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-   -   Carbon Fiber Rims (https://www.rx7club.com/race-car-tech-103/carbon-fiber-rims-602508/)

classicauto 12-04-06 03:31 PM

Carbon Fiber Rims
 
My question is - who makes them? The closest thing I have come across was a show on Speed that covered SEMA this year and showed a vendor with a rim on display...it was used at Laguna Seca and scrubbed into a wall at +100mph...the center spokes/hub of the rim were aluminum, and fucked. The carbon outer portion was untouched.....

The material is supposedly 10X stronger than aluminum or magnesium, and :dunno: how much lighter.

Now, yes, I realize they're hella-expensive and Im only curious IF they're available for the "public" racing community or not, and if so - how much and what sizes are available.

Thanks

Rhode_Dog 12-04-06 04:33 PM

The Koenigsegg comes with carbon fibre wheels if I read that right.

http://www.koenigsegg.com/thecars/ccx.asp?ccx=2

Rhode_Dog 12-04-06 04:37 PM

Well I should have looked a little harder, I found this too


http://www.fastcar.co.uk/Lighter_fas...ONoa2rmWw.html

A brand called Dymag makes the wheels, although they don't have a list of applications.....nor do they list a price.

Black91n/a 12-04-06 07:45 PM

Some Formula SAE teams make their own CF wheels, the whole thing is CF minus metal inserts for the studs and nuts. If you're looking to buy some don't expect change from $10k, if you can even get a set that "cheaply".

R_PROWESS 12-04-06 07:58 PM

like the looks of those "dymag" rims

Rotary Noob 12-04-06 08:04 PM

Dont like the price tag.

mirabile 12-04-06 08:22 PM

I am looking, there is a company carbon innovations...they makes Carbon wheels. Not custom offsets though. Way cheaper, probably not as light. I looked into it heavily, price not much of an object, but no one made custom ones anywhere close to considerable.

eivad1 12-04-06 11:51 PM

i am looking for light drag rims for ft and rear

classicauto 12-05-06 09:16 AM

Thanks for the links, those Dymags look exactly like the ones I saw....

Unreal - 19kg savings on putting the set of rims on! Disgustingly expensive, but nonetheless, is that cool or what? I think its the first time Ive seen carbon fibre as purely structural on a car...(aside from an F1 chassis or similar)

tidbit 12-05-06 10:36 AM

dont just think about the weight savings.. you need to also take into account the unsprung weight saved. You will stop faster and free up some HP and torque..

cf rims have been around awhile in the motorcycle world .. if you want the best of both worlds.. look into a mangesium set

Tanjo 12-05-06 02:07 PM

6.3kgs? for a magnesium and CF wheel? I guess thats light for a 17 or 18", but not as light as I would expect something made entirely of CF and mag....

classicauto 12-05-06 02:31 PM


Originally Posted by Tanjo
6.3kgs? for a magnesium and CF wheel? I guess thats light for a 17 or 18", but not as light as I would expect something made entirely of CF and mag....

Maybe its a mounted weight? (tire mounted)

But it does seem a little high now that I think about it......its about 15ish-lbs....

But then again maybe my arm-scales are getting in-accurate :)

Gorilla RE 12-05-06 06:53 PM


Originally Posted by eivad1
i am looking for light drag rims for ft and rear

i dont think i would want CF wheels for drag racing...

Dick Elliott 12-10-06 02:49 PM

Carbon Fiber Wheels
 
Marsh racing wheels has carbon fiberf wheels. Their at http://www.mrt-wheels.com

fsae_alum 12-11-06 10:10 PM

Interesting that you're bringing this up. I'm in charge of Automotive Business Development for a company that manufacturers high end composite parts primarily for the aerospace industry. Anyways, last year we were looking at getting into developing and manufacturing CF rims and I did quite a bit of research on Dymag and other OEM CF rim manufacturers. The Dymag rim has been executed very well and has a magnesium center section primarily for the following reasons:

1.) Heat dissipation: Carbon is not very good at dissipating heat. Excessive heat can actually break down the resins and cause micro-cracking in the laminate structure which could lead to failure over time. Heat can be caused by very heavy braking, stuck caliper, or a bad bearing.

2.) Load Transfer: The braking and acceleration torques are transmitted through the hub/wheel studs into the wheel. These are very high loads and by using a magnesium center section, the loads can be dispersed upon the many spokes into the wheel rim. Carbon Fiber failure modes are very complex and as such, going to a Magnesium center is a way to build in safety into the design when compared to just carbon.

3.) Mounting the wheels on the car: Most lugnuts now days use some sort of tapered/hemispherical seat for the nuts. This could really only be accomodated through the use of a metallic insert into the wheel. Any time you have a lightweight metallic insert that is either bonded or overmolded into a composite structure, you have coeffecient of thermal expansion issues because the 2 dis-similar materials grow at different rates as temperature is changed. This causes the bond between the two materials to break and a failure results. Not good on a rim.

