Honda CBR1000F Manual page 251

Technical Feature
3-Piston Caliper
(2) OUTER PISTONS
The Dual Combined Brake System 3-piston caliper is controlled by two independent hydraulic systems. The two outer
pistons are connected by an internal passage and operated by either the lever-actuated master cylinder or, in case of the
rear brake caliper, by the secondary master cylinder. The center piston of all three calipers is connected to the pedal-
actuated hydraulic system and controlled by its master cylinder. These three pistons act on each caliper's active brake pad
and allow it to be controlled by either or both of the two separate hydraulic systems.
19-4