Anti-Lock Brakes

In article >,
"PolicySpy" > wrote:

> > PolicySpy wrote:
>
> >> Anti-lock brakes...and that's ABS...work mostly in the rain or snow. On
> >> dry pavement and with the wheels straight...a car will most often make a
> >> emergency stop without any wheel lock-up...and that's due to
> >> electronic-brake-balance along with modern tires.
> >
>
> Nate Nagel wrote:
>
> > Not if you have good brakes, good reflexes, and aren't afraid to give the
> > brake pedal a good healthy shove. A car will stop a heck of a lot faster
> > than most people have ever braked. If you're truly panic stopping, as in
> > if you need to stop RIGHT NOW and don't know if you have enough space to
> > do it but gosh darn it you're going to try, on dry asphalt and you don't
> > feel the ABS kicking in (ASSuming an ABS-equipped car) you're not pushing
> > hard enough.
> >
>
> No...electronic-brake-balance and modern tires...eliminates wheel lock up on
> dry pavement...when the wheels are pointed straight.

No, sorry. That is just not true.

ABS will prevent lock-up, not modern tires, not
"electronic-brake-balance"

>
> Now race cars have mechanical-brake-balance and no problem with wheel
> lock-up during a long, long, history of motorsports. In fact in setting up a
> race car...there is only brake size, rotor size, tire size, and
> mechanical-brake-balance. Well...a race car brakes the same way every time
> and only needs one brake-balance rather than a variable brake-balance of an
> electronic-brake-balance. But again...there can be uphills and downhills on
> a racetrack so the most modern race cars MIGHT have an
> electronic-brake-balance.

I don't think you even know whether "electronic-brake-balance" even
exists.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

>
> PolicySpy wrote:
>
> ABS...MODULATION...is inactive during coasting. Hopefully the ABS system
> does not have any undesired characteristics on the baking system...when it
> is inacative. And if it does then decide if it is a characteristic of ABS
> or if it is a maintenance or repair problem.
>
You need to study ABS systems a bit harder. ABS may monitor the tire
rotation but don't do a darn thing until you mash on the brakes.
As cars get more complex, it will behoove you not to mess with the system.
They are getting tied together to do more than abs.

>>
>> PolicySpy wrote:
>>
>> ABS...MODULATION...is inactive during coasting. Hopefully the ABS system
>> does not have any undesired characteristics on the baking system...when
>> it is inacative. And if it does then decide if it is a characteristic of
>> ABS or if it is a maintenance or repair problem.
>>

S Hanson wrote:

> You need to study ABS systems a bit harder. ABS may monitor the tire
> rotation but don't do a darn thing until you mash on the brakes.
> As cars get more complex, it will behoove you not to mess with the system.
> They are getting tied together to do more than abs.

PolicySpy wrote:

The ABS is also the traction control. You could have a bad
wheel-speed-sensor thinking that there was a small amount of wheelspin and
thus applying a small amount of braking to a drive wheel.

And the ABS is also the stability control...

Alan Baker wrote:

> ABS will prevent lock-up, not modern tires, not
> "electronic-brake-balance"
>

PolicySpy wrote:

With the correct amount of brake-balance...there is no wheel lock-up on dry
pavement with the wheels pointed straight. (On most race cars there is no
adjustment other than brake-balance. Now modern street cars
have...electronic-brake-balance that reduces brake hydraulic pressure to the
rear brakes as the brake pedal is pushed harder.)

ABS essentially unlocks a wheel that is locked-up. Well...a wheel
approaching lock-up is turning slowly...and then the ABS kicks-in. So ABS
most often works on slick roads or when emergency braking with the wheels
turned...

>>>
>>> PolicySpy wrote:
>>>
>>> ABS...MODULATION...is inactive during coasting. Hopefully the ABS system
>>> does not have any undesired characteristics on the baking system...when
>>> it is inacative. And if it does then decide if it is a characteristic of
>>> ABS or if it is a maintenance or repair problem.
>>>
>
> S Hanson wrote:
>
>> You need to study ABS systems a bit harder. ABS may monitor the tire
>> rotation but don't do a darn thing until you mash on the brakes.
>> As cars get more complex, it will behoove you not to mess with the
>> system. They are getting tied together to do more than abs.
>
> PolicySpy wrote:
>
> The ABS is also the traction control. You could have a bad
> wheel-speed-sensor thinking that there was a small amount of wheelspin and
> thus applying a small amount of braking to a drive wheel.
>
> And the ABS is also the stability control...

