Alum vs Carbon

Discussion in 'Cycling Equipment' started by Proudfoot, Jul 7, 2006.

  1. Proudfoot

    Proudfoot New Member

    Joined:
    Apr 25, 2006
    Messages:
    10
    Likes Received:
    0
    Newb question from official newb: I ride 60 - 80 miles per week in 3-4 rides, pretty much a serious recreational rider + 2-3 triathlons per summer. Need to upgrade a very old bike and am wondering if the "all carbon" is worth the extra loot for someone at my level.

    Most of what I can find says it's lighter (easier to push) and more comfortable. But the comfort part doesn't seem to get much comment except on very long rides (+50 miles). I'm not a millionaire, nor did I marry one; so if I don't need to spend the extra $1k or more, that would be a very good thing.

    I've been comparing Trek aluminum/carbon combo's & all carbons, for what that's worth.

    Thanks for any help . . .
     
    Tags:


  2. artmichalek

    artmichalek New Member

    Joined:
    Sep 15, 2004
    Messages:
    2,010
    Likes Received:
    0
    You'll have to take some test rides to decide if the difference in ride is really worth it to you. From a practical stanpoint, your budget is going to give you the choice between pretty good aluminum and low end carbon. Unless you can score a killer deal on a good carbon frame, you'll probably get a better value with aluminum.
     
  3. Proudfoot

    Proudfoot New Member

    Joined:
    Apr 25, 2006
    Messages:
    10
    Likes Received:
    0
    That's kind of the root of my question: my test rides have all been pretty short and I'm feeling some, but not a whole lot of, difference in a short ride. My concern is how much that difference would grow over a longer, more typical ride?

    I'm really leaning toward aluminum, thinking that if it turns out to be that big a deal, I can upgrade in a few years. Just what to make sure that I'm not screwing up - from the perspective & experience of those who know MUCH better.
     
  4. DiabloScott

    DiabloScott New Member

    Joined:
    May 15, 2003
    Messages:
    2,284
    Likes Received:
    2
    The bike that feels most natural underneath you and makes you want to ride more is the one you'll be happiest with in the long run. Hardly any of that comes from the material the frame's made out of. I don't think aluminum and carbon fiber actually feel that much different, but they SOUND different (like when you go over bumps or on rough pavement) and that SOUND makes it SEEM like it feels different.

    If you get an aluminum bike, then you'll probably start calling carbon fiber bikes "plastic" and if you get a plastic bike you'll start calling aluminum bikes "beer cans". Then come back here and answer the same question you just asked about three times a month.
     
  5. Proudfoot

    Proudfoot New Member

    Joined:
    Apr 25, 2006
    Messages:
    10
    Likes Received:
    0
    D-man: I think you just answered my question - I like the alum/carbon combo better, but didn't trust myself/lack of experience.

    I'll do my part to share the load on this question soon!
     
  6. deckard

    deckard New Member

    Joined:
    Feb 22, 2006
    Messages:
    74
    Likes Received:
    0
    Since you do Tri's and road, Cervelo Soloist Team, great light aluminum frame and a good price....did I mention a great frame.
     
  7. azdroptop

    azdroptop New Member

    Joined:
    May 25, 2005
    Messages:
    872
    Likes Received:
    0
    I just moved from a Lemond, Steel/Carbon set up to the Soloist Team, Alu, with carbon post and fork, and I love it. I was nervous about Alum being really harst and uncomfortable, but so far the Soloist is fantastic-Stiff, Fast, light, and comfy.
     
  8. capwater

    capwater New Member

    Joined:
    Sep 15, 2003
    Messages:
    1,574
    Likes Received:
    1
    Congrats! You have bought into the Trek marketing scheme that portrays carbon as better than carbon/aluminum which is better than all aluminum and thus worth every penny in extra expense. They are 3 totally different rides and not actually indicative of quality. As previously stated, you need to try the frame that is best for you. Personally I like Al and Al/Carbon blends over all carbon and even Ti (both a bit to flexy for me especially in the sprint). An all aluminum CAAD8 is certainly no low end cruiser!
     
  9. free_rideman

    free_rideman New Member

    Joined:
    Mar 20, 2006
    Messages:
    254
    Likes Received:
    0
    There is definitely a big difference between carbon and aluminum. Granted that the carbon frame you are getting is well made. Almost anyone can just lay carbon fiber down and make a frame, but it is the orientation of the fibers that makes all the difference. That is why the frame has to be a good frame. (not too cheap nor too expensive since at both ends of spectrum you are getting kinda screwed)

    I used to own a aluminum bike, with a crappy bontrager fork that had a aluminum steerer tube. The ride was very harsh, and my a$$ could definitely feel it.

