No wasted rotor really....just not enough hat. Today you'll see the 13" TCE hats are both larger and also pillar mount for air flow to the outer friction surface. Also now 12 bolt for a more stable mount. The reason for the (former) 8 bolt (still used on 11.75 and 12.2 rotors) is that 18yrs ago running 13" rotors not common. In fact "back in the day" a 12.2 rotor was considered a large rotor. Thus the common hat and bolt design were all based upon that size. With the market moving up in size I finally had to do this with my hats also. They are now 9"dia and overall a much better part while providing an improved appearance. It also allows the fit of a 14" rotor which never worked well on the 8 bolt. *And did I mention that this fully 50% increase in production cost (no bull if you saw the other side) was not reflected in a retail price increase the past few years??- going to the other discussion)
