Sheldon Brown wrote:
Seems a bit bizarre to me that a device that reduces
braking power could be considered a "safety feature" though.

I have no objection to the concept of modifying torque or preventing
skidding. ABS does both and is considered a safety feature.

I am only concerned about the implementation. ABS modifies torque if
vehicle motion exceeds wheel motion and operates low or high friction
surfaces. The Shimano system merely puts an upper limit on torque.

Shimano quotes ISO 4120 and DIN 79100-2. This requires a weight of 100
kg and a brake lever force of 100 N. I understand that the requirement
is to exceed 2.2 m/s^2 wet and 3.4 m/s^2 dry.

Shimano quotes a deceleration capability of 3 m/s^2 for the SG-8c20
rear hub. Magura claims rim brakes can achieve 4 m/s^2 and discs 8
m/s^2. It would be interesting to know the torque or deceleration
values for the Shimano front hub.