OT anti-lock brakes.

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On 6/23/2011 3:53 PM, Steve Barker wrote:

My GMC truck has antilock brakes, and they have periodically malfunctioned to the point I had to pull the fuse on them. If you ever had anti-lock brakes activate on dry pavement when you are trying to stop at 40mph, you ain't lived yet. They work about 50% as good as w/o them. Personally, I think they should be banned.
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<...snipped...>

Disabling a defective ABS is not a bad idea if you'd rather not pay to have them fixed, I'd probably do it myself. When they are working properly, they do provide a great improvement in stopping distance on wet or slippery surfaces. On dry pavement, a "skilled" driver of a non-ABS vehicle can equal or slightly exceed the performance of the same vehicle with ABS. IMHO most drivers are not that skilled, so ABS is a net gain for safety.
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Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar.org
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Larry W wrote:

Hi, Only time I disabled ABS was when I was towing 7000 pound 5th wheel with 3/4 ton pick up. ABS is good thing to have for general driving situation for ordinary drivers. In cold slippery winter on a busy free way, with good set of snow tires and ABS, worst I can do is hit one car in the front. W/O ABS I may hit multiple cars going out of control.
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Larry W wrote:

No they don't. They reduce the braking at all 4 wheels match whichever one has the least traction. If one wheel has no traction, "Surprise!", even if 3 wheels were doing just fine until the ABS kicked in.
Every vehicle I've driven with ABS has been treacherous on icy roads until I pop out the fuse, then they revert to normal brakes and you can actually stop.
The only time ABS helps is panic stops on dry pavement.
-Bob
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wrote:

Incorrect. When ONE wheel slides, it releases the braks on ONLY that one wheel (on 4 channel ABS, which is virtually universal today). The big problem is when you hit a bad patch with ALL FOUR and it just shuts off the brakes - particularly when you are in wet slop, where allowing the brakes to slide would allow a decent snow tire to "squeegie down" and find some pavement to grip on.
A VERY SERIOUS problem with the wide tires that are standard equipment on so many of today's ABS equiped cars (and trucks) in the winter conditions we've been seeing around here over the last number of years

. One point where we agree

And I have to dissagree here too - on WET pavement, or possibly HOT tarry pavement - but not on clean, dry pavement at anything resembling "cool" (whatever that means) pavement. Most cars today have trouble locking the wheels on clean dry pavement without ABS.

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snipped-for-privacy@snyder.on.ca wrote: [snipped the part about icy roads]

I replaced the wide OEM tires that came on my truck (P255/70R16) with very skinny tires of the same height (LT215/85R16D) and was amazed at how much better traction I have in the snow now. I knew it would be an improvement, but did not expect such a *huge* improvement. I also get better gas mileage.

I mostly drive trucks and somewhat older cars with pretty good towing capacity (big brakes.) They'll lock the wheels just fine. But that might not be a representative sample.
Too many people in this thread are just parroting "ABS are good, M'Kay" from the car companies. (it must be good, it cost $400) She Who Shall Remain Nameless does that. I would pay extra to NOT have ABS. Luckily I can get rid of it by pulling one fuse.
-Bob
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zxcvbob wrote:

When I went through the Pursuit Driving School we watched a NASA film about the development of tires for the space shuttle. They started with a car braking from 50mph on a wet runway with the tires inflated to 50psi. The car finally stopped after so-many feet.
The investigators let 10 pounds of air out of each tire and repeated the experiment. The car took a 10% greater distance to stop. Hmm.
They kept lowering the air pressure until they got down (as I recall) to 10 psi and discovered the stopping distance had doubled over the original distance.
The difference, they found, was that the wider the tire - because of lowered air pressure - the more it hydroplaned across the wet surface. A narrow(er) tire sliced through the wet to better contact the road surface. The coefficient of friction between rubber and concrete is close to 1.0 whereas the coefficient between rubber an water is so near zero as to be almost unmeasurable.
(N.B., frictional force is independent of surface area.)
Conclusion: Wide tires on slickery surfaces can get you killed. No extra charge.
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I'm sorry for the bad luck you've had with ABS equipped vehicles. Apparently every time you've driven one on icy roads, the ABS was not working properly. Perhaps the vehicle owners should maintain them better.
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Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar.org
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On 6/25/2011 4:17 AM, Larry W wrote:

