floating rotors?

[DaveN323i]

Just curious. Can anyone tell me how does a floating rotor works as compared with a fixed rotor?

Also, why BMWNA won't import the M3 with that? I heard its is because of the lawyers in the U.S.

Thanks :)

[Guest84]

Not sure exactly how they work, but..The construction of these rotors allows for better dissipation of the heat buildup from the large front brakes on the ///M coupes and roadsters. They are lighter weight than the stock U.S.rotors, plus the center hub portion of the rotor is made of non-rusting aluminum.

[Mr Paddle.Shift]

I can explain the concepts behind fixed and floating. First imagine the rotor as a CD spinning. Your job is to stop the disc with your fingers. There are two ways to accomplish that:

1) Use your thumb and forefinger, each on one side of the CD. Clamp the disc but moving the thumb and forefinger towards the disc. This is how the FIXED DISC works.

2)Instead of using both the thumb and forefinger, you are allowed to use only either. Let's pick the thumb. Stopping the disc means you use the thumb and press on the top surface edge of the disc, thus "pushing" the disc towards the bottom. But of course, the disc will be out of its spinning plane. In order to preserve its spinning plane, the disc is allowed to slide along the center axis. This sliding concept is what we called the FLOATING DISC.

Which is better? Fixed disc is much better for high-performance braking. For daily driving, floating disc is good enough. And why most car manufacturers prefer floating discs? Becuase these are easier to design and fabricate, thus lower manufacturing costs.

Aye! :)

Originally posted by DaveN323i
Just curious. Can anyone tell me how does a floating rotor works as compared with a fixed rotor?

Also, why BMWNA won't import the M3 with that? I heard its is because of the lawyers in the U.S.

Thanks :)

[ayn]

Which is better? Fixed disc is much better for high-performance braking. For daily driving, floating disc is good enough. And why most car manufacturers prefer floating discs? Becuase these are easier to design and fabricate, thus lower manufacturing costs.[/B]

seriously? I was under the impression that floating rotors are better because they're usually 2-parted with different material thus heat doesn't transfer as well and they stay cooler. the fact that they "float" also prevent them from getting warped. I thought only real high performance brakes have floating rotors, and bikes got them too. I can't imagine them being not as high-performance than regular fixed rotors...

--Andrew

[Mr Paddle.Shift]

Doh!!! My bad...I was thinking of FLOATING and FIXED calipers! :p

Originally posted by ayn


seriously? I was under the impression that floating rotors are better because they're usually 2-parted with different material thus heat doesn't transfer as well and they stay cooler. the fact that they "float" also prevent them from getting warped. I thought only real high performance brakes have floating rotors, and bikes got them too. I can't imagine them being not as high-performance than regular fixed rotors...

--Andrew

[DaveN323i]

I thought Vince's original answer was not right, but I am no expert either.

Ayn says that a floating rotor is made of two kinds of material and they also float.

So, how does it actually "floats" compared with a fixed rotor? (I assume that Vince's original answer deals actually with a floating caliper, which I did not even know it exists).

Getting dumbmer and dumbmer :cry:

[The HACK]

Originally posted by VinceTopasBlau3
Doh!!! My bad...I was thinking of FLOATING and FIXED calipers! :p



Thank you...I was about to correct you on that.

By the way, our calipers are the "floating" design since there's only one single caliper pushing it in from the back.

Floating rotors are two piece rotors that has the hub and the disc joined by bolts. That way you can have lightweight alloys for the hub and a different compound/fabrication for the disc and have the best of both worlds. Also heat dissipates faster in floating rotors, why I'm not sure.

The main complain about floating rotors is that they're much louder than normal rotors because they're two piece, thus allowing more noise to be eminate when the disc "vibrate" under braking.

[The HACK]

Originally posted by DaveN323i
I thought Vince's original answer was not right, but I am no expert either.

Ayn says that a floating rotor is made of two kinds of material and they also float.

So, how does it actually "floats" compared with a fixed rotor? (I assume that Vince's original answer deals actually with a floating caliper, which I did not even know it exists).

Getting dumbmer and dumbmer :cry:

Float is the wrong term to use. Floating rotors should be called 2 piece rotors, because the rotor DISC is bolted onto the rotor HUB. Nothing actually floats. That's like cross-drilled rotors or sway bars...Cross drilled rotors aren't crossed nor drilled, the holes are suppose to be cast. Sway bars are actually ANTI-ROLL bars but people just call them sway bars.

Floating rotors are more expensive to make because there's usually two different alloys and materials used...Some of the best floating rotors would have hi-heat resistent ceramic hub and lightweight aluminum alloy disc for fast heat dissipation. They're expensive to make because you need two dies to cast two material, along with two different manufacturing process.

[DaveN323i]

Originally posted by The HACK

The main complain about floating rotors is that they're much louder than normal rotors because they're two piece, thus allowing more noise to be eminate when the disc "vibrate" under braking.

Thanks Dan. I knew you would know about this. Now I see why the M3 does not have floating rotors for the U.S. version. We already ***** a lot about brake noise. :tsk:

Boy! I was censored. This never happened to me at .org :lmao: