Originally Posted by Schtum
If that's correct then that's great and it might be that's why it takes a couple of wheel revolutions before the Brake Failure light extinguishes each time you fire up the bike and ride off. However, I think it's as well to know that and the fact that the ABS begins to take effect long before the wheels lock up.
true, it does measure a difference in wheel speeds. This is why the ABS does not work if one sensor is missing or broken..