4.) Offset, bolt pattern, and spoke design: Using a magnesium (or steel or aluminum) center piece allows for multiple offsets, different bolt patterns, and different spoke designs without the need for very expensive tooling. It also allows for very fast prototyping because the centers can just be machined out of billet.

Yes....there have been some FSAE teams that have made some all carbon wheels. I have seen them in person and held them (holy moley light like you wouldn't believe), but the FSAE car is subjected to different environments than than that of a typical road car.

Ultimately, the company I work for decided to shelf the idea of pursuing a carbon rim due to the liabilities involved. It's a GREAT concept and it's real interesting to see it mature in the market place. Give it 5 years and there will be many, many more on the market. I can say this because I know that it's actually not that hard to make them.....it's the testing and liabilities that are holding the manufacturers back.

ZumSpeedRX-7 12-11-06 10:24 PM

fsae_alum- thanks for the insight on the development and future of CF rims. do you think a magnesium wheel alone would have almost (obviously not nearly as much) as much of an effect as a CF/mag rim? you would still lose a lot of weight, gain strength in your rims, and perform better due to the lack of unsprung weight, so do you think a magnesium set of rims would be close to the performance delivered from CF rims for people who dont want to wait 5 years for development? if so, im looking into some Volk TE37 mag wheels, what are your thoughts?

fsae_alum 12-11-06 11:15 PM

Mag wheels have been used for quite a long time in professional racing and have been proven to be very effective. They are also allowed by virtually all professional sanctioning racing bodies. All the research that we were able to find was that CF rims were not even allowed in most automotive races (read other than autocross and track days) due to the lack of proven reliability. In other words....going with a CF rim may save you weight but what's the use if you can't see the gain because you can't get on a pro track with them?

Mag rims will be MUCH more forgiving than CF rims with respect to abuse. Yes, CF has much higher strength than mag but it doesn't have ductility that Mag has. It's the difference between bending a rim and losing pressure (Mag) versus breaking a rim and having pieces fly off. Likewise, I'm not sure about this but Mag MIGHT rims might be able to be straightned. CF cannot, no way, no how.

Before you decide either way, make sure that your racing sanctioning body will allow which ever one you're leaning to.

Best of luck!

DomFD3S 12-13-06 12:06 PM

The magnesium Volk wheels aren't as light as you would expect, from what I've heard./read.

As quoted from a friend of mine from XS Engineering:

http://forums2.freshalloy.com/showpo...37&postcount=8 (copy/pasted so you don't have to click on the link)
" Yeah the Volk TE37 MAGS are all blue. It's the only color they come in. They're like a super dark blue though. Like sean said, they aren't worth it. They aren't much lighter than a set of CE28's. REAL magnesium racing wheels are lighter than crap. Also magnesiums wheels are throw aways. After a couple years they become brittle and crack (at least race mag wheels).
"

From a cost perspective, get the lightest aluminum wheel possible.
Magnesium and carbon fiber wheels aren't worth it...unless strictly for race purposes...

RoadRaceJosh 12-29-06 02:07 PM

Dom,

I agree that real racing magnesium wheels are very light and are not for street use. Real racing aluminum wheels are also lighter than their street counterparts. If you push an aluminum wheel to the limits of lightness you'll see failures as you do with a light magnesium wheel.

Joshua

Sgt.Stinkfist 12-30-06 09:59 PM

you gotta sacrafice durability for light weight. certain aluminum drag wheels and even light weight steel racing wheels can be bent from something as simple as mounting/demounting the tires.

redsuns3838 12-31-06 06:35 PM

logan over at aspec weighed some TE37-mags and they were about 1-2lbs lighter than regular TE-37s if i recall correctly. 18x10j was like 17lbs i think?


its not like i can afford any in the first place, but what are some other manufacturers of magnesium wheels that are sold to the public?

NissanConvert 01-04-07 08:33 PM

All seriousness aside, you find me one show judge that wouldn't give killer points for mag/ carbon wheels- And i'll show you a mooron. They'd look teh sechs on a trailer queen- even though i'm not really into that kinda thing.


EDIT: what's the url for "carbon innovations"?

FDNewbie 08-22-07 11:42 AM

Well, just to follow up, there are a full range of carbon fiber wheels officially on the market, priced between $1600 - $2000 a wheel, which are somewhat lighter than the average wheel...but nothing drastic. http://360forged.com/. They've teamed up with Dupont Registry, so I assume they gotta be good...

~Ramy

classicauto 08-22-07 12:50 PM

Says on the site they're a CF overlay, still badass though!

Giampiero 08-22-07 01:07 PM

almost all the wheels available for cars in carbon fiber are CF overlay.....
I just bought a set of CF wheels for my Ducati 1098 from this company in South Africa www.blackstonetek.com and I ask them about the possibility to produce wheels in CF for car apllication...i should have an answer by next week.


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