Drives me nuts.

You guys keep pulling Noah's leg.

Noah, it's the time of day you are on them. At the beginning of the day they move at the same speed. The steps get slower as the day goes on because they begin to fill up the hopper at the end and it takes longer for the gnomes to stack them. In the middle of the night the gnomes come out and move the steps back to the other end, and then the next morning they run at the same speed again for a while.