Carbon vs Aluminum
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2007-09-16 7:13 PM |
New user 31 | Subject: Carbon vs Aluminum Looking to give up the old Gary Fisher MTB and getting the tri-bike. I am guessing either will work for me, but I am looking for opinions, experiences, advantages etc. on carbon and aluminum frames. |
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2007-09-16 7:23 PM in reply to: #966903 |
Extreme Veteran 333 Québec City | Subject: RE: Carbon vs Aluminum Aluminum : Works well with a good aluminum. For me, Specialized E5 Alu has been the best ever. Carbon : Now a must for me. I switched from Spec. E5 alu to Spec. S-Works Tarac SL full monocoque carbon and I still don't beleive it... It is such a ride !!!! If you can afford carbon, go for it !
Be warned though that (IMHO), between a 1500$ carbon bike with poor components and poor wheels and a well mounted alu bike for the same price, I would rather choose the alu bike. Look at the components, especially the wheels, that might make a good difference...
good luck !
Christian. |
2007-09-16 7:25 PM in reply to: #966903 |
Extreme Veteran 333 Bend, OR | Subject: RE: Carbon vs Aluminum To start, everyone has there own opinions on what works best for them. This is just my opinion stated and I've talked to many other friends and riders who have agreed. In the end it's all personal preference and I would go out and test ride bikes. It's worth your time. 1) In terms of life expectancy, Aluminum will have a longer life than carbon. Depending on your weight and type of riding (are you a stomper, do you race, etc) >> then carbon has a rather limited life. Most of the terrible things about carbon frames have been corrected. The trek OCLV for example used to have terrible frame problems early in their lives. Aluminum will still last much longer. carbon can lose its already soft feel over time. Aluminum keeps its ride characteristics well over time. I hope my opinion helps. Cheers Edited by Omega 2007-09-16 7:26 PM |
2007-09-16 7:36 PM in reply to: #966903 |
Iron Donkey 38643 , Wisconsin | Subject: RE: Carbon vs Aluminum joemir - 2007-09-16 7:13 PM Looking to give up the old Gary Fisher MTB and getting the tri-bike. I am guessing either will work for me, but I am looking for opinions, experiences, advantages etc. on carbon and aluminum frames. I was asking about the same thing back in March 2007 - here's the thread: You might be able to find some additional comparisons by using the Search Forums area if you want if you don't want to wait for responses: Google is your friend, too, and can provide a number of hits (here's one): One big difference is cost - carbon (composite) is a little more pricey. I'll let others weigh in about maintenance, comfort, etc. |
2007-09-16 8:27 PM in reply to: #966903 |
Master 1603 Connecticut | Subject: RE: Carbon vs Aluminum I have an aluminum frame on my tri bike and carbon frame on my road bike. I much prefer riding the carbon frame. The carbon is more comfortable, but very responsive. However, one of the cool things about carbon is that its characteristics can vary (e.g., stiffness versus flexibility) depending upon how it is built. So if you are looking at carbon frames, find one that is made for your needs and try a few out. Mine is made to be very stiff, but not everybody likes that. It's true that carbon isn't the most durable of materials. I just had to replace a frame a little over a month ago after mine was fractured in a crash. I don't think an aluminum frame would have held up in that particular situation either though. Steel or titanium are the way to go if durability is a priority. |
2007-09-16 8:34 PM in reply to: #966917 |
Champion 10668 Tacoma, Washington | Subject: RE: Carbon vs Aluminum "1) In terms of life expectancy, Aluminum will have a longer life than carbon. Depending on your weight and type of riding (are you a stomper, do you race, etc) >> then carbon has a rather limited life. Most of the terrible things about carbon frames have been corrected. The trek OCLV for example used to have terrible frame problems early in their lives. Aluminum will still last much longer. carbon can lose its already soft feel over time. Aluminum keeps its ride characteristics well over time." As an engineer who works with these materials, I can tell you that these statements sound good, but are completely false. In fact, pretty much the reverse is true. Steel and titanium have a "fatigue limit", meaning that there's a stress level that, as long as you stay under it, will allow that material to have an infinite life. Aluminum does NOT have a fatigue limit, meaning that no matter HOW low the stress level, it WILL fatigue and eventually fail. That "eventually" may be a very long time, but it will still happen (and the higher the stresses, the sooner that will be). Carbon doesn't fatigue at all, but it IS very susceptable to impacts across its laminate (like a pump falling on a frame tube). Old failures of carbon frames were related to the bonding of composite tubes to aluminum lugs (and even those bonding problems have been ironed out). I am leering of buying used aluminum OR carbon, for the reasons above. But that is my personal opinion. |
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2007-09-16 9:00 PM in reply to: #966903 |
