Hello, I own a hustler Fastrak 44" ZTR. I don't own a business, and it's for use on my personal property. However, It currently has turf tires on it, and a decent part of my pasture is soggy most of the year. The result is that I frequently get stuck, or don't mow it and pay someone to come in 3-4 times a year with a bushhog. I'd like to switch to some bar tires for a better bite. However, I also don't want to change the quality of the cut, so I'm thinking of sticking with the stock size. Form the owners manual (http://www.hustlerturf.com/images/product_manuals/365262_0407.PDF) I can see on page 5-4 that the drive tires are 18x8.5, but every tire I look at online has a third number. I assume it's the rim size (similar to a car) but I don't see any info about that in the owners manual. Does anyone know what size bar tire I'd need to order to fit the stock rims on this machine? 18 x 8.5 x ? I'm looking at carlisle r-1 bar tires.