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From: Retired VIP on 2 Jan 2010 09:52
On Wed, 30 Dec 2009 23:16:30 -0500, "C. E. White"
<cewhite3(a)mindspring.com> wrote:

>
>"in2dadark" <in2dadark(a)yahoo.com> wrote in message
>news:4fbaf1a8-6017-49f9-8d9b-cb246bb3a194(a)e27g2000yqd.googlegroups.com...
>On Dec 30, 11:10 am, Popular <pmwebmas...(a)hearst.com> wrote:
>> Hey, Folks,
>> We're rather disturbed to see the posting, above.

snip
>
>I had a chevy blazer that had exactly those types of anti-stop brake
>problems..That was a scary ride..
>
>The ABS on my2006 Frontier was to sensitive. It was particualrly disturbing
>if you were braking while changing surfaces- like braking while turing into
>a dirt lane from a paved road. It was also sensitive on soft surfaces (like
>driving around in a pasture with wet grass).
>
>I have always had the opinion that ABS was at best a mixed blessing. Studies
>have never shown that it was a net safety benefit. At best it reduced some
>sorts of accidents and made others worse. NHTSA never could justify
>mandating ABS based on safety studies.However the safety Nazis and the ABS
>suppliers finally managed to get in mandated by doing an end run and having
>NHTSA make ESC mandatory (ESC requires the ABS components to do its
>"magic"). This time NHTSA didn't bother studying the safety benefits of ESC
>before making it mandatory - too much a risk that it too would be shown to
>be a worthless "safety" device. Better for the ABS manufacturers to just
>force us all to spend a few more hundred (thousand?) dollars per vehicle to
>get the unproven "benefits" of ESC (and ABS).
>
>Ed

I did a study several years ago on Anti-lock Brake Systems (ABS) for a
safety meeting at work. At the time there were two common systems, 2
and 4 Wheel ABS. My study concentrated on two areas, stopping
distance and driver control.

I found that stopping distance could be decreased by a 4 wheel ABS
most of the time but 2 wheel ABS didn't have much effect on stopping
distance. However they actually increase stopping distance in snow or
on gravel roads. By not allowing the wheels to lock, they couldn't
build up a dam of snow or gravel in front of the wheel. This dam will
greatly increase friction between the wheel and the road surface plus
it allows the wheel to push the loose stuff our of the way and get
down to a hard surface. Stopping distance could be greatly reduced on
smooth, hard surface roads and ice, however road surfaces that are
rippled or pot-holed increase stopping distance.

If the front wheels lock you loose directional control. So ABS will
contribute to driver control. But it does so at the cost of depriving
the driver of being able to decide which he needs more, stopping power
or directional control.

ABS is a trade off that is always biased toward steering control and
reduces driver control over the vehicle systems. Once an ABS detects
wheel lock and reduces braking force it can take some time for it to
reapply full braking force. Because ABS's don't have accelerometers
on the wheel it can't tell the difference between a slick road and a
bouncing wheel. Because of these faults my recommendation was that
the company not buy vehicles with ABS. They didn't follow my
recommendations. I know of two wrecks involving company vehicles that
were directly caused by ABS. Both were at down hill intersections that
had a sand or gravel buildup and the driver lost all brake control.
From: Mike Hunter on 2 Jan 2010 15:25
There is a switch to deactivate TCU and a switch to deactivate the ABS can
be installed as well.


"Retired VIP" <jackj.extradots.180(a)windstream.net> wrote in message
news:amkuj59o89sof8doiijb0lpfgvac0n61j8(a)4ax.com...
> On Wed, 30 Dec 2009 23:16:30 -0500, "C. E. White"
> <cewhite3(a)mindspring.com> wrote:
>
>>
>>"in2dadark" <in2dadark(a)yahoo.com> wrote in message
>>news:4fbaf1a8-6017-49f9-8d9b-cb246bb3a194(a)e27g2000yqd.googlegroups.com...
>>On Dec 30, 11:10 am, Popular <pmwebmas...(a)hearst.com> wrote:
>>> Hey, Folks,
>>> We're rather disturbed to see the posting, above.
>
> snip
>>
>>I had a chevy blazer that had exactly those types of anti-stop brake
>>problems..That was a scary ride..
>>
>>The ABS on my2006 Frontier was to sensitive. It was particualrly
>>disturbing
>>if you were braking while changing surfaces- like braking while turing
>>into
>>a dirt lane from a paved road. It was also sensitive on soft surfaces
>>(like
>>driving around in a pasture with wet grass).
>>
>>I have always had the opinion that ABS was at best a mixed blessing.
>>Studies
>>have never shown that it was a net safety benefit. At best it reduced some
>>sorts of accidents and made others worse. NHTSA never could justify
>>mandating ABS based on safety studies.However the safety Nazis and the ABS
>>suppliers finally managed to get in mandated by doing an end run and
>>having
>>NHTSA make ESC mandatory (ESC requires the ABS components to do its
>>"magic"). This time NHTSA didn't bother studying the safety benefits of
>>ESC
>>before making it mandatory - too much a risk that it too would be shown to
>>be a worthless "safety" device. Better for the ABS manufacturers to just
>>force us all to spend a few more hundred (thousand?) dollars per vehicle
>>to
>>get the unproven "benefits" of ESC (and ABS).
>>
>>Ed
>
> I did a study several years ago on Anti-lock Brake Systems (ABS) for a
> safety meeting at work. At the time there were two common systems, 2
> and 4 Wheel ABS. My study concentrated on two areas, stopping
> distance and driver control.
>
> I found that stopping distance could be decreased by a 4 wheel ABS
> most of the time but 2 wheel ABS didn't have much effect on stopping
> distance. However they actually increase stopping distance in snow or
> on gravel roads. By not allowing the wheels to lock, they couldn't
> build up a dam of snow or gravel in front of the wheel. This dam will
> greatly increase friction between the wheel and the road surface plus
> it allows the wheel to push the loose stuff our of the way and get
> down to a hard surface. Stopping distance could be greatly reduced on
> smooth, hard surface roads and ice, however road surfaces that are
> rippled or pot-holed increase stopping distance.
>
> If the front wheels lock you loose directional control. So ABS will
> contribute to driver control. But it does so at the cost of depriving
> the driver of being able to decide which he needs more, stopping power
> or directional control.
>
> ABS is a trade off that is always biased toward steering control and
> reduces driver control over the vehicle systems. Once an ABS detects
> wheel lock and reduces braking force it can take some time for it to
> reapply full braking force. Because ABS's don't have accelerometers
> on the wheel it can't tell the difference between a slick road and a
> bouncing wheel. Because of these faults my recommendation was that
> the company not buy vehicles with ABS. They didn't follow my
> recommendations. I know of two wrecks involving company vehicles that
> were directly caused by ABS. Both were at down hill intersections that
> had a sand or gravel buildup and the driver lost all brake control.


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