Road Cycling - Aluminum or Carbon - Which is stiffer?

Now that we're seeing more and more ful carbon frame bikes (made even more popular by LA's 6th win), I can't help wonder what's best in terms of performance and speed. (my experience is limited to steel, but I'm looking to buy a performance bike)
The owner of my LBS let me ride his Trek OCVL carbon frmae last week and didn't like the "wooden" feel,
AL on the other side feels more uinforgiving, stiffer, which is good for quick accelerations.

Owners of AL and Carbon alike feel free to express your experiences with these two frames and you're lucky to own both so much the better.

What gives, Carbon/ AL?

Corsaire

AL on the other side feels more uinforgiving, stiffer, which is good for quick accelerations.

My two cents: (1) How a frame 'feels', doesn't necessarily tell you much how quickly it accelerates. That you could measure in more or less absolute terms, even though the engine (i.e. you; the most relevant variable) is probably not a constant factor. (2) A great deal of 'stiffness' (or lack thereof) comes from other components than the frame: wheels, tire pressure, etc.

Yes, however I'm trying to compare what type of frame between the two puts out what you (the engine) put into it by pedaling....

Corsaire

Yes, however I'm trying to compare what type of frame between the two puts out what you (the engine) put into it by pedaling....

Corsaire

An all AL bike will be stiffer riding bike than an all Carbon bike. Of course, the stiffness around the crank is what really matters for transfering power from the engine (you) to the road, therefore you will see all sorts of combinations with regard to this question. In the end, it will come down to how you feel about the bike and how it matches your needs.

I just bought a new all carbon bike after riding about 10 different bikes of all sorts of combinations. My LBS and the people here told me that "one bike would just feel right to me" and that is how it played out for me.

DP

Why aren't you considering a performance steel bike? Cost?

I just came off of a Cinelli Starlight w/Columbus Muscle carbon fork made from Columbus Starship tubing. This was a very fast, light and responsive bike unfortunately I was in a pretty bad crash two weeks ago and busted the frame. I've replaced it with an Orbea Orca all carbon frame. To my surprise this bike has a stiffer BB than my Cinelli and delivers it without the harsh ride that alluminum bikes generally have. The Orbea Zuess fork isn't as stiff as the Muscle but overall the all Carbon bike is very stiff but dampens better than my the Starship tubed Cinelli.

I've ridden Looks and Times and the Look Kg 381 seemed a little flexy to me while the Time was rock solid (but they are $3k+) and felt more "metal" like to me.
BTW I am 5'10" weight 165#. I think bigger ridders might not find carbon to their liking but this is just a guess on my part.

Now that we're seeing more and more ful carbon frame bikes (made even more popular by LA's 6th win), I can't help wonder what's best in terms of performance and speed. (my experience is limited to steel, but I'm looking to buy a performance bike)
The owner of my LBS let me ride his Trek OCVL carbon frmae last week and didn't like the "wooden" feel,
AL on the other side feels more uinforgiving, stiffer, which is good for quick accelerations.

Owners of AL and Carbon alike feel free to express your experiences with these two frames and you're lucky to own both so much the better.

What gives, Carbon/ AL?

Corsaire


Do you think his 6th vicotry in the Tour De France has anything to do with people buying carbon frames?? I dont. Having owned both aluminum and carbon in the last month i can say that the aluminum bike (Caad5) with carbon seatpost was way stiffer than the TCR frame i am riding now.

It all depends on the design and manufacturing of the frame. I can make a noodley Al frame or an ultra-stiff kidney pounding Ti frame. Carbon can be made either way (along with any other material).

Andrew

It all depends on the design and manufacturing of the frame. I can make a noodley Al frame or an ultra-stiff kidney pounding Ti frame. Carbon can be made either way (along with any other material).

Andrew

Exactly. Carbon, because of it's weight and other properties, has more scope. It can be thin and noodlely, or chunky and stiff, like this:http://www.cyclingnews.com/photos/2004/may04/WTC04/?id=day4/img_4640
check out all the material around the bottom bracket

Now that we're seeing more and more ful carbon frame bikes (made even more popular by LA's 6th win), I can't help wonder what's best in terms of performance and speed. (my experience is limited to steel, but I'm looking to buy a performance bike)
The owner of my LBS let me ride his Trek OCVL carbon frmae last week and didn't like the "wooden" feel,
AL on the other side feels more uinforgiving, stiffer, which is good for quick accelerations.

