[Vwdiesel] Fwd: mileage

[James Hansen]

> That's not something that ever occurred to me. I've never seen it
> happen, or even heard of it. That would make it a little hard to apply
> full braking force... :)

Yeah, doesn't happen that often really.  I had just installed new brakes a
few months before on the trailer, so that could be it.  Tire shop guys claim
it happens all the time when there is a panic stop on a loaded semi.  I was
pretty surprised, but not nearly as much as the old fellow that saw a giant
truck rad in his rearview, literally inches from his bumper. Man, I wish
people would be more careful sometimes.

> Do you happen to know if the hopping changes the braking distance?
> Yes, there are times when the wheels aren't even touching, but when
> they are touching there is even more normal force than if the wheels
> stay in constant contact with the pavement. I haven't tried hard, but
> I was wondering how that changed things.

I don't have data on that, but it has to increase the stopping distance, it
sure does mess with brake action on a stock car.  A fully loaded legal
weight semi can stop in a remarkably short distance when all factors are
right, including mechanical adjustment of the brakes themselves. The brake
stink is tremendous following a stop like this- the energy dissipation is
enormous and you can't do it repeatedly.
-james