[dopper99]

Noticed this tonight. When I run my nail over the disc there is a very very slight groove where the scores are, is this anything to worry about?

[k44ENT]

Seems very common on BMW discs, some are super smooth whilst others have a slight gramophone effect. If they don't vibrate or pull and clean up when used with no rusty areas on the contact areas then they are fine.

[dopper99]

Ok cheers. I think they look a lot worse than they are, when you run your nail across them, was just quite a bit surprised when I noticed.

[DTP1980]

All brake discs develop this characteristic and is the nature of friction braking because all the particles that make up a brake pad compound, all of which vary in hardness quite severely, are within reason randomly structured within the pad, therefore every millimetre will supply a different level of friction, and therefore wear, across the brake discs, therefore leaving minute high and low spots. Because of this, the surface area that is actually in contact with the pads has increased, therefore increasing braking potential.

So therefore perfectly normal

[dopper99]

Ok thanks.

[roshambo]

I'd be more concerned with your hub. Looks like it needs painting

[dopper99]

Originally Posted by roshambo

I'd be more concerned with your hub. Looks like it needs painting

Haha! At least its not rusty (yet) unlike my E90's!

[Daftasabrush]

Originally Posted by dopper99

Haha! At least its not rusty (yet) unlike my E90's!

Looks like it's ally, in which case, it won't get much worse. Certainly won't get rusty. IIRC the 335Ds have the 4 pot brakes up front as standard which would mean you would have the ally hubs.