Owners of AL and Carbon alike feel free to express your experiences with these two frames and you're lucky to own both so much the better.

What gives, Carbon/ AL?

Corsaire

Aluminum or Carbon...which is stiffer. The answer really depends on how you manipulate the material. You can use either material to build a "flexy" flyer or the stiffest bike you'd ever want to ride. It's all in how you design the tubes (wall thicknesses, tube diameter, etc) and the frame geometry.

I would want to answer this question in terms of advantages/disadvantages of each material.

The advantages of aluminum are its low costs with respect to strength to weight ratio. It is also relatively easy to form this material into different shapes and it is not difficult to weld. One disadvantage is that of all the frame materials used (steel, aluminum, titanium and carbon fiber) it will fatigue quicker (i.e. fail)due to the nature of the metal. I would consider this a factor if I were choosing a mountain bike frame that would be heavily thrashed for many years. For a road bike, it's a non-issue. If it were an issue, jets would be built of something else.

The advantages of carbon fiber are that of all the frame materials used (steel, aluminum, titanium and carbon fiber) it is the strongest (based on engineering tables that calculate relative strength) of all of them which means that correctly designed, you will be able to build a frame that will be strong, stiff and lighter than frames made of any other material. Another advantage of carbon fiber is its ability to damp vibration. This means that you will feel less road shock. I have seen occur often however, where riders are convinced that aluminum frames are stiffer than carbon fiber because with the carbon fiber, you don't feel the harshness. Some riders think a bike has to ride harsh to be stiff...this is nonsense. If many of the top sprinters in the TDF are using carbon fiber, the issue of adequate stiffness has been answered.

The big disadvantage of carbon fiber is cost. While not an issue for pro riders, the purchase of a carbon fiber frame may be beyond the budget of some riders.

A note on titanium: of all the materials, this one is the most difficult to shape which is one reason you don't see a titanium frame with the subtle curves of a Trek Madrone. You could do it, but the cost of shaping the tubes would be astronomical. Carbon fiber has leapfrogged titanium as the material of choice for "cutting edge" frames because you can build a better performing frame that in the end will cost less to produce. If it were not so, you would see top pros riding ti, not carbon and the top companies producing ti, not carbon fiber bikes for their hi-tech offerings. It is the same with other sports. Carbon fiber, not ti
is used for applications on Formula One car bodies because you can shape it!

The bottom line: Establish a budget, then ride a bunch of bikes. Personally, I would not hesitate to buy a bike made of any of the materials mentioned if I liked it the best. All of them, if built by a reputable company will be more than adequately strong and will be backed by an excellent warranty.

When you ride, try some of the aluminum frames with carbon fiber stays and fork. These cost less and you get the benefits of vibration damping with the carbon fiber used in these areas.

Happy hunting!

Wow! CRYSTAL CLEAR answer/explanation to my question bro, dissipated all of my thougths and wonders on the subject, thanks a lot.

Corsaire

The advantages of aluminum are its low costs with respect to strength to weight ratio. It is also relatively easy to form this material into different shapes and it is not difficult to weld. One disadvantage is that of all the frame materials used (steel, aluminum, titanium and carbon fiber) it will fatigue quicker (i.e. fail)due to the nature of the metal. I would consider this a factor if I were choosing a mountain bike frame that would be heavily thrashed for many years. For a road bike, it's a non-issue. If it were an issue, jets would be built of something else.


This is actually not true. The parts on airplanes are designed to fail due to weight requirements. It is just that the parts are replaced prior to their calculated failure point. Furthermore, rigid inspection requirements are put in place to look for hairline cracks...

or you could go with an aluminum biek with carbon seat stays, best of both worlds?

Do you think his 6th vicotry in the Tour De France has anything to do with people buying carbon frames?? I dont. Having owned both aluminum and carbon in the last month i can say that the aluminum bike (Caad5) with carbon seatpost was way stiffer than the TCR frame i am riding now.


g'day,

certainly your opinion is as valid as any other around here, ....but....ya gotta compare apples with apples. The 'dale CAAD 5 ALU frame is arguably one of the better AL frames around, whereas the TCR composite frame is at the very bottom of composite technology, made to suit a price point, rather than a competing with high end composite frames.