I mean...the traction control and the stability control...share or depend on
the mechanism of the ABS. And the traction control or the stability control
could be applying a small amount of braking as a malfunction. Of course the
ABS itself can only...modulate and that would be obvious if a malfunction.

In article >,
"PolicySpy" > wrote:

> Alan Baker wrote:
>
> > ABS will prevent lock-up, not modern tires, not
> > "electronic-brake-balance"
> >
>
> PolicySpy wrote:
>
> With the correct amount of brake-balance...there is no wheel lock-up on dry
> pavement with the wheels pointed straight. (On most race cars there is no
> adjustment other than brake-balance. Now modern street cars
> have...electronic-brake-balance that reduces brake hydraulic pressure to the
> rear brakes as the brake pedal is pushed harder.)

I'm sorry, but you're wrong.

No amount of "balance" can overcome the fact that the brakes of a modern
automobile are powerful enough to lock the wheels.

>
> ABS essentially unlocks a wheel that is locked-up. Well...a wheel
> approaching lock-up is turning slowly...and then the ABS kicks-in. So ABS
> most often works on slick roads or when emergency braking with the wheels
> turned...

....or with wheels straight.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

PolicySpy wrote:
> Alan Baker wrote:
>
>> ABS will prevent lock-up, not modern tires, not
>> "electronic-brake-balance"
>>
>
> PolicySpy wrote:
>
> With the correct amount of brake-balance...there is no wheel lock-up on dry
> pavement with the wheels pointed straight.

Then you're not pushing on the brake pedal hard enough. (assuming you
want to "panic stop.")

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Alan Baker wrote:
> In article >,
> "PolicySpy" > wrote:
>
>> Alan Baker wrote:
>>
>>> ABS will prevent lock-up, not modern tires, not
>>> "electronic-brake-balance"
>>>
>> PolicySpy wrote:
>>
>> With the correct amount of brake-balance...there is no wheel lock-up on dry
>> pavement with the wheels pointed straight. (On most race cars there is no
>> adjustment other than brake-balance. Now modern street cars
>> have...electronic-brake-balance that reduces brake hydraulic pressure to the
>> rear brakes as the brake pedal is pushed harder.)
>
> I'm sorry, but you're wrong.
>
> No amount of "balance" can overcome the fact that the brakes of a modern
> automobile are powerful enough to lock the wheels.

For a loose definition of "modern." It's quite possible to get wheel
lockup in my '55 Stude with manual drum brakes. Very good manual drum
brakes, but still.

*NOT* being able to lock the wheels on dry pavement is a sign that your
brakes aren't good enough.

Nate


--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Nate Nagel wrote:

> Now, in a non-ABS car, the trick is to NOT lock up the wheels - because
> the coefficient of friction between tires and asphalt is significantly
> less when sliding as opposed to rolling - but to get as close to that
> point as you can without actually locking the tires. In practice what
> happens is a good driver will stab the pedal hard, then let off slightly
> when he feels the wheels starting to lock, but no more than necessary to
> keep 'em rolling. Only way to do that is practice...
>
> nate
>


Threshold braking is a lost art. I currently don't own a vehicle with
ABS. The last vehicle I had with ABS spent the last 8 years of its
existence with the ABS fuses (controller and pump) removed and with the
warning light bulb removed. It stopped rather better than it did with
ABS, and a LOT better than it did when the abs started throwing error codes.

PolicySpy wrote:
>> PolicySpy wrote:
>
>>> Anti-lock brakes...and that's ABS...work mostly in the rain or snow. On
>>> dry pavement and with the wheels straight...a car will most often make a
>>> emergency stop without any wheel lock-up...and that's due to
>>> electronic-brake-balance along with modern tires.
>
> Nate Nagel wrote:
>
>> Not if you have good brakes, good reflexes, and aren't afraid to give the
>> brake pedal a good healthy shove. A car will stop a heck of a lot faster
>> than most people have ever braked. If you're truly panic stopping, as in
>> if you need to stop RIGHT NOW and don't know if you have enough space to
>> do it but gosh darn it you're going to try, on dry asphalt and you don't
>> feel the ABS kicking in (ASSuming an ABS-equipped car) you're not pushing
>> hard enough.
>>
>
> No...electronic-brake-balance and modern tires...eliminates wheel lock up on
> dry pavement...when the wheels are pointed straight.


Not necessarily- that depends on the ABS implementation. Better ABS
systems still have a mechanical proportioning valve assembly so that the
front/rear bias is correct even without ABS. Only the low-end crap uses
ABS as a hack-job approximation to brake balance.