On Sat, 16 Feb 2013 19:55:59 -0600, Vic Smith wrote:

I have very little experience with rotors that cause
pulsation. Only times it happened with me was with old worn rotors
that needed replacing anyway because they were grooved and eating
pads.

An interesting aside is that we all have seen grooved rotors,
and we all know the "fingernail test" (i.e., if it catches your
fingernail, it's too deep) - but - if you LOOK UP the specs for
grooves, they have to be absolutely huuuuuuge (like the thickness
of a dime!) to fail a rotor.

At least in my experience.

If anyone actually has a bona-fide "groove" specification for their
rotor - please share!