Brake discs GiroDisc or OEM Volkswagen

The only thing I have done to it before the most recent work was to change out the rotors and pads.

Stock rotors are cheap and effective anything bigger is just for show.

GTI Clubsport rotors drop 2.2lbs per side at the front

FWIW, I recently replaced my front rotors and pads at 40k and I have about 8mm on the back. At this rate, I'll probably have to replace the backs around the same time I do the fronts again. My rotors look nothing like yours though. Mine are smooth and no grooves.

I had the impression that those discs wouldn’t warp as easy as one piece discs but it looks as I was wrong. VW tried to machine my warped discs with them mounted on the car at one point but they failed so badly that they did not even want to show me the result. After that they messured the runout on new discs on the bench and found them OK. After the discs were mounted on the hubs they were messured again and that one of them had warped. That was the way they found the bad hub. I was quite surprised when I was told that VW did not have any tolerances for the runout on the hubs or the discs. I took for granted that they had quite strict tolerances both on the hubs and the discs. I don’t know if the eight piston caliper and the setup with opposed pistons makes the whole system more sensitive to warpage or not but that has been suggested. And to get this a bit more connected to the thread subject I can add that I have not found any alternative to VW original 365 mm floating discs at all. I was quite surprised to find them cheaper than the one piece 334 mm discs to my Passat W8 though.

Could be the hubs. Mine had an axial throw of 0,02-0,03 mm which I thought wouldn’t affect the discs. I filed a complainment to VW regarding warped discs and they blamed the calipers. Told me one of eight pistons was a bit sluggish. With new calipers and two sets of discs later they found what I had meassured before the complainment, a warped hub. The last pair have not warped after the typical 5000 km mark as before. So at least the floating 365 mm discs are very sensitive regarding straight hubs.

My Golf R's brakes look like this as well. I have 10K + miles on them but they have been like this since 2-3K miles. I'll say it's "normal". Even though i haven't experienced it with other cars that i can recall.

Update for all those following along. My brakes were the best they've ever been today - on a very, very hot day (feels-like temp over 100). I had a vibration with light brake pressure, but pressed on giving more pressure and found that as the brakes got more heat in them, and I went deeper into the braking zone, the vibration disappeared. All was well, but after checking the rotors, they appear to have developed cracks.

Just noticed yesterday my front rotors are pretty scored too - got a screw in my tire and the repair shop commented on the rotors too.

Imperfections in either the brake rotors or pads making gouge marks in my rotors