I am a big guy, (190 lbs), producing a lot of power, (i s'pose i would call myself a sprinter). I was skeptical about composite frames suiting my style of riding. Certainly,the highend frames, C50, VRXS, KG486 have little or no flex through the bottom bracket. I agree with one of the early posters, that it is more about the components than frame, at this level. I can't notice any discernable difference between from ALU frame & my new carbon, as regards stiffness. What is discernable, is the absence of 'road shock' through the carbon frame......there is no contest.

cheers,

Hitchy

This is actually not true. The parts on airplanes are designed to fail due to weight requirements. It is just that the parts are replaced prior to their calculated failure point. Furthermore, rigid inspection requirements are put in place to look for hairline cracks...


G'day,

but a composite frame won't 'fatigue' the way alu does. With alu you can have 'unseen' fatigue that can lead to catastropic failure. With carbon, unless the fibre is actually broken, it doesn't fail. Not that I'm a fan of Trek's, but they have the right idea with the warranties on the carbon frames, which basically says, treat it right & it won't break,

cheers,

Hitchy

G'day,

but a composite frame won't 'fatigue' the way alu does. With alu you can have 'unseen' fatigue that can lead to catastropic failure. With carbon, unless the fibre is actually broken, it doesn't fail. Not that I'm a fan of Trek's, but they have the right idea with the warranties on the carbon frames, which basically says, treat it right & it won't break,

cheers,

Hitchy

My Orbea Orca has a lifetime warrantee with basically the same philosophy "don't abuse it and it won't break". My Cinelli was a highend Alu frame set and I broke it with my knee. When I fell the top tube hit the inside of my knee and dented the tube and causing a hair line crack. I was allways worried that a Carbon frame would break in a crash so I avoided them. After busting my Cinelli I decided it didn't matter and I might as well be comfortable!

I also misstook the comfort of a Carbon bike as feeling dead. I misstakingly confused road shock and road feel. I now feel like I'm just floating along without jarring my filling out. This bike climbs and sprints as well if not a little better than my Cinelli.

or you could go with an aluminum biek with carbon seat stays, best of both worlds?


I was about to say the same thing. My next one will be this. My bud at the local LBS just bought a Fuji, that is both. He says it is the shiznit.

g'day,

certainly your opinion is as valid as any other around here, ....but....ya gotta compare apples with apples. The 'dale CAAD 5 ALU frame is arguably one of the better AL frames around, whereas the TCR composite frame is at the very bottom of composite technology, made to suit a price point, rather than a competing with high end composite frames.

I am a big guy, (190 lbs), producing a lot of power, (i s'pose i would call myself a sprinter). I was skeptical about composite frames suiting my style of riding. Certainly,the highend frames, C50, VRXS, KG486 have little or no flex through the bottom bracket. I agree with one of the early posters, that it is more about the components than frame, at this level. I can't notice any discernable difference between from ALU frame & my new carbon, as regards stiffness. What is discernable, is the absence of 'road shock' through the carbon frame......there is no contest.

cheers,

Hitchy

I have to seriously disagree with your comment about the TCR frames being at the bottom of carbon technology, maybe the first gens but definetly not the current. What research are you basing this on

BTW I am 5'10" weight 165#. I think bigger ridders might not find carbon to their liking but this is just a guess on my part.
My sentiments exacly. I weigh 200 pounds and love my OCLV 1200.

On the flats I keep up with the fastest of guys, I just struggle getting my fat butt up the hills. :)

http://www.giant-bicycles.com/uk/050.000.000/050.005.000.asp#40

Have owned steel, aluminum, ti and now have ordered a custom carbon single.
Steel is real, heat treated alu was a bit harsh riding but much stiffer, ti was nice and stiff, and not as harsh.
After having ridden a carbon fiber tandem for about 5,000 miles, I am sold on stiffness/weight/comfort of carbon. Hence the c/f single on order.
Isn't it nice to have choices?

g'day,

certainly your opinion is as valid as any other around here, ....but....ya gotta compare apples with apples. The 'dale CAAD 5 ALU frame is arguably one of the better AL frames around, whereas the TCR composite frame is at the very bottom of composite technology, made to suit a price point, rather than a competing with high end composite frames.

