ExMB

Based on the recent posting of the SIB; beginning on page 51 it talks about the rotors being iron and the hats aluminum - a 2 piece design.
Based on this, how hard would it be to figure out the supplier of these brakes and from there determine if its possible to just get replacement rings and hardware instead of having to buy the assembly at replacement time?

Dan993

Not possible as these rotors are one piece. Hat and ring are not replaceable separately. There may be some aftermarket upgrade options that offer two piece designs.

Dan993

ExMB

From your pic it looks like its not, but since these are GT3 rotors with a different hat - GT3 CLs. The other issue would be the different properties of the metals, having different expansion/contraction with heating/cooling. That would require some sort of floating attachment between both pieces.
Would be interesting to see the backside before making a decision on yes/no.

orthojoe

At least on the GT3, they are definitely one piece rotors

jphughan

I think this is one of those true-not-true statements. The rotors are created as 2 separate pieces made of different materials and they still operate as a 2-piece rotor in that the two pieces can thermally expand and contract independently, but during construction the 2 pieces are permanently joined so that the friction rings cannot be replaced separately. E9x M3 rotors are the same way.

ExMB

Thanx

Interesting

DeerHunter

Do they not have floating pins that attach the two elements together (if you peer between the hat and rotor, you should be able to see them)? If so, it's a pretty trick design that, as jphughan notes, allows for independent thermal expansion but not separate replacement.

orthojoe

Trust me, they are one piece. It's an interesting design.

DeerHunter

So they don't look similar to this (from my Audi S6)?



These front rotors are 400 mm BTW, almost as big as GT3/4 PCCBs.

orthojoe

I'll take some pics and post and then let you decide.

ShakeNBake

BMW/Audi have been doing this for a while. You get the benefit of a lower weight aluminum hub and the ability of the ring to expand or contract without constraint. GT3 rotors are exactly the same kind of design.

orthojoe

Tell me if I'm missing something, but I don't see any way to separate the ring from the hat. This is a one piece unit.

DeerHunter

See boldfaced part. Nobody said that pinned rotors allow separate replacement, just that they allow dissimilar metals to expand at different rates as they heat up.

orthojoe

Whoops! this is what happens when you try to read between sets at the gym. Sorry, I had the OP in mind when I posted.