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Discussion Starter · #1 ·
According to this article in the on line Motor Trend, there is a new CF automobile wheel, which will make its debut on the $189,000 Mosler.

Click here.

CF wheels, according to the article, have been available for motorcycles for some time, but this is a first. Too bad ithey're so damn butt ugly.
 

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I'm wondering why they haven't done this a long time ago? I did a search for them about 2 years ago. Found plenty for motorcycle cf rims, but none for cars. Koeniggsegg CCX actually beats out Mosler for world's first cf rims for cars.

carbon fiber is more brittle than metal so when the rim is compromised, the carbon fiber will "burst' into millions of little brush "busthings" a catastropic failure, whereas metal will just bend. In other words, metal will give before it breaks, whereas carbon fiber won't. I wonder how the engineers compensated for this sort of thing.
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SmoothCruise said:
carbon fiber is more brittle than metal so when the rim is compromised, the carbon fiber will "burst' into millions of little brush "busthings" a catastropic failure, whereas metal will just bend.
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I'm not a materials engineer. Maybe one can weigh-in here. That said, I think your assessment of CF failure is wrong. I know, first hand, rotor hubs and blade cuffs on helicopter rotorheads may crack but do not shatter as you assert. CF is also much better than metal in dealing with ballistic damage from projectiles.
 

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BigHat said:
I'm not a materials engineer. Maybe one can weigh-in here. That said, I think your assessment of CF failure is wrong. I know, first hand, rotor hubs and blade cuffs on helicopter rotorheads may crack but do not shatter as you assert. CF is also much better than metal in dealing with ballistic damage from projectiles.
Furthermore, carbon fiber brakes are now pretty common in aircraft and automobile racing. I'm sure that they don't shatter in those applications.
 

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They probably took so long because the car makers are more interested in carbon fibre body panels first. I read not long ago that some R&D at BMW said that they learning a lot about carbon fibre since they started to incorporate it into the M3 CSL's roof, M6's roof etc. Rumour has it that the new 3 series' folding hardtop might be carbon fibre, maybe all cars or the just M3 convertible. Watch this sapce. CF will be used a lot more in future BMW models. One other reason may be cost? :dunno:
 

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BigHat said:
I'm not a materials engineer. Maybe one can weigh-in here. That said, I think your assessment of CF failure is wrong. I know, first hand, rotor hubs and blade cuffs on helicopter rotorheads may crack but do not shatter as you assert. CF is also much better than metal in dealing with ballistic damage from projectiles.
I didn't say they shattered, I should have said it splinters like a broom. When it completely breaks apart, it looks like a broom, but I usually call it a bush. Anyways, it does so on broken CF driveshaft. That's what makes it great for driveshafts, because it won't shatter, and break into a million pieces and fly through the cabin like a super bullet, which metal driveshafts do when they fail under extreme racing conditions.

You're right that it cracks, but I guess I've seen it fail completely. I guess what I'm concered is if you hit a pothole hard enough to compromise a metal rim, usually all it does is "give a little" by bending. If you hit a pothole hard enough to compromise a CF rim, it will crack or broom, since the CF rim is the inner side of the pressurized "air donut" which is your tire, that would be like blowing a tire.

I'm sure the engineers figured all this out. I'm just curious as to how they compensated for it.
 

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SmoothCruise said:
I didn't say they shattered, I should have said it splinters like a broom. When it completely breaks apart, it looks like a broom, but I usually call it a bush. Anyways, it does so on broken CF driveshaft. That's what makes it great for driveshafts, because it won't shatter, and break into a million pieces and fly through the cabin like a super bullet, which metal driveshafts do when they fail under extreme racing conditions.

You're right that it cracks, but I guess I've seen it fail completely. I guess what I'm concered is if you hit a pothole hard enough to compromise a metal rim, usually all it does is "give a little" by bending. If you hit a pothole hard enough to compromise a CF rim, it will crack or broom, since the CF rim is the inner side of the pressurized "air donut" which is your tire, that would be like blowing a tire.

