this is what has been explained to me by a brembo engineer:Why are brake rotors " floating " ??? would solid one peice rotors not be as good...would seem they would be more rigid and stable. Just curious !!!
It's just that the stock brakes use a two piece rotor with buttons, that supposedly allows for some movement. This is contrasted with a one-piece solid disc.The front brake discs on most of our bikes are "semi-floating", which I guess is less than "full floating", but exactly how is not completely clear to me. I can see that the oem discs can't move from side to side very much, but I don't know if that's what is meant by that term.
That didn't work out as planned on the ST though.