Cycling Guru 15134 Fulton, MD | Subject: RE: Carbon vs Aluminum As I always say ....... any material can be made to have just about any specific ride characteristics (within reasonable limits) ...... it all just depends on the manufacturer and the frame design. You can make an aluminum frame whippy (think Vitus from years ago) and you can make a carbon frame stiff as hell (the beefier Colnago C50's or current Giant TCR Limiteds). The life expectancy for aluminum frames used to be only about 4 - 5 years and that was how long most manufacturers would warranty them for because of that. Carbon was similar but that was more because of the way they were layered and bonded more than anything else. Both types of materials have come a long way even in just the last 10 years. I personally prefer carbon over aluminum by a long shot, but that is more than likely because of the sour taste aluminum has left with me from my years of selling bikes in shops and riding/racing them back in the 90's and because of the responsiveness, weight and design of the two I currently own. I really prefer steel, but it is getting harder and harder to find good light steel frames that can even come remotely close in weight to the carbon/aluminum/ti frames of the current production levels. |
2007-09-17 11:15 AM in reply to: #966903 |
New user 31 | Subject: RE: Carbon vs Aluminum Thanks for taking time to respond and helping me to make an informed decision. As always... BT is great! |
2007-09-17 11:27 AM in reply to: #967020 |
Master 2202 St. Louis | Subject: RE: Carbon vs Aluminum briderdt - 2007-09-16 8:34 PM "1) In terms of life expectancy, Aluminum will have a longer life than carbon. Depending on your weight and type of riding (are you a stomper, do you race, etc) >> then carbon has a rather limited life. Most of the terrible things about carbon frames have been corrected. The trek OCLV for example used to have terrible frame problems early in their lives. Aluminum will still last much longer. carbon can lose its already soft feel over time. Aluminum keeps its ride characteristics well over time." As an engineer who works with these materials, I can tell you that these statements sound good, but are completely false. In fact, pretty much the reverse is true. Steel and titanium have a "fatigue limit", meaning that there's a stress level that, as long as you stay under it, will allow that material to have an infinite life. Aluminum does NOT have a fatigue limit, meaning that no matter HOW low the stress level, it WILL fatigue and eventually fail. That "eventually" may be a very long time, but it will still happen (and the higher the stresses, the sooner that will be). Carbon doesn't fatigue at all, but it IS very susceptable to impacts across its laminate (like a pump falling on a frame tube). Old failures of carbon frames were related to the bonding of composite tubes to aluminum lugs (and even those bonding problems have been ironed out). I am leering of buying used aluminum OR carbon, for the reasons above. But that is my personal opinion. +1 You beat me to it! I also am an engineer, working in the aerospace field. Those statements couldnt be farther from the truth. Carbon's main benefit is that it has no fatigue life. It NEVER fails from fatigue (within its elastic limits). Anyway, I ride aluminum and love it. I have had no problems. Cannondale aluminum design is fantastic, and is compliant. |
2007-09-17 12:45 PM in reply to: #967636 |
Cycling Guru 15134 Fulton, MD | Subject: RE: Carbon vs Aluminum ranger5oh - 2007-09-17 12:27 PM Cannondale aluminum design is fantastic, and is compliant. Wow ....... that is probably one of the only times I've ever heard that ........ compliant was pretty much the LAST thing I'd ever say about a Cannondale to customers (even when I sold the brand). Unless they've changed over the years they were the stiffest and most "fragile" of all the aluminum frames I dealt with. |
2007-09-17 12:53 PM in reply to: #967007 |
Champion 16151 Checkin' out the podium girls | Subject: RE: Carbon vs Aluminum dredwards - 2007-09-16 9:27 PM I have an aluminum frame on my tri bike and carbon frame on my road bike. I much prefer riding the carbon frame. The carbon is more comfortable, but very responsive. However, one of the cool things about carbon is that its characteristics can vary (e.g., stiffness versus flexibility) depending upon how it is built. So if you are looking at carbon frames, find one that is made for your needs and try a few out. Mine is made to be very stiff, but not everybody likes that. It's true that carbon isn't the most durable of materials. I just had to replace a frame a little over a month ago after mine was fractured in a crash. I don't think an aluminum frame would have held up in that particular situation either though. Steel or titanium are the way to go if durability is a priority. Kim: You're spot on with your assesment, but I'd add 1 caveat: When you crash a carbon frame, it might LOOK OK, but you can easily have hidden structural damage. Only X-ray could truly find it. As you say, it's laid up multi-directionally and, the inside layers might have been stressed widly while the outside ones seem OK. You don't have to fracture it to trash it. A slight bubble, clear coat or paint crack after an impact should indicate to be suspicious. Just like the helmet, if it's in a crash, you'd better think long and hard about replacement. Calfee will repair any manufacturer's CF frame, but it's expensive and better be worth the $$$ you'll spend. A 3-4yo low end frame likely won't be economical. |
