Carbon vs Aluminum

mbrune

What are the appreciable differences between a carbon bicycle frame and an aluminum one. Assuming the weight difference is only about 2 lbs, and that the carbon frame is a decent grade frame (not the cheapest carbon frame you can buy) and assuming the same from the aluminum frame. Are the differences in frame going to actually amount to much (other than a $3000 price difference?)

cougie

My carbon bike gives a lovely ride and damps out vibration.

I swapped my groupset and wheels over so it was only the frame making the difference.

Of course you can get harsh riding carbon frames too.

You don't need to spend 3000 extra over an aluminium frame though. That's very much diminishing returns.

bonzo_banana

If your a competitive cyclist who does races etc then every gram you remove from the bike can help you to win if your not competitive then you don't really achieve much. A basic entry level bike is about 95% as efficient.

Carbon offers possibly slightly better comfort and a stiffer power delivery depending on frame design. Aluminium offers a more durable, safer less brittle material although will fatigue over the years. Carbon only fatigues if there is some flaw in manufacture but unfortunately many carbon frames have flaws as they are hand made by fairly low paid workers and it is time consuming constructing them. Missing glue in critical areas, cracks, ripples, voids all sorts of issues in carbon layup. Check out Luescher Technik on youtube for some good videos on carbon frame construction problems.

Maintaining an aluminium frame may be slightly easier slightly less critical torque tolerances when fastening bolts etc. You can damage carbon frames and forks quite easily over-tightening.

A single crash or even the bike falling over could render a carbon frame or forks unsafe and might need expensive scanning to see if the bike is still road worthy. Aluminium you can pretty much inspect yourself.

Without getting too personal you need to factor in yourself. Basically you are the engine of this vehicle. Do you see yourself as a sport's car engine or perhaps a more mundane slower paced car. For me a basic Giant Contend with Claris groupset is probably a better bike than I can justify. It's sub 10kg and sub £500 some of the time.

There have been many reports on cheap vs expensive bikes and there is very little in it for casual riders. Durianrider on youtube worked it out that his $500 road bike vs the best bike available was a difference of 1 second per minute. Other tests show even a £200 bike is almost 95% as efficient as an expensive aero carbon bike. If you look at the tour de france winning times you will see that even old steel road bikes achieved decent times and that winning times only gradually improved over the years and many entry level bikes nowadays exceed the performance of older tour de france road bikes.

Also factor in how often you will be using the bike and where. If you want a workhorse bike that you are going to use often and get abused etc then probably not carbon. If you are looking for a bike for sunday rides from home and back in fair weather only then carbon makes a lot of sense. Remember carbon forks are more likely to fail than a carbon frame though. If you want a safer bike with less chance of a instant unexpected critical failure of the frame or forks then an aluminium frame and carbon forks is only marginally safer than a carbon frame and forks bike. In fact if you went with a carbon frame you could then allow more weight for more heavy duty carbon forks. Iv'e seen some aluminium road bikes with very weak looking carbon forks clearly trying to achieve a very low weight.

It's really down to how much bling you want if you are not a competitive cyclist or how much money you can afford to waste. Remember cycling speed is 99% about the engine.

shortfall

Having read and contributed to a few of these threads on BR before I would offer the following thoughts.
1, Tyres make a much bigger difference to ride characteristics than frame material.
2, Different materials can be made to give whatever characteristics the frame builder chooses. Conventional wisdom says that aluminium is harsh, carbon is smooth, and that steel is springy, but by choosing different tube diameters, frame angles and geometry it's possible to engineer a frame to behave any way the builder intends regardless of whether it's made from steel, bamboo or titanium.
3, All things being equal its easier to make lighter frames from carbon which some people think is the be all and end all.
It isn't.
4, It's easy to spunk a ton of cash on a frame that someone on a forum or in a magazine says is the best but is completely wrong for you.

joe_totale-2

Aluminium bikes are far more brittle than carbon bikes in some areas, the top tube of a CAAD 12 for example.

Pantani was faster than the pro's of today on an alloy bike but we all know why that was. Pro cycling is probably a lot cleaner today then it was in the past so you cannot compare.

It's true that it's mainly about the engine, but the engine needs to be happy and comfortable about the chassis it's on.

StillGoing

Bonzo Banana wrote:

If your a competitive cyclist who does races etc then every gram you remove from the bike can help you to win if your not competitive then you don't really achieve much. A basic entry level bike is about 95% as efficient.

Carbon offers possibly slightly better comfort and a stiffer power delivery depending on frame design. Aluminium offers a more durable, safer less brittle material although will fatigue over the years. Carbon only fatigues if there is some flaw in manufacture but unfortunately many carbon frames have flaws as they are hand made by fairly low paid workers and it is time consuming constructing them. Missing glue in critical areas, cracks, ripples, voids all sorts of issues in carbon layup. Check out Luescher Technik on youtube for some good videos on carbon frame construction problems.

