Aluminum vs. Carbon fiber vs. Titanium

Anyone who is involved in the product development process is familiar with some form of destructive testing. Admit it, it is fun to push materials to their limit and watch them fail. This post is not really about a test per se, but more of a demonstration. Still, if you are interested in seeing a few bicycle tubes being crushed (and I know you are), check out this Google video from the folks at Litespeed. Brad, the company’s chief engineer, narrates the video as Scott drives a big crew cab pickup truck over a carbon tube, an aluminum tube, and finally a titanium tube. I won’t spoil the ending for you, but I am pretty sure you can guess which tube emerges intact. Stay tuned to the end. Brad seems to be pretty happy with the results as he laughs devilishly while the video closes.

This demonstration does not, of course, simulate the stresses on a bike frame during normal use, but it does point to the toughness of titanium as a raw material. I enjoyed watching it and I did come away with a very valuable lesson; stay away from big F250 trucks while you are riding regardless of your frame material.

Posted

June 22, 2006

Miscellaneous

James

Tags:

destructive testing, Litespeed, materials, titanium

Comments

37 responses to “Aluminum vs. Carbon fiber vs. Titanium”

Anonymous

June 22, 2006

I wonder what technique they used to cut the carbon tube. Micro-cracks in the end could have propagated more due to the fact that they rode over the tube at the end that it was cut at, as opposed to the center.

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pedalmaniac

June 22, 2006

Wow, I guess I can roll over my DC Hummer with my car now, thank goodness for that 😉

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Herbert

June 22, 2006

The carbon tube was actually not cut at all, as that tube was created as it was used for a lugged frame. So there were actually no micro cracks.
As for the demonstration itself, it was actually meant to simulate a traumatic stress on a frame in the category of crashing hard, or the bike falling of the roof rack or the bike being driven into the garage on top of the roof rack.

Herbert
Litespeed

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The Ford F250

June 22, 2006

Let me put on my Seth Godin hat for a minute and say bull. Your little movie was not intended “to simulate a traumatic stress on a frame in the category of crashing hard, or the bike falling of the roof rack or the bike being driven into the garage on top of the roof rack.” If that was your intension, you would have said so in the movie.

Your real objective is pretty clear:

Carbon is not safe.
Aluminum is only a little better.
Ti won’t let you down.
Think twice about what you ride.

Not exactly copy you can put into VeloNews ad, but clearly the message you want to get out. Your argument might be valid, but it is definitely not fair. I would chalk this video up to the second salvo in the “look what we found out about material X” war. The most recent being Trek email with the photos of newspapers stuffed into the carbon tubes. As for launching the movie as a marketing tool (nice touch putting it on Google Video – go viral little mpeg!), I give it a C+.

P.S. Love the blog James.

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jeanthibca

June 23, 2006

What about steel?

http://bicycledesignblog.blogspot.com/

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James

June 23, 2006

Wow, a truck that can type! Kind of scary, but thanks for the blog compliment.

I appreciate your comment, but I have a few issues with it. Since you mentioned Seth Godin, I assume you don’t have a problem with the whole idea of viral marketing. So what is wrong with this video? Of course Litespeed wants to spread the message that titanium is the best material for bikes and that it “won’t let you down”. I don’t see a problem with that at all. You may or may not agree, but it is certainly understandable to me that they are believers in the material and want to spread the word. At the same time, Trek wants to make potential customers suspicious of inexpensive carbon frames so they will buy OCLV frames. So what? In both cases, I don’t think the companies are presenting anything that is at all deceptive. Would Litespeed have posted the video to the web if the ti tube had flattened like a pancake? No, but as expected, it didn’t, so what is wrong with them using it to their advantage.

Personally, I own several bikes made from different materials, including an older titanium Litespeed. Currently, my main road, mountain, and cross bikes all happen to be aluminum. I like aluminum frames because they are light, stiff, and relatively inexpensive. I certainly do not think they are going to last forever if I ride them hard (I have cracked one in the past), but I knew that when I bought them. If I did not already know that and was in the market for a bike that I planned to keep forever, this video might convince me to consider a Litespeed. So I think it is a pretty good little marketing tool. Besides, content only spreads virally if it generates enough interest to be forwarded. I thought this video was interesting enough to post. We’ll have to see if it spreads further.

