On 13 Jan 2006 09:47:41 -0800, "Professor"
<briangriffey (AT) sbcglobal (DOT) net> wrote:

And, as everyone else who actually knows what they're talking about
has said, ABS is NOT the best thing in all situations. On loose
ground, locking the wheels is preferable to cadence braking (manual or
ABS-automated) as it packs material under the tyres, shortening the
stopping distance. As others have said, read what the manufacturers
say about ABS - even they say its 'not ideal in all circumstances'

It's nice to know that there are so many people responding to this
thread that are much smarter than the automotive engineers that
designed the ABS system. Thanks for all your invaluable knowledge.

Professor
www.telstar-electronics.com

On 13 Jan 2006 10:53:03 -0800, "Professor"
<briangriffey (AT) sbcglobal (DOT) net> wrote:

niec to see there's people like you who don't read what they ACTUALLY
say either. You take the Cliff-notes route through life, and thats
fine for you, but don't profsres knowledge in any areas when you do
so.

As many have said, including myself, read the caviets for the ABS
systems one of my vehicles says in its owners manual "ABS system may
not provide optimal braking in all conditions"

I have an old rally handbook from the early 70s too, for new drivers
comming into the sport, it says pretty much the same, that on loose
surfaces, locking the wheels is a more effective braking method.

In short though, material packs in front of your wheels, and you dig
yourself in effectively, and rearranges the forces being dissapoated
differently to standard tarmac braking. Its hard to explain without
good deal of diagrams and calculus. Suffice to say that this is
another subject, where high school educations are the basic
generalities, and not the actualities.

"flobert" <nomail (AT) here (DOT) NOT> wrote

I completely agree with you, and I too took the time to actually read my
instruction manual and noticed that little caveat about ABS. My manual
actually specifically said that in snowy conditions, ABS would INCREASE
stopping distances. Also, in extention of what you were saying, a simple
way of demonstrating how it works is to say that basically, the material
being packed in front of the tires acts in a similar fashion to a door stop.

Sean

Sounds like the best solution is to have a toggle switch to turn ABS
on and off as appropriate. Does anyone know of an easy way to do this
without damaging the car?

"joe" <joe (AT) yahoo (DOT) org> wrote

That would be tricky since I think the fuse for the ABS system is under the
hood as opposed to in the dash. I would also be a little concerned about
the legality of disabling a safety feature that the car came equipped with.
I think some jurisdiction forbid the disabling of standard safety features.
This became an issue when some people wanted to disable air bags for
personal safety reasons. I've been told for example, that in many Canadian
provinces, disabling the air bags is illegal since they came with the car as
a safety feature. ABS may also fall under that category. In addition, if
you were to have an accident and your insurance company discovered that you
disabled your ABS, they could technically refuse coverage by arguing that
the missing safety feature was a contributing factor in the accident. Just
a little food for thought.

You are all overlooking a key feature of ABS... that nobody has
mentioned. It's the ability to steer after you stomp on the brake in a
panic situation. This steering ability could be key in crash
avoidance...

Professor
www.telstar-electronics.com

Professor wrote:
because you have abs doesn't mean you can steer. all that abs achieves,
and my grandmother is a great example of this, is some hope of
crash-avoidance in a situation where a panicking driver locks the wheels
and won't release them again. /you/ seem to be overlooking the key
disclaimer of the owners manual.

I think you better sit back and have another whiskey... Jim Beam

Professor
www.telstar-electronics.com

"jim beam" <nospam (AT) example (DOT) net> wrote

"you can /only/ steer if you have sufficient adhesion."

Exactly, it's anti-LOCK brakes, not anti-skid brakes. If you are doing 30
miles per hour on an icy turn and you slam on the brakes, the wheel may not
lock but there is a decent chance the car's inertia will make you slide on
the ice because of the sudden deceleration, front tires without traction
don't steer, even if they are turning.

Mr. Professor seems to assume that all people slam on the brakes with full
force in a panic situation. There are some of us who have had driver
training and learned "threshold braking". It's basically the manual way of
doing what ABS is doing. There's called skills. ABS was invented to
protect the people who don't know that technique. As for the professor's
question in an earlier post about some being able to outperform the
computer, properly exacuted threshold braking can stop a car in a shorter
distance than ABS.

No computer system will ever be able to outperform a skilled driver. The
key word being "skilled". Not everyone is. This is why ABS exist.