In the story about the Tucson Motorcycles racer, you may have noticed the front brakes in the various images and they looked a bit small. Those brakes are only 230mm compared to a more normal 320mm disc. But if you look more closely, you'll see something else, there's 2 of them on each side of the wheel for a total of 4 discs.
Why 4 small discs? According to Beringer, the advantages include:
* Power Increase of 20% compared to a single 320mm cast iron disc which allows to the riders to shorten their braking distances significantly. Some comparative tests have shown evidence of this gain as well as a lower temperature of the discs.
* Weight saving is significant compared to the standard systems Cast Iron 320 weight: 1950 g Quadruple Disc 230 weight 1460 g The 980 g saved in unsprung weight improves the grip of the front wheel.
* Reduce the gyroscopic inertia to make turning easier: "The gyroscopic inertia of the Quadruple Disc is 3 times less than the inertia of 320 discs and 30% less the inertia of carbon discs"
The Beringer quadruple discs use a fixed center pad with caliper operated outer pads.
If you've been reading The Kneeslider for a while, you may remember another front brake design intended to reduce gyroscopic inertia, the reverse rotating brake rotors from designer Rob Kasten. How well any of these work in practice to reduce steering forces isn't clear, though anecdotal reports from racers seem to be positive.
I'm not sure how long this Beringer design has been around but it's available for a number of current sportbikes. Interesting.
Link: Beringer Brakes