I am a big guy, (190 lbs), producing a lot of power, (i s'pose i would call myself a sprinter). I was skeptical about composite frames suiting my style of riding. Certainly,the highend frames, C50, VRXS, KG486 have little or no flex through the bottom bracket. I agree with one of the early posters, that it is more about the components than frame, at this level. I can't notice any discernable difference between from ALU frame & my new carbon, as regards stiffness. What is discernable, is the absence of 'road shock' through the carbon frame......there is no contest.

cheers,

Hitchy


Sorry for the triple reply, i misunderstood. your statements come off as facts instead of opinion like they should be more geared toward sounding like, I think your comments on the Caad5 being one of the better aluminum frames is as bad as the one about the giant frames. You cant tell me Caad5 is one of the best alu frames around. :eek:

Sorry for the triple reply, i misunderstood. your statements come off as facts instead of opinion like they should be more geared toward sounding like, I think your comments on the Caad5 being one of the better aluminum frames is as bad as the one about the giant frames. You cant tell me Caad5 is one of the best alu frames around. :eek:

g'day,

these forums are about opinions...opinions are a bit like a***holes, we've all got one!. MY opinion is based upon having raced a CAAD 4 frame for 2 years (sorry no direct experience with the CAAD 5 but i think it's safe to assume that it's as good if not better than the 4). i've raced many frames over the years & a similarly specced CAAD4 frame is as good a frame as most anything else i have ridden. As an ALU frame I rate it highly. The TCR frames, (the latest on the market in Aus), ARE low end, made for the masses frames that provide little as far as innovation & are basically 'knock offs' of other peoples developments. In my recent purchase of my carbon bike, I test rode everything available in composite. I was lucky enough to be able to race a TCR, (whatever the one is with kysirriums & ultegra). I didn't like it at all. i thought it felt 'dead', unresponsive & 'twitchy' in the front end. I don't need research to tell me what I feel, (or a technical manifesto's posted on a website designed to sell me the bike). This is an opinion!. On the plus side, it was hideously cheap compared to other bikes...but you pay for what you get!...you might like it, i don't. My original post just said, compare apples with apples...the TCR is not representative of all that is available in composite frames. That's not an opinion...that's a fact Jack!

cheers,

Hitchy

"ARE low end, made for the masses frames that provide little as far as innovation & are basically 'knock offs' of other peoples developments"


This doesnt make any sense, they are low end because they are made for the masses frames that provide little as far as innovation & are basically 'knock offs' of other peoples developments


Also, dont take me to serious!

when posting it should be mandatory to list the size frame you ride. a 54cm frame has different stiffness than a 60cm frame.

and i can't believe that this thread has not one mention of Ti frames.

I wouldnt ride Alum again but i'm old and dont think i'm a racer. Carbon or most likly Ti for me next.

Some figures I've dug up from postings about Tour magazine at weight weenies. I think their weights are off on the frames as most are known to be lighter than what they list. I believe they're all based somewhere around a 56/58cm frame (the Giant's are probably mediums).

g'day,

these forums are about opinions...opinions are a bit like a***holes, we've all got one!. MY opinion is based upon having raced a CAAD 4 frame for 2 years (sorry no direct experience with the CAAD 5 but i think it's safe to assume that it's as good if not better than the 4). i've raced many frames over the years & a similarly specced CAAD4 frame is as good a frame as most anything else i have ridden. As an ALU frame I rate it highly. The TCR frames, (the latest on the market in Aus), ARE low end, made for the masses frames that provide little as far as innovation & are basically 'knock offs' of other peoples developments. In my recent purchase of my carbon bike, I test rode everything available in composite. I was lucky enough to be able to race a TCR, (whatever the one is with kysirriums & ultegra). I didn't like it at all. i thought it felt 'dead', unresponsive & 'twitchy' in the front end. I don't need research to tell me what I feel, (or a technical manifesto's posted on a website designed to sell me the bike). This is an opinion!. On the plus side, it was hideously cheap compared to other bikes...but you pay for what you get!...you might like it, i don't. My original post just said, compare apples with apples...the TCR is not representative of all that is available in composite frames. That's not an opinion...that's a fact Jack!

cheers,

Hitchy

Your opinion as stated in the above post, is clearly one of experience and knowledge. However, as an observer that read your post, which finished with...."That's not an opinion...that's a fact Jack!", I can't help but bring your attention to the fact that you referred to yourself fifteen times in the post, as the source for your statements about the frame characteristics. Not once did you reference any other source for your statements. Even though your opinion deserves respect, it is still but an opinion.

