Dumb title, but I don't know how else to describe it...
I picked up a sweet Panasonic road bike from a garage sale not long ago. As part of the very little maintenance it did on it, I took some steel wood to the rims to clean them up and very lightly sanded the brake pads with very fine sandpaper. After using it as somewhat of a commute/school rig for a few months I am now noticing a lot grayish grim on the rim. Not so noticeable to the eye but, If you so much as touch one of the rims your finger tips are instantly Gray/back. And to top it off, after riding in the rain the other day, I can now see where the stuff has gotten wet and dripped onto the chain stays or has ran down the fork. No way is this normal! Anyone know what's up? Is it just a matter of old break pads?