Carbon vs Alum stress test
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Carbon vs Alum stress test
This might be old, but its new to me - interesting watch.
https://www.pinkbike.com/news/santa-c...-test-lab.html
https://www.pinkbike.com/news/santa-c...-test-lab.html
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Wow ... I hadn't seen this before, but it's impressive. Probably has little to do with road riding, which might be why they tested mountain frames.
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They tested mountain bike frames because that's all Santa Cruz makes. The article doesn't make it clear, but I suspect they do more than two types of tests; some might be more appropriate to road bikes.
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There's a thread going on about this in the road forum: https://www.bikeforums.net/showthread...inium-testing-!
One of the posters claims that the CF frames in the test have been ridden for two years, and aren't in pristine condition when they're put to the test. I have no idea whether this is true or not. Sounds slightly dubious.
One of the posters claims that the CF frames in the test have been ridden for two years, and aren't in pristine condition when they're put to the test. I have no idea whether this is true or not. Sounds slightly dubious.
#6
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There's a thread going on about this in the road forum: https://www.bikeforums.net/showthread...inium-testing-!
One of the posters claims that the CF frames in the test have been ridden for two years, and aren't in pristine condition when they're put to the test. I have no idea whether this is true or not. Sounds slightly dubious.
One of the posters claims that the CF frames in the test have been ridden for two years, and aren't in pristine condition when they're put to the test. I have no idea whether this is true or not. Sounds slightly dubious.
This particular Nomad Carbon has already seen its fair share of abuse, having been through 200,000 cycles of fatigue testing, two different impact test scenarios, and then ridden hard for two years by a Santa Cruz employee.
Next up, another Nomad Carbon, this time Sven Martin's personal frame that, prior to us deliberately trying to break it, spent much of its life travelling the world under the ex-pro WC downhiller. Yeah, it has already had a tough life, but its time had come.
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Well, I certainly didn't read the whole article ... but thanks for providing the cliff notes. That makes the test results all the more impressive.
#8
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It's for this reason that Santa Cruz encourages larger and more aggressive riders to choose carbon when considering a new frame - they are simply stronger.
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After seeing this I'm glad the carbon versions of the Santa Cruz Blur TR and Tallboy are on my very short list to replace my venerable 1997 Ellsworth Truth MTB.
#11
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I'm not one of the "sponateously sploding" proponents. But, I am one of the "failure mode" proponents. And one thing that video certainly demonstrates and that they even make mention of, is that the carbon, while stronger, fails in a more dramatic fashion. Complete seperation of both down and top tubes as opposed to the crumpling of the alu frame, but, with head tube still attached to frame.
I don't think you'll find many people absolutely condemning "carbon". What you do find is quite a few who point out not only the above, but also, that carbon reinforced plastic frames can and do hide damage before failing in that "more dramatic" manner. And, subsequently, advising caution in the selection of carbon components and frames for use by clydes.
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I'm not one of the "sponateously sploding" proponents. But, I am one of the "failure mode" proponents. And one thing that video certainly demonstrates and that they even make mention of, is that the carbon, while stronger, fails in a more dramatic fashion. Complete seperation of both down and top tubes as opposed to the crumpling of the alu frame, but, with head tube still attached to frame.
I don't think you'll find many people absolutely condemning "carbon". What you do find is quite a few who point out not only the above, but also, that carbon reinforced plastic frames can and do hide damage before failing in that "more dramatic" manner. And, subsequently, advising caution in the selection of carbon components and frames for use by clydes.
I don't think you'll find many people absolutely condemning "carbon". What you do find is quite a few who point out not only the above, but also, that carbon reinforced plastic frames can and do hide damage before failing in that "more dramatic" manner. And, subsequently, advising caution in the selection of carbon components and frames for use by clydes.
I would "double dog dare" (yes double dog) any titanium,steel, aluminium frame builder to take ONE just ONE swing like that to
the downtube and see the results. It wouldn't be pretty.
I have several AL bikes and some light weight ones have down tubes with tubing only 4X thicker than a beer can.
#13
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I'm not one of the "sponateously sploding" proponents. But, I am one of the "failure mode" proponents. And one thing that video certainly demonstrates and that they even make mention of, is that the carbon, while stronger, fails in a more dramatic fashion. Complete seperation of both down and top tubes as opposed to the crumpling of the alu frame, but, with head tube still attached to frame.
What you do find is quite a few who point out not only the above, but also, that carbon reinforced plastic frames can and do hide damage before failing in that "more dramatic" manner. And, subsequently, advising caution in the selection of carbon components and frames for use by clydes.
#14
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This seems like a spurious argument to me... Both the aluminum and carbon frames ended up broken and unusable. Does it matter that the head tube of the aluminum bike was was still attached to the rest of the crumpled and unusable frame? If you were riding the carbon frame and slammed into a brick wall with 2,050 pounds of force do you really think you'd care that the frame broke in two places? Or would your broken ribs, punctured lung and missing teeth be a greater concern?
