MACHC5

WedsSport Dry Carbon Wheels

Rumored to weigh 6 lbs each and cost $10-12K a set.

Trying to find additional information, link below.

http://www.newcelica.org/forums/show...47&postcount=1 - 13k -

JamE55

Just curious. What makes this different from Dymag's CF wheel. Dymags currently weight around 14-15lbs somewhere along those lines.

MACHC5

The difference is their 9 lbs lighter - 6 lbs vs. 15 lbs each wheel.

The pricing seems to be about the same though.

Jim Brady

Dymags have magnesium center section with the weight centered in the middle. Dry Carbon appear to be all carbon fiber.

JamE55

So would one be stronger than the other or are they both equally strong?

Jim Brady

Good question. I've seen DYmags at GMG motorsports who used them on a GT3 and they swear they are beyond strong. I'll wait till the TUV or JWL put their stamp on them. I have no information on the 6 LBS Carbon wheels.

Although carbon fiber is stronger than steel it is brittle and we've all seen carbon fiber suspension fail in F1 for reasons of getting too hot from an exhaust header, or failing from seemingly minor collisions where the impact was against the stressed member.

As far as looks they really didn't look good on any of the porsches I've seen. But the set on JRCART's Black was a knockout.

JamE55

Last time i was at GMG they had a busted Dymag wheels and the center was still completely intact. It was sort of on display for people to see how strong they were. Did you happen to see it?

Addicted2Speed

I'm sorry to say this, but these claims are BS. Its physically impossible for a 5lb wheel to be structurally strong enough to support a car. Even Dymag's claims are not 100% true, they actually weigh around 18-19lbs (not 15-16lbs as claimed). The wheels that are used on almost all race cars (including F1) are 100% forged magnesium for durability reasons... have you ever seen a CF wheel on a race car? A wheel made solely from carbon fiber would not last long period and is downright dangerous to use.

Jim Brady

Yes I saw the wheel. I asked why the wheels were not more prevalent in racing and the response was most sanctioning bodies didn't allow them.

Jim Brady

I find the 6 lbs wheel almost incomprehensible as well to withstand the rigors of normal driving never mind racing. But I will part company with you on the use in F1. The technical regulations require that all wheels be made of an homogeneous metallic material. Absent that regulation I guarantee a team would have tried CF wheels. They only have to last 1.5 hours.

jrcart

I have one of the largest Dymags made 19"x11" it only weighs 17 lbs 6 oz. So I would tend to beleive the Dymag claim of 15-16lbs for a 18"x9" fitment. That being said, I would like to get my hands on one of these 5-6lb wheels and check it out myself, I have a hard time believing that weight as well.

Dr. C36

Dymags 18x8 are 14lbs, 18x9 roughly 15-16lbs. Still very light. However you have to account that the center of rotating mass is DRASTICALLY different so the weight gains are actually much greater than that. On normal wheel the majority of the mass of the wheel is at its outer rim, on Dymags its in the center so the inertia is greatly reduced ( A = M * R^2 ) .

With that said I spoke to the Dymag rep 2 years ago at SEMA and I asked him "why not just do the whole wheel in CF" and his response made sense. B/C magnesium is a metal (obviously) it exands and contracts with heat. however CF does not expand & contract like metal does as it comes in contact with heat so that became a serious issue b/c hubs naturally expand & contract as braking heat and other sources of heat play a part. As a result they chose magnesium cores. However, this may be an issue with only certain types of hubs so maybe its not with honda guys.

Also I think you have it backwards Jam, when I went to SEMA and spoke to the rep they said its the core that snapped, the outter CF ring was still 100% intact (as it should be after all CF is stronger than steel and magnisium is weak by comparison.

Honestly it makes logical sense to do a full wheel out of CF. It only a matter of time before we all will have CF wheels once the technology truly develops (I know I will).

JamE55

Thanks for correcting me. You are correct. It's the center the gave in and not the barrel.

Riverscarbon

I work for a company in New Zealand, that has made 100% carbon fibre wheels for a 2000hp dragster The have been used for nearly 3 seasons with no signs of damage. In fact one of the first times they were used all the wheel studs sheared off with no damage done to the wheel, check out the video here http://www.kiwidragracing.com/multim...quig_Slide.mpg. Also pictures can be found on our website http://www.riverscarbon.com

I am currently designing wheels for street use but I need to know if there is a market and which size and offsets to make. The wheels will have SAE standard DOT ratings and race wheels SFI ratings. They will cost about $US2000 each but if there is enough interest the price may drop. Your input would be much appreciated.

AMGOODNESS

the forces on a drag car are ridiculous. if they are holding up there maybe they could hold up on a track. i would worry about lateral forces (left and right turns). still pretty darn cool to see that companies are already considering and possibily perfecting carbon fiber wheels. i would certainly by a set.

Riverscarbon

That is what has stopped everybody making carbon wheels. It has taken a lot of computer modelling and analysis (FEA) to come up with a product the uses carbon to its fullest. It is easy to just make it as thick as a aluminium wheel and you could bet it would be okay, but to make it much lighter and stiffer there needs to be a lot of design.

People are afraid of carbon wheels exploding if you hit something hard, if you hit something hard enough to buckle wheels are you going to drive home or will you be calling a tow truck? Then would you bend the wheels back or buy new ones? And as a plus there is no fatigue issues with composites (carbon helicopter blades don't need replacing).

