Why Use Inboard Brakes?

Its main advantages are twofold: a reduction in the unsprung weight of the wheel hubs, as this no longer includes the brake discs and calipers; and braking torque is applied directly to the chassis, rather than being transferred to it through the suspension arms.

What is inboard braking system?

As the inboard braking system uses brakes rigidly mounted on the vehicle, the weight of the braking mechanism is moved from being carried by the wheels directly, to being carried indirectly by the wheels via suspension [4]. This reduces the unsprung mass of the vehicle.

Why did they stop using drum brakes?

Drum brakes last longer because drum brakes have increased friction contact area than a disc. Drum brakes are cheaper to manufacture than disc brakes. Rear drum brakes generate lower heat.