It is the same with other sports. Carbon fiber, not ti
is used for applications on Formula One car bodies because you can shape it!


You can shape titanium... not as easily as carbon fiber but it can be done. Ferraris F2004 has a titanium gearbox. F1 teams have a unlimited budget, the cost of shaping titanium would not prevent them from using titanium. Carbon fiber is just used more because most of the components they are used for do not require the strength, or heat resistance of titanium.

Carbon fiber has leapfrogged titanium as the material of choice for "cutting edge" frames because you can build a better performing frame that in the end will cost less to produce. If it were not so, you would see top pros riding ti, not carbon and the top companies producing ti, not carbon fiber bikes for their hi-tech offerings.

Great post - I would just add though that "better performing" for pros might well mean something different for the every day rider. For most of us who don't race for a living and get several new bikes every year, it might make sense to give up a few ounces of weight for something that will be more durable, more comfortable, and take more years of use and abuse. I see a lot of casual riders chasing the latest and greatest materials when in reality, a good old steel frame would serve them exceptionally well.

when posting it should be mandatory to list the size frame you ride. a 54cm frame has different stiffness than a 60cm frame.

and i can't believe that this thread has not one mention of Ti frames.

Actually, I mentioned Ti frames in my earlier post.....

Great post - I would just add though that "better performing" for pros might well mean something different for the every day rider. For most of us who don't race for a living and get several new bikes every year, it might make sense to give up a few ounces of weight for something that will be more durable, more comfortable, and take more years of use and abuse. I see a lot of casual riders chasing the latest and greatest materials when in reality, a good old steel frame would serve them exceptionally well.

Well everybody needs more then one bike and i see no reason not to make one steel and one Ti.

Make them whatever material you want - ain't America great?

Your opinion as stated in the above post, is clearly one of experience and knowledge. However, as an observer that read your post, which finished with...."That's not an opinion...that's a fact Jack!", I can't help but bring your attention to the fact that you referred to yourself fifteen times in the post, as the source for your statements about the frame characteristics. Not once did you reference any other source for your statements. Even though your opinion deserves respect, it is still but an opinion.

G'day Don,

you've misread my post. The sentence '....and thats a fact Jack", refers to the statement immediately preceding it, that, "the TCR is not representative of the carbon frames available", that IS a fact Jack. Everything else in my post is opinion, my opinion...If people don't like it, ignore it....My opinion is worth no more or no less than anyone elses. If people don't want opinions, don't ask questions!.No skin off my nose!....but please don't misrepresent what i have said,

cheers,

hitchy

Well if you want to feel every little thing you run over,mile after mile after mile and if stiff,then by all means get Alum. If on the other hand you want a bit more of a forgiving ride,go with steel,carbon or ti. Me,i'm not a racer or think i'm LA or need to drop everybody i pass so i dont have a problem with a dead feel. I'm set on ti as my next BUT will test some carbons like the Giant which from the riders i've talked to saw its much better then the 5200 as in stiffness if you want a compact frame. I will test both and the Lemond and Litespeed.

You cant tell me Caad5 is one of the best alu frames around. :eek:

The fact that it is top tier is old news

what!

I don't believe that a carbon fibre bike tube could be engineered to be "noodley" and ridable. Carbon fibre frame tubes in current use, can withstand very little (relative to titanium or steel) non-linear stress before breaking. If a frame tube of carbon fibre were noodley, you couldn't ride the bike, it would breakapart. A glass tube is the closest (though not perfect) analogy I can think of. It's greatest strength is in a plane that is linear to it's length. But non-linear (side impacts) stress can much more easily damage the structure beyond repair. That's the way carbon fibre frame tubes are designed.