    Then I bought a bike with a much better carbon fork, a carbon steerer tube, and a frame that had carbon stays. And now road chatter is a thing of the past.

    But at your budget, you might need to do some thinking. The components are much more important, since a crappy component could stop you from riding.
     
  10. Erzulis Boat

    Erzulis Boat New Member

    Joined:
    Oct 13, 2005
    Messages:
    85
    Likes Received:
    0
    Cheap aluminum frames are the worst thing going.

    High and ultra high end aluminum frames are fantastic beyond words, but the low end stuff really suffers.

    Carbon, by the nature of the construction and inherent properties, allows some lack of "Rocket Science", and a good riding frameset might be had for a reasonable price.

    Because most cyclists have not experienced the ultra high end framesets, the judging is skewed.

    An aluminum Giant compact frame may feel great, but if you were to ride the top of the line Pinarello for instance, the Giant would pale in comparison.

    Cost being equal, the choice between a middle of the road carbon vs. a middle aluminum....I would probably go carbon.

    Aluminun frames typically start getting good at $1500.00 maybe. The very expensive aluminum frames by famous builders are not overpriced. Ride one.
     
  11. Phill P

    Phill P New Member

    Joined:
    Jul 9, 2006
    Messages:
    513
    Likes Received:
    0
    I don't see how you can more easily make a carbon frame with no "rocket science" but it is hard to make a good Al frame??

    An Al frame maker buys in some pre formed tubes, picks the geometry, cuts and welds the tubes, heat treats, faces and machines the head tube and bottom bracket, then paints it.

    A carbon frame has to have the tube shapes and sizes choosen to match the carbon properties and fibre directions to achieve the desired stiffness and strength. Then either the entire front triangle or tubes must be laid up (rather than machine formed as with Al), lugs and tooling must be size dependant (adding to cost), "bake" the frame and parts, machine the head and bottom bracket, and paint on some fake carbon weave and other colours.

    Designing the tube size and shapes with fibre direction IS "rocket science". If done well you get a stiff strong comfortable frame. If done wrong you get a noodle which will crack, often failing instantly (rarely happens these days as carbon fibres have improved in quality).

    Can't say I've had the privledge to ride many bikes at all to be able to give first hand experience of the differences. But one thing for sure, cheap straight gauge Al frames are harsh to ride.

    I'm currently debating wether to buy a low end brand name carbon frame, or a carbon/Al frame with name brand tubing sold by another low end name brand company.
    The carbon frame is made out of a factory that makes thousands of frames a year, many are likely sold as "Italian", but since I've read no reviews on the frame and don't know any one who has had one and given it a good thrashing I'm not sure of the all round performance.
    The Al frame however is again made by a large asian factory making thousands of bikes (so they know how to weld), likely making frames for big names, so the only question is the quality of the welding used in this case, and the paint (I hate cheap paint!)
    The Al/carbon frame is few hundred cheaper, both good enough parts, and similar geometry that suits me (rare thing for me :( )

    The clear advice from the posters here, which makes a lot of sense, is ride a lot of bikes, decide where the price to performance ratio suits you, and ride the hell out of it because the bike may only make up 5% of any performance gain!

    Personally I say, get a bike that fits you and is comfortable to ride, then put good quality wheels on it! Spending a few hundred more on your wheels will give you more performance feel than a few hundred on a frame. If you feel fast, comfortable, and enjoy riding isn't that the most important part?

    Don't ride what you can't afford to crash!!!!
     
  12. dm69

    dm69 New Member

    Joined:
    Jan 24, 2006
    Messages:
    533
    Likes Received:
    0
    It isn't a matter of aluminium versus carbon because both can be very good and very poor.

    Take a giant tcr comp full carbon frame for example. Very flexy, noodly and made very dodgily. Then take a cervelo soloist full aluminium, innovative, smartwall technology for comfort and stiffness, superior welding, very aerodynamic (aero far more important than weight), and best of all cheap because aluminium bikes don't take a long time to build. Your choice?

    Why exactly do you get the idea that a lighter bike is easier to push? Stiffness is what you need there! a 2kg frame that is really stiff will be "easier to push than a carbon giant!".

    Lastly its not about the bike, Armstrong won races with motirola on a 11kg steel beast from eddy merckx.

    For your type of riding you dont need good carbon fibre or good aluminium you just need a steel bike thats cheap and comfortable. JUST RIDE.
     
  13. isdsms

    isdsms New Member

    Joined:
    Sep 21, 2003
    Messages:
    61
    Likes Received:
    0
    I would strongly recommend the aluminum Cannondale Caad8. First of all, it's pretty light and very stiff, so you're not gonna be wasting too much energy. However, unlike some other stiff aluminum frames, it gives a very comfortable ride due to a number of unique characteristics, especially the hourglass seatstays. Most importantly of all, you can get a brand new one for probably around $700-800, so you can put more cash into components that really matter, like wheels. I personally have the old Caad7 /w full ultegra and Kysrium SLs. I love it.

