Re: FrontBrakeComments/Questions

[Doug Rasmussen <DougRasmussen@domain.elided>]

Tom H wrote:
>I was thinking that ratio of master cylinder compression volume
to caliper volume would be the important factor in amount of pressure
applied at brakes. Of course, we modulate the pressure with our foot on the
pedal, hence, maybe only a "reaction time" difference or some such
insignificance.<

Tom,

  The amount of potential pressure on front brakes would be directly 
proportional to
the cross sectional area of the master cylinder piston versus the caliper
piston area.
  Big caliper piston with small master cylinder piston equals large
mechanical
 advantage.  The rear brakes may not be so easy to quantify since
proportionoing
valves usually act as flow restrictors on the rear brakes.

  Normally, i guess we do modulate the braking with foot pressure.  It's
the panic
situations that are important.  By altering the front/rear percentages you
can create
a very dangerous situation.    The worst possible braking situation is a
rear brake lockup
without front lockup.   Rear only lockup equals total loss of vehicle
control. 

Doug