocky descents. I can hear them bouncing off my 853 MTB frame but I'm happy that that isn't about to suddenly crack and shatter.

 

[Alun]

I like CF for a roadbike, but wouldn't have it on a MTB.
I'd like to try steel again, where is my old Clockwork now?

 

[Globalti]

When I first got my carbon Specialized Roubaix it had Roubaix tyres, which are quite deep for a comfortable ride. The rear stays are bendy and you can actually feel the bounce in them if you ride over a stony surface. Some time after I got the bike I discovered that the tyres had been contacting the underneath of the upper bridge and eroding the paint - this can only have been happening on fast bumps and momentarily as the frame flexed to absorb the hit because I never heard anything.

I also have a carbon seatpost on my hardtail mountain bike and on lumpy ground I can sometimes feel it flexing like crazy.

 

[Sapper]

So - when your LBS tells you that you can have a carbon frame the real question is 'which one?'

Exactly...

As I understand, there are only a few carbon bike manufacturers. Essentially these frames are then sold on to either othe rmanfactureres or to bike shops for them to add the fittings and make into a bike.

So if I were to go carbon frame, are there any manuracturers I should avoid. or any basic models?

I am wanting a road bike for commuting and the odd longer charity style fun ride.

Adrian