Personally, I've never heard a hidden damage claim that held up if you bothered to dig beneath the surface. They usually end up being something along the lines of: guy crashes bike, guy keeps riding bike without having it inspected by someone who knows what they're doing, eventually bike fails. Sorry, but in my mind that's a failure of the rider not the material.
You're correct with regard to these being rider/owner issues, not material issues. There's nothing wrong with carbon. And, as demonstrated at the end of the clip with the swing at concrete, it can be design to hit a ball out of the park. It can also be design to just fulfill a design brief with minimal service/safety factor and be a time bomb just waiting to go off. If I remember correctly, in another thread you expressed how hesitant you would be to purchase a used "carbon" frame unless it had been a single owner, who you knew and the history of the bike, etc. But, didn't express the same concerns about steel options. Doesn't that suggest that we're both on the same sheet of music with regard to carbons ability to conceal previous damage that may result in future issues?
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I t-boned a van at 40mph on a full carbon bike in 2006.
The damage to me was like this: 80+ stitches from the knee to the hip and on the broken elbow. Glass imbedded in skin and muscle, a chunk of meat ripped out of the side of my knee the diameter of a golf ball and almost to the bone, the associated road rash everywhere.
The damage to the full carbon (wheels, everything) bike was like this: One (rear) tubular wheel, one broken carbon crank arm, one broken shoe and the bar tape.
The rear wheel was destroyed because the tire rolled off the rim under braking and the asphalt chewed it up.
I've been riding that same bike ever since around 6-10k miles a year. I don't know what the force of my 230lbs hitting the side of the van at 40mph was but there doesn't seem to be any "hidden damage" almost 6 years and at least 40k miles latter.
The damage to me was like this: 80+ stitches from the knee to the hip and on the broken elbow. Glass imbedded in skin and muscle, a chunk of meat ripped out of the side of my knee the diameter of a golf ball and almost to the bone, the associated road rash everywhere.
The damage to the full carbon (wheels, everything) bike was like this: One (rear) tubular wheel, one broken carbon crank arm, one broken shoe and the bar tape.
The rear wheel was destroyed because the tire rolled off the rim under braking and the asphalt chewed it up.
I've been riding that same bike ever since around 6-10k miles a year. I don't know what the force of my 230lbs hitting the side of the van at 40mph was but there doesn't seem to be any "hidden damage" almost 6 years and at least 40k miles latter.
Last edited by Homeyba; 02-24-12 at 07:59 PM.
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... However, we ride bikes that have all suffered some real world wear and tear and we all make judgement calls about those bikes. Just this morning, Mrs. Fred had her bike support by a pedal on the curb when a gust caught it and caused it to fall over. It landed in the grass, no noticable damage. Had it falled over and impacted on its carbon tubes in the middle on said curb, it could very easily be subject to the sort of hidden damage that we're talking about. Or, 70mph stone chips to the down tube of an extremely light racing frame mounted on the roof rack of a car....
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I love my CF bike but I wouldn't tighten the seatpost clamp without a torque wrench. It has a totally different feel than anything else.
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I'm reasonably sure that your point holds true. There probably aren't any/many hidden damage claims that would have been as a consequence of manufacturing defect. However, we ride bikes that have all suffered some real world wear and tear and we all make judgement calls about those bikes. Just this morning, Mrs. Fred had her bike support by a pedal on the curb when a gust caught it and caused it to fall over. It landed in the grass, no noticable damage. Had it falled over and impacted on its carbon tubes in the middle on said curb, it could very easily be subject to the sort of hidden damage that we're talking about. Or, 70mph stone chips to the down tube of an extremely light racing frame mounted on the roof rack of a car.
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And one thing that video certainly demonstrates and that they even make mention of, is that the carbon, while stronger, fails in a more dramatic fashion. Complete seperation of both down and top tubes as opposed to the crumpling of the alu frame, but, with head tube still attached to frame.
Carbon one fails, and sharp, strong carbon fiber spears stab you in the crotch.
I know which one I would prefer.
The strength of the carbon is impressive, though.
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Really?? When was the last time you saw a top tub on any bike fail???? Realistic fears I don't mind...
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#22
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Would you like to place any sort of wager at all on the outcome of doing the same with a Storck Fascenario?
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I'd have no problem with that wager but to be fair if you are going to choose one of the lightest carbon frames you should compare it to one of the lightest steel frames like maybe the Rodriguez S3. I think you are stretching here...
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Aesthetics aside (an awful important side to me), composites really are the future of bicycles when it comes to pure performance. Almost every performance bike out there is made of carbon - even the downhillers are moving that way. As I said though, aesthetics are important to me. Its hard for me to look at a really nice bike frame like this one (Pegoretti) and not prefer it over something else.
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