    However, if you're really serious about triathlons, the Cervelo Soloist might be your best bet. It would be easier to switch positions between road riding and TT.

    So it really comes down to which frame feels best. Make sure to get in a couple test rides, as long as your LBS will allow. I would stay away from the Trek... they're overpriced in my opinion, and you really wouldn't get anything special.
     
  14. vchu7105

    vchu7105 New Member

    Joined:
    May 31, 2005
    Messages:
    105
    Likes Received:
    0
    I agree, I have a trek 1000 (AL), year 2005 and a tarmac Comp 2006 (carbon), now it might be the geometry but I do know the Tarmac is a very big improvement in comfort. The Trek just beats the hell out of you compared to the Tarmac...After riding the trek i feel Jarred in the arms and lower back..The tarmac...I never feel great after every ride and never that jarred feeling.




     
  15. Cycle2100

    Cycle2100 New Member

    Joined:
    Aug 27, 2005
    Messages:
    21
    Likes Received:
    0
    I rode a 2005 Trek 2100 (carbon contact points and Trek's high-end aluminum) for a year, and just last week got an all carbon 2006 Trek Pilot. I'd like to say, apart from the geometry differeces, that the Pilot is more comfortable, but can't. They are both comfortable. Like others have implied, one cannot make a blanket statement that carbon is more comfortable than aluminum, or vice versa. There are too many variables.
     
  16. ScienceIsCool

    ScienceIsCool New Member

    Joined:
    Jun 25, 2006
    Messages:
    333
    Likes Received:
    0
    Yeah, I've always wondered about that. Vertical compliance of a frame is propbably measured in microns, whereas your tire deflection is measured in mm. How the heck could you decouple that and feel the frame's vertical compliance? I'm sure the vibration dampening effects are different between frames (i.e., resonance points are different), but I'm pretty sure that your saddle, handlebar tape, gloves and shoes soak up most of that motion too.

    People swear they can feel a difference between frames, but I'm not really sure what they are feeling. It all seems a bit weird.

    I think I'll be investigating this and adding another paper to my website some time soon. www.bikephysics.com

    John Swanson

     
  17. artmichalek

    artmichalek New Member

    Joined:
    Sep 15, 2004
    Messages:
    2,010
    Likes Received:
    0
    Nice to know that those marketing dollars were well spent. Hourglass seatstays are a hardly unique manufacturing shortcut, and have no inherent effect on how a bike rides. Running the right tire pressure has about a hundred fold greater effect on comfort.
     
  18. ScienceIsCool

    ScienceIsCool New Member

    Joined:
    Jun 25, 2006
    Messages:
    333
    Likes Received:
    0
    Yeah, I think the whole thing just screams for some experimentation. I've been thinking about this for a while and will probably put together a test some time this summer. Something to measure frame vibration and vertical compliance. Stay tuned...

    John Swanson
    www.bikephysics.com

     
  19. Jeff D.

    Jeff D. New Member

    Joined:
    Dec 29, 2005
    Messages:
    30
    Likes Received:
    0
    Carbon does two things. First of all it doesn't carry vibrations through it as well, compared to a metal. And also you can weave it in different directions.

    So you can make it have more bend in one direction, and then have more stiffness in another.

    But this bend is created only by a different orientation of the fibers. Carbon doesn't carry vibrations like steel. Hopefully you get what I am saying. Kinda confusing. Anyways, these vibrations are what cause problems concerning with fatigue. Carbon can't compress enough to become something that of suspension. It would be too little of a difference, but it can lower road chatter.

    This is why carbon could be considered superior. But all materials are good, and all of them have their own places. In some cases, you can really choose two for the same task. I guess that is when it becomes preference.
     
  20. ScienceIsCool

    ScienceIsCool New Member

    Joined:
    Jun 25, 2006
    Messages:
    333
    Likes Received:
    0
    I agree, though I doubt you're getting much multi-directional weaving in something as small-diameter as a seatstay or chainstay. The emphasis would be on making sure it doesn't fall apart by creating a tightly woven helical pattern.

    I guess what I'm wondering is what is the magnitude of vibration and compliance in a "stiff", "harsh" aluminum frame? What are the numbers? How does that compare to a "plush" carbon frame? Are the funky design elements such as S-curve stays actually doing anything?

    It would be nice to put numbers to these things. And then do a comparison study by doinf something like changing tire pressure. Does a super expensive carbon frame have the same damping qualities as a simple and free 3 psi change in tire pressure? That would be good to know!

    John Swanson
    www.bikephysics.com

     
Loading...
Loading...