Carbon vs Titanium???

[Wonder Woman]

But they do often ride top of the range bikes....c'mon non of those top boys will ride anything less!!

 

You think Lance just rode what was given to him...we all know how fussy some of these guys can be!!

 

I think they need the responsiveness of a carbon bike!!

 

 

[Edition 507]

One question...if titanium is the best material for a bike' date=' why aren't all the pro's riding titanium????

[/quote']

 

WW, there is nothing wrong with carbon frames, they are fantastic, very light, very responsive and above all very sexy. But, the main reason for the popularity of carbon frames is that they have become cheap to make thru the advancement of technology whereas Ti still remains an extremely difficult material to work with hence the cost that puts out of the reach of the common old garden cyclist. It is purely market driven and anyway, a pro rides what he is sponsored, he does not have too much of a say in the matter.

[Christie]

Carbon composite is the better material for frame construction. It is lighter, stifer and stronger and has a better fatigue life than titanium. Ti is more expensive, as well, and as I understand, Ti welds are very very difficult to do right, so the risk of problems down the line on a Ti frame is greater.

 

The magic of composites is that its structural response can be "tuned" by manipulating the laminate stacking, fiber type and fiber orientation. If done right, a carbon frame will give better stiffness, better strength, longer fatigue life and better ride comfort at less mass compared to a Ti frame.

 

IMO Ti frames is for people who want to be unique, pay a lot more for their frame, so much so that they are willing to live with the drawbacks of Ti.

[Wonder Woman]

Yay, I was hoping to get a reply from you....Thanks Christie!!!

[Christie]

I forgot to add, if ride quality is your priority, why not get a Colnago Master or a Pegoreti steel? Steel is supposed to give a better feel than Ti, the only reason Ti became popular long ago is that it is lighter. But Ti is not the king of light  weight materials anymore ! 

Christie2008-06-25 09:09:03

[Christie]

Yay' date=' I was hoping to get a reply from you....Thanks Christie!!!

[/quote']

Christie2008-06-25 09:13:12

[Edition 507]

I beg to differ Christie, you are so misinformed. Ti frames have a lifetime guarantee, something I have never seen on a carbon frame. Fatigue is almost non-existent in Ti which is why it is so prevalent in the aeronautical and space industry. Crash a Ti bike and you get up and continue riding, crash a carbon bike and it has a big chance of needing replacement. When carbon breaks, it breaks catastrophically, but it is almost impossible to break Ti, although you may bend it with extreme difficulty. Bottom line is carbon is cheap and easy to make which is why it is popular and why there are a gazillion Taiwanese carbon frame manufactures out there all competing for a small slice of the market. By the way, the lightest frame you can buy is a Litespeed, and with geometrically enhanced tubing, there is no evidence that they are any more flexible than the equivalent carbon frame and it will outlive any carbon frame. Carbon bikes are very decent mass produced commodity frames for the general populace while Ti bikes are hand crafted, guaranteed for life, bullet proof equivalents ridden by the connoisseur for whom money is no obstacle!<?: prefix = o ns = "urn:schemas-microsoft-com:office:office" />

[boeing]

 

Carbon composite is the better material for frame construction. It is lighter' date=' stifer and stronger and has a better fatigue life than titanium. Ti is more expensive, as well, and as I understand, Ti welds are very very difficult to do right, so the risk of problems down the line on a Ti frame is greater.

 

The magic of composites is that its structural response can be "tuned" by manipulating the laminate stacking, fiber type and fiber orientation. If done right, a carbon frame will give better stiffness, better strength, longer fatigue life and better ride comfort at less mass compared to a Ti frame.

 

IMO Ti frames is for people who want to be unique, pay a lot more for their frame, so much so that they are willing to live with the drawbacks of Ti.

[/quote']

 

I beg o differ too. Carbon needs to be replaced every couple of years due to fatigue, whereas Titanium doesn't lose any of its stiffness. As to the reason why pros ride Carbon bikes, apart from the obvious; they get a new bike every 6 months dont they! As a result, composite fatigue does not factor into the material.

 

Titanium is just excessively expensive, and difficult to manipulate into a frame

 

[Spaceboy]

This is awesome input guys, and a good discussion to boot.

 

So basically, Ti is a bit heavier, but the ride is more comfortable, where Carbon is lighter and stiffer(more responsive), but not as comfy?

