Not sure how big of a deal this is, noticed it after inspecting the wheels. Is it cracking?

 

It's hard to tell conclusively from that pic alone. Can you post more pics, and from some different angles?

 

It appears that is only brake pad build up from a hard stop, which is normal and nothing to worry about. Those rotors are in pretty rough shape though.

 

That's actually what I was hoping more pics would show for sure. It sort of appears that the spread between the two lines is about the width of a pad, so it does look like it could be an imprint of some pad transfer when stopped. Plus, there is no cracking visible in that pic on the outer edge of the rotor.

 

Sorry for the less than ideal pictures! I looked at the rotors and your diagnosis seems to be correct about it being a deposit. I know it was mentioned that the rotors are in crappy shape. Recommend replacing? Thanks again everyone!

 

Rotor cracks are *typically* tangent to the hub as opposed to circumferential. That white "ring" looks like the result of junk in the pad groove. If you pull the pad, clean the groove with a screwdriver (or the like) and reinstall. Re-bed the pads afterwards to rid the rotor face of junk.

As for rotor replacement, does the face feel smooth or are there ridges? How much of a lip is there at the outer edge? If there is a noticeable lip, it's probably time to replace. Do they shudder under braking?

(I used to race (time trial) and have spent a LOT of time messing with brakes, FWIW.)

 

I'm pretty sure he was only referring to the two radial lines at (approx) 8:00 and 9:00, which he's already confirmed were just a pad deposit imprints, and not the concentric rings.

 

Thanks everyone once again! The pads were low and in getting new pads i decided to install new rotors all at the same time.