Jeanthibca, I wondered about steel as well. I suspect that an older round steel tube would fare pretty well. A new thin wall one would probably flatten. Maybe somebody should try it at home and report back.

Thanks to all of you for the comments. I like the discussion.

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bigz

June 25, 2006

Thats what I call protecting an investment. I had an Ali Easton frame road bike. That survived a fall of a roof rack at 60mph(raced it that night, damage was only ripped tape and scratches to derailer). Bent the steel forks in another crash. Bent the replaceable derailer attachment after getting caught in tram lines busting 2 wheels until finally being wiped out by a car 7 years later. Not bad for a mere Ali frame for a fraction of the price.

Just between us 2.Did you ever make any for the GAN team? But badged under a certain Belgian cyclists name.

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Anonymous

June 25, 2006

Herbert, if the “test” was to simulate a hard crash shouldn’t the ti sample come from a bike instead of being raw material?. I wonder how an “enhanced” Ghisallo tube would have performed here.

To me this seems like a cheerleading act targeted to a cheerleaders audience. Litespeed’s tagline is “World Leader in Cycling Technology”. Shouldn’t a brand so proud in their engineering and production methods communicate with greater accuracy?

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Dirk

June 26, 2006

I wonder how relevant this is. Sure, it is a nice populist marketing movie but how relevant?

When you design a good composite bike then you design it to the expected forces on each of the sections of the frame. Based on these forces you decide which materials to use, the lay up direction and how many layers.

That is the great thing of composite, you can really design a bike the way you want it. Torsional stifness here. push forces there etc etc.

I am talking about monoque frames like the Giant TCR series and some others. Just a composite tube is never designed for a truck to go over it. So to do this test is maybe viral marketing but it has nothing to do with the real world.

If needed one could design a tube to withstand a truck riding over it. But there are no generic composite parts, if done proberly, each section is desgined with a particular force(s) in mind.

The properties of a composite part are designed at the drawing table (computer) unlike metal tubing.

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Herbert

June 26, 2006

Here it is, the “test” was actually not our idea at all. We had a European TV Network visiting who was doing a story on our fabrication process and they wanted a visual demonstration of ti versus carbon versus aluminum in terms of strength.
Initially we ran over complete bike frames, but the reporter thought that conspiracy theory fans might think that we may have filled the ti frame or manipulated the wall thickness. So they asked us to use plain tubes so everyone could see what was inside and how thick the walls were.
The result of that demonstration just ended up being funny and we all had a laugh about it. As for true frame testing we do that with machines that simulate pedal strokes and torque on the frame, that unfortunately was actually visually just not that exciting for the tv crew. But that will actually be on our website before too long.

Herbert
Litespeed

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Anonymous

June 27, 2006

Shouldn’t all the tubes be of similar diameter to be a true test too? I’m guessing that the smaller diameter would fare better in athe truck tire test too. Get four mountain bike handlebars: one steel, one aluminum, one carbon, and and titanium. Why did bar ends crimp my titanium handlebars, yey not leave a mark on the steel and carbon ones?

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54

June 28, 2006

This is just a bunch of marketing BS.

The Ti tube is “unenhanced”, that means the tube walls has not been machined/tapered down to actual thickness. With the tube enhacements, the Ti tube will likely to be half as thin.

Try doing it with a actual Ti tube that you put on your bike, Litespeed.

I got nothing against Ti, Al or Cabon. I think that are all great engineering materials to build a bike. How well your bike stands up in real world use, depends on your engineers’ ability to harness the material’s strengths.

I bet I can set up a demonstration to show three different winners, too.

This is what happens when the marketing dept. takes over. Lets face it… Bicycles been around for ages, and there are hundreds of company around the world that can design and build these things, and it’s becoming a commodity product.

It’s nothing more than just some maketing guy trying to add a little new buzz word to the same old.