 

I must say i like the look of Litespeed. The Archon is definitely not a consideration.... was thinking more along the lines of a Siena. Anybody familiar with this frame?

 

Litespeed or Cervelo?

 

This is a tough questiuon for me, but I am happy to be in a position to sit with this kind of a problem

[boeing]

 

Lightspeed. The sienna is a fantastic frame.

If possible though, why not try and organise a test ride on each with similar components

 

boeing2008-06-25 10:02:41

[Spaceboy]

This is nice, right?

 

 

 

[Christie]

I beg to differ Christie' date=' you are so misinformed. Ti frames have a lifetime guarantee, something I have never seen on a carbon frame.

[/quote']

Trek? Cervelo? Cannondale? etc etc ?

Fatigue is almost non-existent in Ti which is why it is so prevalent in the aeronautical and space industry.

Below is a fatigue curve from a fatigue and fracture course by Dr Neil Bishop. (Specific fatigue strength is stress/density). The graphite epoxy (or what we call carbon) vastly outperformes the rest' date=' that is why F1 syspension arms are made from carbon, instead of Ti like long ago.

Crash a Ti bike and you get up and continue riding, crash a carbon bike and it has a big chance of needing replacement. When carbon breaks, it breaks catastrophically, but it is almost impossible to break Ti, although you may bend it with extreme difficulty.

Depends on the crash! Ewep wrote off his ti Colnago the other day riding into a car. Bicycle frames are not designed to crash. Not having frame damage after a crash has much to do with luck.

By the way' date=' the lightest frame you can buy is a Litespeed, and with geometrically enhanced tubing, there is no evidence that they are any more flexible than the equivalent carbon frame and it will outlive any carbon frame.

[/quote']

Lightest production frame is the Scott Addict, not so? As far as custom frames go, the world record lightest bike has a carbon frame too.

The Ghisallo Tour magazine tested in their lab was a noodle compared to the other frames, it was light, but it had the lowest BB stiffness of about 14 or 15 frames tested.

Carbon bikes are very decent mass produced commodity frames for the general populace while Ti bikes are hand crafted' date=' guaranteed for life, bullet proof equivalents ridden by the connoisseur for whom money is no obstacle!<?: prefix = o ns = "urn:schemas-microsoft-com:office:office" />

[/quote']

Like I said, buy Ti, pay more, get less.

Christie2008-06-25 10:32:19

[Spaceboy]

So Christie, you reckon Cervelo over Litespeed?

[Christie]

So Christie' date=' you reckon Cervelo over Litespeed?[/quote']

 

Depends what you are looking for.

For low mass, stiffness, and comfort, Cervelo R3

For comfort, nice road feel, dont worry amout mass, Colnago Master X-light

For "I'm loaded and dont care what I buy as long as it is the most expensive" go for a Litespeed Vortex, a custom Seven or Linskey. (edit - these are superb frames, but the point Im trying to make is you can get a carbon frame that is better in every aspect, for less money)

 

Christie2008-06-25 10:48:47

[boeing]

 

Below is a fatigue curve from a fatigue and fracture course by Dr Neil Bishop. (Specific fatigue strength is stress/density). The graphite epoxy (or what we call carbon) vastly outperformes the rest' date=' that is why F1 syspension arms are made from carbon, instead of Ti like long ago.

[/quote']

 

Firstly, Carbon Fiber and Graphite are not the same material. They are isotopes! Graphite flexes, something you wouldn't want in carbon fiber. However, due to carbon fiber not flexing, there is a big fatigue factor with the material.

 

[Christie]

Carbon needs to be replaced every couple of years due to fatigue' date=' whereas Titanium doesn't lose any of its stiffness.

Titanium is just excessively expensive, and difficult to manipulate into a frame
[/quote']

 

See the graph I posted above. The curve represents cycles to crack initiation. Carbon has by far the best fatigue life of frame materials.

 

Also, none of the materials, Alu, Steel, Ti or carbon lose stiffness over time. (unless you ride at at high temperatures, in the range of a couple hundred degrees C)

 

After a certain fatigue life, it will crack. Up to the point of crack initiation, stiffness remains unchanged. Bottom line is: If you cant see a crack, any frame is as stiff as the day it left the factory.