New Tires now have flat spots...

[ultrarunner]

Looks to be about 6 car lengths?

Not really sure... truck is about 18' long

The motorcycle veered off to the side when I locked up and the SUV that had braked hard was moving again...

Sure the outcome would have been different if it was a dead stop...

 

[3930dave]

I guess it's possible that a skilled driver could beat an ABS system under some conditions. A skilled driver will be able to approach the threshold of traction without going over it, whereas ABS inherently has to go over the threshold slightly before it can compensate. But the point I raised was not whether it was possible for a non-ABS car to outbrake an ABS car, but whether locking the wheels produced shorter stopping distances than ABS. If we set aside gravel and dirt, which are not relevant to the story that started the thread, it's really hard for me to believe that the situation would have been made worse by the presence of ABS. The vehicle's wheels locked up and wore flat spots on them, which means that the vehicle was over the "threshold" of static friction and into kinetic friction.

Gen I GM truck ABS was pretty dismal. I'm thinking that was what UR was in (sans ABS), but could be wrong.... he has quite a collection of 4 wheel devices.....

I'd take good quality new tires on a non-ABS vehicles, over what I see on the road with ABS in many cases, but esp. on that older GM platform - anyday. But, that's based in part on my Winter climate here, and driving experience.

To really answer that question, we'd need a controlled access test track, a similar truck with switchable ABS, and a whole pile of identical brand-new tires to play with. I don't have the coin to fund that test, but I'll add it to my Geek Stuff to Do with Lottery Winnings list....

Regular readers know.... I don't hang out to preach or argue...... just to highlight some data for review.... I'm spending a little more time on this topic than normal, given it's significance....

I offer one last source for review, the NHTSA:

Q&A REGARDING ABS BRAKES

"ABS allows the driver to maintain directional stability,control over steering, and in some situations, to reduce stopping distances during emergency braking situation, particularly on wet and slippery road surface."

"Do cars with ABS stop more quickly than cars without? ABS is designed to help the driver maintain control of the vehicle during emergency braking situations, not make the car stop more quickly. ABS may shorten stopping distances on wet or slippery roads and many systems will shorten stopping distances on dry roads. On very soft surfaces, such as loose gravel or unpacked snow, an ABS system may actually lengthen stopping distances."

Enough :soapbox: time from me..... thanks for listening....

Rgds, D.