That’s a tough one. Only guessing here, but they look like they may have been re-anodised. If and I stress if they have, then there’s a problem. The hole the piston sits in is a critical size. Too big it leaks, too small it will bind. When holes get hot they get bigger.
Anodising goes down into the substrate as much as it builds up. So 40 microns is 20 down into the substrate and 20 above its original surface. So when you strip you have to go down 20 microns in this example.
For reference a good slide fit is 20 micron. 20um or 0.02mm.
Anodising can be quite thick (google it) so unless the anodiser guy is ISO approved, who knows what your getting back. Too thick and rapid seal wear and possible binding, to thin leaky seals at high temperatures.
As I don’t know if Brembo sold GP2’s in gold line like appearance, i’d be writing to them or doing some serious research.
What I do know is that these are GP2’s as fitted to WSB. Note: they are not gold, not even close, the disc carrier is standard gold. Thin anodising as well. They are pre monoblock. They went to monoblock for heat dissipation. Racing brakes get seriously hot and distort resulting in brake failure.
A thing to think about here is that these are brakes going on a machine capable of 250kmph +. If they crap out, death or serious injury of somebody’s dad (or mum) can happen. I for one couldn’t live with that.
