displacement ratio of master cylinder - explain?

[Tom F&L GoR]

The '94 service manual says the displacement ratio of the brake master cylinder is 65/35. Since it is an inline 27mm dual master cylinder, how can the displacement (volume?) be different between the front and rear brakes? And after taking up all the slack, it's based on pressure, anyway...

Anybody know how to explain this? Thanks.

 

[HP]

I think the answer is in the differential valve, the rear brakes
both feed off one outlet, where as left, and right front brakes
each have a separate outlet, so the brakes are biased in favor
of the front.

 

[HP]

In hydraulic language, I suppose the 2 to 1 ratio of outlets,
gives you a 2:1 clamping force.