Tires and ABS

I'm trying to understand how tire selection affects ABS performance. I never thought it would, but I had a few interesting experiences this year that have led me to believe otherwise.

I ran BFGs (KOs then KO2s) on my Tacoma for the better part of the last 7 years. A few times, while running the KO2s (I don't recall if this happened with the KOs), I had to make an emergency stop on the freeway and the back end of the truck locked up. I never thought much of it, wondering whether the ABS should have kicked in.

A few months ago, a friend upgraded his wheels and tires and I had a chance to test out the Cooper Discover A/T3s on the exact same wheels that I was running (FJ/4Runner Trail wheels). During that test period, I had to make an emergency stop on the freeway and the ABS kicked in, preventing the rear axle from locking up. Strangely, conditions were nearly identical (unloaded truck, same stretch of freeway, same direction, same time of day).

I am trying to figure out why ABS would work with one tire model and not with a different model. Can anyone shed some light on this?

 

No one?

 

hard to duplicate same conditions, how hard u slammed on the brakes,,, abs is a pain,,, mine has done it a couple times when i slammed on the brakes,, just the way it is.