Re: Rofren Pads???

[Jeremy R King <kingjer@eng.auburn.edu>]

Wrong.  A rolling mass has a certain amount of kinetic (motion) energy.  
In order to stop that mass (in our case a car), you MUST convert that 
kinetic energy into thermal energy (heat) using the friction of the brake 
pads against the disc.  The amount of kinetic energy of say a 3500lb car 
moving at 60MPH is the same no matter what type of brake pad you use.  
You still have to dissipate the same amount of kinetic energy to thermal 
energy to get the car stopped.  If your pad has a frictional coefficient 
of .36, you must apply a force F to them to stop the car.  If your pads 
have a frictional coefficient of .72 (twice the other pads), you must 
only apply a force F/2 (half the force required with the other pads).  
Yes, you only have to apply half the force to the brake pedal to get the 
same stopping power, which means you're stopping more efficiently.  But,
regardless of coefficient of friction, the frictional force created by 
the pads on the rotors for a given mass at a given speed (ie. under the 
same conditions) is constant.  In other words, the RESULTANT frictional 
force must be the same for the hard pads as it is for the grippy ones.  
Thus, the same amount of heat will be produced.  

Once again, the difference is in the ability of the discs to dissipate 
heat to the much cooler air and the ability of the pad to withstand the 
high temperature.

Jeremy R. King
1986 VW Quantum GL5
Audi at Heart
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On Tue, 31 Oct 1995 STEADIRIC@aol.com wrote:

> >This part I don't follow.  I would assume the cf determines how much force
> >needs to be applied to the pad to generate a certain braking force.  The
> >amount of heat generated would presumably depend on the braking force and
> >its duration.  I don't see how cf relates to heat generation or rejection.
> >Am I missing something?
> 
> cf works this way the higher the cf the more agressive the pad and the 
> more grip that it produces per unit of input force. therefore the higher 
> the specfic heat that can be generated
> 
> 
> 
> Later!
> 
> Eric Fletcher
> '87 5KCSTQIA2RSR2B
> 
> STEADI RIC@aol.com
> 
>