Maintaining an aluminium frame may be slightly easier slightly less critical torque tolerances when fastening bolts etc. You can damage carbon frames and forks quite easily over-tightening.

A single crash or even the bike falling over could render a carbon frame or forks unsafe and might need expensive scanning to see if the bike is still road worthy. Aluminium you can pretty much inspect yourself.

Without getting too personal you need to factor in yourself. Basically you are the engine of this vehicle. Do you see yourself as a sport's car engine or perhaps a more mundane slower paced car. For me a basic Giant Contend with Claris groupset is probably a better bike than I can justify. It's sub 10kg and sub £500 some of the time.

There have been many reports on cheap vs expensive bikes and there is very little in it for casual riders. Durianrider on youtube worked it out that his $500 road bike vs the best bike available was a difference of 1 second per minute. Other tests show even a £200 bike is almost 95% as efficient as an expensive aero carbon bike. If you look at the tour de france winning times you will see that even old steel road bikes achieved decent times and that winning times only gradually improved over the years and many entry level bikes nowadays exceed the performance of older tour de france road bikes.

Also factor in how often you will be using the bike and where. If you want a workhorse bike that you are going to use often and get abused etc then probably not carbon. If you are looking for a bike for sunday rides from home and back in fair weather only then carbon makes a lot of sense. Remember carbon forks are more likely to fail than a carbon frame though. If you want a safer bike with less chance of a instant unexpected critical failure of the frame or forks then an aluminium frame and carbon forks is only marginally safer than a carbon frame and forks bike. In fact if you went with a carbon frame you could then allow more weight for more heavy duty carbon forks. Iv'e seen some aluminium road bikes with very weak looking carbon forks clearly trying to achieve a very low weight.

It's really down to how much bling you want if you are not a competitive cyclist or how much money you can afford to waste. Remember cycling speed is 99% about the engine.

I glanced through the above, but a couple of things were spotted.

Carbon frames are not on the whole made by low paid workers in back street factories. Merida are one of the biggest manufacturers of bicycle frames knocking them out for other "manufacturers" including Specialized who they have a major share in. The Merida and Giant plants are in the same area sharing freight facilities.

Carbon is not more brittle than aluminium. There are numerous stress and impact tests of one v the other on You Tube with surprising results.

Durienrider talks shite.

ayjaycee

Joe Totale wrote:

Aluminium bikes are far more brittle than carbon bikes in some areas, the top tube of a CAAD 12 for example.

Joe - I'll go out on a limb here and suggest that you don't really understand what 'brittle' means - that statement is nonsense (I'm trying to be polite or I'd say it's ballocks!).

First.Aspect

ayjaycee wrote:

Joe Totale wrote:

Aluminium bikes are far more brittle than carbon bikes in some areas, the top tube of a CAAD 12 for example.

Joe - I'll go out on a limb here and suggest that you don't really understand what 'brittle' means - that statement is nonsense (I'm trying to be polite or I'd say it's ballocks!).

I think it was a post by someone who until recently owned a Cannondale.

craigus89

A lot of misinformation given in this thread. I can’t be bothered to go over it all though, OP I suggest you do a search and give it some thought.

kingrollo

Carbon gives a nicer ride.
There may be some cross over..in that a high end alu rides nicer than a budget carbon.

thats about it really.

mbrune

lot of conflicting reports here, sounds like this topic has already been beat up on this board and I should do a search. Overall I'm guessing many of you are right about who the carbon bike is for. My secteur is aluminum with carbon fork, I've crashed twice, but never had any noticeable damage to that fork. Limited experience I know, but it makes me think that carbon can't be as fragile as some report. Carbon bikes that I've ridden (test rides/short rides) seem to accelerate more quickly and smoothly and climb more easily but that's based on very limited experience. I'm not sure if the feeling is due to carbon, stiffer frame, or just down to I expect the feeling so invent it. From what's written here 90% of us would be better off buying aluminum frames with awesome wheel sets. Why is it then, when you go to a big sportive event (say a 100 mile ride with 6500 ft of climb) most of the bikes are carbon? good marketing?

And yes, it does come down to the engine. I've loved passing those carbon folks on my aluminum bike while we climbed the steepest sections. Somehow satisfying. (Of course some of them were passing me too)

Thank you all for your replies, it's interesting to see what others think. I'm guessing there is a divide in opinion between those that own carbon and those who own aluminum bikes. Could be wrong, but it seems we all like to justify our actions either way. (I know I do)

singleton

mbrune wrote:

Assuming the weight difference is only about 2 lbs,

A good aluminium frame and fork will weight under 2.5lbs, so not sure where this is coming from.
I've ridden both - good versions of both - and I prefer aluminium.
Why does 1 person prefer one colour over another? Try them and see what you prefer.

shortfall

kingrollo wrote:

Carbon gives a nicer ride.
There may be some cross over..in that a high end alu rides nicer than a budget carbon.

thats about it really.

