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Originally Posted by AtomicLabMonkey
I think I have to disagree with some of what you said. If a tire locks up, by definition the caliper has applied more braking torque, and hence more force opposite the direction of tire rotation, than the tire was capable of developing for its given (instantaneous) normal force and coefficient of friction with the road surface. Take a given tire with a given downforce, section of road, and coefficient of friction of 1.0 which locks up at a braking torque of 1000lb*ft. If you strap a different tire on the car with a coefficient of friction of 2.0 on that section of road, and apply the exact same braking torque of 1000lb*ft, the wheel will now not lock up; it will now take 2000lb*ft to lock up the wheel. I think this pretty much defines being deceleration-limited by the tires, not the brakes.
I think maybe what you were trying to say was more concerning how effective a braking system (and operator) is at modulating force near the limit of what the tire can produce?
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Yes and no. I did actualy use the word modulation in the first sentance of my soapbox, but...
Take my Pin and Hole example. The brake interface transitions from dynamic to static friction before the tire transitions from rolling/static friction to dynamic of skidding. the tire itself provides the delay between the two events. In all but a "perfect" system one of the two events must happen first, and that is what I am getting at.
An incrediable amount of money goes into just designing pads with different friction charecteristics. Some transition from dynamic to static friction more easily than others at a given load and temperature.
In many ways, ABS is a primitave way to make up for other shortcomings in a brake system after the fact. With a soft enough sidewall, and a fast enough ABS system the tire may never even transition to dynamic friction even though the brakes are swithcing back and forth from static to dynamic as they lock and unlock. The tire never locks even though the brakes do repeatedly.
Do you see what I mean by the brakes failing/transitioning before the tire?