My friend Jimmy has only one lawn that he has to use a 21" mower on. The rest he uses his ZTR. He decided just to leave the 21" at this house. Then he wouldn't have to drag it around. When he sent the home owner the final lawn bill last year, the owner sent him a rental storage charge for leaving the mower there. It was the same amount as Jimmy's lawn bill. I still don't know how he resolved this.