That is highly subjective and as I have said, there are harsh riding carbon bikes and smooth riding alu bikes depending on what characteristics the frame builder wants to introduce. Tyre and wheel combinations can also affect ride quality hugely.

PinarelloPrince

How long is a piece of string?

Nonsense question and some nonsense answers.

My own experience FWIW is the worst bike I've ever ridden was carbon. The best bike I've ever ridden is carbon

svetty

Bonzo Banana wrote:

Durianrider on youtube

Anyone citing durianrider as a credible source automatically renders themselves as flaky. Might as well cite Milemuncher....

First.Aspect

PinarelloPrince wrote:

My own experience FWIW is the worst bike I've ever ridden was carbon. The best bike I've ever ridden is carbon

Was it the same bike?

beanstalk

Bonzo Banana wrote:

If your a competitive cyclist who does races etc then every gram you remove from the bike can help you to win...
A single crash or even the bike falling over could render a carbon frame or forks unsafe and might need expensive scanning to see if the bike is still road worthy.

A crash like they are due to happen when you race a lot?

Ritchey is offering a carbon version of his break away frame, claiming it to be tough enough to be pushed around in a bag.

So apart from performance and durability which can be achieved with carbon and aluminium frames, one could consider other aspects.
Like fitting standards. For example threaded bottom brackets are slightly more likely to be found on aluminium frames these days.
Carbon is special waste, not recyclable if one is into that kind of thing.

bonzo_banana

philthy3 wrote:

I glanced through the above, but a couple of things were spotted.

Carbon frames are not on the whole made by low paid workers in back street factories. Merida are one of the biggest manufacturers of bicycle frames knocking them out for other "manufacturers" including Specialized who they have a major share in. The Merida and Giant plants are in the same area sharing freight facilities.

Carbon is not more brittle than aluminium. There are numerous stress and impact tests of one v the other on You Tube with surprising results.

Durienrider talks shite.

Someone has already corrected you about your lack of understanding of 'brittle' but I would also point out no one has mentioned back street factories but you. To criticize a comment by adding something never written by that person seems very unfair. Clearly they are low payed workers because its a fairly basic manual process. A welder of aluminium for example would be paid much more but he would probably produce a huge number of frames in comparison to a person assembling carbon frames and forks.

Here is an image from quest composites who make Canyon and Trek carbon frames and forks. It is a less sophisticated facility than Giant and Merida for sure but would still expect those facilities to be similar if slightly improved. It's a boring slow process manufacturing carbon parts.



Durianrider is pretty plain speaking and unsponsored and has shown the Osprey $500 road bike performing very well and competing with other riders on high end bikes without issue and there are sources of similar information.

According to this video a basic sports direct mountain bike costing £200 is achieving just under 95% of the efficiency of a boardman carbon aero bike. I.e. for the same time as the boardman aero bike this basic sports direct road bike would have achieved about 95% of the distance of the Boardman bike.

https://www.youtube.com/watch?v=ow7MdsSVQuw

I suspect a slightly better bike like the Giant Contend Claris would close the gap a bit too. I'd probably put the Osprey between the muddyfox bike and the Giant contend. Anyway the point is more expensive bikes only achieve marginal gains in performance. Clearly very significant to competitive cyclists who want to win but for more casual cyclists in my opinion not really justified but I can still see the appeal to some of these high end bikes as a product to enjoy owning but just not achieving much beyond that.

MisterMuncher

That is an abysmal test protocol.

For a start, RPE/Heart rate isn't going to tell you anything meaningful about how equal the effort involved was, particularly one after the other. Without an objective measurement, that is to say power, it's absolutely meaningless. Hell's teeth, he even cites the estimated power on Strava as if it means something. Absolute nonsense.

Second, one run only? A minimum of three each, an average taken, then compare. That's just basic.

Third. 13 K of pan flat at barely over even money is neither long enough or fast enough to elicit a meaningful result. Yes, it shows them as being quite close together, just over a minute in it. Over 8 miles. Do you do many 8 mile rides? Are we to assume the difference would vary linearly over longer distances? What's that based on?

mbrune

Okay, so a nerve has been struck. I suppose it comes down to buy what's comfortable and in your price range. Some people want a carbon bike because they want a carbon bike. Some are happy, even prefer, the aluminum. But most would agree that lots of cash produces marginal gains. If you like what you ride, you'll ride it more. I suppose that's the end goal. I think most deep down know it comes down to the engine, but some people like the look of a Ferrari even if it has the engine of a beetle. I suppose that's their choice. Mostly i'm disappointed that I have a carbon frame because now all the aluminum guys who pass me on the hills are gonna blow their snot rockets in my direction. At least I'll provide some satisfaction to someone as we struggle up the same rise enjoying the same sport.

dstev55

Shortfall wrote:

kingrollo wrote:

Carbon gives a nicer ride.
There may be some cross over..in that a high end alu rides nicer than a budget carbon.

thats about it really.