I'm sure his ABS vehicles were no more out of order than mine are. And i purchased my vehicles in a fairly new state. (never new). ABS is just downright dangerous ESPECIALLY in questionable traction conditions such as snow or ice. I like to have the control over my vehicle. Not give it to the government. I also don't like them telling me when my headlights will be on. So i have to modify that stupid assed feature also.
www.lightsout.org
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On Sun, 26 Jun 2011 12:47:52 -0500, Steve Barker

I'll agree on the ABS, but respectfully dissagree on the DRL.
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On 06/26/2011 03:48 PM, snipped-for-privacy@snyder.on.ca wrote:

Some DRLs are OK, some are dangerous (high beams? turn signals? should never have been allowed) but I think all of them are dumb because all the benefits that you get from DRLs you can get and then some by simply turning on your low beams (which will also light lights on the sides and rear of your car.)
So I think DRLs are a pretty stupid idea.
nate
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In wrote:

I nominate you are a certified fool and possible troll. Your ignorance is obvious so no reason to go nto that one.
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In wrote:

You are 100% wrong and I've had four past vehicles that prove you wrong. When I happen to get mired in snow or mud and a tire spins, I simply push the button for 4-wheel drive and the other 3 will walk me right out. On new snow & unknown roads, I use Auto-4-wheel drive and if I actually get stuck to where the chassis touches the ground at all, I'll use lo-range 4-wheel so all 4 wheels, including the spinning one, have power - as soon as the vehicle moves a couple inches that wheel usually can regain traction.
You seem to talk as though you drive in 4-wheel 24/7 which isn't necessary and is even stupid at speeds over 30 mph or so. I love watching a 4-wheel vehicle spinning out for apparently no reason at intersections, knowing it's because they've got 4-wheel drive engaged. You talk as though it's on 24/7 which mainly is a very stupid way to drive a vehcle. Your tire wear must be fantastic, too. You lie about whatever suits you, don't you? And troll also.

Then you have driven exactly ONE vehicle, one time, which had broken ABS.

That one is so silly as to be laughable and easily demonstrates your ignorance.

That whole paragraph makes little sense no matter how it's looked at. The most glaring statement of ignorance is that you are likely to not be driving much longer if there is any truth to any of your statements. And since you think only you should decide when to use your headlights, you are a danger to yourself and others on the road around you. And that s REALLY ignorant! You're hell on there being any resale value to any vehicle you touch.

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On 06/25/2011 12:20 AM, zxcvbob wrote:

Depends on the steering geometry and scrub radius. If you have a car with traditional geometry/negative scrub radius, the ABS doesn't have to dump pressure to the high-mu wheels so you get better braking. With a large positive scrub radius (think 4WD trucks, or some FWD cars) if you are in a split-mu braking situation the ABS is often programmed to dump pressure to the high-mu side to keep the vehicle from tending to yaw.
http://en.wikipedia.org/wiki/Scrub_radius
So really how well an ABS system works also depends on the fundamentals of the vehicle design... it has to have good base brakes, good tires, and good geometry to work well. However unfortunately it seems that some people and even sadly some designers think of ABS as a magic bullet that can band-aid all sorts of compromises made in the fundamental design/spec of the vehicle...
nate
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You got that wrong. They only work on the wheel that locks up. IMO, it was a great invention and gives you control on slippery surfaces.
Moving on, lets go to ESC. My last two cars had it. Fantastic.
I took the car in our parking lot after a few inches of snow. I did some maneuvers with the ESC off, then repeated it with the ESC back on. You can make turns tighter, faster, safer with the ESC. It makes lance changes safer also.
About a year later, on a wet road at 65 mph, I had to make a sudden lane change to avoid hitting another car. I was able to cut hard left, then right, to get to the other lane. If I was in a different car, I'm pretty sure I'd be rolling down the grass in the median.
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On 6/25/2011 12:20 AM, zxcvbob wrote:

Actually no. The ABS modulates the pressure to the wheel that isn't moving.

