I have the BX2230 with both sets of turfs and bars. Both sets of rears are loaded with rimguard and it adds at least 100 lbs to each rear tire. I am 240lbs so that helps too! I have taken full buckets of dirt and felt the rear get light, but it wasn't scary. If I am doing a bunch of loader work I also put on my rear blade which adds a couple hundred more pounds and also acts as a wheelie bar if going up and down hills. I mow with the tractor and the added weight of the loaded tires makes no marks in my yard. I have had the bars on for months and have had no marking on the lawn even when it is a little damp. I pulled my aerator around after an inch of rain and didn't tear up the yard. I even mow with the loader on sometimes and don't leave marks. If it is swampy, I stay off the lawn. I highly recommend the loaded tires. The weight stays nice and low on the machine and helps when I mow sidehills also. I also like the idea of the ballest box, it looks like it would work slick, and I think it is only about $140.