What size wheels and offsets would you go for AMGOODNESS?

jrcart

I currently run Dymags on my Black Series, I am happy with the performance and very happy with their customer service based on a recent warranty issue, however, if your wheels offer a significant weight/performance advantage I would be interested in getting more information, I'm always looking ofor an edge over the next guy. Do you have any pics, stats, weight? I would be interested in stats on 19X10f, 19x11r

Riverscarbon

Sorry I can't give you a 100% accurate weight as we haven't made the wheels but they will be about a third lighter than an aluminium wheel of the same design. I'm currently in the process of CAD'ing and FEA'ing the wheels so should be able to have a guess in a couple of weeks and some screen shots.

The design will be similar to the front drag wheel on our website: http://www.riverscarbon.com/carbon-fiber-race-wheels, but with 6 spokes and we will be able to offer it in the big weave (12k) and the normal small weave (3k). We are also looking at using some of the other types of fibres like the so called "Silver Carbon" and coloured Fibreglasses

Could you please tell me if the Dymag's have a DOT rating on the rims?

AMGOODNESS

jrcart has enormously wide wheels. i would be looking for something more along the lines of 19x8.5 front and 19x9.5 in the rear. That is what i run now.

jrcart

A third lighter than an aluminum wheel? That is not too light, my rear Dymag which measures 19x11 weighs in at 15 pounds 7 ounces, a high quality 19x11 forged wheel will weigh 26-27 pounds at best (OZ Superleggera is the lightest 19" wheel I have seen available and weighs 26.6 in 19x10 MB fitment), my stock 19x10 forged wheels weigh well over 30 pounds each. Lets just call it 27 pounds for sake of conversation. 27lbs - 9lbs (1/3) = 18 pounds, which is nearly 3 pounds heavier than my CF/magnesium Dymags. Did you mean they would weigh 1/3 of the weight of an aluminum wheel of the same size? That would equate to 9 pounds, which would make a lot more sense than 18lbs. Don't get me wrong, 18 pounds is still pretty light but I'm not too sure how many people would cough up the kind of $$$ these puppies are going to cost on an unproven wheel or wheel company, I aasume most people would go for the Dymag which is lighter and has a proven track record.

Any more info you could offer us would be great.

Riverscarbon

I mean if it has the same volume of carbon as an aluminium wheel. Of course we can reduce the weight a lot more by optimising the fibre directions to create a stiffer wheel. We make our wheels with hollow spokes so they are a lot stiffer of the same weight of carbon.

I don't want to blow smoke up your rear end making claims that our wheels are 'X' kgs only for them not be close. They should be lighter than the Dymags as they are all carbon and one piece so don't have any fasteners. We have been designing and producing composite products for many years for super yachts and aircraft as well as a number of monocoque chassis and the wheels for the drag car.

In a few weeks I should have a better idea, but it will take a few months before we have a wheel made. I don't like to deal in speculations so I you spin me a PM I'll keep you informed.

Simon @ evosport

If you can make a lighter wheel with at least the same strength and properties, then it should be ok. But you have to consider a few things. First you will need to test the load rating because whereas a lighter alloy wheel is normally weaker and thus can't sustain a heavier load, you may be able to get away with this using carbon or a composite. This is partly due to the tensile strength. It also depends on how the carbon wheel is designed and how much stiffness is considered. A carbon wheel can easily split if it has a weak point and weak design. I can't answer the question of is there such a thing as too light with regards to the physics of rotating mass. But theoretically if the properties of a material yields a high tensile strength or Ultimate Strengh (MPa) with a low density, then it is possible, although it may be cost prohibitive. If you can make a wheel out of carbon nanotubes (an allotrope of carbon that takes the form of cylindrical carbon molecules that gives them the highest tensile strength of any material yet measured), imagine the possibilities. One day, nano technology will see it's way to the tuning market!

For comparison of strength and density:

Material | Ultimate Strenth (MPa) | Density
Aluminum Alloy 455 2.7
Titanium Alloy 900 4.51
Carbon Fiber 5,650 1.75
Silicon (m-Si) 7,000 2.33
Carbon Nanotube 62,000+ 1.34



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Riverscarbon

It is a balancing act of weight to stiffness. One of the biggest problems any designer faces is what the product is designed for vs how the product will be used. We could produce a wheel that will be fine on a smooth autocross track but will fail when fitted to a road car that is loaded with 8 people, a dead moose and then driven down a dirt road.

A feature of composites that most people are unaware of is that they prevent crack propagation, unlike metals. This is because a micro crack will travel along until it meets a fibre in another direction and stops, in a metal the crack will travel along the grain boundaries until the part fractures. Sorry if this sounds a bit like a lecture on materials, but I spent an hour today explaining this to a cyclist who assured me his bike was going to explode due to a stone chip.

As for nanotubes, it's just a mater of time till universities get bored of them and let industry have a go, then it will be all on. I'm looking forward to it.

C43AMG

This thread is very interesting........

blackbenzz

That seems to be the most commonly used size. 19x8.5 and 19x9.5 or 10. But if you are going to be using it for racing, tire selection at 18" is much better than 19"