Adnectere

I read recently that ABS on rough roads can increase the stopping distance. Of course I would never disable or not use ABS, but is this true? What exactly would rough road mean: gravel, asphalt with severe potholes and undulations, dirt with holes, etc. Any advice you can shed on this statement would help.

coolformula

iTrader: (21)

Well try on dirt of gravel rode and slam the brakes to prevetn the card from locking the brakes the abs kicks in sooner. That make sense?

brandonppr

iTrader: (9)

My old truck, 99 s10 extreme I noticed some problems with that.
when I would drive in gravel parking lots the truck would turn on the abs very easily and not let you stop even though you would have been able to stop if it had not came on.
on my current cars I don't have this problem though.
a few other cars I drove were like that, just too sensitive.

Hugger Z

iTrader: (4)

ABS prevents the wheels from locking up. Thus they are still rotating and you are still moving forward. So yes your stopping distance will be shorter in slippery conditions, but longer on dirt and gravel. Normally if you were skidding on dirt and gravel you are pushing piles in front of your tires helping you slow down. But ABS allows them to continue to rotate and those piles are not formed. That help to explain it?

spy2520

iTrader: (3)

i also heard that in dirt and gravel it is better to lock the wheels up so the holes you dig and the piles in front of the wheels help stop you. ABS really only shines when you need to stand on the brakes AND maneuver at the same time, i cant say that it saved my life but it definitely saved my car a few times wet and dry, although in the rain the brakes really dont help much once you break traction no matter what they do...

michaelg589

iTrader: (1)

ABS is not meant to DECREASE stopping distance. Its purpose is to help you maintain control of your vehicle in slippery conditions or if you do hit the brakes hard enough that it would lock the wheels. ABS, on rough roads, WOULD probably INCREASE your stopping distance. Over rough roads, your tires periodically leave the ground for split seconds as you hit bumps. When the tire leaves the ground, there is no longer any force being exerted on it from the momentum of the car. This causes the brakes to lock that wheel until the ABS unlocks it, allowing the wheel to spin again. (of course that little process there will happen hundreds of times in those couple seconds). Its the same result if you have badly warped brake rotors, like I did. I almost couldnt stop one time before a 4-way intersection. The ABS was engaging way too frequent because of the warped rotors and I stopped right in the middle of the intersection. (I was going about 100 mph before I tried to hit the brakes).
Warped rotors = bumps in roads : Like when the tires leave the ground for those split seconds and are easily locked by the calipers, the warped portion of the rotor will press more firmly against the brake pads and make it easier for the caliper to lock that wheel and cause the ABS to kick in.

loyolacub68

iTrader: (16)

WRONG. By keeping the wheels from locking up in extreme braking conditions the ABS system decreases stopping distance.

I think you're describing the traction control system, ABS was not designed to work on rough road surfaces and I've heard it does increase the stopping distance.

Anyways, the fact is that ABS was created to decrease stopping distance by keeping the wheels moving instead of skidding.

ksuburban

Abs is ment to keep directional stability, not shortening stopping distance. It keeps your car from facing the wrong way during a panic stop on the freeway. Go lock up the brakes on an old car without abs and see what hapens, the stoping distance may be shorter but you might end up looking at the person behind you.

Adnectere

Sounds good. I've found out that ABS will sometimes be disabled below 5 mph or some small threshold level. Evidently at very slow speeds and roads like gravel, it can be better to lock the wheel. As to piles, I don't know if that's right or not. Good answers. ABS is made to keep directional stability and shorten stopping distances. Without ABS you have to operate below 100% of your braking potential for fear of locking the brakes (admittedly with abs you aren't using 100% b/c you save some for cornering but it's still probably shorter than without).