I've seen those Beringer's before. On ebay of all places.
http://www.ebay.com/itm/NEW-YAMAHA-R1-0 ... 60&vxp=mtr"Objectives of the 4D system
The power gain compared to a Ø320mm cast iron disc is 20%, which allows to the riders to shorten their braking distances significantly. Some comparative tests have shown the obviousness of this gain as well as a lower temperature of the discs.
Maneuverability improvement of the motorbike: the gyroscopic inertia of the quadruple disc is 3 times lower than the inertia of Ø320mm discs and 30% lower than the inertia of carbon discs, which is the main advantage of this system. For example, the transit time through a chicane or the time necesary to lean on angle is highly reduced.
Weight saving is significant compared to standard systems :
CAST IRON DISCS Ø320mm weight : 1950 g // QUADRUPLE DISC Ø230mm weight: 1460 g
The 980 grams saved in non suspended weight improve the grip of the front wheel and the acceleration of the bike.
Lifetime much higher
In fact, tests have shown a small wear of the system, which allows to consider a lifetime well above the average."
http://www.beringer-brakes.com/en/moto/ ... tem-10.htm