I'm far from an expert on this, but you probably are having issues with the new pads mating to the worn rotor surface. Since they are a different pad, they probably won't wear the same and require a different bed in process.Hiya, question just recently change my front pads on my F from stock to Stoptech...all is well but month later I notice a little vibration during mid speed braking. You can really feel it on the steering wheels and its bothersome, my piece of shiet civic didnt do this. I dont beat on her so was wondering what can be the cause? She has 17k miles 08' my rotors are bad?
Stop Tech has a decent article here:
Stop Tech Bed in Theory
So assuming you didn't warp the rotors at the track, you probably are having issues with worn rotors and a new pad type not playing nice.the objective of the bed-in process is to deposit an even layer of brake pad material, or transfer layer , on the rubbing surface of the rotor disc. Note the emphasis on the word even, as uneven pad deposits on the rotor face are the number one, and almost exclusive cause of brake judder or vibration.
Side note: Centric makes an OEM replacement rotor you can find just about anywhere. They are sometimes rebranded, but they are the only OEM replacements being manufactured AFAIK. You may be able to get away with reusing the rotors next time if you buy the same stoptech pads.