I live in the northeast and have driven numerous different vehicles during the winter with either ABS or not and the ABS systems always allows much better control when stopping on icy/snowy roads.

And when stopping on slippery roads.

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On 6/23/2011 6:02 AM, mm wrote:

Anti-lock if for the anti-brained person. I never had trouble in winter slippery conditions with REGULAR brakes.
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wrote:

I must admit, I havent' either. Even that accident I think I mentioned, on the black ice, I *did* go straight ahead. I think all four wheels lost traction equally so ABS wouldn't have helped anyhow.
I have a '95 now, without it. This car is lasting longer than most, but the next car will be about a 2005 or 6 and I guess they all have it. More expensive parts to break.
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In typed:

As opposed to NOT stopping! Once a wheel locks up, nearly all traction/stopping power is lost from that tire. Boy, there are some stupid allegations beng made in this thread.

IF you do not brake hard enough to lock up a tire, absolutely nothing is any different than not having anti-lock. If one does lock up a tire, the brake quickly releases to let the tire start turning again and then braking is reapplied (wthin milliseconds), adding back the lost traction from the lockup. The actiion repeats until the car either stops or the brake pedal is released. So rather than a locked up, low-traction tire/s, you have the added traction replaced and one of the by products of that is by not being locked up momentarily, some semblence of steering ability is returned if it's a front tire, less if it's a back tire. Usually the back tires will lock up first, because in a hard stop, the vehicle's weight is thrown forward, with mass placing more weight on the front tires while the back tires tend to lift, losing traction compared to the front tires.

One thing about the court system anywhere: Regardless of who's really right or wrong, if it's a law, it's a law; there's very seldom any way around it but to prove there were extenuating circumstances that skews the law so it can't be directly applied. But often there's another that can, depending on the type of court.

Neither did my Gram; but then again, she never drove a car or even had a license.
You appear to be anti-brained, in the context of your usage IMO. I never had any trouble in winter driving either because I learned to drive on ice & snow early & knew how to pump the brakes and recover direction of travel if I needed it. And I knew what speeds hills & curves could be negotiated. Fortunately I knew how to drive and how to perform on ice & snow as a result. But that does NOT mean in any way that anti-lock brakes didn't improve the situatons considerably. However, the appearance of ant-lock brakes has always been "fun" to have for me. And it certainly stops me a LOT faster than any physical pedal-pumping can do on ice, is never noticeable on clean, dry roads, and a superb addition to any vehicle that can use anti-lock brakes. No way is the pedal-return/rest to braking manually going to outperform the incredibly fast pumping anti-lock brakes can provide. Anyone that says differenty is guessing, has listened to a few of the posters here, or misread something because they are wrong and have very likely never actually had any actual comparative experiences.
Let's hope if there are more people going to post here, that they are either already knowledgeable OR at least take the time to research the subject a bit.
HTH,
Twayne`
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You must be referring to your own allegation above. On dry pavement a locked up wheel does not "lose nearly all stopping power". If it did, we would not be seeing black tire marks left on pavement for 100 ft or so until the car stopped. Those of us who have been around before ABS know that not only do you see these short skid marks, but cars without ABS did in fact stop in relatively short distances with locked wheels. If what you claim were true, we'd see these cars continuing on down the road for thousands of feet. In short, you've misapplied what happens on wet, low traction surfaces to dry surfaces.

The main and critical advantage that ABS brings is not related to stopping distance. And I'm not sure you can state that they will always stop a car under any conditions faster than a conventional braking system. The big advantage they are supposed to bring is that they allow the driver to maintain control of the car and avoid skidding out of control. And even that is questionable. I remember seeing a study a few years ago that looked at serious accident statistics and fatalities of accidents with and without ABS. There was no evidence that ABS was reducing those accidents.

This coming from the guy who just claimed a locked wheel on dry pavement has lost almost all it's stopping ability. And the guy who claimed in this thread that the standard of preponderance of evidence only applies in small claims court. Go figure.
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