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Tim Jackson- Masi Guy

June 29, 2006

Wow, Herbert, sorry for the hostility. Personally, as one of those guys competing against you, I believe your story. Why? Because that is the kind of thing that actually happens. Giving people what they ask for can come back to bite you in the butt.

For what it’s worth, I thought it was pretty entertaining.

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James

June 29, 2006

I am all for discussion; that is what I enjoy about writing this blog. Still, if you have a criticism, you should be willing to back it up with a name and an email or profile link like Dirk and 54 did. If you are scared to stand behind what you say, then really how valid is your opinion? I have continued to allow anonymous comments on my blog and I will probably continue to do so, but they seem to carry less and less weight as the readership grows. I know that some people comment anonymously because it is an easily available option so I will continue to give those people the benefit of the doubt, but I would prefer if commenters would at least type in a name.

Also, I think it is worth pointing out that Brad in the video is an engineer, not a marketing guy and as I said in the post, this is a demonstration and not a test. Herbert, I will look forward to seeing some of the real tests on the Litespeed website soon.

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Anonymous

July 24, 2006

why not use wood?

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mf218

July 28, 2006

Wow! some people get really bent out of shape about a little video. I’m not sure if everyone can read but I believe he said it was not a test but a demonstration. Also, it’s not like Litespeed sent this video out as a mass marketing ploy. It took me 20 minutes of searching to find this video. so all of the people who are crying about how this is wrong, you have two choices. Either shut up, or make your own video that contradicts this one.
I thought the video was very entertaining. Hope you boys at Litespeed are well.

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Oswaldo

September 4, 2006

I’m thinking about changing my aluminum bike for a lighter, more flexible, faster and absorbent Cross Country Mountain Bike.

I don’t know if I should go for Carbon or Titanium. What do you recommend?

Regards,

Oswaldo

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Anonymous

October 30, 2006

My racing experience goes back to the early nineties when you still heard stories about early carbon construction failures, aluminum top tubes that crushed when sat on during a crash, and first hand experience helping someone carry the pieces of a steel bike off the course when the frame broke from being run over by another rider.
Usually you hear terms like equivalent or more strength for the same weight. So if we are ‘testing’, we should either use actual tubes as they are assembled onto a frame, or perhaps tubes of the same weight to simulate say the tubes in a 17lb bike or a 20+lb bike.
There are also the modes of failure to be reflected on. Landing on the top tube is both painful to you and hurtful to the tube. It could be represented for most of us by dropping a 50 bag of sand on the top tubes of various bike frames.
Also, in cyclocross and mountain biking, hitting a rock would be another common mode of tube failure. So perhaps a ballpean hammer of a fixed weight dropped on the top tube of each bike frame would be a good test.
Soon we would be discussing ductile vs brittle failures modes and residual stress affects on the longevity of the frame, etc. And everyone would go to sleep.

So for my money, keep running over the tubes, very intertaining! Thanks.

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Anonymous

October 30, 2006

Okay, I’m back from the hardware store and I have the results for regular old galvanized 3/4″ steel pipe!
While my 1977 Datsun pickup does not weigh as much as the truck in the demo, here are the results.
Doesn’t matter how you cut galvanized pipe, it will not crush. I even dropped a few 1/2man sized stones from my rock walls on it and hardly scratched it.
So I am off to the hardware store for some welding equipment. Going into the frame building business. Look for my new line of galvanized pipe frames on ebay, keyword, “indestructible”!!!

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Anonymous

November 20, 2006

Sorry IT”S A TRICK!

Did you guys see that the truck’s front wheel (in the case of the Ti tube) started from behind a lowered crack in the cement? Thus changing the angle of attack on the Ti tube? Watch it again!!!!!!

Sly devils!!!!

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Anonymous

May 23, 2007

JUST RIDE YOUR BIKE!!!!!!!

