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Discussion Starter #1
Ok, so what crank is going to be stronger and more durable...Record carbon or Centaur alloy. Reason I ask is that I'm a bigger rider and I recently swapped from the Centaur to the Record carbon and I'm just wondering how it will hold up. I know the Record is a lot lighter and so it could be weaker, but it's also designed for riders putting in big miles and who have lots and lots of power....so, what do you guys think? To be honest, the carbon cranks make me just slightly nervous but I like the light weight and ya know...they look awesome!
 

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there is no answer..

I can guarantee you that no one on this forum would have a clue, except by pure speculation. Why worry about it?

Also, why compare Record carbon, the most expensive, versus the much cheaper Centaur alloy that uses a longer spindle? Seems totally apples and oranges.
 

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C-40 said:
Also, why compare Record carbon, the most expensive, versus the much cheaper Centaur alloy that uses a longer spindle? Seems totally apples and oranges.
Ahem.

Reason I ask is that I'm a bigger rider and I recently swapped from the Centaur to the Record carbon and I'm just wondering how it will hold up.
 

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Got me there,

but what's the poster going to do, switch back to Centaur because somebody says they Record carbon is weaker?
 

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C-40 said:
but what's the poster going to do, switch back to Centaur because somebody says they Record carbon is weaker?
Got me, I think he wanted to be reassured everything was going to be ok, and it wouldn't snap off on him.
 

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Kant phuckin sphell
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Am I missing something here?

The centaur crank is stronger.
The carbon crank is lighter and cost more, and might even get you the podium girl you always dreamed of. :0
But the centaur crank is just a heavy bad ass hunk of aluminum.

There is less places for failure, you C-40 "the teacher" should know this.
Dam I feel disappointed in you.
 

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"bull"oney

From Hexcel:

The resulting carbon fiber is stronger than steel, lighter than aluminum and as stiff as titanium. It can be supplied in two basic forms: Continuous Fiber and Chopped Fiber.


From another carbon manufacturer:

Our Carbon Fiber materials yield strength is almost three times higher than 6061-T2 aluminum (CF40 = 44.5KSI compared to 6061-T2 = 16KSI). The low mass of our material allows us to use a thicker cross sections, which also adds to the strength. Twice the strength is an understatement.
 

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Discussion Starter #8
I'm just looking to see if anyone has any actual knowledge on the subject because I don't. That's all. Situation is that I'm a shop employee, I have both cranksets here and now. Money isn't a big factor for me at this point. The Record carbons came on a bike I bought complete, but ended up not liking the fit of the frame. Decided to break it down and keep some of the parts to upgrade my other frame with. Have a full Record groupo on there now and love it both functionally and asthetically, but I do have some concerns about cranks strength. Would like to keep them because they match the rest of the groupo (which i don't have any concerns about since none of the rest are weight bearing parts really) but want to make sure they are tough enough. Not really willing to sacrifice safet and realiability for a little weight savings, but like I said, since I already have them I would sure like to keep them on their.
 

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the bull said:
The centaur crank is stronger.
The carbon crank is lighter and cost more, and might even get you the podium girl you always dreamed of. :0
But the centaur crank is just a heavy bad ass hunk of aluminum.

There is less places for failure, you C-40 "the teacher" should know this.
Dam I feel disappointed in you.
This is a tragic miscarriage of logic.

Before being allowed to post a first post on RBR, a person ought to be forced to read 100 times the following:

"Component and frame properties--i.e., strength, stiffness, et al--are not functions of material properties alone. They are functions of design, construction method, actual use characteristics, and proper use of a chosen material."

Once that's been repeated 100 times, then a person should be tested on that. Then they should be forced to electronically sign a statement agreeing not to say things like "Material X is THE uber shiznit material," "Material Y will break," "Material Z will explode spontaneously."

Alas, that prolly won't work....hell, there's still a Flat Earth Society, so why should we expect people to think logically about pieces parts?
 

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Kant phuckin sphell
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dont forget

C-40 said:
From Hexcel:

The resulting carbon fiber is stronger than steel, lighter than aluminum and as stiff as titanium. It can be supplied in two basic forms: Continuous Fiber and Chopped Fiber.


From another carbon manufacturer:

Our Carbon Fiber materials yield strength is almost three times higher than 6061-T2 aluminum (CF40 = 44.5KSI compared to 6061-T2 = 16KSI). The low mass of our material allows us to use a thicker cross sections, which also adds to the strength. Twice the strength is an understatement.

Dont forget:
The aluminum cranks are solid. the carbon cranks are hollow bonded to aluminum in many different places.
 

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Kant phuckin sphell
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You should read this a hundred times...

functions of design, construction method

Remember the carbon that is said to be stronger is still bonded to aluminum at the ends.

Is your post directed to me? Seems like it should be going out to the carbon worshiper.
 

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slide said:
I'm just looking to see if anyone has any actual knowledge on the subject because I don't. .
I seriously doubt that anyone does. Some speculation maybe, but that's all. I don't exactly understand what you're worried about. I pretty experienced, and I've never heard of anyone breaking a crank or crank arm. Years ago, my a team mate and I folded over a 60 tooth Stronglight chainring on my tandem. The crank was fine, though.
 

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hrmm, everyone brings a good point...

my thing is... how heavy is heavy? if you are below say 90-100kg i think you should be alright, since i'm sure many pros run this and can weigh or put as much punishment on them as you can. Much more than that and i dont think lightweight parts are in your future whatever they are made out of, even unobtainium!

my other thing is, its not so much the "if" they fail as how they fail. I'm hoping my record alloy cranks should show a crack or two before they snap, perhaps they might bend before totally failing? wishful thinking? In any case, from the pics i've seen, carbon tends to go without warning and shatter... not good. The other thing is it will encourage you to run light pedals, and these carbon items i dont trust at all... no sir.. I dont think i would feel confident on carbon cranks and pedals... heavier alloy pedals would kill the purpose behind ultra lightweight cranks. soo.. no, but maybe that's just me...

i love my record alloy/ daytona pedals combo... i really crank it going up hill and i have every confidence in the equipment, which is worth much more than a few grams... IMO

remember, the bigger you are, the bigger you fall.. ouch. :(
 
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