Yes, the speedometer still works, you are basically faulting out the ABS system. I actually think this mod kept me from rolling when I was hit in March and my truck was totaled. Instead of the tires maintaining traction with the road, they were already locked up and sliding, so I was able to just slide with the impact and still steer it to safety. Where as, if the tires had grip, it might have been enough to roll me on my side.
Dan