Carbon Frames Are they really needed.

[dellzeqq]

It should be noted that not all steel bikes are 'Brommies' and that 'Brommies' are folding bikes intended for the commuter!

Comparing a carbon road bike with a Brompton is disingenuous and unhelpful.

I wasn't. I was suggesting that the only steel bike I'd ride is a Brompton.

I rode steel bikes for decades (to John O'Groats, on day rides up to 200 miles, and through the Pyrenees), and I have an aluminium hybrid (in the garden) which is a cheap way of getting round town. And my view is that time has moved on and steel frames are for shopping - not for rides of a decent length. Hence the Brompton.

And magnesium frames are wonderful collectors items. You can have mine for £300

 

[Fletch456]

I wasn't. I was suggesting that the only steel bike I'd ride is a Brompton.

I rode steel bikes for decades (to John O'Groats, on day rides up to 200 miles, and through the Pyrenees), and I have an aluminium hybrid (in the garden) which is a cheap way of getting round town. And my view is that time has moved on and steel frames are for shopping - not for rides of a decent length. Hence the Brompton.

And magnesium frames are wonderful collectors items. You can have mine for £300

Out of interest / curiosity what are the pros / cons of magnesium frames? Not one I can recall being written about for some time in magazines. I studied materials a little bit at university though that's quite a while ago now and remember it being light but nothing else right now.

 

[Rob3rt]

Huh? So carbon frames aren't usually lighter than steel or alu? My frame weighs 920g - can you point me to steel or alu frames that weighs less? Carbon bars, stems and seatposts, etc. generally are as light as top end alu.

What model is your carbon bike? What size? Frame and fork or just frame? Without having some idea of the price point of your bike, any point you are trying to make is pointless.

Maybe you are missing some of the finer points in the comparison between alu and carbon.

Equivalent carbon frames and components arent neccesarily lighter, a lot of carbon components are lighter, but these usually cost a considerable amount more because they are a step above what is achievable with alu, their design has been pushed beyond what alu could achieve safely. If you compare equivalently priced items its a much better way to go about such comparisons, say for £100 how much difference is there between a carbon and alu handlebar? Not just one isolated comparison, but a good sample and look at the averages.

Equivalently priced alu and carbon frames and components are likely to be in the same ballpark with regards to weights, the carbon might be marginally lower, if its MUCH lighter than a top end alloy frame then its most likely lacking in some other desirable attribute, i.e. "stiffness". You are not just paying for material, you are paying for the design work thats gone into it and top end frames are designed more optimally than entry level bikes, often they are designed beyond the capabilies of alu and thus the carbon is essential.

Of course there will always be exceptions, or massive price hikes occasionaly due to brand names etc but this aside, if you are spending say £1k on a bike, I think you would be hard pressed to find any huge functional difference between carbon and alu. It would likely come down to feel and fit.

 

[amaferanga]

What model is your carbon bike? What size? Frame and fork or just frame? Without having some idea of the price point of your bike, any point you are trying to make is pointless.

Maybe you are missing some of the finer points in the comparison between alu and carbon.

Equivalent carbon frames and components arent neccesarily lighter, a lot of carbon components are lighter, but these usually cost a considerable amount more because they are a step above what is achievable with alu. If you compare equivalently priced items its a much better way to go about it, say for £100 how much difference is there between a carbon and alu handlebar? Not just one isolated comparison, but a good sample and look at the averages.

Equivalently priced alu and carbon frames and components are likely to be in the same ballpark with regards to weights, the carbon might be marginally lower, if its MUCH lighter than a top end alloy frame then its most likely lacking in some other desirable attribute, i.e. "stiffness".You are not just paying for material, you are paying for the design work thats gone into it and top end frames are designed more optimally than entry level bikes.

Of course there will always be exceptions, or massive price hikes occasionaly due to brand names etc but this aside, if you are spending say £1k on a bike, I think you would be hard pressed to find any huge functional difference between carbon and alu. It would likely come down to feel and fit.

I was responding to a statement that carbon frames and components are not lighter than their steel/alu counterparts. The simple fact is they usually are. Whether they are made the way they are for lightness or for other reasons wasn't the point I was addressing - I was merely responding to a misleading comment.

Please point me to an alu frame that costs around £600 that weighs 920g. In fact, please point me to an alu frame that weighs 920g or less - is there even such a thing?

(my frame is a Planet X Nanolight, size small and 920g is the claimed weight - I expect its a bit more, but I bought the complete bike so never had a chance to weigh just the frame)

 

[Herzog]

Weight is not the absolute here.

Carbon can be moulded into aerodynamic shapes, therefore reducing the work the rider has to do. Should the weight of a non-areo aluminium and an aero (evenly slightly areo) carbon framed bike be same, the carbon bike would require less work to travel the same distance.

 

[Fletch456]

I thought it worth posting that for many of us, including me, our understanding of how a material rides is limited to our experience of riding a bike made of that material.

It should also be borne in mind that it varies with manufacturer / brand and when the bike was built. So what we may think of how say alu or carbon rides may not be true for every bike of that material.

I've an alu bike that is about 7 yrs old - a Terry Dolan frame with Fulcrum 7 wheels - that has a very hard ride in my book. I can feel literally every tiny stone, piece of dirt, that is on the road. Yet I've learnt that the geometry - every stay is straight, no curves and the top tube is straight - may mean that some alu bikes don't ride like this. I know quite a few people (those I've read on here I think) really like how their alu rides yet others like a friend of my brothers, rode alu once and swore to never to return to it.

Last year I rode carbon and ti for the first time - with the ti it was like there was a layer of rubber on the road whilst the carbon suprised me with how comfortable it was (a Scott CR1) and wanted to go up the hill far quicker than the ti. It was the latter and it being more comfortable than I was expecting that sold me on carbon. Bear in mind that it was no ordinary ti bike but £4000 worth of carbon / ti mix!!! Not that I could afford it but the shop let me ride it because it was my size.

So I after that experience I couldn't imagine how people would race on ti, yet they do. There is a team called Qoroz who ride on ti bikes; ok Qoroz is a make of ti bike and it's their team so they probably have the best of the best but this was a £4000 bike that I rode. I also recently learnt of a gal who rides for a women's team and after her carbon was badly damaged during an attempted theft she replaced it with a ti and loves racing on it.

For me I am actually a little nervous about riding the alu again in the winter cos I've now bought a carbon bike and one that is too good to ride in the bad weather. It is so much more comfortable than my alu though will look out for a second hand carbon seat post to improve the ride.

 

[the_mikey]

I love both my alu and carbon framed bikes, but they feel very different to ride. I can't make claims of superior performance with one frame over another, although I regularly record higher average speeds on the carbon framed bike, that bike also has lighter wheels, lighter tyres, and lighter components. The aluminium framed bike is much less forgiving, every tiny bump in the road surface is faithfully reproduced at the saddle, my average speeds recorded on this bike are 2km/h slower, but also it has heavier wheels, heavier puncture resistant tyres and a heavier chainset.