We are sounding closer all the time.....
David's figures tell us that 80% reduction OFF road speed is tantamount to BEING locked......
Look at this stuff logically. Let's take a car travelling at 100kph and applying your view of reduction by 20% of rolling speed as being the 'ideal braking rate'...... That would have the tyres 'skidding' but rotating at 80kph.... i.e., moving (sliding) over the ground at 20kph... Remember, that's GOLD STANDARD braking for this discussion....
How does the tyre KNOW that it's doing this and NOT:-
A) On a car at 120kph and 'skidding forward' at 83% of rotation speed (i.e., NOT gold standard) because it's STILL skidding over the ground at 20kph.
B) On a car at 300kph and 'skidding forward at 93% of rotation speed (i.e., NOT gold standard) becasue it's STILL skidding over the ground at 20kph.
Think that through..... closely... and you'll note that.... as far as the contact patch is 'concerned', it's doing EXACTLY the same thing..... sliding forward at 20kph........ How does it KNOW that it is supposed to react differently in each of those cases?
If you guys are RIGHT about this, it HAS to 'know' what's it's percentage of rotation/rolling rate IS!!
The energy being transferred from the car to the tyre/track is IDENTICAL in all three cases..... it's whatever the friction rate is for a tyre/track sliding at 20kph
Taken to it's logical extreme..... how does the tyre KNOW that it's NOT....
C) On a car at 20kph and 'skidding forward' locked SOLID (i.e., NOT gold standard) becausee it's STILL skidding over the ground at 20kph....
The latter case only differs because the SAME piece of tread remains as the contact patch for the WHILE manouvre....
.... however, that could be dealt with by the following:-
D) On a car at 15kph but the car being in reverse gear with the wheels being driven BACKWARD at 5mph (i.e., NOT gold standard) becasue it's STILL skidding over the ground at 20kph
I am not sure we have got to the bottom of this, yet!
Ian
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