Brake Question: Fixed or Floating Calipers

[Chung]

I do not know too much about brakes. Are our front calipers fixed or floating? I think from searching the forum that the rear calipers are floating.

Just curiosity on my part.

[kday]

The fronts are fixed. I haven't looked at the rears.

[4everRS]

Our rotors are pretty unique (with unique price tag). can't rally call them floating as the cast iron ring is fixed to the aluminum hats using titanium pins. Having this gap between the two help cooling tremendously. It also causes to fantastic pinging and cracking noises after a hard braking session. As the different metals cool, there is differences in expansion and contraction, thus the cracking and pinging.

[JSRS6]

OP is referring to the calipers. The fronts are fixed 8-pot, and the rears are floating 1 pot.

[4everRS]

I'll just leave this here for myself.



I'll try to read the title next time.

[JSRS6]

Lol Kyle. Nobody's perfect.

I'll just leave this here for myself.



I'll try to read the title next time.

[Chung]

I disagree with the fail it is a learning experience for me. In my vast knowledge of brakes my understanding is either the rotors or calipers need to be floated to allow for some give. If you (or in this case me) replace their rotors with aftermarket JHM rotors, do those rotors also need to unique design that Audi has done?

[kday]

"Fixed," with respect to calipers, refers to the fact that there are pistons on both sides of the rotor, and the caliper body is fixed with respect to the upright. A sliding caliper has pistons on only one side. Both halves slide together with respect to the upright, so when the pistons extend it clamps the rotor on both sides (kind of like a C-clamp). Fixed calipers are more rigid and result in better pedal feel and modulation.

This is independent of the way the friction surface of the rotor is affixed to the hub. I think the main reason for the "floating" rotor ring is to allow for dissimilar metals to be used, so that a lighter weight material like aluminum can be used for the hat portion. But that's just a guess.

[4everRS]

This is independent of the way the friction surface of the rotor is affixed to the hub. I think the main reason for the "floating" rotor ring is to allow for dissimilar metals to be used, so that a lighter weight material like aluminum can be used for the hat portion. But that's just a guess.

Right. Our discs are kind of a hybrid between fixed and floating. Those titanium pins are "fixed" to both the aluminum hat, and the outer cast iron rotor. However, there is some action that takes place proven by the noises they make after a heavy braking session.

Also, this method transfers much less heat into the hub(and bearing) creating longer life for those parts.

[hahnmgh63]

Oh....it was a failure as the pins are just Stainless, nothing high tech like Titanium

[4everRS]

Oh....it was a failure as the pins are just Stainless, nothing high tech like Titanium

Huh, well there I go again. I had been told this by 2 different rs6 techs.

[JSRS6]

The ceramic c6 rotors use titanium fasteners. They must have been "confused"...

[Amulet-S6]

Huh, well there I go again. I had been told this by 2 different rs6 techs.

At least you're trying! Swing enough times and you're bound to get a hit.

Jim

[streetsoffire]

What vendor would you guys use for purchasing RS6 calipers? I would like to go BBK on my S6........