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Anonymous

July 6, 2007

wow I guess they will start making formula one cars out of titanium instead on carbon fiber….not!
Can’t beat strength to weight ratio of carbon fiber/composite..F1 manufactures spend millions in R & D to reduce the weight of these cars.

kevin_848@hotmail.com

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Anonymous

July 21, 2007

carbon fibre is light and strong but the carbon fibre tubing used for the test should have had a thicker wall.
if they used CF tubing that weighs as much as the aluminum tubing (or maybe a little bit heavier) then maybe it could’ve been strong enough to withstand the weight of the vehicle.

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Mario Grgic

July 26, 2007

Breaking of tubes has a lot to do with brittleness of the material rather than absolute strength, i.e. what happens when the force applied is higher than the maximum.

Most metals will yield (i.e. they will bend and have plastic deformation and will stay bent). Carbon fiber, glass, concrete are brittle and do not have a yield point, they simply crack.

So we have just seen a demonstration of what happens with materials when a huge force is applied to them.

From a safety point of view steel or titanium bike is safer to ride esp after the crash (I have bent my steel forks back into position after crashes many times). You can not super glue your carbon fiber fork back on however.

However, if you never crash the bike carbon fiber bike is perfectly safe and good ones are made rigid where they need to be rigid to transfer power efficiently and flex y on the other hand to absorb road chatter (which is extremely hard to do with other materials).

I would prefer to see a demo of someone given titanium, steel, aluminum and carbon bikes and asked to wreck them by hand (e.g. bend and fatigue the fork and see what kind of force is required to break it).

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Anonymous

September 6, 2007

In reply to: “Did you guys see that the truck’s front wheel (in the case of the Ti tube) started from behind a lowered crack in the cement? Thus changing the angle of attack on the Ti tube? Watch it again!!!!!!”

I agree with you that the test wasn’t true with respect to what all 3 materials endured. With that said, the Titanium tube got a pounding. The others didn’t get scraped along the ground.

FYI – I’ve ridden an aluminum bike and currently ride a CF bike. I’ve heard/read a lot of stories (and warning stickers on CF bikes) telling you not to ride them after a crash or stories of how people that suffered crashes on CF bikes/forks could’t ride home.

If I was on the Ti bandwagon I’d get a Ti bike (probably a generic brand since I don’t have the money for a LiteSpeed) but as a scientist I’d ride away from a crash without thinking twice if I was on any metal bike vs. my generic CF framed bike.

Indy cars teams, etc. are in business to make money – that’s why they put their lives at risk going rediculously fast speeds with machines and parts that can be instantly replaced in the event of a crash. I’m not that rich – I can’t replace a CF frame if I crash. Can you? If I do crash (and I’m sure I will eventually), I’ll replace my frame with a Ti rather than another carbon. I’m not a pro and could care less about 1 pound.

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Steve

September 22, 2007

As a Florida triathlete, I’ve been told that the salt water will corrode an aluminum bike and I should go carbon. Huh?

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Johnathan

November 1, 2007

Well, I saw a ali tube fold, and a carbon tube snap. I don’t build bike frames, but at 200 plus pounds, build me a bike that withstand a pothole at 18+ with a 250 pound rider on it, and I’ll buy it. For now I’ll stick wtih my mailorder ali frame until I get my carbon Jamis built up.

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Anonymous

November 27, 2007

well, i ran into a car (that appeared from nowhere on the cycling path) at around 22km/h. Not that fast, but it was front impact. Just got the news: my titanium frame looks pretty, but it’s not. Have to change the whole bike (except the rear wheel). Loved my ti for ten years, gonna get a new one (still… cuz it never dents, stays nice, never rusts). As for resisting impact, imoho, nothing does except a good helmet (went right thru her window). Never thought i’d damage my ti like that. Just depends on HOW you hit it I guess…

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Anonymous

July 8, 2008

I am mechanical engineer and a cyclist weighing 100kg.
I have owned several frames made from steel, aluminium, carbon and titanium.
2 steel frames failed close to braze area. Titanium (litespeed) failed at headtube to downtube weld. Carbon trek Madone and carbon Specialized Roubaix have not failed.
All failures occurred during riding.
I think my experience is more valid than the Litespeed test video.
Titanium is a supreme material where tensile strength and durability are concerned, but as soon as it is welded there is a weakness introduced.
I have heard of so many Litespeed frame failures. Mine failed after 3 months, Litespeed would only repair the frame and it would take 6 weeks minimum, no replacement or refund was offered.

