Gary - the roadster's used 3/4" bore brake master cylinders. So the
bias is accomplished with the different size of the rear wheel
cylinders.
There are SOME Vehicles that use a dual bore master cylinder.
I remember one (off an Audi?) that used a 1" bore for the front
brakes, and 3/4" bore for the rear brakes. That is one way to
bias the front.
Other vehicles will use a "limiting" or "proportional valve"
commonly you find these on trucks. Idea is to decrease rear
braking under a no load condition (very light rear end),
and increase braking pressure when the bed is fully loaded.
If you find a mechanical lever attached to the frame, and
some sort of valve on the rear axle that has the brake line
connected to it... that is why it is there.
Bill - You might have made the same mistake I did when I first
responded. I recalled using SMALLER rear wheel cylinders, duh...
didn't dawn on me until later it was to PREVENT locking the rear
wheels first. I used to autox and run off road. In the dirt I
wanted the rears to have more bite, but not on pavement. Later
I fitted a "in-line" pressure valve to the rear wheels. Larger
rear wheel cylinders, and a "six adjustment" pressure valve with
a lever on it. I seem to recall it was made by Girling.
HAPPY THANKSGIVING ALL,
Tom
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