If you all recognize me, you probably know that I have little to say, except the occassional question. I spend my time lurking and sponging up your knowledge!
I live on the side of an Appelation hill. I don't know my slop measurements, or really how to measure them. If what you are measuring is the acute angle between the hypotnuse and the base, I'd estimate my slopes to be between 25 and 40 degrees. I don't even attempt the steepest with my 180. I hire local kids to weedeat it a couple of times in the summer. I am hitting the 25 degree ones regularly, though. All the way up to last week, I'd done it by going straight up the hill with the mower raised and off, then back down with it lowered and on, without changing the wheels. Last week, I thought that I'd try changing the wheels to see if I could get some more out of the 180.
Now, granted, I have another side progect going that may have tainted my experiment. I am also filling in an inground pool with dirt that I am digging out of the hillside. That is what I was doing the day before I mowed with the wheels changed. I worked it pretty hard. I'll start another thread about that project if I ever get my digital camera stuff straightened out to give pictures.
On to changing the wheels... I went down my paved driveway and after mowing just a few minutes on a relatively flat part of my property, I noticed a squeeling sound coming from my right rear wheel. After about fifteen minutes I stopped mowing because I had to go get my son. As I drove up the driveway, there was a noticable decrease in the 180's power from what it usually has going up the drive. After I picked up my son, I changed the wheels back. I still had some power loss, though it got a little better.
I don't know if I can attribute this to changing the wheels, overworking it digging, poor digging technique (although, I tried to bear in mind previously mentioned tips on digging), or maybe I just need to do something simple like change the hydrolic oil filter, but there was a measurable power loss. I'll be changing the filter and oil on my next day off. Hopefully that will fix it.