viatierra said:
The problem is off pavement when traveling on loose dirt or gravelly surfaces... particularly when going down a steep hill. You will be on the brakes hard to go slow, BUT it will be very tricky to avoid all wheel slippage on the loose surface. When the wheels slips, ABS engage, you will find yourself going downhill unable to control your speed. Yeah, its lame. Anyone with an ABS vehicle has had this happen. There are a few other issues, but I think this is the biggie. Lockers help alot as well as always choosing your lowest gear during steep descents.
Whether to use or not use ABS in an off-road situation depends on who is driving and under what circumstances. As explained, the function of ABS is to keep one or more of the wheels from skidding (stopping or going far slower than the rest) by releasing brake pressure to that wheel, in order to balance rotational speeds. However, all ABS that I have used are incapable of stopping wheel lockup absolutely. Once all four wheels are turning slowly, or skidding at approximately the same rate, ABS can no longer sense a situation to be corrected, and it simply stops doing anything. My Audi, for example, will pulse the brakes until vehicle speeds are under about 5 mph, at which point, the brakes simply lock up.
Off road, if you are in a limited traction situation, ABS doing its job will not cause a driving issue that does not already exist. If there is little or no traction available, whether you have brakes locked or don't won't matter because you can't control your speed anyway, and if you are going quite slowly, the difference in rotational speed between a rolling wheel and a stopped wheel will be so slight that most ABS systems won't sense the difference. All ABS systems allow a degree of variation to account for different wheel speeds while braking and turning a corner. Going slowly in loose traction won't create a wheel speed differential any different from turning a corner on pavement, and ABS should not fight you. Besides, if traction is in fact quite limited to the point of tire slippage with wheels locked, brakes won't stop you anyway and the wheels should be allowed to turn, even to the point of gaining speed in order to retain directional control. If you have not driven in these circumstances, you have not lived on the edge and would not really have had a chance yet to see what ABS can or can't do for you. Trying to keep the wheels turning under such circumstances is exactly what you will be trying to do yourself, so having the ABS do it for you isn't necessarily a problem.
I think there is a lot of negative opinion in the off road crowd simply because of attitude regarding driver control versus computer "interference." I have some of that prejudice myself, having learned to drive before computers were invented. But I have also driven off road with ABS equipped vehicles and have never had a situation where control was taken from me by the ABS system. Even if the wheels didn't always do what I expected, still what they were doing was not necessarily wrong, dangerous, or undesirable. Frequently I am so busy doing whatever it is I am doing that I don't have brain time to closely monitor wheel speeds and traction, so having ABS do that for me would be a benefit, not a burden.
Certainly, ABS can be defeated. Sometimes it is as simple as finding the fuse and pulling it. Unless or until you drive off road with ABS to the point of frustration over the system, I would not do or not do anything about it if your vehicle is so equipped. Short of building a rock crawler, I wouldn't worry about it.