Andy T

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Anonymous

July 18, 2008

Does this mean Litespeed’s are over-engineered and heavier than necessary?

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Anonymous

October 30, 2008

I snapped an ’09 Specialized Roubaix elite in two a week ago. Beautiful full carbon. I’m not sure if I’ll go carbon or steel for replacement. I think the important thing about materials is suiting your needs. I have a habit of destroying bikes, but I know certain materials accelerate faster. People shouldn’t be personally attached to materials. I’ve got an aluminum bike that I love, and I’ve got a lovely custom Ti bike also. But I’m not going to say “ooh! Ti beats carbon!” Carbon is torsionally stiff. Ti is absorbant. Steel is real. What can I rhyme with aluminium? Come on people.

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Bici

January 6, 2009

Hi All!

What material do you recommend for a road bike?
Very important:
– lifetime and
– as comfortable as possible
Important:
– weight
– stiffness

Thanks!

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Anonymous

July 9, 2009

regardless of the variables, the ti is stronger than any of the other materials. that doesnt mean that its better for a frame. it adds a high priced option to those looking for something extremely durable. EVERYONE knows that when carbon fails, and it will, it fails catastrophically. aluminum is used by huffy, pacific, murray etc… even carbon is being produced in cheap. pinarello uses magnesium for gods sake. magnesium burns at a pretty low temp. buy what feels good.

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Anonymous

August 8, 2009

The overwhelming choice of frame material at the 2010 Tour De France was and will continue to be Carbon Fiber. Case closed. If I ever decide to race my bike underneath a truck wheel, I'll buy Ti.

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Anonymous

September 5, 2009

This thread is in desperate need for a materials engineer.

Carbon fiber is a *fiber*.

A *fiber*.

When it comes to stresses, two of the most basic types are compression and tension (bending, shear, torsion are others).

Summarizing a material's endurance of these stresses to a single word – "strength" – is woefully inadequate.

While carbon fiber's tensile strength is ridiculously high…

YOU CAN'T PUSH ON A ROPE.

In other words, carbon fiber *as a fiber* offers no meaningful compressive strength.

When a carbon fiber composite tube endures a compressive force, it would be accurate to say that pretty much all of the compressive load is taken on by the "composite" part of the material only.

Now if the video demonstrated a truck attempting to pull these tubes apart, the carbon fiber tube would have performed more admirably. But it didn't, because this wasn't a tension test, this was a compressive strength test.

So to summarize:
1. Materials do not have one "strength".
2. You can't push on a rope.
3. "Stronger" does not simply imply "better". "Stronger" only is "better" when it's taken to in the context of "more appropriate for its environment".

So while carbon fiber failed miserably in this demonstration of compressive stress, this does not mean that titanium is "better" than carbon fiber. What this demonstration concludes is a titanium tube is much better at resisting a compressive load than a carbon fiber tube!

So does this mean a titanium tube "better" than a carbon fiber tube?? From what this video demonstrates, only in situations/environments where it will be subject to high compressive stresses!

So you people with carbon fiber bikes and fragile egos can just relax.

Now this doesn't mean resisting compression is all a titanium frame is good for (vs a carbon fiber frame). There are other qualities too. But those are for other clueless discussions following other video demonstrations…

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Anonymous

November 12, 2009

you guys are all stupid. they just did a demo messing around, and now u all act like this is the next superbowl commercialfor marketing. relax and shut up.

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Superhandyman

March 7, 2010

I am no scientist, but that demonstration did not impress me. I have been demolishing bikes at least once a year since x-mas 1979. No one mention using a composite of materials in the same frame. Using carbon fiber reinforcements where tension is required and Titanium where compression forces would be necessary we optimize the “strenght” of the frame. I believe that there are companies already using these technologies. Check out Titus exo–whatchmacallit frames. Can anyone here demonstrate the exo-thingy material vs. Titanium alone? — on video obviously.

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