That is highly subjective and as I have said, there are harsh riding carbon bikes and smooth riding alu bikes depending on what characteristics the frame builder wants to introduce. Tyre and wheel combinations can also affect ride quality hugely.

I can vouch for these comments.

I have a Bianchi Infinito CV summer bike, running on high end carbon wheels and 28mm tyres. A high end carbon frame that is marketed around it's comfort improving features.

I also have a Planet X London Road winter bike running on cheap aluminium wheels and 28mm tyres. A budget aluminium frame.

The most comfortable? The PX by a country mile. The Bianchi is still much more comfortable than other bikes I have owned but the PX is ultra comfortable to the point where you could easily be forgiven for thinking it was running 35mm+ tyres. The trade off for this comfort? A large amount of power is lost when you give it some, it just doesn't put the power through the wheels like the Bianchi does. It also weighs about 800g more(frame and forks only). I think any bike can be made comfortable or on the other hand stiff, the key advantage in using carbon in my opinion is that it provides the best opportunity for manufacturers to achieve the ideal mix of comfort and stiffness whilst maintaining a relatively low weight.

PinarelloPrince

First Aspect wrote:

PinarelloPrince wrote:

My own experience FWIW is the worst bike I've ever ridden was carbon. The best bike I've ever ridden is carbon

Was it the same bike?

No. Of course not.

thegreatdivide

You lot are falling for this hook line and sinker. Have a look at Bonzo’s previous posts and work it out.

StillGoing

Bonzo Banana wrote:

Someone has already corrected you about your lack of understanding of 'brittle' but I would also point out no one has mentioned back street factories but you. To criticize a comment by adding something never written by that person seems very unfair. Clearly they are low payed workers because its a fairly basic manual process. A welder of aluminium for example would be paid much more but he would probably produce a huge number of frames in comparison to a person assembling carbon frames and forks.

Here is an image from quest composites who make Canyon and Trek carbon frames and forks. It is a less sophisticated facility than Giant and Merida for sure but would still expect those facilities to be similar if slightly improved. It's a boring slow process manufacturing carbon parts.



Durianrider is pretty plain speaking and unsponsored and has shown the Osprey $500 road bike performing very well and competing with other riders on high end bikes without issue and there are sources of similar information.

According to this video a basic sports direct mountain bike costing £200 is achieving just under 95% of the efficiency of a boardman carbon aero bike. I.e. for the same time as the boardman aero bike this basic sports direct road bike would have achieved about 95% of the distance of the Boardman bike.

https://www.youtube.com/watch?v=ow7MdsSVQuw

I suspect a slightly better bike like the Giant Contend Claris would close the gap a bit too. I'd probably put the Osprey between the muddyfox bike and the Giant contend. Anyway the point is more expensive bikes only achieve marginal gains in performance. Clearly very significant to competitive cyclists who want to win but for more casual cyclists in my opinion not really justified but I can still see the appeal to some of these high end bikes as a product to enjoy owning but just not achieving much beyond that.

1. It wasn't me claiming carbon is more brittle than aluminium. It isn't.
2. The same poster talked about carbon being inferior due to underpaid workers. The point being made was it isn't made in some back street.

Here's one of your orignal posts stating the exact thing.

Bonzo Banana wrote:

TheSledge wrote:

The bike was transported inside my Mondeo - I’d prefer to strap the kids to the roof rack than my best bike!!

It's just a low cost Chinese carbon frame that will get bad examples. All this spirit of Italy for Italian brands and solid engineering for German brands is all marketing both are going to end up being a frame from some sweatshop Chinese factory but with a huge markup on top.

The reason people are trying to find a way to blame you is possibly their own perception of the brand's quality but that is achieved through marketing.

When the original 'Made in Germany' label came out it was by the British to warn of poor quality goods which was typical of German goods at the time and a similar story for Japan and then both had a transformation in quality. Nowadays German cars for example are the least reliable overall with the highest cost of ownership but it takes a long time for people's perceptions to change. Japanese cars in contrast have maintained their very high levels of reliability and low cost of ownership over many decades. The true engineering and quality geniuses in my opinion. You should always judge quality on a product by product basis though as even with Japanese cars there are some poor models.

http://www.reliabilityindex.com/manufacturer

3. Durianrider does talk shite and has been exposed in numerous videos for the shite he speaks.

StillGoing

thegreatdivide wrote:

You lot are falling for this hook line and sinker. Have a look at Bonzo’s previous posts and work it out.

Strewth! Why doesn't he go and look at porn if he's that bored and short of real friends.