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Aluminum or Carbon - Which is stiffer?

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Old 08-05-04 | 06:20 AM
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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

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Old 08-05-04 | 06:28 AM
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Originally Posted by 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.
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Old 08-05-04 | 06:33 AM
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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....

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Old 08-05-04 | 07:23 AM
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Originally Posted by 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
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Old 08-05-04 | 11:42 AM
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Why aren't you considering a performance steel bike? Cost?
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Old 08-05-04 | 11:53 AM
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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.
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Old 08-05-04 | 11:56 AM
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Originally Posted by Corsaire
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.
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Old 08-05-04 | 12:06 PM
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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
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Old 08-05-04 | 12:11 PM
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Originally Posted by Ajay213
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:https://www.cyclingnews.com/photos/20...=day4/img_4640
check out all the material around the bottom bracket
 
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Old 08-05-04 | 12:34 PM
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Originally Posted by Corsaire
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!
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Old 08-05-04 | 01:00 PM
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Wow! CRYSTAL CLEAR answer/explanation to my question bro, dissipated all of my thougths and wonders on the subject, thanks a lot.

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Old 08-05-04 | 07:05 PM
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Originally Posted by Tom Pedale
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...
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Old 08-05-04 | 07:12 PM
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or you could go with an aluminum biek with carbon seat stays, best of both worlds?
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Old 08-05-04 | 07:33 PM
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Originally Posted by djbowen1
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
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Old 08-05-04 | 07:39 PM
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Originally Posted by K6-III
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
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Old 08-05-04 | 08:23 PM
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Originally Posted by 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.
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Old 08-05-04 | 08:33 PM
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Originally Posted by Kris Flatlander
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.
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Old 08-05-04 | 08:44 PM
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Originally Posted by Hitchy
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
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Old 08-05-04 | 08:45 PM
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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.
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Old 08-05-04 | 08:48 PM
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https://www.giant-bicycles.com/uk/050...005.000.asp#40
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Old 08-05-04 | 08:53 PM
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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?
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Old 08-05-04 | 08:55 PM
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Originally Posted by Hitchy
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.
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Old 08-05-04 | 09:48 PM
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Originally Posted by djbowen1
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.
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
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Old 08-06-04 | 08:03 AM
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"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!
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Old 08-06-04 | 08:10 AM
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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.
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