The trains were specifically designed for Son of Beast, but they weren't designed well enough. I'd like to know what person decided that the cars
must seat six people, because that's half the problem right there. That loop is the critical factor in the whole design. The wheelbase is as short as it is because if it were any longer, the train couldn't make it through a loop of that size. The loop is as big as it is because that's as big as they could build it with the energy they have going into that part of the ride. That's where the trouble starts. The long car coupled with the short wheelbase takes any shuffling action that the train does and magnifies it for the passengers in rows 1, 3, 4, 6, 7, 9, 10, 12, 13, 15, 16, and 18...the distance amplifies the force in exactly the same way as a pipe slipped over the end of a wrench.
The reason it shuffles isn't because there is anything wrong with the track...it shuffles because the cars can't follow the curves...they must slide, and there isn't enough lateral force to hold the outside wheels against the outer rail...the train slides back and forth. Particularly at the top of the second hill.
--Dave Althoff, Jr.