Disc Rotor Groove

[boomtheroom]

just replaced my disc rotors today ,if you look at the inner of the disc you can see about a inch ir so wide an about 1-2 mil thick groove worn into the disc,the pads werent worn ,about 80% new actually so not sure what caused this the other side is the same but not as deep about 1/2-1 mil anyone had this or any ideas as to what would cause it?

[skyride32]

i'd be interested in knowing what's causing the striations in the rotor as well. my whole disc is covered in shallow grooves, almost like an oldschool record for a record player ...

[maccattack]

The groove is simply where the pad garbs onto the rotor. After a while the rotors begin to wear - eventually getting to the point whereby they become too thin and need to be replaced. Not only do you pads wear down - so do your rotors.

The smaller grooves (like a vinyl record) are generally caused by imperfections in and on the pads. Pads basically get hard and soft spots which wear the rotor at differing rates.

[ferni]

the grooves on the outside will be where your pad doesn't hit the disc. The pad mustn't be using the whole face of the disc. If its not touching that part of the disc - it can't wear it out