meilers

Not that I am a materials expert of any kind, but carbon fiber seems poorly suited as a wheel material. It is brittle and its tensile strength lies along a specific "grain" created by the overlapping layers of carbon weave and expoxy. In this case it looks like the carbon fiber is just decorative -- there is still an aluminum wheel inside -- in which case you'd just have a normal wheel with a textured surface which would be quick to show damage.

whitelegacy98

yeah, thats all for show as it is just cf wrapped around aluminum, the cf is pointless its probobaly a fairly heavy aluminum wheel. You can do better.

Choku Dori

iTrader: (2)

Useless rice part. Simple as that. They've been around for a while though, so I guess they're making sales to the Civic boys?

SUB-ZERO

I just checked with the vendor and let me tell you, these things are just for looks. The benefiits of carbonfiber include heat dissipation, weight reduction and strength. IMO these rims provide none of the above and they are 19 pounds! Real racing carbon fiber rims (Common for motorcycles) are actually extremely light and strong. I think these rims are just like any other rim but with a layer of carbon fiber weave cleared to the surface. They look pretty nice but I cannot justify $1450 for them. I prefer to spend that money on a sweet set of Volk's.

-SZ

doughboy

iTrader: (3)

i agree. though carbon fibre is strong for it's weight, when CF fails, it fails catastrophically. this is the same reason why bike frame and seat posts made from CF aren't in very high demand. imagine rolling on CF wheels! to me, that's asking for trouble...

meilers

I used to race mountain bikes in Tucson, and almost all of my friends who were either trail or road cyclists switched away from CF parts after a few months. CF bike frames are actually TOO strong -- they are so stiff that they are very uncomfortable to ride, and the tensile strength is so directional that they literally pull themselves apart at the seams. Because the material has so little flex, ALL of the stress gets passed to the joint directly, causing a lot of failures at the places where two angles meet or a join is sealed with expoxy.

Now they make CF bikes that have CF frame members, but all of the joints are actually aluminum parts, to add some bounce and shock resistance back into the frame geometry.

doughboy

iTrader: (3)

good point. we can carry this point to rims....when rims bend, they take the stress away from the other suspension components. CF rims will not bend, thus adding another point of failure into the system. i would much rather have an SSR rim bend than to have a CF rim fail on me.

redrex

iTrader: (9)

A good question to ask yourself is: Would you use fiberglass wheels? CF and Fiberglass share basic characteristics and appropriate uses (body panels, seat moldings, etc.). These wheels are just another gimmick to try and differentiate itself from other wheels (I can see all the poor noobs lining up to buy these wheels as we speak). Now if they were selling magnesium alloy wheels, that would be another story.

meilers

Heh! Magnesium is NASTY STUFF!

It has a burning point of 3600 degress (F), at which point it will flash into a superhot plasma. If you try to put the fire out with water, the flame is hot enough that the magnesium liberates the oxygen from the hydrogen, and you have burning hydrogen gas as well as the chemical reaction of the magnesium oxidizing simultaneously. In other words, water on burning magnesium is like gasoline on a wood fire!

Magnesium oxide is the main ingredient in signal flares, and they will even burn underwater (as any good pyromaniac 12-year-old knows). Magnesium alloy wheels sure would be light, but I would hate to see what happened if you lost a tire completely and ended up skidding on the rim -- you could generate 3600 degrees pretty easily at highway speeds... Then FOOSH!

doughboy

iTrader: (3)

you learn something new everyday....

db

meilers

My high school chemistry teacher nearly burned down the building demonstrating to us how easily magnesium burns (you can light it with a gas flame) and how it reacts when you try to put out the magnesium by immersing it in water...

He was NUTS!

Then again he also used to drop chunks of sodium and potassium into beakers of distilled water for fun... He built "boats" out of aluminum foil with a chunk of sodium mounted in a little pocket on the back as the "motor" and they'd go zipping across the water tank trailing a blue-white flame... Chemistry class was the best part of the day.

Choku Dori

iTrader: (2)

Hehe I still remember wasting school supplies by putting magnesium strips over the bunsen burner in Chem to get that bright white light

redrex

iTrader: (9)

Interesting information, but blowing out a tire and having a magnesium alloy wheel skid on the ground will not produce anything close to 3600 degrees (F). Magnesium alloy wheels are used by the more expensive racing series. The Maclaren F1 uses Magnesium alloy wheels. They are suppose to be lighter and stronger than aluminum alloys. Then again, Formula 1 cars used skid plates with traces of berilium (remember when Formula 1 cars used to spark when they bottomed out), so for them to use a dangerous material in unheard off ways is not out of the question.

meilers

I talked with a buddy of mine at work who was a materials engineer for Boeing for quite a few years. He said that magnesium is light, but extremely brittle compared to aluminum and doesn't respond well to fatigue -- in other words, suited for race wheels that get used a few times and thrown away, not useful for daily drivers. Same with those carbon fiber motorcycle or road bicycle wheels -- use them for a few races, ditch them. Heck, that's why you have sponsors! He also mentioned that magnesium racing wheels have most likely been "doped" with aluminum and other light metals to reduce the chance that they would actually combust.

He also told me a story about magnesium's combustibility you might find interesting -- at the end of WWII, London was upgrading their "tube" (subway) and decided to build the new cars out of a newly-created magnesium alloy, with magnesium wheels to save weight. After a while, one of the higher-speed trains jumped a rail and slid down the tunnel, striking sparks from the wall and tunnel floor. This was indeed hot enough to ignite the magnesium, and the entire train burned at 3600 degrees -- it was several days before the tunnel was cool enough for them to go back in and collect the very fine ash that all of the passengers had been reduced to!