The deck wheels on all riders need to be adjusted for different mowing heights if you want the best cut. Most people never do this and that's why you see gouges and cutting lines on uneven ground. Most riding mowers give a crappy cut for this very reason. Even going around corners on flat ground can cause a wide deck to gouge. The plastic deck wheels should ride just above the ground. They "catch or raise" the deck when the mower encounters an uneven area. If adjusted to roll all the time they will wear out in no time at all. In my opinion a good deck should have deck wheels on all four corners as well as front and rear center rollers. It would be quite complex to design deck wheels that move up and down with ever variation of cutting height.

Thanks much guy! I'll set them up that way.