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2007-09-17 5:04 PM in reply to: #966903 |
Master 3019 West Jordan, UT | Subject: RE: Carbon vs Aluminum Can you engineers explaing the "fatigue" to me? Do you mean the frame will actually break or that it will lose it's rigidity? How would one know when their frame has fatigued? I have a 10yo Alum MTB frame that still seems great to me. |
2007-09-17 6:19 PM in reply to: #966903 |
Elite 3371 | Subject: RE: Carbon vs Aluminum If you want to try to find a carbon tri bike (which I recommend over aluminum), and want to save some serious cash, go used. You can find some bargains. A site called craigslist.org has some amazing deals. |
2007-09-18 6:14 AM in reply to: #968362 |
Extreme Veteran 333 Québec City | Subject: RE: Carbon vs Aluminum tkbslc - 2007-09-17 5:04 PM Can you engineers explaing the "fatigue" to me? Do you mean the frame will actually break or that it will lose it's rigidity? How would one know when their frame has fatigued? I have a 10yo Alum MTB frame that still seems great to me. Here is a good example of a rupture from fatigue. My alu bike broke on the chainstay near the cassette after about 20000km. Fatigue is caused by the loss of ductility from the materials after a certain amount of stress cycles... Carbon is not likely to do that, having a much better resistance to fatigue...
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2007-09-18 8:39 AM in reply to: #966903 |
Champion 4902 Ottawa, Ontario | Subject: RE: Carbon vs Aluminum I am not a metalurgist or a structural engineer but I do love bikes. I have two aluminum bikes. One is a Pecco Eclipse with no carbon and it is a bit rough after a few hours. My other bike, a P2SL with carbon fork and carbon seat post is as smooth as silk. I don't know shite about structural fatigue but my 1998 Eclipse with welll over 30,000kms on it is fully intact and still rides very well. Never mind trying to analyse the situation to death. Just go to the bike shops and try out alu and carbon bikes in your price range. Your body ... and most especially, yourbutt ... will tell you which bike is best for you. |
2007-09-18 11:08 AM in reply to: #968362 |
Master 2202 St. Louis | Subject: RE: Carbon vs Aluminum tkbslc - 2007-09-17 5:04 PM Can you engineers explaing the "fatigue" to me? Do you mean the frame will actually break or that it will lose it's rigidity? How would one know when their frame has fatigued? I have a 10yo Alum MTB frame that still seems great to me. Fatigue is like when you bend a piece of plastic back and forth a whole bunch of times. After a while, it will break at the point it is being bent at. This is fatigue, in its most basic. This is happening to frames on a much smaller level of bending, but it is still happeneing. Also, yes... Cannondale seat stays are actually compliant. It may come as a surprise, but their CAAD8, and I assume CAAD9, design is fantastic. The seat stays are far less ridgid than other portions of the frame, and actually do absorb some bumps and vibration. I am sure not to the level of a good carbon frame, but to me, the CAAD8 seems to offer fantastic ridgidity, and some compliance(seat stays only)... and for a great price. Granted, its not a tri-specific frame. |
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2007-09-18 4:11 PM in reply to: #966903 |
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2007-09-18 5:32 PM in reply to: #969786 |
Subject: RE: Carbon vs Aluminum spokes - 2007-09-18 2:11 PM I keep wondering whether it makes more sense to buy a ti frame, though, vs. carbon because the ti has a much better chance of surviving a crash, correct? Besides a good deal, this is the primary reason I went Ti. That frame should last my entire life..... |
2007-09-19 8:36 AM in reply to: #966903 |
Elite 3022 Preferably on my bike somewhere | Subject: RE: Carbon vs Aluminum I can only add some really life examples to what the engineers have said. Many older sailboats have aluminum masts (they hold the sails UP). Over time, the masts will fatigue and will become soft. The mast on my old sailboat was sloppy - you could actually see it bend and flex when you really wanted it to be stiff. Newer aluminum masts were MUCH stiffer, and therefore faster. Carbon masts are stiffer and lighter than aluminum masts. And faster. I used to work in the car wash industry, and I would watch aluminum fail all the time. Vibrations simply wear it out, and with the equipment working over and over, it would simply vibrate itself to death. Steel would withstand those vibrations better, but the steel equipment tended to be heavier and more expensive. I learned to be more careful inspecting the aluminum equipment than the steel simply because aluminum was more brittle. This isn't to knock aluminum. It's is what it is. Carbon is what it is. We just need to understand the strengths and weaknesses of the tools we work with. |