I'm sure the engineers figured all this out. I'm just curious as to how they compensated for it.
What you said is they "burst" into millions of "busthings" whatever they are, so I made my comment. I agree with you on the "broom" comment. When a V-22 prop /rotor hits ground the damage is described as "broomsticking." I to would like to know what a CF wheel actually does upon hitting a potholes etc. I think we can rest assured that it doesnt break like glass. Maybe someone knows what tests have shown.
 

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BigHat said:
What you said is they "burst" into millions of "busthings" whatever they are, so I made my comment. I agree with you on the "broom" comment. When a V-22 prop /rotor hits ground the damage is described as "broomsticking." I to would like to know what a CF wheel actually does upon hitting a potholes etc. I think we can rest assured that it doesnt break like glass. Maybe someone knows what tests have shown.
my guess is that you would have to hit the wheel pretty hard w/ more force than just from potholes to crack a cf rim. just the same you don't often see alloy rims flattened. i can see the suspension giving in before the cf rim cracks.

i'd be more fearful of cf hoods coming off the hinges rather then bending like an accordian and decapitating occupants. :eek:
 

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Carbon Fibre

What is it about all this carbon fibre... Are we all racers now?:dunno:

Give me BIG hefty wheels and a 1000 pound Supercharged V12 anyday, ask Mercedes; they do it all the time...:rofl: Oh, AUDI too!:rofl::rofl:
 

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HW said:
my guess is that you would have to hit the wheel pretty hard w/ more force than just from potholes to crack a cf rim. just the same you don't often see alloy rims flattened. i can see the suspension giving in before the cf rim cracks.

i'd be more fearful of cf hoods coming off the hinges rather then bending like an accordian and decapitating occupants. :eek:
I had a friend who had a carbon fiber hood on his M3 and it blew off while he was going down the road at 110 mph, he didnt latch it back correctly *cough*dumbass*cough*:tsk:.
 

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Yep!

:thumbup:You got that right.:thumbup: But I wonder how Mercedes gets away with their little brakes.:dunno:
 

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gbelton said:
:thumbup:You got that right.:thumbup: But I wonder how Mercedes gets away with their little brakes.:dunno:
--M6--
"Brake disc dimensions are 374 x 36 millimeters (14.72 x 1.42´´) at the front and 370 x 24 millimeters (14.57 x 0.94´´) at the rear. The aluminum double-piston swing calipers,"

--S65--
http://www.autosite.com/content/shared/articles/templates/index.cfm/article_id_int/1019
"Other upgrades that turn a regular S600 into a 2007 Mercedes S65 AMG include high-performance two-piece brake rotors squeezed by stout eight-piston calipers. Mercedes claims that this compound rotor design saves weight by 20 percent over conventional systems. Helping to haul the Benz down from speed, those front discs are internally-ventilated, perforated, and measure 15.4 inches in diameter. In back, the S65 AMG is equipped with 14.4-inch discs clamped by four-piston calipers. ABS and brake assist are standard."

:dunno: i guess their puny. slap on a set of 22" rims and you have a huge gap in between. do they sell 18" brake disks yet?
 

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Discussion Starter · #14 ·
BmW745On19's said:
I had a friend who had a carbon fiber hood on his M3 and it blew off while he was going down the road at 110 mph, he didnt latch it back correctly *cough*dumbass*cough*:tsk:.
You should have someone check out that cough if it persists.
 

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I am no physicist or engineer, but CF wheels for bikes are great performance enhancers in reducing unsprung weight so the accelerating, braking, and turning parameters are greatly improved. Then again, losing 20 pounds off 2 wheels on a 450 pound bike is more significant than maybe 80 pounds off a 4,000 pound car. Would the unsprung weight savings on a car rim give it the same boost in performance relative to a motorcycle?

Also, a set of CF rims for a bike is about $4k-5k. Durability is another question. As far as racing applications go, all the race rims are actually magnesium or forged aluminum to reduce weight but also give it enough strength to endure the rigours of racing. Not sure how CF compares to those 2 materials under hard usage.

That being said, those rims are butt ugly!
 
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