This is the technical definition, to be more practical and to apply what we just said about the gyroscopic effect to the bike, we would have to say that the more the wheel weighs and the faster it rotates, the greater the force required to tilt it with respect to its axis will be.
This means that the aspects that influence this force are essentially two: the speed of rotation and the weight of the wheel itself. The further the weight is away from the rotation axis, the greater the resistance to motion is. To make an example: a heavier hub is not able to significantly affect the negative gyroscopic effect of the rotating wheel as a heavier tire would be able to do.
What a double disk system improves is the most external weight of the wheel, the one that is located in the furthest part from the center of rotation and that is the most critical due to its physical effect. By removing the difference in weight of the bigger mono disc, the weight of the wheel is reduced just enough to get a more responsive and fluid drive.
The data is striking: the mono disc with diameter 310mm - 320mm weighs from 1,150 to 1,600 grams depending on the diameter. The 2 disks with 240mm diameter weigh 900 grams in total. As speed increases, the grams turn into several kilograms resulting in a disadvantage of the agility in the turn. Think about it, when you travel at more than 100 Km/h and you have to bend this much weight around the corner.
Straightening Effect
When turning, a physical effect is attempting to straiten the bike back up as a result of rotational weight. In the double disk system, that is much less. The bike seems lighter in both entering and riding through the bend. The bike is not pulled out of the curve.
Brake inside the curve
With the Double Disc you can brake and lean the bike effortless, so you can delay the brake point and increase the entering speed.
Breathe in difficult conditions
Unlike the powerful low-progressive mono disc, the Double Disc is sweeter in the braking approach, giving you almost the feeling of not stopping, turning in to the corner it makes you realis it stays glued on the asphalt without any problems. On the dirt road and on the wet asphalt you can brake without any fear. You can lock the front wheel into the ground.
In conclusion
All these benefits lead to improved lap times.